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Aspects of nutrient cycling and nutrient use pattern of Bhabar Shisham forests in central Himalaya, India
Forest Ecology and Management 176 (2003) 237±252
Aspects of nutrient cycling and nutrient use pattern of Bhabar Shisham forests in central Himalaya, India Neelu Lodhiyala, L.S. Lodhiyalb,* a b
Department of Botany, D.S.B Campus, Kumaun University, Nainital 263002, Uttaranchal, India Department of Forestry, D.S.B Campus, Kumaun University, Nainital 263002, Uttaranchal, India Received 4 October 2001; received in revised form 20 February 2002; accepted 10 May 2002
Abstract This paper illustrates the nutrient related variables such as storage, uptake, nutrient use ef®ciency (NUE) and nutrient cycling in 5±15 years old Dalbergia sissoo Roxb. forests growing in Bhabar belt (a nutrient poor and low water table site) in central Himalaya previously studied for biomass and productivity. The percent nutrient concentration and nutrient storage in vegetation is in order: trees > shrubs > herbs. However, different strata accounted in order: soil 80 92% > vegetation 7 18% > litter (1±1.5%). The nutrient retranslocation in leaves of different vegetation layer was in order: trees 29 44% > shrubs 27 35% > herbs (17±23%). The nutrient uptake, i.e. gross and net by trees, shrubs, herbs and total vegetation was studied. The total nutrient transfer through litter inputs to the soil was 71±90 N kg ha 1 per year, 5±7 P kg ha 1 per year and 43±47 K kg ha 1 per year. The turnover rate and turnover time of litter nutrients (NPK) ranged from 57 to 60% and 1.6±1.8 years, respectively. The turnover rate indicates that about 60% litter nutrient release on the forest ¯oor, which showed that the litter nutrients are also equally important for the nutrient cycling as the other aspects such as retranslocation and uptake. The NUE in Shisham forests ranged from 140 to 150 N kg ha 1 per year, 1560±1769 P kg ha 1 per year and 340±345 K kg ha 1 per year. Compared with the Tarai Shisham forests, exotic plantations (eucalypt and poplar) and central Himalayan natural forests. It is concluded that Bhabar Shisham forests have shown better nutrient conservation ef®ciency than those of Tarai Shisham forests. For nutrient dynamics compartment graphs represent the distribution of nutrient pools and net annual ¯uxes of the investigated forest ecosystems. # 2002 Elsevier Science B.V. All rights reserved. Keywords: Dalbergia sissoo Roxb.; Nutrient; Concentration; Retranslocation; Uptake; Return; Nutrient use ef®ciency; Nutrient pools; Nutrient ¯uxes
1. Introduction The structure and functioning of forest ecosystem in relation to their sustainability is not only dependent on dynamic status of organic components but is also in¯uenced by various nutrient variables and the *
Corresponding author. Present address: c/o Sri P.S. Rautela, M.P. Niwas, Stoneleigh Compound, Tallital, Nainital 263002, Uttaranchal, India. Tel.: 91-5942-36754.
applied management procedures. Thus, nutrient use pattern, cycling and ¯ows within and between components and soil sub-system played a central role. Alvim (1964) and Waring and Patrick (1975) argued that various physiologically active parts of plants may compete with water, nutrients and metabolites. However, ¯ux of materials is essential for continuity and stability of living systems (Pomeroy, 1970). Contribution and cycling of nutrients to different plant components form a major character in any forest
0378-1127/02/$ ± see front matter # 2002 Elsevier Science B.V. All rights reserved. PII: S 0 3 7 8 - 1 1 2 7 ( 0 2 ) 0 0 2 6 8 - 2
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ecosystem. Singh and Singh (1993) pointed out that short-lived components played a major role in the aspects of productivity and nutrient cycling in dry tropical forests. The functioning of forests in relation to primary production is generally in¯uenced by the nutrient availability, which in turn depends on the pattern and rate of their cycling (Rawat and Singh, 1988). The nutrient availability is the most in¯uencing factor of plant species distribution (Chapin and Kedrowski, 1983). However, production of crop limits by the macronutrients such as N, P and K (Lodhiyal et al., 1994). As far as the cultural operations are concerned, if not applied properly it degrades the stand structure and also causes of major nutrient loss in the forest. Veblen (1986) argued that stand structure is highly dependent on regeneration ability but most of the northern natural forests may be conditioned by climatic variability (Wein and El-Bayoumi, 1983). However, the functioning of man-made forest in relation to the production and nutrient cycling in¯uenced by the species characteristics, site and spacing on which they are planted. From the dry matter accumulation, utility and conservation point of view Shisham forests along the central Himalayan Tarai and Bhabar regions are well known (Lodhiyal, 2000; Lodhiyal et al., 2002). But in the recent year, interest on nutrient use ef®ciency (NUE) and nutrient cycling of Shisham forests in relation to ecological management which immerged as one of the most important issues in nutrient poor site of the region. Besides this, forests are suffering by tremendous pressure in their existing areas because of its multipurpose nature. As far as the quantitative information about the nutrient demands is concerned still it is limited. The paper deals with nutrient concentration of different plant fractions, standing state of nutrients, uptake, return, turnover and cycling of nutrients in Bhabar Shisham forests of central Himalaya, India. The details of study area, vegetation, geology and soils of forest sites have been described in the previous paper of biomass and productivity (Lodhiyal and Lodhiyal, 2003). 2. Material and methods The three study sites were located between 29830 and 298120 N and 798200 and 798230 E longitude at an
altitude 300 m in Bhabar belt (a plain area with sandy coarse soil having less nutrient and low water table) falls between Tarai and foothills of central Himalaya. The details of geology, soils and meteorological data, i.e. annual rainfall and temperature, are given in the previous paper of dry matter dynamics (Lodhiyal and Lodhiyal, 2003). The climate of the study site is subtropical monsoon type, with a long dry season from early October. A detailed description of vegetation types and sampling methods of trees, shrubs and herbs are the same as given in Lodhiyal and Lodhiyal (2003). Sal mixed broad-leaved forest was original vegetation in the study site of Champion and Seth (1968). According to Lodhiyal et al. (1995), most of vegetation in the region was converted into croplands by the 1960s and followed by tree plantations in the 1970s. The present Shisham forests occupy about 37 ha. The ages of Shisham (Dalbergia sissoo) forests investigated were 5-, 10- and 15 years old. These forests were raised in 1991, 1986 and 1981 at 4 4 m2 spacing, respectively. Samples of different tree components, viz. bole wood, bole bark, branch, twig, leaf and reproductive parts of the aboveground, and coarse roots (stump root lateral roots) and ®ne roots of the belowground parts of trees were collected from 12 harvested trees (three trees from each sub-plot, one from each diameter at breast height (dbh, 1.37 m) class; see Lodhiyal and Lodhiyal, 2003) for their nutrient analysis (nutrient concentration and nutrient content) in each Bhabar Shisham forest. The roots (stump root and lateral roots) were excavated to 2 m3 volume of soil for each harvested tree. The ®ne roots (roots with 5 mm diameter associated with mycorrhizae) were sampled by digging out three randomly distributed 25 25 25 cm3 block of soil around harvested tree in each dbh class of each sub-plot (total of 12 from each forest) as followed by Lodhiyal (1990) and Lodhiyal et al. (1995, 2002). The samples for tree and shrub components were collected during the month of September 1996 and the herb samples for aboveground and belowground part collected in different seasons, i.e. summer, rainy and winter seasons for each component. Composite samples (three samples of each component taken from the upper, middle and lower plant parts and mixed together to form a composite sample)
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for each of the tree, shrub and herb components were taken separately to the laboratory and oven-dried at 60 8C to constant weight. Oven-dried samples were mill-ground for nutrient analysis. Litter samples were collected using 20 l traps at monthly intervals from each forest. The size of each trap was 50 50 cm2 with 15 cm high wooden sides ®tted with a nylon net bottom. The composite litter samples (litter samples collected from each dbh class of tree and mixed to form a composite, separately for component) for each litter component, i.e. leaf, wood, reproductive litter and other litter, were ground separately and analyzed for nitrogen, phosphorus and potassium. Five replicates of dry plant material (0.5 g each) were analyzed for total nitrogen after digestion of 10 ml concentrated sulfuric acid using 5 g of a catalyst mixture (potassium sulfate and cupric sulfate in a 9:1 ratio) in a quick digestion unit. Total nitrogen was determined by micro-Kjeldahl technique (Peach and Tracy, 1956; Misra, 1968; Lodhiyal and Lodhiyal, 1997; Lodhiyal et al., 2002). Phosphorus and potassium were extracted by wet ashing of 0.5 g plant material in an acid mixture consisting of 10 ml H2SO4, 3 ml HNO3 and 1 ml HClO4, following the method of Jackson (1958). Phosphorus was determined by spectrophotometer and potassium by ¯ame photometer (Jackson, 1958). The standing state of nutrients of trees, shrubs and herbs were computed separately by multiplying the dry weight of each component by the respective mean nutrient concentration. Nutrient values in trees, shrubs and herbs were summed to obtain the total standing state of nutrients in the vegetation. The amount of nutrients (N, P and K) in the soil was determined by the micro-Kjeldahl technique for N (Peach and Tracy, 1956), absorption spectrophotometry for P and ¯ame photometry for K (Jackson, 1958). The amount of nutrients in the top 30 cm of soil was calculated by summing values for 0±10, 10±20 and 20±30 cm soil depths in each forest. Soil volume multiplied by the respective average bulk density gave the weight of the soil, which was in turn multiplied by corresponding nutrient concentration to obtain the amount of soil nutrients (N, P, and K). The mean nutrient concentration was multiplied by the weight of annual litter fall, i.e. leaf, wood, repro-
239
ductive parts of trees, and leaves of shrubs and herbs to give the amount of nutrients transferred to the forest ¯oor of vegetation of forests at different ages. The turnover rate (K) for each nutrient on the forest ¯oor was estimated following (Chaturvedi and Singh, 1987; Lodhiyal, 1990; Lodhiyal and Lodhiyal, 1997; Lodhiyal et al., 2002) as K
A AF
where A is the amount of nutrients added to the forest ¯oor by litter fall and F the nutrient content of the lowest value of standing crop of litter in the annual cycle. Turnover time (t) for nutrients was calculated as for standing litter biomass. Turnover time (t) is the reciprocal of turnover rate (K) and is expressed as 1 t K Nutrient uptake by components of vegetation in forests of different age was computed by multiplying the net primary productivity (NPP) of different components by their nutrient concentration. The values of nutrient uptake by trees, shrubs and herbs were summed to estimate the total annual uptake by the forest vegetation. Some of the relative retranslocation values of the nutrients (N, P and K) occurred during the senescence of foliage. This was assessed following Lodhiyal (1990), Lodhiyal et al. (1995, 2002) and Lodhiyal and Lodhiyal (1997), i.e.: X Y R 100 X where R is the nutrient retranslocation percent, X the nutrient mass in mature green leaves, and Y the nutrient mass in senesced leaves. The X and Y were calculated on the basis of nutrient per unit weight of mature green and senesced leaf, respectively, multiplied by total amount of leaf litter fall. To estimate nutrient retranslocation, 120 mature green and senesced leaves were collected in September (peak month of leaf maturity) and December (leaf senescing period) 1997, respectively. Since rainfall is negligible in the region when leaves senesce (December), leaching is likely to have only a minimal effect on nutrient loss from the leaves (Ralhan and Singh, 1987; Lodhiyal and Lodhiyal, 1997; Lodhiyal et al., 2002).
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The NUE (E) per unit area of D. sissoo forests was calculated on the basis of the following formula: E
P U
where P is the NPP (kg ha 1 per year) and U the net nutrient uptake (kg ha 1 per year) by the Shisham forest. 3. Results and discussion Before mentioning the results of nutrient cycling and nutrient use pattern of Bhabar Shisham forests, some accounts of stand structure and dry matter estimates is given here in brief. However, all these estimates are published in the previous paper of biomass and productivity (Lodhiyal and Lodhiyal, 2003). The whole process of nutrient dynamics depends on these dry matter estimates. The density and basal area of Shisham forests was 625 trees ha 1 and 9.2±27.7 m2 ha 1, respectively. The total vegetation biomass, NPP, forest ¯oor litter and litter fall was 53±118 t ha 1, 11±15 t ha 1 per year, 2.9±5.4 t ha 1 and 2.3±4.4 t ha 1 per year, respectively, and all these estimates were found in increasing order with increase in forest age. 3.1. Nutrient concentration Percent nutrient concentration of different components in tree, shrub and herb layers of Bhabar Shisham forests is given in Table 1. The nutrient concentration among the tree components was in order: reproductive parts > leaf > bole bark > branch > bole wood in aboveground part, and ®ne roots > lateral roots > stump root in belowground part. Compared to the young forest (5 years old) with old forest (15 years old), the percent nutrient concentration in different components of 5 years old forest was higher than 15 years old forest. This indicates that the nutrient concentration in lower age tree components have a tendency to accumulate higher nutrient because of lower dry matter content and also for the future sustainability of species, which is also just reverse to the higher age stand because of greater dry matter accumulation. This showed that as the dry matter storage in plant parts increased with age, the nutrient concentration decreases because of dilution of
nutrient concentration. The similar trend were also reported for exotic plantations (Lodhiyal et al., 1995; Bargali et al., 1992; Lodhiyal and Lodhiyal, 1997) and Tarai Shisham forests (Lodhiyal et al., 2002). The leaf tissue nitrogen concentration were in higher range (2.55±2.59% N) than those reported for eucalypt (1.21% N; Bargali et al., 1992), poplar (2.35±2.39% N; Lodhiyal et al., 1994) and central Himalayan forests (1.89±2.11% N; Singh and Singh, 1992). However, present estimates are lower than Tarai Shisham forests (2.64±2.75% N; Lodhiyal et al., 2002). In reproductive parts, the N concentration was higher (3.082±3.180% N) than leaf tissues and other components. However, P and K were higher than leaves. Leaf to wood concentration ratios for N (8.52± 8.67), P (5.25±6.23) and K (4.28±4.51) were higher to the central Himalayan natural forests and Tarai Shisham forests. However, present estimates was lower than poplar (11±12 for N, 6±7 for P; Lodhiyal et al., 1995) and temperate forests (Whittaker, 1975). Nutrient concentration in ®ne roots was higher (0.950±1.010% N, 0.152±0.180% P and 0.528± 0.558% K) than the ®ne roots of poplar plantations (0.48±0.52% N, 0.04±0.05% P and 0.26±0.27% K; Lodhiyal et al., 1995), and lower than ®ne roots of Tarai Shisham forests (0.995±1.012% N, 0.188± 0.198% P and 0.589±0.610% K; Lodhiyal et al., 2002). The nutrient concentration in soils decreased with increase in forest age. Details of soil nutrients are given in Lodhiyal and Lodhiyal (2003). Similar trends was reported for Tarai Shisham forests (Lodhiyal et al., 2002) and exotic plantations (Bargali et al., 1992; Lodhiyal et al., 1995; Lodhiyal and Lodhiyal, 1997). This happened because of (i) higher slope which cause fast runoff rate of nutrients and (ii) higher uptake of nutrients by plants. The uptake and leaching of nutrients from vegetation is one of the reasons (Lodhiyal et al., 1995). According to Bormann and Likens (1979) high amount of nutrient loss can be considerable in the initial site preparation activities such as clearing of ground vegetation and litter by cutting, burning and ploughing. 3.2. Nutrient storage In present study forests, nutrient storage in standing state increased with age of stand. The details of results are given in Table 2. The bole component (bole
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Table 1 Concentrations of nutrients (NPK, % dry weight) in different plant components of Bhabar Shisham forests at different ages in central Himalaya Component
Nutrient N
5 years old Tree layer Bole wood Bole bark Branch Twig Leaf Reproductive parts Stump root Lateral roots Fine roots Shrub layer Lantana camara Stem Foliage Roots Murraya koenigii Stem Foliage Roots Clerodendrum viscosum Stem Foliage Roots Pogostemon benghalense Stem Foliage Roots Herb layer Aboveground Belowground
0.304 1.389 0.948 1.548 2.590 3.180 0.538 0.599 1.010
P
0.014 0.020 0.028 0.035 0.056 0.039 0.045 0.039 0.054
0.032 0.088 0.082 0.090 0.168 0.315 0.042 0.062 0.180
K
0.019 0.028 0.030 0.040 0.052 0.030 0.032 0.040 0.046
0.168 0.595 0.044 0.548 0.720 0.840 0.370 0.468 0.558
0.014 0.022 0.027 0.036 0.046 0.032 0.038 0.033 0.050
0.698 0.034 2.340 0.056 0.775 0.037
0.076 0.080 0.152 0.064 0.074 0.039
0.504 0.074 0.730 0.053 0.540 0.048
0.670 0.058 1.250 0.042 0.754 0.054
0.045 0.042 0.115 0.064 0.045 0.050
0.344 0.040 0.746 0.080 0.404 0.074
0.638 0.059 1.150 0.050 0.664 0.072
0.050 0.052 0.125 0.048 0.050 0.050
0.330 0.048 0.670 0.050 0.351 0.064
0.680 0.068 1.175 0.040 0.740 0.035
0.052 0.052 0.130 0.040 0.050 0.080
0.340 0.036 0.680 0.050 0.450 0.044
1.531 0.069 1.205 0.070
0.084 0.054 0.075 0.048
1.326 0.052 1.142 0.073
Tree layer Bole wood Bole bark Branch Twig Leaf Reproductive parts Stump root Lateral roots Fine roots
0.298 1.380 0.932 1.535 2.564 3.105 0.535 0.590 0.998
0.028 0.078 0.078 0.088 0.164 0.302 0.038 0.058 0.174
0.162 0.582 0.038 0.534 0.718 0.830 0.368 0.456 0.552
Shrub layer Lantana camara Stem Foliage Roots
0.690 0.082 2.280 0.090 0.770 0.058
10 years old
0.018 0.026 0.032 0.040 0.050 0.029 0.041 0.031 0.048
0.019 0.036 0.029 0.036 0.048 0.054 0.018 0.040 0.040
0.074 0.054 0.149 0.048 0.072 0.052
0.020 0.033 0.028 0.030 0.050 0.046 0.027 0.038 0.036
0.501 0.050 0.728 0.043 0.536 0.064
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Table 1 (Continued ) Component
Murraya koenigii Stem Foliage Roots Clerodendrum viscosum Stem Foliage Roots Pogostemon benghalense Stem Foliage Roots Herb layer Aboveground Belowground
Nutrient N
P
K
0.668 0.062 1.246 0.049 0.750 0.054
0.044 0.048 0.112 0.050 0.043 0.060
0.432 0.072 0.740 0.054 0.402 0.063
0.638 0.073 1.146 0.049 0.662 0.054
0.048 0.072 0.124 0.064 0.047 0.058
0.327 0.068 0.667 0.039 0.349 0.053
0.678 0.064 1.172 0.050 0.737 0.048
0.051 0.043 0.128 0.038 0.048 0.042
0.338 0.067 0.676 0.070 0.442 0.052
1.520 0.070 1.182 0.077
0.083 0.047 0.073 0.043
1.302 0.057 1.135 0.066
0.294 1.312 0.921 1.520 2.550 3.082 0.530 0.584 0.982
0.026 0.075 0.071 0.083 0.162 0.301 0.033 0.050 0.168
0.158 0.562 0.177 0.521 0.712 0.816 0.362 0.450 0.548
15 years old Tree layer Bole wood Bole bark Branch Twig Leaf Reproductive parts Stump root Lateral roots Fine roots Shrub layer Lantana camara Stem Foliage Roots Murraya koenigii Stem Foliage Roots Clerodendrum viscosum Stem Foliage Roots Pogostemon benghalense Stem Foliage Roots Herb layer Aboveground Belowground
0.024 0.030 0.026 0.030 0.028 0.030 0.027 0.034 0.051
0.012 0.024 0.021 0.026 0.020 0.028 0.032 0.030 0.048
0.022 0.016 0.028 0.032 0.024 0.022 0.025 0.034 0.040
0.688 0.034 2.278 0.053 0.768 0.045
0.071 0.084 0.147 0.057 0.070 0.063
0.498 0.064 0.725 0.042 0.535 0.056
0.665 0.056 1.240 0.037 0.744 0.044
0.042 0.070 0.110 0.043 0.042 0.038
0.340 0.077 0.736 0.052 0.398 0.036
0.634 0.074 1.142 0.059 0.660 0.082
0.045 0.044 0.122 0.052 0.042 0.066
0.325 0.068 0.663 0.040 0.340 0.055
0.670 0.090 1.170 0.054 0.730 0.068
0.048 0.050 0.125 0.039 0.044 0.062
0.332 0.069 0.670 0.043 0.436 0.052
1.504 0.056 1.140 0.059
0.081 0.062 0.071 0.058
1.284 0.068 1.124 0.058
N. Lodhiyal, L.S. Lodhiyal / Forest Ecology and Management 176 (2003) 237±252 Table 2 Nutrient accumulation (N, P, K) in different components of standing vegetation of Bhabar Shisham forests Components
5 years old Tree layer % allocation in Bolea Branchb Leaf Reproductive parts Coarse rootsc Fine roots
267.8 (75.3)
28.6 (81.9) 134.5 (69.1)
K
42.1 25.5 22.9 6.3
38.4 17.8 14.0 5.9
47.3 8.8 12.7 3.3
2.5 0.7
13.3 10.5
23.3 4.5
52.9 (14.9)
Herb layer % allocation in Aboveground Belowground
34.9 (9.8)
42.0 29.5 28.5
79.9 20.1
4.4 (12.6) 45.4 27.3 27.3 1.9 (5.5) 78.9 21.1
194.5 (100)
Shrub layer % allocation in Stem Foliage Roots
61.5 (10.1)
Herb layer % allocation in Aboveground Belowground
31.6 (5.2)
33.8 25.5 11.2 10.6
48.5 9.4 12.7 4.0
13.0 4.0
11.4 7.5
20.1 5.3
77.8 22.2
20.3 5.6
Total vegetation
41.8 23.3 11.5 6.3
79.4 20.6
11.2 9.4
30.7 (15.8)
48.2 (87.3) 215.4 (77.6)
1.8 (3.3)
11.7 4.2
28.2 (3.3)
515.2 (84.7)
44.2 28.8 26.9
45.6 14.7 9.6 4.1
Herb layer % allocation in Aboveground Belowground
Tree layer % allocation in Bolea Branchb Leaf Reproductive parts Coarse rootsc Fine roots
41.5 29.4 29.1
37.8 21.4 12.0 8.2
46.1 22.2 31.7
78.5 21.5
34.5 (12.4) 45.5 22.9 31.6 27.7 (10.0) 77.6 22.4
608.3 (100)
55.2 (100)
277.6 (100)
783.9 (90.4)
59.8 (91.0) 326.9 (85.6)
15 years old
K
39.1 24.2 14.4 6.4
29.3 (15.1)
10 years old
5.2 (9.4)
% allocation in Bolea Branchb Leaf Reproductive parts Coarse rootsc Fine roots
P
54.8 (6.3)
34.9 (100)
Tree layer
Standing state of nutrients (kg ha 1 per year)
Shrub layer % allocation in Stem Foliage Roots
355.6 (100)
Total vegetation
Components
N
P
Shrub layer % allocation in Stem Foliage Roots
Total vegetation
Table 2 (Continued )
Standing state of nutrients (kg ha 1 per year) N
243
38.7 33.6 27.7
4.3 (6.5) 39.5 34.9 25.6
79.1 20.9
41.0 28.3 30.7
1.6 (2.5) 75.0 25.0
866.9 (100)
30.0 (7.9)
24.8 (6.5) 76.6 23.4
65.7 (100)
381.7 (100)
a Nitrogen: bole wood bole bark, which accounted for 14.3± 20.3% of the values; phosphorus: bole wood bole bark, which accounted for 12.2±14.3% of the values; potassium: bole wood bole bark, which accounted for 18.8±20.5% of the values. b Nitrogen: branch twig (current shoots bearing leaves, which accounted for 9.8±10.7% of the values); phosphorus: branch twig, which accounted for 5.9±13.5% of the values; potassium: branch twig, which accounted for 7.5±8.1% of the values. c Nitrogen: stump root main root lateral roots (lateral branches of main root), which accounted for 1.2±5.6% of the values; phosphorus: stump root main root lateral roots, which accounted for 5.8±6.3% of the values; potassium: stump root lateral roots, which shared 9.8±10.4%.
Table 3 Percent nutrient retranslocation from leaves of different vegetation layers in Bhabar Shisham forests Vegetation
Nutrient
Age of Shisham forests (years) 5
10
15
Tree layer
N P K
37.3 31.5 43.5
36.4 30.6 42.6
34.8 29.0 41.6
Shrub layer
N P K
35.1 28.6 30.4
34.3 28.3 29.7
32.0 26.7 28.9
Herb layer
N P K
23.0 17.6 20.4
22.1 17.5 20.2
21.6 16.8 19.5
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Table 4 Uptake of nutrient (kg ha 1 per year) by different vegetation layers of Bhabar Shisham forests (values in parenthesis are the net uptake after the adjustment of retranslocation values) Component
Shrub layer % allocation in Stem Foliage Roots Herb layer % allocation in Aboveground Belowground Total vegetation
10 63.8 (59.6)
83.1 (78.2)
85.2 (81.3)
37.3 19.6 17.7 4.9
36.4 21.7 15.9 5.4
38.3 21.6 12.8 6.3
12.4 8.1
11.2 9.4
10.6 10.4
5.7 (5.1)
5.6 (5.1)
5.4 (4.8)
42.1 29.8 28.1
41.1 28.6 30.3
38.9 33.3 27.8
34.9 (28.5)
31.6 (26.0)
28.2 (23.3)
Shrub layer % allocation in Stem Foliage Roots Herb layer % allocation in Aboveground Belowground Total vegetation
% allocation in Bolea Branchb Leaf Reproductive parts Coarse rootsc Fine roots Shrub layer % allocation in Stem Foliage Roots
10
15
45.5 8.7 9.4 3.1
43.4 9.8 10.9 3.5
43.6 12.9 8.5 3.8
22.3 11.0
19.7 12.7
17.8 13.4
3.2 (3.0)
3.1 (2.9)
2.9 (2.7)
46.9 21.9 31.2
45.2 22.6 32.2
41.4 27.6 31.0
Herb layer % allocation in Aboveground Belowground
30.7 (26.8)
27.7 (23.3)
24.8 (21.1)
78.5 21.5
77.6 22.4
76.6 23.4
Total vegetation
59.4 (54.2)
64.7 (58.5)
64.2 (59.0)
a
79.9 20.1
79.4 20.6
79.1 20.9
104.4 (93.2) 120.3 (109.3) 118.8 (109.4)
5.5 (5.3)
7.0 (6.7)
7.1 (6.9)
36.3 16.4 12.7 5.5
31.5 18.6 12.8 5.7
35.3 17.0 9.8 7.0
12.8 16.3
11.4 20.0
9.8 21.1
1.6 (1.5) 13.2 8.8 78.0 2.0 (1.7) 78.9 21.1
0.5 (0.4) 45.6 26.1 28.3 1.8 (1.5) 77.4 22.6
0.4 (0.3) 39.5 34.9 25.6 1.6 (1.4) 76.3 23.7
9.1 (8.5)
9.3 (8.6)
9.1 (8.6)
25.5 (24.4)
33.9 (32.3)
36.5 (35.2)
Potassium Tree layer
Age of Shisham forests (years) 5
15
Phosphorus Tree layer % allocation in Bolea Branchb Leaf Reproductive parts Coarse rootsc Fine roots
Component
Age of Shisham forests (years) 5
Nitrogen Tree layer % allocation in Bolea Branchb Leaf Reproductive parts Coarse rootsc Fine roots
Table 4 (Continued )
Nitrogen: bole wood bole bark, which accounted for 16.3± 18.5% of the values; phosphorus: bole wood bole bark, which accounted for 11.3±12.7% of the values; potassium: bole wood bole bark, which accounted for 16.2±19.6% of the values. b Nitrogen: branch twig (current shoots bearing leaves, which accounted for 8.2±10.1% of the values); phosphorus: branch twig (current shoots bearing leaves, 5.5±5.7% of the values); potassium: branch twig (current shoots bearing leaves, which accounted for 7.1±8.6% of values). c Nitrogen: stump root main root lateral roots, which shared about 4.8±5.1% of the values; phosphorus: stump root main root lateral roots, which shared 5.5±5.7% of the values; potassium: stump root main root lateral roots, which shared about 9.0±9.4% of the values.
wood bole bark) accounted for maximum (33.8± 48.5%) nutrients (N, P, K). The relative contribution to the standing state of nutrient in different components were in order: bole wood > bole bark > leaf > branch > twig > reproductive parts in aboveground and stump root > lateral roots > fine roots in belowground part. The nutrient storage in different vegetation layer was in order: trees > shrubs > herbs. The total nitrogen in vegetation ranged from 356 (5 years old) to 867 kg ha 1 (15 years old) of which tree, shrub and herb layer shared 75±90, 6±15 and 3±10%, respectively (Table 2). Phosphorus was 35±66 kg ha 1; of this tree accounted for 82±91%, shrub for 6±13% and herb for 3±6% (Table 2).
N. Lodhiyal, L.S. Lodhiyal / Forest Ecology and Management 176 (2003) 237±252
245
Table 5 Comparative accounts of nutrients (N, P, K) uptake in different forest vegetation of the world Forest type
Temperate deciduous forest Sal forest Teak plantation Shisham forest Poplar plantations D. sissoo plantation Cassia siamea plantation Gmelina arborea plantation Shisham forests Bhabar Shisham forests
Location and age
Nutrient (kg ha
India India India, 30 years India, 24 years India, 1±4 years India, 8 years India, 8 years India, 8 years Tarai of central Himalaya (India), 5±15 years Central Himalaya (India), 5±15 years
Potassium storage ranged 195±382 kg ha 1. Of this, tree, shrub and herb layer accounted for 69±86, 8±15 and 7±16%, respectively (Table 2). The nutrient percentage shared by trees increased with increase in age of forest. However, it was found in decreasing order in shrubs and herbs. Similar trend was reported for exotic plantations (Lodhiyal et al., 1995) and Tarai Shisham forests (Lodhiyal et al., 2002). The reasons are that: (i) tree canopy affects
1
per year)
References
N
P
K
75 105.5 108 106 234±284 278 180 106 103±154
6 7.5 16.0 6 20±30 12 11 5 9±13
51 ± ± 33 129±177 61 50 56 63±85
104±119
9.1±9.3
59±65
Cole and Rapp (1980) Singh (1974) Jha (1995) Sharma et al. (1988) Lodhiyal and Lodhiyal (1997) Pacholi (1997) Pacholi (1997) Pacholi (1997) Lodhiyal et al. (2002) Present study
the growth of under-canopy species, i.e. shrubs and herbs, because of less availability of light; (ii) high rate of nutrient uptake as compared to lower-canopy species. 3.3. Nutrient retranslocation The percent nutrient retranslocation in different vegetation layer was in order: trees 29 44% >
Table 6 Average nutrient concentration (% S:E:) in different aboveground litter components of vegetation of Bhabar Shisham forests in central Himalaya Nutrient
Component
Age of Shisham forests (years) 5
Nitrogen Trees Shrubsa Herbsb Phosphorus Trees Shrubsa Herbsb Potassium Trees Shrubsa Herbsb a b
10
15
Leaf Wood Reproductive parts
1.624 0.926 1.098 0.958 1.179
0.077 0.056 0.072 0.088 0.192
1.631 0.916 1.863 0.958 0.069
0.076 0.057 0.068 0.086 0.186
1.662 0.907 1.849 0.991 1.055
0.074 0.055 0.070 0.085 0.188
Leaf Wood Reproductive parts
0.115 0.061 0.205 0.092 1.184
0.051 0.048 0.054 0.054 0.189
0.114 0.058 0.196 0.092 0.068
0.050 0.046 0.052 0.056 0.199
0.114 0.055 0.195 0.092 1.039
0.064 0.047 0.053 0.053 0.178
Leaf Wood Reproductive parts
0.407 0.358 0.462 0.491 1.179
0.069 0.059 0.066 0.064 0.188
0.413 0.348 0.456 0.494 0.067
0.065 0.054 0.064 0.060 0.194
0.414 0.339 0.449 0.496 1.034
0.064 0.052 0.062 0.062 0.190
It includes the composite mean nutrient concentration (%) of leaves, twig and reproductive parts. It includes the (%) nutrient concentration of leaves.
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Table 7 Nutrient return (kg ha Nutrient
Nitrogen
Phosphorus
Potassium
a
1
per year) through different litter components of Bhabar Shisham forests in central Himalayaa Component
Age of Shisham forests (years) 5
10
Trees % allocation in Leaf Wood Reproductive parts Roots Shrubs Herbs
29.7 (41.7)
48.7 (54.8)
61.4 (61.1)
84.5 2.7 2.4 10.4 6.7 (9.4) 34.9 (48.9)
82.1 5.8 3.3 8.8 8.6 (9.7) 31.6 (35.5)
80.1 5.7 4.7 9.5 9.9 (9.9) 29.2 (29.0)
Total vegetation
71.3 (100)
88.9 (100)
100.5 (100)
2.5 (50.0)
4.0 (60.6)
4.9 (66.2)
72.0 4.0 4.0 20.0 0.6 (12.0) 1.9 (38.0)
70.0 5.0 5.0 20.0 0.8 (12.1) 1.8 (27.3)
69.4 4.1 6.1 20.4 0.9 (12.2) 1.6 (21.6)
Total vegetation
5.0 (100)
6.6 (100)
7.4 (100)
Trees % allocation in Leaf Wood Reproductive parts Roots Shrubs Herbs
8.5 (19.9)
14.2 (30.6)
17.5 (36.9)
74.1 3.5 2.4 20.0 3.5 (8.2) 30.7 (71.9)
71.2 7.0 2.8 19.0 4.5 (9.7) 27.7 (59.7)
70.3 7.4 4.0 18.3 5.1 (10.8) 24.8 (52.3)
Total vegetation
42.7 (100)
46.4 (100)
47.4 (100)
Trees % allocation in Leaf Wood Reproductive parts Roots Shrubs Herbs
15
Values in parenthesis are the percent contribution of the total vegetation.
shrubs 27 35% > herbs (17±23%) (Table 3). However, percent retranslocation of nutrients (NPK) in tree layer was in order: K 42 44% > N 35 37% > P (29±32%) (Table 3). In shrubs and herbs percent nutrient retranslocation was in order: N > K > P (Table 3). The present estimates of percent retranslocation of nutrients from senesced leaves are slightly higher than Tarai Shisham forests (Lodhiyal et al., 2002) but much higher than Eucalyptus hybrid plantations (18±25%; Bargali et al., 1992), Quercus rubra (23±39%; Grizzard et al., 1976) and close to the values (38±49%) for Betula alleghaniensis (Hoyle, 1965). Our estimates are much lower than Tarai poplar plantations (42±64%; Lodhiyal et al., 1995), Populus
Table 8 Turnover of forest ¯oor nutrients (NPK) of Bhabar Shisham forests in central Himalaya Nutrient
Turnover
a
Age of Shisham forests (years) 5
10
15
0.59 1.69
0.64 1.56
0.66 1.51
Nitrogen
K tb
Phosphorus
K t
0.57 1.74
0.62 1.61
0.64 1.56
Potassium
K t
0.58 1.72
0.63 1.59
0.65 1.54
a b
Turnover rate (per year). Turnover time (year).
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tremuloides (42±65%; Verry and Timmons, 1976) and cottonwood stands (74±89%; Baker and Blackman, 1977). Lodhiyal and Lodhiyal (1997) argued that higher is the leaf tissue nutrient level, greater would be the percent retranslocation capacity. However, Chapin and Kedrowski (1983), pointed out that the both percent retranslocation and concentrations of nutrients are positively correlated. 3.4. Uptake of nutrients The gross uptake of nutrient estimates in vegetation ranged from 104 to 119 N kg ha 1 per year, 9.1± 9.3 P kg ha 1 per year and 59±65 K kg ha 1 per year. Of these nutrients, tree layer accounted for 61±72% N, 60±78% P and 43±57% K; shrub layer 5±6% N, 4± 17% P and 4±5% K; herb layer 24±33% N, 18±22% P and 38±52% K (Table 4). The net uptake of nutrients (after adjustment of nutrient retranslocation values) by vegetation ranged from 93±109 N kg ha 1 per year, 8±9 P kg ha 1 per year and 54±59 K kg ha 1 per year. Of this, tree layer accounted for 64±72% N, 62±80% P and 45±60% K; shrub layer 4±6% N, 4±18% P and 5±6% K; herb layer 21±31% N, 16±20% P and 36±49% K (Table 4). The net uptake of tree layer was lower than the estimates 64±117 N kg ha 1 per year, 6±11 P kg ha 1 per year and 29±54 K kg ha 1 per year reported for Tarai Shisham forests (Lodhiyal et al., 2002) and 102± 176 N kg ha 1 per year, 12±19 P kg ha 1 per year and 49±94 K kg ha 1 per year for high density Populus deltoides plantations (Lodhiyal and Lodhiyal, 1997). According to Lodhiyal and Lodhiyal (1997) higher is the retention value, greater will be the availability of nutrients to the vegetation. Some accounts of uptake for comparison of different vegetation is given in Table 5. 3.5. Nutrient return through litter The percent nutrient concentration of litter is given in Table 6. However, the amount of nutrient (N, P and K) return through litter of vegetation is given in Table 7. The total nutrient return from vegetation was 71±101 N kg ha 1 per year, 5±7 P kg ha 1 per year and 43±47 K kg ha 1 per year. Of this, tree, shrub and herb layer, respectively, accounted for 42±61, 9±10 and 29±49% nitrogen, 50±66, 12.0±12.2 and
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Table 9 NUE (NPP/net nutrient uptake; kg ha Shisham forests in central Himalaya NUE
Nitrogen Phosphorus Potassium
1
per year) of Bhabar
Age of Shisham forests (years) 5
10
15
141 (108) 1560 (1203) 340 (262)
140 (108) 1627 (1262) 340 (264)
140 (108) 1769 (1403) 345 (274)
22±38% phosphorus and 20±37, 8±11 and 52±72% potassium (Table 7). Our estimates are close to the values reported for Tarai Shisham forests (Lodhiyal et al., 2002) and lower than the values reported for P. deltoides plantations (Lodhiyal et al., 1995) and similar to the value reported for eucalypt plantations (Bargali et al., 1992) adjacent to foothills of central Himalaya. 3.6. Turnover of nutrients on the forest ¯oor The turnover time of nutrients (NPK, 1.5±1.7 years) on the forest ¯oor of Bhabar Shisham forests (Table 8). These estimates are similar to the turnover time of nutrients (NPK) of Tarai Shisham forests (1.5±1.8 years; Lodhiyal et al., 2002). However, the present values are longer than the poplar (1.1±1.4 years; Lodhiyal et al., 1995), eucalypt (1.1±1.3 years; Bargali et al., 1992) and much higher than tropical dry deciduous forests (0.3±0.5 years; Pandey, 1980). These ®ndings showed that high amount of forest ¯oor litter biomass remained in steady state. According to Lodhiyal et al. (2002) lower annual decomposition rate of litter in relation to higher rates of litter input. Therefore, the longer Table 10 Soil NEE (net nutrient uptake/total nutrient in soil) of Bhabar Shisham forests in central Himalaya Nutrient
Component
Age of Shisham forests (years) 5
10
15
Nitrogen
Trees Total vegetation
1.3 2.0
1.7 2.4
1.8 2.4
Phosphorus
Trees Total vegetation
1.5 2.4
1.9 2.6
1.9 2.5
Potassium
Trees Total vegetation
1.4 2.9
1.8 3.4
2.1 3.6
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Fig. 1. Compartment graphs of (A) 5, (B) 10 and (C) 15 years old of Bhabar Shisham (D. sissoo Roxb.) forests. These ®gures show the distribution and cycling of nitrogen (N), phosphorus (P) and potassium (K) in tree, shrub and herb layers of 5-, 10- and 15 years old D. sissoo forests. Rectangles represent a pool for standing state of nutrients from one compartment to next. The values in the pools represent the average nutrient contents. Net annual ¯uxes of nutrients (N, P, K) between pools are given on the arrows. Units are kg ha 1 for pools and kg ha 1 per year for ¯uxes between pools. Values in parenthesis indicate adjustment for internal cycling. Recycling rates between leaf and twig for trees, foliage and stem and aboveground to belowground part for herbs are shown by broken lines.
N. Lodhiyal, L.S. Lodhiyal / Forest Ecology and Management 176 (2003) 237±252
Fig. 1. (Continued ).
249
250
N. Lodhiyal, L.S. Lodhiyal / Forest Ecology and Management 176 (2003) 237±252
Fig. 1. (Continued ).
N. Lodhiyal, L.S. Lodhiyal / Forest Ecology and Management 176 (2003) 237±252
turnover time shows the steady state of forest ¯oor litter biomass (Lodhiyal and Lodhiyal, 1997). Thus, the somewhat similar results of turnover of nutrients have been observed in the present investigation. 3.7. Nutrient use pattern The nutrient use pattern of tree species is based on the production and uptake ratio. Therefore, we have calculated the NUE (NPP/net nutrient uptake) of each Shisham forests. The NUE for different nutrients in Bhabar Shisham forests ranged from 140 to 141 for N, 1560±1769 for P and 340±345 for K (Table 9). These values are higher than the values reported for Tarai Shisham forests (Lodhiyal et al., 2002). Many scientists have estimated higher NUE for evergreen forests than deciduous forests in central Himalaya (Bargali et al., 1992; Lodhiyal et al., 1995; Lodhiyal and Lodhiyal, 1997). Thus present estimates are lower than Pinus roxburghii forest (Singh and Singh, 1992) and Eucalypt plantations (Bargali et al., 1992). The P and K use ef®ciency was higher but N use ef®ciency is lower than poplar plantations (Lodhiyal and Lodhiyal, 1997). The NUE for P increased with age of the Shisham forest. However, the NUE of N and K did not show much variations (mean remain somewhat constant). Similar observations for N, P and K were reported for high density poplar plantations (Lodhiyal, 1990; Lodhiyal and Lodhiyal, 1997). The soil nutrient extraction ef®ciency (NEE, nutrient uptake per unit nutrient present in soil) of Shisham forests is given in Table 10. Soil NEE was generally in increasing order with age of forest. The present estimates of NEE seems to be lower than exotic plantations (1.8±3.4 N, 2.4±4.7 P and 2.4±4.5 K; Lodhiyal et al., 1994) but higher than 8-year-old eucalypt plantation (0.018 N, 0.041 P and 0.039 K; Bargali et al., 1992) and oak forest (0.036 N, 0.065 P and 0.039 K; Rawat and Singh, 1988). 3.8. Nutrient cycling Compartment graphs of nutrient dynamics (pools and ¯uxes) are presented in Fig. 1A±C. The amount present in the soil to a depth of 30 cm is considered as a source and that associated with decomposition is released into the soil for reuse. The direction of nutrient ¯ux from soil to foliage indicates a one
251
way movement, although it is realized that the nutrient are utilized by the foliage in organic matter synthesis and they are redistributed among different components at varying rates giving rise to internal recycling. The total quantity of nutrients (N, P, K) stored in the forest increased with age mentioned. Of the total nutrients, the tree layer accounted for 75±90% in the 5 years old forest and 69±86% in the 15 years old forest. However, the total quantity of nutrients in the soil decreased with increase in forest age. The allocation of uptake of nutrients (N, P, K) to total vegetation was as follows: 5 years old Bhabar Shisham forestÐtrees 43 61% > herbs 22 52% > shrubs (5±18%); 15 years old Bhabar Shisham forestÐtrees 57 72% > herbs 18 39% > shrubs (4±5%). The total amount of nutrient retranslocation from the aboveground senescing plant parts of the tree layer increased with forest age from 4.3 N kg ha 1 per year, 0.2 P kg ha 1 per year and 1.1 K kg ha 1 per year in 5 years old forest to 3.9 N kg ha 1 per year, 0.2 P kg ha 1 per year and 1.3 K kg ha 1 per year in the 15 years old Shisham forest. In shrubs, the amount of nitrogen did not show any consistent pattern but phosphorus and potassium had shown a constant pattern in all age forests. In herb layer, the amount of nitrogen (4.9±6.4 kg ha 1 per year) decreased with age, whereas phosphorus and potassium did not show any pattern. Thus it is concluded that Shisham forests have responded better in the Bhabar site because of its higher NUE than exotic poplar and central Himalayan natural oak forests of the region.
Acknowledgements Authors are thankful to Professor Y.P.S. Pangtey, Department of Botany, Kumaun University, Nainital, India, for the encouragement and suggestions given throughout the study period, and Professor R.P. Singh, Head, Department of Forestry, Kumaun University, Nainital, India, for providing necessary facilities.
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Baker, J.B., Blackman, B.G., 1977. Biomass and nutrient accumulation in a cottonwood plantation: the ®rst growing season. Soil Sci. Soc. Am. J. 41, 632±636. Bargali, S.S., Singh, S.P., Singh, R.P., 1992. Structure and function of an age series of eucalypt plantations in central Himalaya. II. Nutrient dynamics. Ann. Bot. 69, 413±442. Bormann, F.H., Likens, G.E., 1979. Patterns and Process in a Forested Ecosystem. Springer/Verlag, Berlin. Champion, H.G., Seth, S.K., 1968. A revised survey of forest types of India. Delhi Manager of Publications, Government of India. Chapin III, F.S., Kedrowski, R.A., 1983. Seasonal changes in nitrogen and phosphorus fraction and autumn retranslocation in evergreen and deciduous Taiga trees. Ecology 64, 376± 391. Chaturvedi, O.P., Singh, J.S., 1987. The structure and function of pine forest in central Himalaya. II. Nutrient dynamics. Ann. Bot. 60, 253±267. Cole, D.W., Rapp, M., 1980. Elemental cycling in forest ecosystems. In: Reichle, D.E. (Ed.), Dynamic Properties of Forest Ecosystems. Cambridge University Press, Cambridge. Grizzard, T., Henderson, G.S., Clebsch, E.E.C., Reichle, D.E., 1976. Seasonal nutrient dynamics of foliage and litter fall on Walker Branch Watershed, a deciduous forest ecosystem, Publication 814. Oak Ridge Natural Laboratory, Environmental Sciences Division, Oak Ridge, TN, USA. Hoyle, M.C., 1965. Variation in foliage composition and diameter growth of yellow birch with season. Soil Sci. Soc. Am. Proc. 29, 475±480. Jackson, M.L., 1958. Soil Chemical Analysis. Prentice-Hall, Englewood Cliffs, NJ. Jha, K.K., 1995. Structure and functioning of an age series of teak (Tectona grandis Linn.) plantations in Kumaun Himalayan Tarai. Ph.D. Thesis. Kumaun University, India, 151 pp. Lodhiyal, L.S., 1990. Structure and functioning of poplar plantations in Tarai belt of Kumaun Himalaya. Ph.D. Thesis. Kumaun University, Nainital, India, p. 351. Lodhiyal, N., 2000. Structure and functioning of Shisham (Dalbergia sissoo Roxb.) forests in Tarai and Bhabar belts of central Himalaya. Ph.D. Thesis. Kumaun University, Nainital, India, p. 317. Lodhiyal, L.S., Lodhiyal, N., 1997. Nutrient cycling and nutrient use ef®ciency in short rotation, high density central Himalayan Tarai poplar plantations. Ann. Bot. 79, 517±527. Lodhiyal, N., Lodhiyal, L.S., 2003. Biomass and net primary productivity of Bhabar Shisham forests in central Himalaya, India. For. Ecol. Manage. 176, 217±235. Lodhiyal, L.S., Singh, R.P., Singh, S.P., 1994. Productivity and nutrient cycling in poplar stands in central Himalaya, India. Can. J. For. Res. 24, 1199±1209.
Lodhiyal, L.S., Singh, R.P., Singh, S.P., 1995. Structure and function of an age series of poplar plantations in central Himalaya. II. Nutrient dynamics. Ann. Bot. 76, 201±210. Lodhiyal, N., Lodhiyal, L.S., Pangtey, Y.P.S., 2002. Structure and function of Shisham forests in central Himalaya, India: nutrient dynamics. Ann. Bot. 89, 55±65. Misra, R., 1968. Ecology Work Book. Oxford and IBH Publishing, Calcutta. Pacholi, R.K., 1997. Biomass productivity and nutrient cycling in Cassia siamea, Dalbergia sissoo and Gmelina arborea plantations. Ph.D. Thesis. Kumaun University, India, 184 pp. Pandey, O.N., 1980. Cycling of nitrogen, phosphorus and potassium in the soil±vegetation system of tropical dry deciduous forest of Chandraprabha region, Varanasi. Ph.D. Thesis. Banaras Hindu University, India. Peach, K., Tracy, M.V., 1956. Modern Methods of Plant Analysis, Vol. I. Springer/Verlag, Berlin. Pomeroy, L.R., 1970. The strategy of mineral cycling. Annu. Rev. Ecol. Syst. 1, 171±190. Ralhan, P.K., Singh, S.P., 1987. Dynamics of nutrients and leaf mass in central Himalayan forest trees and shrubs. Ecology 68, 1974±1983. Rawat, Y.S., Singh, J.S., 1988. Structure and function of oak forest in central Himalayas. II. Nutrient dynamics. Ann. Bot. 62, 413±427. Sharma, D.C., Taneja, P.L., Bisht, A.P.S., 1988. Biomass, productivity and nutrient cycling in a Dalbergia sissoo plantation. Indian For. 114 (5), 261±268. Singh, R.P., 1974. A study of primary productivity and nutrient cycling in Chakia forest, Varanasi. Ph.D. Thesis. Banaras Hindu University, Varanasi, India. Singh, J.S., Singh, S.P., 1992. Forest of Himalaya: Structure, Functioning and Impact of Man. Gyanodaya Prakashan, Nainital, India. Singh, L., Singh, J.S., 1993. Importance of short-lived components of a dry tropical forest for biomass production and nutrient cycling. J. Veg. Sci. 4, 681±686. Veblen, T.T., 1986. Age and size structure of subalpine forests in the Colorado Front Range. Bull. Torrey Bot. Club 113, 225±240. Verry, E.S., Timmons, D.R., 1976. Elements in leaves of a trembling aspen clone by crown position and season. Can. J. For. Res. 6, 436±440. Waring, P.F., Patrick, J., 1975. Source±sink relations and the partition of assimilates in the plant. In: Copper, J.P. (Ed.), Photosynthesis and Productivity in Different Environment. Cambridge University Press, Cambridge, pp. 482±499. Wein, R.W., El-Bayoumi, M.A., 1983. Limitation to predictability of plant succession in northern ecosystems. In: Wein, R.W., Rieve, R.R., Methven, T.R. (Eds.), Resources and Dynamics of the Boreal Zone. ACUNS, Ottawa, pp. 214±225. Whittaker, R.H., 1975. Community and Ecosystems, 2nd Edition. Macmillan, New York.
Aspects of nutrient cycling and nutrient use pattern of Bhabar Shisham forests in central Himalaya, India Neelu Lodhiyala, L.S. Lodhiyalb,* a b
Department of Botany, D.S.B Campus, Kumaun University, Nainital 263002, Uttaranchal, India Department of Forestry, D.S.B Campus, Kumaun University, Nainital 263002, Uttaranchal, India Received 4 October 2001; received in revised form 20 February 2002; accepted 10 May 2002
Abstract This paper illustrates the nutrient related variables such as storage, uptake, nutrient use ef®ciency (NUE) and nutrient cycling in 5±15 years old Dalbergia sissoo Roxb. forests growing in Bhabar belt (a nutrient poor and low water table site) in central Himalaya previously studied for biomass and productivity. The percent nutrient concentration and nutrient storage in vegetation is in order: trees > shrubs > herbs. However, different strata accounted in order: soil 80 92% > vegetation 7 18% > litter (1±1.5%). The nutrient retranslocation in leaves of different vegetation layer was in order: trees 29 44% > shrubs 27 35% > herbs (17±23%). The nutrient uptake, i.e. gross and net by trees, shrubs, herbs and total vegetation was studied. The total nutrient transfer through litter inputs to the soil was 71±90 N kg ha 1 per year, 5±7 P kg ha 1 per year and 43±47 K kg ha 1 per year. The turnover rate and turnover time of litter nutrients (NPK) ranged from 57 to 60% and 1.6±1.8 years, respectively. The turnover rate indicates that about 60% litter nutrient release on the forest ¯oor, which showed that the litter nutrients are also equally important for the nutrient cycling as the other aspects such as retranslocation and uptake. The NUE in Shisham forests ranged from 140 to 150 N kg ha 1 per year, 1560±1769 P kg ha 1 per year and 340±345 K kg ha 1 per year. Compared with the Tarai Shisham forests, exotic plantations (eucalypt and poplar) and central Himalayan natural forests. It is concluded that Bhabar Shisham forests have shown better nutrient conservation ef®ciency than those of Tarai Shisham forests. For nutrient dynamics compartment graphs represent the distribution of nutrient pools and net annual ¯uxes of the investigated forest ecosystems. # 2002 Elsevier Science B.V. All rights reserved. Keywords: Dalbergia sissoo Roxb.; Nutrient; Concentration; Retranslocation; Uptake; Return; Nutrient use ef®ciency; Nutrient pools; Nutrient ¯uxes
1. Introduction The structure and functioning of forest ecosystem in relation to their sustainability is not only dependent on dynamic status of organic components but is also in¯uenced by various nutrient variables and the *
Corresponding author. Present address: c/o Sri P.S. Rautela, M.P. Niwas, Stoneleigh Compound, Tallital, Nainital 263002, Uttaranchal, India. Tel.: 91-5942-36754.
applied management procedures. Thus, nutrient use pattern, cycling and ¯ows within and between components and soil sub-system played a central role. Alvim (1964) and Waring and Patrick (1975) argued that various physiologically active parts of plants may compete with water, nutrients and metabolites. However, ¯ux of materials is essential for continuity and stability of living systems (Pomeroy, 1970). Contribution and cycling of nutrients to different plant components form a major character in any forest
0378-1127/02/$ ± see front matter # 2002 Elsevier Science B.V. All rights reserved. PII: S 0 3 7 8 - 1 1 2 7 ( 0 2 ) 0 0 2 6 8 - 2
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ecosystem. Singh and Singh (1993) pointed out that short-lived components played a major role in the aspects of productivity and nutrient cycling in dry tropical forests. The functioning of forests in relation to primary production is generally in¯uenced by the nutrient availability, which in turn depends on the pattern and rate of their cycling (Rawat and Singh, 1988). The nutrient availability is the most in¯uencing factor of plant species distribution (Chapin and Kedrowski, 1983). However, production of crop limits by the macronutrients such as N, P and K (Lodhiyal et al., 1994). As far as the cultural operations are concerned, if not applied properly it degrades the stand structure and also causes of major nutrient loss in the forest. Veblen (1986) argued that stand structure is highly dependent on regeneration ability but most of the northern natural forests may be conditioned by climatic variability (Wein and El-Bayoumi, 1983). However, the functioning of man-made forest in relation to the production and nutrient cycling in¯uenced by the species characteristics, site and spacing on which they are planted. From the dry matter accumulation, utility and conservation point of view Shisham forests along the central Himalayan Tarai and Bhabar regions are well known (Lodhiyal, 2000; Lodhiyal et al., 2002). But in the recent year, interest on nutrient use ef®ciency (NUE) and nutrient cycling of Shisham forests in relation to ecological management which immerged as one of the most important issues in nutrient poor site of the region. Besides this, forests are suffering by tremendous pressure in their existing areas because of its multipurpose nature. As far as the quantitative information about the nutrient demands is concerned still it is limited. The paper deals with nutrient concentration of different plant fractions, standing state of nutrients, uptake, return, turnover and cycling of nutrients in Bhabar Shisham forests of central Himalaya, India. The details of study area, vegetation, geology and soils of forest sites have been described in the previous paper of biomass and productivity (Lodhiyal and Lodhiyal, 2003). 2. Material and methods The three study sites were located between 29830 and 298120 N and 798200 and 798230 E longitude at an
altitude 300 m in Bhabar belt (a plain area with sandy coarse soil having less nutrient and low water table) falls between Tarai and foothills of central Himalaya. The details of geology, soils and meteorological data, i.e. annual rainfall and temperature, are given in the previous paper of dry matter dynamics (Lodhiyal and Lodhiyal, 2003). The climate of the study site is subtropical monsoon type, with a long dry season from early October. A detailed description of vegetation types and sampling methods of trees, shrubs and herbs are the same as given in Lodhiyal and Lodhiyal (2003). Sal mixed broad-leaved forest was original vegetation in the study site of Champion and Seth (1968). According to Lodhiyal et al. (1995), most of vegetation in the region was converted into croplands by the 1960s and followed by tree plantations in the 1970s. The present Shisham forests occupy about 37 ha. The ages of Shisham (Dalbergia sissoo) forests investigated were 5-, 10- and 15 years old. These forests were raised in 1991, 1986 and 1981 at 4 4 m2 spacing, respectively. Samples of different tree components, viz. bole wood, bole bark, branch, twig, leaf and reproductive parts of the aboveground, and coarse roots (stump root lateral roots) and ®ne roots of the belowground parts of trees were collected from 12 harvested trees (three trees from each sub-plot, one from each diameter at breast height (dbh, 1.37 m) class; see Lodhiyal and Lodhiyal, 2003) for their nutrient analysis (nutrient concentration and nutrient content) in each Bhabar Shisham forest. The roots (stump root and lateral roots) were excavated to 2 m3 volume of soil for each harvested tree. The ®ne roots (roots with 5 mm diameter associated with mycorrhizae) were sampled by digging out three randomly distributed 25 25 25 cm3 block of soil around harvested tree in each dbh class of each sub-plot (total of 12 from each forest) as followed by Lodhiyal (1990) and Lodhiyal et al. (1995, 2002). The samples for tree and shrub components were collected during the month of September 1996 and the herb samples for aboveground and belowground part collected in different seasons, i.e. summer, rainy and winter seasons for each component. Composite samples (three samples of each component taken from the upper, middle and lower plant parts and mixed together to form a composite sample)
N. Lodhiyal, L.S. Lodhiyal / Forest Ecology and Management 176 (2003) 237±252
for each of the tree, shrub and herb components were taken separately to the laboratory and oven-dried at 60 8C to constant weight. Oven-dried samples were mill-ground for nutrient analysis. Litter samples were collected using 20 l traps at monthly intervals from each forest. The size of each trap was 50 50 cm2 with 15 cm high wooden sides ®tted with a nylon net bottom. The composite litter samples (litter samples collected from each dbh class of tree and mixed to form a composite, separately for component) for each litter component, i.e. leaf, wood, reproductive litter and other litter, were ground separately and analyzed for nitrogen, phosphorus and potassium. Five replicates of dry plant material (0.5 g each) were analyzed for total nitrogen after digestion of 10 ml concentrated sulfuric acid using 5 g of a catalyst mixture (potassium sulfate and cupric sulfate in a 9:1 ratio) in a quick digestion unit. Total nitrogen was determined by micro-Kjeldahl technique (Peach and Tracy, 1956; Misra, 1968; Lodhiyal and Lodhiyal, 1997; Lodhiyal et al., 2002). Phosphorus and potassium were extracted by wet ashing of 0.5 g plant material in an acid mixture consisting of 10 ml H2SO4, 3 ml HNO3 and 1 ml HClO4, following the method of Jackson (1958). Phosphorus was determined by spectrophotometer and potassium by ¯ame photometer (Jackson, 1958). The standing state of nutrients of trees, shrubs and herbs were computed separately by multiplying the dry weight of each component by the respective mean nutrient concentration. Nutrient values in trees, shrubs and herbs were summed to obtain the total standing state of nutrients in the vegetation. The amount of nutrients (N, P and K) in the soil was determined by the micro-Kjeldahl technique for N (Peach and Tracy, 1956), absorption spectrophotometry for P and ¯ame photometry for K (Jackson, 1958). The amount of nutrients in the top 30 cm of soil was calculated by summing values for 0±10, 10±20 and 20±30 cm soil depths in each forest. Soil volume multiplied by the respective average bulk density gave the weight of the soil, which was in turn multiplied by corresponding nutrient concentration to obtain the amount of soil nutrients (N, P, and K). The mean nutrient concentration was multiplied by the weight of annual litter fall, i.e. leaf, wood, repro-
239
ductive parts of trees, and leaves of shrubs and herbs to give the amount of nutrients transferred to the forest ¯oor of vegetation of forests at different ages. The turnover rate (K) for each nutrient on the forest ¯oor was estimated following (Chaturvedi and Singh, 1987; Lodhiyal, 1990; Lodhiyal and Lodhiyal, 1997; Lodhiyal et al., 2002) as K
A AF
where A is the amount of nutrients added to the forest ¯oor by litter fall and F the nutrient content of the lowest value of standing crop of litter in the annual cycle. Turnover time (t) for nutrients was calculated as for standing litter biomass. Turnover time (t) is the reciprocal of turnover rate (K) and is expressed as 1 t K Nutrient uptake by components of vegetation in forests of different age was computed by multiplying the net primary productivity (NPP) of different components by their nutrient concentration. The values of nutrient uptake by trees, shrubs and herbs were summed to estimate the total annual uptake by the forest vegetation. Some of the relative retranslocation values of the nutrients (N, P and K) occurred during the senescence of foliage. This was assessed following Lodhiyal (1990), Lodhiyal et al. (1995, 2002) and Lodhiyal and Lodhiyal (1997), i.e.: X Y R 100 X where R is the nutrient retranslocation percent, X the nutrient mass in mature green leaves, and Y the nutrient mass in senesced leaves. The X and Y were calculated on the basis of nutrient per unit weight of mature green and senesced leaf, respectively, multiplied by total amount of leaf litter fall. To estimate nutrient retranslocation, 120 mature green and senesced leaves were collected in September (peak month of leaf maturity) and December (leaf senescing period) 1997, respectively. Since rainfall is negligible in the region when leaves senesce (December), leaching is likely to have only a minimal effect on nutrient loss from the leaves (Ralhan and Singh, 1987; Lodhiyal and Lodhiyal, 1997; Lodhiyal et al., 2002).
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The NUE (E) per unit area of D. sissoo forests was calculated on the basis of the following formula: E
P U
where P is the NPP (kg ha 1 per year) and U the net nutrient uptake (kg ha 1 per year) by the Shisham forest. 3. Results and discussion Before mentioning the results of nutrient cycling and nutrient use pattern of Bhabar Shisham forests, some accounts of stand structure and dry matter estimates is given here in brief. However, all these estimates are published in the previous paper of biomass and productivity (Lodhiyal and Lodhiyal, 2003). The whole process of nutrient dynamics depends on these dry matter estimates. The density and basal area of Shisham forests was 625 trees ha 1 and 9.2±27.7 m2 ha 1, respectively. The total vegetation biomass, NPP, forest ¯oor litter and litter fall was 53±118 t ha 1, 11±15 t ha 1 per year, 2.9±5.4 t ha 1 and 2.3±4.4 t ha 1 per year, respectively, and all these estimates were found in increasing order with increase in forest age. 3.1. Nutrient concentration Percent nutrient concentration of different components in tree, shrub and herb layers of Bhabar Shisham forests is given in Table 1. The nutrient concentration among the tree components was in order: reproductive parts > leaf > bole bark > branch > bole wood in aboveground part, and ®ne roots > lateral roots > stump root in belowground part. Compared to the young forest (5 years old) with old forest (15 years old), the percent nutrient concentration in different components of 5 years old forest was higher than 15 years old forest. This indicates that the nutrient concentration in lower age tree components have a tendency to accumulate higher nutrient because of lower dry matter content and also for the future sustainability of species, which is also just reverse to the higher age stand because of greater dry matter accumulation. This showed that as the dry matter storage in plant parts increased with age, the nutrient concentration decreases because of dilution of
nutrient concentration. The similar trend were also reported for exotic plantations (Lodhiyal et al., 1995; Bargali et al., 1992; Lodhiyal and Lodhiyal, 1997) and Tarai Shisham forests (Lodhiyal et al., 2002). The leaf tissue nitrogen concentration were in higher range (2.55±2.59% N) than those reported for eucalypt (1.21% N; Bargali et al., 1992), poplar (2.35±2.39% N; Lodhiyal et al., 1994) and central Himalayan forests (1.89±2.11% N; Singh and Singh, 1992). However, present estimates are lower than Tarai Shisham forests (2.64±2.75% N; Lodhiyal et al., 2002). In reproductive parts, the N concentration was higher (3.082±3.180% N) than leaf tissues and other components. However, P and K were higher than leaves. Leaf to wood concentration ratios for N (8.52± 8.67), P (5.25±6.23) and K (4.28±4.51) were higher to the central Himalayan natural forests and Tarai Shisham forests. However, present estimates was lower than poplar (11±12 for N, 6±7 for P; Lodhiyal et al., 1995) and temperate forests (Whittaker, 1975). Nutrient concentration in ®ne roots was higher (0.950±1.010% N, 0.152±0.180% P and 0.528± 0.558% K) than the ®ne roots of poplar plantations (0.48±0.52% N, 0.04±0.05% P and 0.26±0.27% K; Lodhiyal et al., 1995), and lower than ®ne roots of Tarai Shisham forests (0.995±1.012% N, 0.188± 0.198% P and 0.589±0.610% K; Lodhiyal et al., 2002). The nutrient concentration in soils decreased with increase in forest age. Details of soil nutrients are given in Lodhiyal and Lodhiyal (2003). Similar trends was reported for Tarai Shisham forests (Lodhiyal et al., 2002) and exotic plantations (Bargali et al., 1992; Lodhiyal et al., 1995; Lodhiyal and Lodhiyal, 1997). This happened because of (i) higher slope which cause fast runoff rate of nutrients and (ii) higher uptake of nutrients by plants. The uptake and leaching of nutrients from vegetation is one of the reasons (Lodhiyal et al., 1995). According to Bormann and Likens (1979) high amount of nutrient loss can be considerable in the initial site preparation activities such as clearing of ground vegetation and litter by cutting, burning and ploughing. 3.2. Nutrient storage In present study forests, nutrient storage in standing state increased with age of stand. The details of results are given in Table 2. The bole component (bole
N. Lodhiyal, L.S. Lodhiyal / Forest Ecology and Management 176 (2003) 237±252
241
Table 1 Concentrations of nutrients (NPK, % dry weight) in different plant components of Bhabar Shisham forests at different ages in central Himalaya Component
Nutrient N
5 years old Tree layer Bole wood Bole bark Branch Twig Leaf Reproductive parts Stump root Lateral roots Fine roots Shrub layer Lantana camara Stem Foliage Roots Murraya koenigii Stem Foliage Roots Clerodendrum viscosum Stem Foliage Roots Pogostemon benghalense Stem Foliage Roots Herb layer Aboveground Belowground
0.304 1.389 0.948 1.548 2.590 3.180 0.538 0.599 1.010
P
0.014 0.020 0.028 0.035 0.056 0.039 0.045 0.039 0.054
0.032 0.088 0.082 0.090 0.168 0.315 0.042 0.062 0.180
K
0.019 0.028 0.030 0.040 0.052 0.030 0.032 0.040 0.046
0.168 0.595 0.044 0.548 0.720 0.840 0.370 0.468 0.558
0.014 0.022 0.027 0.036 0.046 0.032 0.038 0.033 0.050
0.698 0.034 2.340 0.056 0.775 0.037
0.076 0.080 0.152 0.064 0.074 0.039
0.504 0.074 0.730 0.053 0.540 0.048
0.670 0.058 1.250 0.042 0.754 0.054
0.045 0.042 0.115 0.064 0.045 0.050
0.344 0.040 0.746 0.080 0.404 0.074
0.638 0.059 1.150 0.050 0.664 0.072
0.050 0.052 0.125 0.048 0.050 0.050
0.330 0.048 0.670 0.050 0.351 0.064
0.680 0.068 1.175 0.040 0.740 0.035
0.052 0.052 0.130 0.040 0.050 0.080
0.340 0.036 0.680 0.050 0.450 0.044
1.531 0.069 1.205 0.070
0.084 0.054 0.075 0.048
1.326 0.052 1.142 0.073
Tree layer Bole wood Bole bark Branch Twig Leaf Reproductive parts Stump root Lateral roots Fine roots
0.298 1.380 0.932 1.535 2.564 3.105 0.535 0.590 0.998
0.028 0.078 0.078 0.088 0.164 0.302 0.038 0.058 0.174
0.162 0.582 0.038 0.534 0.718 0.830 0.368 0.456 0.552
Shrub layer Lantana camara Stem Foliage Roots
0.690 0.082 2.280 0.090 0.770 0.058
10 years old
0.018 0.026 0.032 0.040 0.050 0.029 0.041 0.031 0.048
0.019 0.036 0.029 0.036 0.048 0.054 0.018 0.040 0.040
0.074 0.054 0.149 0.048 0.072 0.052
0.020 0.033 0.028 0.030 0.050 0.046 0.027 0.038 0.036
0.501 0.050 0.728 0.043 0.536 0.064
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Table 1 (Continued ) Component
Murraya koenigii Stem Foliage Roots Clerodendrum viscosum Stem Foliage Roots Pogostemon benghalense Stem Foliage Roots Herb layer Aboveground Belowground
Nutrient N
P
K
0.668 0.062 1.246 0.049 0.750 0.054
0.044 0.048 0.112 0.050 0.043 0.060
0.432 0.072 0.740 0.054 0.402 0.063
0.638 0.073 1.146 0.049 0.662 0.054
0.048 0.072 0.124 0.064 0.047 0.058
0.327 0.068 0.667 0.039 0.349 0.053
0.678 0.064 1.172 0.050 0.737 0.048
0.051 0.043 0.128 0.038 0.048 0.042
0.338 0.067 0.676 0.070 0.442 0.052
1.520 0.070 1.182 0.077
0.083 0.047 0.073 0.043
1.302 0.057 1.135 0.066
0.294 1.312 0.921 1.520 2.550 3.082 0.530 0.584 0.982
0.026 0.075 0.071 0.083 0.162 0.301 0.033 0.050 0.168
0.158 0.562 0.177 0.521 0.712 0.816 0.362 0.450 0.548
15 years old Tree layer Bole wood Bole bark Branch Twig Leaf Reproductive parts Stump root Lateral roots Fine roots Shrub layer Lantana camara Stem Foliage Roots Murraya koenigii Stem Foliage Roots Clerodendrum viscosum Stem Foliage Roots Pogostemon benghalense Stem Foliage Roots Herb layer Aboveground Belowground
0.024 0.030 0.026 0.030 0.028 0.030 0.027 0.034 0.051
0.012 0.024 0.021 0.026 0.020 0.028 0.032 0.030 0.048
0.022 0.016 0.028 0.032 0.024 0.022 0.025 0.034 0.040
0.688 0.034 2.278 0.053 0.768 0.045
0.071 0.084 0.147 0.057 0.070 0.063
0.498 0.064 0.725 0.042 0.535 0.056
0.665 0.056 1.240 0.037 0.744 0.044
0.042 0.070 0.110 0.043 0.042 0.038
0.340 0.077 0.736 0.052 0.398 0.036
0.634 0.074 1.142 0.059 0.660 0.082
0.045 0.044 0.122 0.052 0.042 0.066
0.325 0.068 0.663 0.040 0.340 0.055
0.670 0.090 1.170 0.054 0.730 0.068
0.048 0.050 0.125 0.039 0.044 0.062
0.332 0.069 0.670 0.043 0.436 0.052
1.504 0.056 1.140 0.059
0.081 0.062 0.071 0.058
1.284 0.068 1.124 0.058
N. Lodhiyal, L.S. Lodhiyal / Forest Ecology and Management 176 (2003) 237±252 Table 2 Nutrient accumulation (N, P, K) in different components of standing vegetation of Bhabar Shisham forests Components
5 years old Tree layer % allocation in Bolea Branchb Leaf Reproductive parts Coarse rootsc Fine roots
267.8 (75.3)
28.6 (81.9) 134.5 (69.1)
K
42.1 25.5 22.9 6.3
38.4 17.8 14.0 5.9
47.3 8.8 12.7 3.3
2.5 0.7
13.3 10.5
23.3 4.5
52.9 (14.9)
Herb layer % allocation in Aboveground Belowground
34.9 (9.8)
42.0 29.5 28.5
79.9 20.1
4.4 (12.6) 45.4 27.3 27.3 1.9 (5.5) 78.9 21.1
194.5 (100)
Shrub layer % allocation in Stem Foliage Roots
61.5 (10.1)
Herb layer % allocation in Aboveground Belowground
31.6 (5.2)
33.8 25.5 11.2 10.6
48.5 9.4 12.7 4.0
13.0 4.0
11.4 7.5
20.1 5.3
77.8 22.2
20.3 5.6
Total vegetation
41.8 23.3 11.5 6.3
79.4 20.6
11.2 9.4
30.7 (15.8)
48.2 (87.3) 215.4 (77.6)
1.8 (3.3)
11.7 4.2
28.2 (3.3)
515.2 (84.7)
44.2 28.8 26.9
45.6 14.7 9.6 4.1
Herb layer % allocation in Aboveground Belowground
Tree layer % allocation in Bolea Branchb Leaf Reproductive parts Coarse rootsc Fine roots
41.5 29.4 29.1
37.8 21.4 12.0 8.2
46.1 22.2 31.7
78.5 21.5
34.5 (12.4) 45.5 22.9 31.6 27.7 (10.0) 77.6 22.4
608.3 (100)
55.2 (100)
277.6 (100)
783.9 (90.4)
59.8 (91.0) 326.9 (85.6)
15 years old
K
39.1 24.2 14.4 6.4
29.3 (15.1)
10 years old
5.2 (9.4)
% allocation in Bolea Branchb Leaf Reproductive parts Coarse rootsc Fine roots
P
54.8 (6.3)
34.9 (100)
Tree layer
Standing state of nutrients (kg ha 1 per year)
Shrub layer % allocation in Stem Foliage Roots
355.6 (100)
Total vegetation
Components
N
P
Shrub layer % allocation in Stem Foliage Roots
Total vegetation
Table 2 (Continued )
Standing state of nutrients (kg ha 1 per year) N
243
38.7 33.6 27.7
4.3 (6.5) 39.5 34.9 25.6
79.1 20.9
41.0 28.3 30.7
1.6 (2.5) 75.0 25.0
866.9 (100)
30.0 (7.9)
24.8 (6.5) 76.6 23.4
65.7 (100)
381.7 (100)
a Nitrogen: bole wood bole bark, which accounted for 14.3± 20.3% of the values; phosphorus: bole wood bole bark, which accounted for 12.2±14.3% of the values; potassium: bole wood bole bark, which accounted for 18.8±20.5% of the values. b Nitrogen: branch twig (current shoots bearing leaves, which accounted for 9.8±10.7% of the values); phosphorus: branch twig, which accounted for 5.9±13.5% of the values; potassium: branch twig, which accounted for 7.5±8.1% of the values. c Nitrogen: stump root main root lateral roots (lateral branches of main root), which accounted for 1.2±5.6% of the values; phosphorus: stump root main root lateral roots, which accounted for 5.8±6.3% of the values; potassium: stump root lateral roots, which shared 9.8±10.4%.
Table 3 Percent nutrient retranslocation from leaves of different vegetation layers in Bhabar Shisham forests Vegetation
Nutrient
Age of Shisham forests (years) 5
10
15
Tree layer
N P K
37.3 31.5 43.5
36.4 30.6 42.6
34.8 29.0 41.6
Shrub layer
N P K
35.1 28.6 30.4
34.3 28.3 29.7
32.0 26.7 28.9
Herb layer
N P K
23.0 17.6 20.4
22.1 17.5 20.2
21.6 16.8 19.5
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N. Lodhiyal, L.S. Lodhiyal / Forest Ecology and Management 176 (2003) 237±252
Table 4 Uptake of nutrient (kg ha 1 per year) by different vegetation layers of Bhabar Shisham forests (values in parenthesis are the net uptake after the adjustment of retranslocation values) Component
Shrub layer % allocation in Stem Foliage Roots Herb layer % allocation in Aboveground Belowground Total vegetation
10 63.8 (59.6)
83.1 (78.2)
85.2 (81.3)
37.3 19.6 17.7 4.9
36.4 21.7 15.9 5.4
38.3 21.6 12.8 6.3
12.4 8.1
11.2 9.4
10.6 10.4
5.7 (5.1)
5.6 (5.1)
5.4 (4.8)
42.1 29.8 28.1
41.1 28.6 30.3
38.9 33.3 27.8
34.9 (28.5)
31.6 (26.0)
28.2 (23.3)
Shrub layer % allocation in Stem Foliage Roots Herb layer % allocation in Aboveground Belowground Total vegetation
% allocation in Bolea Branchb Leaf Reproductive parts Coarse rootsc Fine roots Shrub layer % allocation in Stem Foliage Roots
10
15
45.5 8.7 9.4 3.1
43.4 9.8 10.9 3.5
43.6 12.9 8.5 3.8
22.3 11.0
19.7 12.7
17.8 13.4
3.2 (3.0)
3.1 (2.9)
2.9 (2.7)
46.9 21.9 31.2
45.2 22.6 32.2
41.4 27.6 31.0
Herb layer % allocation in Aboveground Belowground
30.7 (26.8)
27.7 (23.3)
24.8 (21.1)
78.5 21.5
77.6 22.4
76.6 23.4
Total vegetation
59.4 (54.2)
64.7 (58.5)
64.2 (59.0)
a
79.9 20.1
79.4 20.6
79.1 20.9
104.4 (93.2) 120.3 (109.3) 118.8 (109.4)
5.5 (5.3)
7.0 (6.7)
7.1 (6.9)
36.3 16.4 12.7 5.5
31.5 18.6 12.8 5.7
35.3 17.0 9.8 7.0
12.8 16.3
11.4 20.0
9.8 21.1
1.6 (1.5) 13.2 8.8 78.0 2.0 (1.7) 78.9 21.1
0.5 (0.4) 45.6 26.1 28.3 1.8 (1.5) 77.4 22.6
0.4 (0.3) 39.5 34.9 25.6 1.6 (1.4) 76.3 23.7
9.1 (8.5)
9.3 (8.6)
9.1 (8.6)
25.5 (24.4)
33.9 (32.3)
36.5 (35.2)
Potassium Tree layer
Age of Shisham forests (years) 5
15
Phosphorus Tree layer % allocation in Bolea Branchb Leaf Reproductive parts Coarse rootsc Fine roots
Component
Age of Shisham forests (years) 5
Nitrogen Tree layer % allocation in Bolea Branchb Leaf Reproductive parts Coarse rootsc Fine roots
Table 4 (Continued )
Nitrogen: bole wood bole bark, which accounted for 16.3± 18.5% of the values; phosphorus: bole wood bole bark, which accounted for 11.3±12.7% of the values; potassium: bole wood bole bark, which accounted for 16.2±19.6% of the values. b Nitrogen: branch twig (current shoots bearing leaves, which accounted for 8.2±10.1% of the values); phosphorus: branch twig (current shoots bearing leaves, 5.5±5.7% of the values); potassium: branch twig (current shoots bearing leaves, which accounted for 7.1±8.6% of values). c Nitrogen: stump root main root lateral roots, which shared about 4.8±5.1% of the values; phosphorus: stump root main root lateral roots, which shared 5.5±5.7% of the values; potassium: stump root main root lateral roots, which shared about 9.0±9.4% of the values.
wood bole bark) accounted for maximum (33.8± 48.5%) nutrients (N, P, K). The relative contribution to the standing state of nutrient in different components were in order: bole wood > bole bark > leaf > branch > twig > reproductive parts in aboveground and stump root > lateral roots > fine roots in belowground part. The nutrient storage in different vegetation layer was in order: trees > shrubs > herbs. The total nitrogen in vegetation ranged from 356 (5 years old) to 867 kg ha 1 (15 years old) of which tree, shrub and herb layer shared 75±90, 6±15 and 3±10%, respectively (Table 2). Phosphorus was 35±66 kg ha 1; of this tree accounted for 82±91%, shrub for 6±13% and herb for 3±6% (Table 2).
N. Lodhiyal, L.S. Lodhiyal / Forest Ecology and Management 176 (2003) 237±252
245
Table 5 Comparative accounts of nutrients (N, P, K) uptake in different forest vegetation of the world Forest type
Temperate deciduous forest Sal forest Teak plantation Shisham forest Poplar plantations D. sissoo plantation Cassia siamea plantation Gmelina arborea plantation Shisham forests Bhabar Shisham forests
Location and age
Nutrient (kg ha
India India India, 30 years India, 24 years India, 1±4 years India, 8 years India, 8 years India, 8 years Tarai of central Himalaya (India), 5±15 years Central Himalaya (India), 5±15 years
Potassium storage ranged 195±382 kg ha 1. Of this, tree, shrub and herb layer accounted for 69±86, 8±15 and 7±16%, respectively (Table 2). The nutrient percentage shared by trees increased with increase in age of forest. However, it was found in decreasing order in shrubs and herbs. Similar trend was reported for exotic plantations (Lodhiyal et al., 1995) and Tarai Shisham forests (Lodhiyal et al., 2002). The reasons are that: (i) tree canopy affects
1
per year)
References
N
P
K
75 105.5 108 106 234±284 278 180 106 103±154
6 7.5 16.0 6 20±30 12 11 5 9±13
51 ± ± 33 129±177 61 50 56 63±85
104±119
9.1±9.3
59±65
Cole and Rapp (1980) Singh (1974) Jha (1995) Sharma et al. (1988) Lodhiyal and Lodhiyal (1997) Pacholi (1997) Pacholi (1997) Pacholi (1997) Lodhiyal et al. (2002) Present study
the growth of under-canopy species, i.e. shrubs and herbs, because of less availability of light; (ii) high rate of nutrient uptake as compared to lower-canopy species. 3.3. Nutrient retranslocation The percent nutrient retranslocation in different vegetation layer was in order: trees 29 44% >
Table 6 Average nutrient concentration (% S:E:) in different aboveground litter components of vegetation of Bhabar Shisham forests in central Himalaya Nutrient
Component
Age of Shisham forests (years) 5
Nitrogen Trees Shrubsa Herbsb Phosphorus Trees Shrubsa Herbsb Potassium Trees Shrubsa Herbsb a b
10
15
Leaf Wood Reproductive parts
1.624 0.926 1.098 0.958 1.179
0.077 0.056 0.072 0.088 0.192
1.631 0.916 1.863 0.958 0.069
0.076 0.057 0.068 0.086 0.186
1.662 0.907 1.849 0.991 1.055
0.074 0.055 0.070 0.085 0.188
Leaf Wood Reproductive parts
0.115 0.061 0.205 0.092 1.184
0.051 0.048 0.054 0.054 0.189
0.114 0.058 0.196 0.092 0.068
0.050 0.046 0.052 0.056 0.199
0.114 0.055 0.195 0.092 1.039
0.064 0.047 0.053 0.053 0.178
Leaf Wood Reproductive parts
0.407 0.358 0.462 0.491 1.179
0.069 0.059 0.066 0.064 0.188
0.413 0.348 0.456 0.494 0.067
0.065 0.054 0.064 0.060 0.194
0.414 0.339 0.449 0.496 1.034
0.064 0.052 0.062 0.062 0.190
It includes the composite mean nutrient concentration (%) of leaves, twig and reproductive parts. It includes the (%) nutrient concentration of leaves.
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Table 7 Nutrient return (kg ha Nutrient
Nitrogen
Phosphorus
Potassium
a
1
per year) through different litter components of Bhabar Shisham forests in central Himalayaa Component
Age of Shisham forests (years) 5
10
Trees % allocation in Leaf Wood Reproductive parts Roots Shrubs Herbs
29.7 (41.7)
48.7 (54.8)
61.4 (61.1)
84.5 2.7 2.4 10.4 6.7 (9.4) 34.9 (48.9)
82.1 5.8 3.3 8.8 8.6 (9.7) 31.6 (35.5)
80.1 5.7 4.7 9.5 9.9 (9.9) 29.2 (29.0)
Total vegetation
71.3 (100)
88.9 (100)
100.5 (100)
2.5 (50.0)
4.0 (60.6)
4.9 (66.2)
72.0 4.0 4.0 20.0 0.6 (12.0) 1.9 (38.0)
70.0 5.0 5.0 20.0 0.8 (12.1) 1.8 (27.3)
69.4 4.1 6.1 20.4 0.9 (12.2) 1.6 (21.6)
Total vegetation
5.0 (100)
6.6 (100)
7.4 (100)
Trees % allocation in Leaf Wood Reproductive parts Roots Shrubs Herbs
8.5 (19.9)
14.2 (30.6)
17.5 (36.9)
74.1 3.5 2.4 20.0 3.5 (8.2) 30.7 (71.9)
71.2 7.0 2.8 19.0 4.5 (9.7) 27.7 (59.7)
70.3 7.4 4.0 18.3 5.1 (10.8) 24.8 (52.3)
Total vegetation
42.7 (100)
46.4 (100)
47.4 (100)
Trees % allocation in Leaf Wood Reproductive parts Roots Shrubs Herbs
15
Values in parenthesis are the percent contribution of the total vegetation.
shrubs 27 35% > herbs (17±23%) (Table 3). However, percent retranslocation of nutrients (NPK) in tree layer was in order: K 42 44% > N 35 37% > P (29±32%) (Table 3). In shrubs and herbs percent nutrient retranslocation was in order: N > K > P (Table 3). The present estimates of percent retranslocation of nutrients from senesced leaves are slightly higher than Tarai Shisham forests (Lodhiyal et al., 2002) but much higher than Eucalyptus hybrid plantations (18±25%; Bargali et al., 1992), Quercus rubra (23±39%; Grizzard et al., 1976) and close to the values (38±49%) for Betula alleghaniensis (Hoyle, 1965). Our estimates are much lower than Tarai poplar plantations (42±64%; Lodhiyal et al., 1995), Populus
Table 8 Turnover of forest ¯oor nutrients (NPK) of Bhabar Shisham forests in central Himalaya Nutrient
Turnover
a
Age of Shisham forests (years) 5
10
15
0.59 1.69
0.64 1.56
0.66 1.51
Nitrogen
K tb
Phosphorus
K t
0.57 1.74
0.62 1.61
0.64 1.56
Potassium
K t
0.58 1.72
0.63 1.59
0.65 1.54
a b
Turnover rate (per year). Turnover time (year).
N. Lodhiyal, L.S. Lodhiyal / Forest Ecology and Management 176 (2003) 237±252
tremuloides (42±65%; Verry and Timmons, 1976) and cottonwood stands (74±89%; Baker and Blackman, 1977). Lodhiyal and Lodhiyal (1997) argued that higher is the leaf tissue nutrient level, greater would be the percent retranslocation capacity. However, Chapin and Kedrowski (1983), pointed out that the both percent retranslocation and concentrations of nutrients are positively correlated. 3.4. Uptake of nutrients The gross uptake of nutrient estimates in vegetation ranged from 104 to 119 N kg ha 1 per year, 9.1± 9.3 P kg ha 1 per year and 59±65 K kg ha 1 per year. Of these nutrients, tree layer accounted for 61±72% N, 60±78% P and 43±57% K; shrub layer 5±6% N, 4± 17% P and 4±5% K; herb layer 24±33% N, 18±22% P and 38±52% K (Table 4). The net uptake of nutrients (after adjustment of nutrient retranslocation values) by vegetation ranged from 93±109 N kg ha 1 per year, 8±9 P kg ha 1 per year and 54±59 K kg ha 1 per year. Of this, tree layer accounted for 64±72% N, 62±80% P and 45±60% K; shrub layer 4±6% N, 4±18% P and 5±6% K; herb layer 21±31% N, 16±20% P and 36±49% K (Table 4). The net uptake of tree layer was lower than the estimates 64±117 N kg ha 1 per year, 6±11 P kg ha 1 per year and 29±54 K kg ha 1 per year reported for Tarai Shisham forests (Lodhiyal et al., 2002) and 102± 176 N kg ha 1 per year, 12±19 P kg ha 1 per year and 49±94 K kg ha 1 per year for high density Populus deltoides plantations (Lodhiyal and Lodhiyal, 1997). According to Lodhiyal and Lodhiyal (1997) higher is the retention value, greater will be the availability of nutrients to the vegetation. Some accounts of uptake for comparison of different vegetation is given in Table 5. 3.5. Nutrient return through litter The percent nutrient concentration of litter is given in Table 6. However, the amount of nutrient (N, P and K) return through litter of vegetation is given in Table 7. The total nutrient return from vegetation was 71±101 N kg ha 1 per year, 5±7 P kg ha 1 per year and 43±47 K kg ha 1 per year. Of this, tree, shrub and herb layer, respectively, accounted for 42±61, 9±10 and 29±49% nitrogen, 50±66, 12.0±12.2 and
247
Table 9 NUE (NPP/net nutrient uptake; kg ha Shisham forests in central Himalaya NUE
Nitrogen Phosphorus Potassium
1
per year) of Bhabar
Age of Shisham forests (years) 5
10
15
141 (108) 1560 (1203) 340 (262)
140 (108) 1627 (1262) 340 (264)
140 (108) 1769 (1403) 345 (274)
22±38% phosphorus and 20±37, 8±11 and 52±72% potassium (Table 7). Our estimates are close to the values reported for Tarai Shisham forests (Lodhiyal et al., 2002) and lower than the values reported for P. deltoides plantations (Lodhiyal et al., 1995) and similar to the value reported for eucalypt plantations (Bargali et al., 1992) adjacent to foothills of central Himalaya. 3.6. Turnover of nutrients on the forest ¯oor The turnover time of nutrients (NPK, 1.5±1.7 years) on the forest ¯oor of Bhabar Shisham forests (Table 8). These estimates are similar to the turnover time of nutrients (NPK) of Tarai Shisham forests (1.5±1.8 years; Lodhiyal et al., 2002). However, the present values are longer than the poplar (1.1±1.4 years; Lodhiyal et al., 1995), eucalypt (1.1±1.3 years; Bargali et al., 1992) and much higher than tropical dry deciduous forests (0.3±0.5 years; Pandey, 1980). These ®ndings showed that high amount of forest ¯oor litter biomass remained in steady state. According to Lodhiyal et al. (2002) lower annual decomposition rate of litter in relation to higher rates of litter input. Therefore, the longer Table 10 Soil NEE (net nutrient uptake/total nutrient in soil) of Bhabar Shisham forests in central Himalaya Nutrient
Component
Age of Shisham forests (years) 5
10
15
Nitrogen
Trees Total vegetation
1.3 2.0
1.7 2.4
1.8 2.4
Phosphorus
Trees Total vegetation
1.5 2.4
1.9 2.6
1.9 2.5
Potassium
Trees Total vegetation
1.4 2.9
1.8 3.4
2.1 3.6
248
N. Lodhiyal, L.S. Lodhiyal / Forest Ecology and Management 176 (2003) 237±252
Fig. 1. Compartment graphs of (A) 5, (B) 10 and (C) 15 years old of Bhabar Shisham (D. sissoo Roxb.) forests. These ®gures show the distribution and cycling of nitrogen (N), phosphorus (P) and potassium (K) in tree, shrub and herb layers of 5-, 10- and 15 years old D. sissoo forests. Rectangles represent a pool for standing state of nutrients from one compartment to next. The values in the pools represent the average nutrient contents. Net annual ¯uxes of nutrients (N, P, K) between pools are given on the arrows. Units are kg ha 1 for pools and kg ha 1 per year for ¯uxes between pools. Values in parenthesis indicate adjustment for internal cycling. Recycling rates between leaf and twig for trees, foliage and stem and aboveground to belowground part for herbs are shown by broken lines.
N. Lodhiyal, L.S. Lodhiyal / Forest Ecology and Management 176 (2003) 237±252
Fig. 1. (Continued ).
249
250
N. Lodhiyal, L.S. Lodhiyal / Forest Ecology and Management 176 (2003) 237±252
Fig. 1. (Continued ).
N. Lodhiyal, L.S. Lodhiyal / Forest Ecology and Management 176 (2003) 237±252
turnover time shows the steady state of forest ¯oor litter biomass (Lodhiyal and Lodhiyal, 1997). Thus, the somewhat similar results of turnover of nutrients have been observed in the present investigation. 3.7. Nutrient use pattern The nutrient use pattern of tree species is based on the production and uptake ratio. Therefore, we have calculated the NUE (NPP/net nutrient uptake) of each Shisham forests. The NUE for different nutrients in Bhabar Shisham forests ranged from 140 to 141 for N, 1560±1769 for P and 340±345 for K (Table 9). These values are higher than the values reported for Tarai Shisham forests (Lodhiyal et al., 2002). Many scientists have estimated higher NUE for evergreen forests than deciduous forests in central Himalaya (Bargali et al., 1992; Lodhiyal et al., 1995; Lodhiyal and Lodhiyal, 1997). Thus present estimates are lower than Pinus roxburghii forest (Singh and Singh, 1992) and Eucalypt plantations (Bargali et al., 1992). The P and K use ef®ciency was higher but N use ef®ciency is lower than poplar plantations (Lodhiyal and Lodhiyal, 1997). The NUE for P increased with age of the Shisham forest. However, the NUE of N and K did not show much variations (mean remain somewhat constant). Similar observations for N, P and K were reported for high density poplar plantations (Lodhiyal, 1990; Lodhiyal and Lodhiyal, 1997). The soil nutrient extraction ef®ciency (NEE, nutrient uptake per unit nutrient present in soil) of Shisham forests is given in Table 10. Soil NEE was generally in increasing order with age of forest. The present estimates of NEE seems to be lower than exotic plantations (1.8±3.4 N, 2.4±4.7 P and 2.4±4.5 K; Lodhiyal et al., 1994) but higher than 8-year-old eucalypt plantation (0.018 N, 0.041 P and 0.039 K; Bargali et al., 1992) and oak forest (0.036 N, 0.065 P and 0.039 K; Rawat and Singh, 1988). 3.8. Nutrient cycling Compartment graphs of nutrient dynamics (pools and ¯uxes) are presented in Fig. 1A±C. The amount present in the soil to a depth of 30 cm is considered as a source and that associated with decomposition is released into the soil for reuse. The direction of nutrient ¯ux from soil to foliage indicates a one
251
way movement, although it is realized that the nutrient are utilized by the foliage in organic matter synthesis and they are redistributed among different components at varying rates giving rise to internal recycling. The total quantity of nutrients (N, P, K) stored in the forest increased with age mentioned. Of the total nutrients, the tree layer accounted for 75±90% in the 5 years old forest and 69±86% in the 15 years old forest. However, the total quantity of nutrients in the soil decreased with increase in forest age. The allocation of uptake of nutrients (N, P, K) to total vegetation was as follows: 5 years old Bhabar Shisham forestÐtrees 43 61% > herbs 22 52% > shrubs (5±18%); 15 years old Bhabar Shisham forestÐtrees 57 72% > herbs 18 39% > shrubs (4±5%). The total amount of nutrient retranslocation from the aboveground senescing plant parts of the tree layer increased with forest age from 4.3 N kg ha 1 per year, 0.2 P kg ha 1 per year and 1.1 K kg ha 1 per year in 5 years old forest to 3.9 N kg ha 1 per year, 0.2 P kg ha 1 per year and 1.3 K kg ha 1 per year in the 15 years old Shisham forest. In shrubs, the amount of nitrogen did not show any consistent pattern but phosphorus and potassium had shown a constant pattern in all age forests. In herb layer, the amount of nitrogen (4.9±6.4 kg ha 1 per year) decreased with age, whereas phosphorus and potassium did not show any pattern. Thus it is concluded that Shisham forests have responded better in the Bhabar site because of its higher NUE than exotic poplar and central Himalayan natural oak forests of the region.
Acknowledgements Authors are thankful to Professor Y.P.S. Pangtey, Department of Botany, Kumaun University, Nainital, India, for the encouragement and suggestions given throughout the study period, and Professor R.P. Singh, Head, Department of Forestry, Kumaun University, Nainital, India, for providing necessary facilities.
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