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Study on the effects of different levels of grazing and exclosure on vegetation and soil properties in semi-arid rangelands of Iran
CHNAES-00665; No of Pages 7 Acta Ecologica Sinica xxx (2019) xxx
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Acta Ecologica Sinica journal homepage: www.elsevier.com/locate/chnaes
Study on the effects of different levels of grazing and exclosure on vegetation and soil properties in semi-arid rangelands of Iran Jamal Bakhshi a,⁎, Seyed Akbar Javadi a, Ali Tavili b, Hossein Arzani b a b
Department of range management, Science and Research Branch, Islamic Azad University, Tehran, Iran College of Natural Resource, University of Tehran, Tehran, Iran
a r t i c l e
i n f o
Article history: Received 18 June 2019 Received in revised form 25 July 2019 Accepted 26 July 2019 Available online xxxx Keywords: Grazing Diversity Similarity Rangeland Vegetation Semi-arid
a b s t r a c t Livestock grazing is one of the main factors of vegetation and soil degradation in arid and semi-arid rangelands of Iran and causes changes in diversity, vegetation, litter and soil characteristics. Therefore, this study has been conducted aimed to examine the effects of exclosure and livestock grazing on vegetation and soil. For this purpose, two grazing areas of medium and high grazing intensity and two exclosure areas (Non-grazing livestock) with duration of 8 and 11 years were selected for sampling. Then, we identified plant species, percentage of coverage of each species, measurement of diversity indices, species similarity and soil chemical properties including electrical conductivity (mho), acidity, organic matter(%), organic carbon (%), nitrogen (%), phosphorus (mg/L) and bulk density (gr/cm3) in each area and they were compared using variance analysis. The results showed that exclosure significantly at 5% level reduced organic matter percentage, electrical conductivity and organic carbon percentage, but it caused a significant increase in soil bulk density at 1% level. Similarity of plant species due to the reduction of livestock grazing intensity and increasing exclosure duration. The results also indicate Livestock grazing increased Coverage of plant family such as Poaceae, Zygophyllacea in the area due to the increase of plant species such as Peganum harmala and Poa bulbosa (non-pleasant species of class III). Based on the results, despite increasing the diversity of plant species in the area over time, increasing diversity does not increase dominant species of the area, as well as companion species increased in the composition of vegetation. It concluded that exclusion has a significant effect on vegetation improvement, vegetation cover percentage, diversity, palatability and litter percentage in the region. © 2019 Ecological Society of China. Published by Elsevier B.V. All rights reserved.
Contents 1. 2.
3.
Introduction . . . . . . . . . . . . . . . . . . . Materials and methods . . . . . . . . . . . . . . 2.1. Study area. . . . . . . . . . . . . . . . . 2.2. Identification of the study area . . . . . . . 2.3. Visit the field and select homogeneous stands 2.4. Sampling of the studied areas . . . . . . . . 2.5. Vegetation sampling . . . . . . . . . . . . 2.6. Coefficient of Jaccard . . . . . . . . . . . . 2.7. Soil sampling . . . . . . . . . . . . . . . 2.8. Data analysis . . . . . . . . . . . . . . . Results . . . . . . . . . . . . . . . . . . . . . 3.1. Characteristic of plant species . . . . . . . . 3.2. Physical and chemical properties of soil . . . 3.3. Coverage percentage of plant species. . . . . 3.4. Litter percentage . . . . . . . . . . . . . . 3.5. Indices of plant species diversity. . . . . . . 3.6. Indicators of plant species' similarity . . . . .
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⁎ Corresponding author. E-mail addresses: [email protected] (J. Bakhshi), [email protected] (S.A. Javadi), [email protected] (A. Tavili), [email protected] (H. Arzani).
https://doi.org/10.1016/j.chnaes.2019.07.003 1872-2032/© 2019 Ecological Society of China. Published by Elsevier B.V. All rights reserved.
Please cite this article as: J. Bakhshi, S.A. Javadi, A. Tavili, et al., Study on the effects of different levels of grazing and exclosure on vegetation and soil properties ..., Acta Ecologica Sinica, https://doi.org/10.1016/j.chnaes.2019.07.003
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J. Bakhshi et al. / Acta Ecologica Sinica xxx (2019) xxx
4. Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5. Conclusions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1. Introduction Despite the importance of vegetation in supplying livestock and protein needed, unfortunately, the potential for production in natural areas is reducing [37]. The comprehensive protection of rangeland ecosystem depends on management based on quantitative development and maintenance of the largest number of indigenous species in this population. Therefore, one of the ways of recognizing and evaluating rangelands is the recognition of biodiversity and its measurement and estimation. Livestock and plants in natural ecosystems always interact with each other, and as long as livestock population in each ecosystem is proportional to its capacity with no damage to its resources, such as water, soil and plant [19]. Inappropriate exploitation reduces the biological capacity and non-establishment of valuable rangeland species [19]. Identification of the process and the amount of changes caused by grazing is one of the factors affecting vegetation changes in rangeland [3]. Human activities (such as livestock grazing) in natural ecosystems in the last century have caused disruption and changes in their structure and function [15]. Preventing further degradation of these natural ecosystems and regeneration of degraded rangelands is an important part of the activities of rangeland managers. Regeneration refers to a set of activities that return ecosystems to conditions prior to destruction. In this regard, regeneration is one of the methods currently being used in rangelands and watersheds to protect water, soil and vegetation, with exclosure as one of the most commonly used methods of doing so [25,26]. Exclosure is the easiest and least costly method of regenerating rangelands, which increases the Coverage natural vegetation [26]. In other words, exclosure provides conditions for the natural regeneration of rangelands through the creation of opportunities for plant species' seeding. Execution of exclosure in the presence of rare and pleasant (palatable) plants causes changes in the replacement of high quality and perennial forage species and has a direct effect on increasing the rate of water permeability in the soil and reducing soil erosion [6]. The purpose of the regeneration projects is to improve the composition and quantity of high-quality vegetation in the area in order to preserve water and soil, reduce soil erosion, and finally increase forage production and improve the economic and social conditions of the exploiters [20]. Such an intervention in rangeland ecosystems can have effects on different components of the ecosystem. Evaluating such changes in the components of the regenerating ecosystem can show the success rate or positive effects of regeneration operations, operational difficulties and efficiency of the treatments used [20]. Some studies show the effect of exclosure regeneration operation, positive changes in vegetation indicators such as species diversity and richness [5,13,33], and improvement of soil qualitative properties [1,10]. Other studies show negative changes in vegetation indicators (species composition, variety, and richness) that lead to degradation of the rangeland. The regeneration operation that works in the direction of the above changes is very important. Moradi and Mofidi [28] believe that, in addition to resources' loss, in the case of exclosure, diversity reduced and the rangeland plants lose their vitality. Zare Chahuki et al. [41] showed that highest distribution frequency was related to the species of Bromus tomentellus, Hypericum perforatum and Thymus kotschyanus. Siah Mansour et al. [34] found that coverage outside exclosure increased significantly in relation to the inside of exclosure. The amount of unprotected soil is also higher outside of exclosure than inside and rock and gravel coverage had a contrast ratio with coverage and litter. Fakhimi Abarghouie and Javadi [11] the amount of soil nitrogen and organic carbon reduced but the amount of
0 0 0
soil phosphorus, potassium, electrical conductivity, and saturation acidity increased. Gholami et al. [12] concluded that with increasing grazing intensity, the amount of nitrogen and organic matter reduced, but the amount of phosphorus, potassium, electrical conductivity and saturation acidity increased. Moghimi Nejad et al. [27] showed that exclosure had positive effects on the physical and chemical properties of the studied rangelands' soil. Tavakoli et al. [36] in such areas, exclosure alone does not change much the composition and percentage of vegetation for the production of forage and the creation of green space. Khazaeipour et al. [23] concluded that exclosure reduced soil EC significantly and increased nitrogen, but had no significant effect on pH and organic matter of soil. Ahmadi et al. [2] concluded that exclosure increased soil organic matter, organic carbon, phosphorus and EC, reduced the amount of limestone and conceptual weight of soil and had no no effect on soil texture, pH, calcium and magnesium. Heydarian Aghakhani et al. [17] concluded that exclosure increased the amount of soil carbon, nitrogen, organic matter and electrical conductivity, but reduced soil acidity. Also, no significant change was seen in the amount of phosphorus and carbon to nitrogen ratio in the area. Studies on the effect of different grazing intensities on soil physical and chemical properties are more than the negative impact of livestock grazing on soil properties and reduction in quantities of qualitative properties such as organic matter, nitrogen and phosphorus [14,17,33,40]. Hosseinzadeh et al. [16] concluded that the soil of the reference area, which had high vegetation, compared to the soil of the grazed area had higher organic matter, total nitrogen, phosphorus and potassium and less acidity in the surface horizons. The result showed that short-term exclosure was very effective on maintaining and improving vegetation and soil due to desired rainfall and climate of the area, indicating the high production capacity of the area. Exclosure reduced acidity and electrical conductivity, and increased nitrogen, phosphorus and potassium absorption [16,33,42]. He et al. [18] concluded that the lack of livestock grazing significantly increased soil carbon at depths of 0–10 cm compared to grazed rangelands. Exclosure studies in different areas show a change in physical and chemical properties of soil [31]. There are some reports on the effects of livestock grazing on acidity, nitrate release and alkaline cations from soil, and changes in potassium and phosphorus intake in rangeland soils affected by different grazing intensities [35]. However, we attempted to investigate the effects of livestock grazing with two mean and high intensities on some of vegetation and soil properties to determine how grazing livestock changes vegetation over time as well as on soil chemical properties. In this study, the following hypotheses are proposed: 1. Livestock grazing has a significant effect on diversity and similarity of plant species. 2. Livestock grazing causes changes in rangeland vegetation and soil. 2. Materials and methods 2.1. Study area The climate study areas on the method of Domarten have a cold dry. This area is located in the southern rangelands of Markazi Province, which is considered as a part of the semi-steppe areas of Iran due to special climate conditions. Geographic coordinates were between longitude 50°, 30΄, 0.4΄΄ to 50°, 44΄, 59.7΄΄ and latitude 33°, 37΄, 29.2΄΄ to 33°, 49΄, 47.7΄΄ The highest altitude point is Dogol with a height of 2519
Please cite this article as: J. Bakhshi, S.A. Javadi, A. Tavili, et al., Study on the effects of different levels of grazing and exclosure on vegetation and soil properties ..., Acta Ecologica Sinica, https://doi.org/10.1016/j.chnaes.2019.07.003
J. Bakhshi et al. / Acta Ecologica Sinica xxx (2019) xxx
meters above sea level and in the east of the area and lowest point is 1754 meters above sea level, the mean height is 1971.5 m, and the mean slope is 7.03 percent. The average rainfall in this region is 185 mm, the average rainfall minimum is 1.3 mm in August and the average rainfall maximum is 38.6 mm in April. The average annual relative humidity of the region is 33.53%, The average annual temperature of the study area is 16.66 °C. The minimum absolute temperature is 26.2 °C and the maximum absolute temperature is 8.8 °C respectively in January and July. The location of the area is shown in Fig. 1.
2.2. Identification of the study area First, we collected basic statistics and information including meteorology, and topography (mapping slope) related to the area. Then, the study areas were identified. For this purpose, four areas were identified high grazing area about 730 ha (The grazing pressure of livestock is more than about 2.5 equal to the rangeland capacity), medium grazing area about 200 ha (The grazing pressure of livestock is more than about 1.5 equal to the rangeland capacity), 8-year exclosure area about 365 ha and 11-year exclosure area about 300 ha. The characteristics by which they were identified are as follows. - They are as close as possible to each other. - They have the same climate.
3
2.3. Visit the field and select homogeneous stands In order to determine homogeneous stands representing each area for sampling, different types of exclosure and grazed areas were visited and these stands were identified for sampling. 2.4. Sampling of the studied areas In this study, the minimum sample area was obtained to determine the plot size using the screw plot method. In this regard, the plot size of 1*1 m was obtained regarding the appearance and unsteady structure of the rangeland. Since the study area is under two different types of management, the exclosure areas since 2005 and 2008, and livestock grazing areas (control) by sheep and goats, for this purpose, after specifying the range of areas by the cumulative mean of dominant species. Plot count was calculated using the drawing method and for ease in all area, 60 plots per unit were used, sampling method systematic random was carried out in 2016, and in each plot, species were identified and counted. Sampling consists of two groups: sampling of vegetation and soil of the study area. Vegetation sampling involves identification of existing species, litter percentage; coverage percentage of plant species, variety and similarity of plant species in the studied areas. 2.5. Vegetation sampling
Since the slope has a significant effect on the soil and vegetation in the natural environment, therefore, in order to ensure the selection of areas for studying the slope map of the area was prepared. In order to obtain the area slope map and distribution of slope to area, the area slope map was prepared according to the slope classes, which were determined based on the precision required in the area topography. According to the slope map, the study area has a slope of less than 5%, which shows the same topographic conditions of the studied areas.
We identified plant species, percentage of coverage of each species, measurement of diversity indicators, species similarity. This study was conducted the diversity and similarity of plant species Using the formulas and equations below: D¼
X
p2i
1 1 ¼P 2 D Pi
Fig. 1. Location of the study area.
Please cite this article as: J. Bakhshi, S.A. Javadi, A. Tavili, et al., Study on the effects of different levels of grazing and exclosure on vegetation and soil properties ..., Acta Ecologica Sinica, https://doi.org/10.1016/j.chnaes.2019.07.003
4
J. Bakhshi et al. / Acta Ecologica Sinica xxx (2019) xxx
Hˊ ¼
s X ðP i Þð log2 P i Þ
SB ¼
i¼1
pffiffiffiffiffiffi ad þ a pffiffiffiffiffiffi a þ b þ c þ ad
S j: Jaccard's similarity coefficient. a, b, c: As defined above in presenceabsence matrix.SS: Sorensens similarity coefficient.SSM: Simple matching similarity coefficient.SB: Baroni-Urbani and Buser similarity coefficient.
N1 ¼ eHˊ N! ^ ¼ 1 log H N n1 !n2 !n3 !…
2.7. Soil sampling D: Simpson's index, 1/D: Simpson's reciprocal index, Hˊ: Shannon-Wiener index, N1: Equally of common species, Hˆ: Brillouin's indexs: Number of species, Pi: Proportion of species in the community, N: Total number of individuals in entire collection, e: 2.71828 (base of natural logs), n1: Number of individuals belonging to species 1, n2: Number of individuals belonging to species 2. 2.6. Coefficient of Jaccard
In this study, given that the main roots of the area plants are on surface, soil sampling was performed at a depth of 0–30 cm randomly with a combination of the studied plots, and after transferring to the laboratory soil chemical variables were measured including electrical conductivity (EC meter), acidity (pH meter), %organic matter [39], % organic carbon (Dry combustion method),%nitrogen [43], phosphorus [30] and bulk density (gr/cm3). 2.8. Data analysis
Sj ¼
a aþbþc
Ss ¼
2a 2a þ b þ c
Ssm ¼
Diversity indicators including and similarity indicators were estimated using Ecological Methodology 6.2 software (charles j. krebs) for inside and outside of exclosure in all studied areas. Before analyzing the data, first of all, first normality should be considered. For this purpose, several methods have been proposed, one of which is Kolmogorov-Smirnov test. Using this test, the data normality was controlled. Then statistical analysis was done about them (oneway ANOVA) and because the study groups were more than two used
aþb aþbþcþd
Table 1 Descriptive statistics of different variety in the studied area. Species
Stipa barbata Salvia officinalis Euphorbia virgata Astragalus pseudo becki Eremopyrum confusum Noaea mucronata Nepeta racemosa Alyssum desertorum Gagea (sp) Ziziphora tenuior Bromus tomentellus Allium scabriscapum Bromus tectorum Erodium cicutarium Poa bulbosa launaea acanthodes Silene campion Astragalus gossypinus Peganum harmala Agropyron desertorum Cousinia verbascifolia bunge Erysimum capitatum Scorzonera humilis Secale montanum Saussurea sp Acantholimon litvinovii Salsola baryosma Crocus haussknechtii Artemisia sieberi Scariola orientalis Ajuga chmacistus Eryngium bungei Hordeum murinum Bossiera (sp) Echinops robustus Centaurea virgata Alhagi camelorum
Family
Poaceae Lamiaceae Euphorbiaceae Fabaceae Poaceae Chenopodiaceae Lamiaceae Cruciferae Liliaceae Lamiaceae Poaceae Liliaceae Poaceae Geraniaceae Poaceae Fabaceae Caryophyllaceae Fabaceae Zygophylaceae Poaceae Asteraceae Brassicaceae Asteraceae Poaceae Asteraceae Caryophylaceae Chenopodiaceae Iridaceae Asteraceae Asteraceae Lamiaceae Umbeliferae Poaceae Poaceae Asteraceae Asteraceae Fabaceae
11-Year exclosure
1.7869 ± 0.53261 2.9426 ± 0.55145 1.3049 ± 0.27675 3.2984 ± 0.36676 1.52 ± 0.297 3.07 ± 0.4509 0.0067 ± 0.0066 0.5867 ± 0.1982 0.16 ± 0.1202 1.7783 ± 0.4003 4.2333 ± 1.1885 0.033 ± 0.0262 1.2750 ± 0.5239 0.1333 ± 0.0964 4.3333 ± 0.9810 0.8933 ± 0.4382 2.5833 ± 0.6126 1.1 ± 0.6164 0 0 0.750 ± 0.4874 0 0 0 0 0.1058 ± 0.15 0 0 3.3833 ± 1.0311 0.65 ± 0.3897 0 0.75 ± 0.5291 0.3567 ± 0.1498 0.7617 ± 0.1796 0.25 ± 0.185 0.033 ± 0.0333 0
8-Year exclosure
2.3167 ± 0.68126 6.6833 ± 0.77002 0.9350 ± 0.36788 4.2083 ± 0.63291 0.4475 ± 0.1392 0.9689 ± 0.2814 0 0.6721 ± 0.3168 0.082 ± 0.0673 1.0082 ± 0.2186 3.5246 ± 0.9866 0.1 ± 0.0836 0.4098 ± 0.1904 0 1.1803 ± 0.4099 0.9836 ± 0.5459 0.9754 ± 0.2098 1.0557 ± 0.5113 0 0.41 ± 0.02293 0.7869 ± 0.329 0 0 0 0 0.4098 ± 0.3366 0 0.082 ± 0.0819 4.1639 ± 1.0357 0.082 ± 0.0819 0.6066 ± 0.3793 0 0.3115 ± 0.1393 0.4016 ± 0.1305 0.8197 ± 0.4243 0 0
Moderate
Heavy
Grazing
Grazing
0.3767 ± 0.18469 3.0367 ± 0.53297 1.5750 ± 0.30643 2.2133 ± 0.31827 1.1167 ± 0.34432 1.0667 ± 0.30217 0 1.7833 ± 0.60183 0 0.1183 ± 0.0463 0 0 0 0 0.2917 ± 0.1184 0.0833 ± 0.0833 0.4 ± 0.2222 1.3983 ± 0.4686 0 0 1.8 ± 0.692 0.833 ± 0.584 0.0167 ± 0.0166 0.05 ± 0.035 0.0167 ± 0.0166 0.7167 ± 0.295 0.9167 ± 0.6454 0 6.9833 ± 1.314 0.5333 ± 0.2944 0 0 2.7167 ± 0.4621 0.2667 ± 0.1299 0 0 0
0.9333 ± 0.51082 2.1667 ± 0.72648 1.5333 ± 0.68827 0 0 0.1167 ± 0.08923 0 0 0 0 0 0 0 0.6667 ± 0.3844 13.75 ± 1.3377 0.8667 ± 0.5391 0 0 8.6167 ± 1.5535 0 2.8333 ± 0.934 0 0 0 0 0 0 0 0.7 ± 0.4267 0.75 ± 0.3086 0 0 11.65 ± 1.43 0 2.6333 ± 0.6279 0 0.05 ± 0.3873
Please cite this article as: J. Bakhshi, S.A. Javadi, A. Tavili, et al., Study on the effects of different levels of grazing and exclosure on vegetation and soil properties ..., Acta Ecologica Sinica, https://doi.org/10.1016/j.chnaes.2019.07.003
J. Bakhshi et al. / Acta Ecologica Sinica xxx (2019) xxx
the analysis of variance and using Duncan's test, means were compared to obtain the difference between different treatments [7]. Software SPSS (v24.0) was used to analyze the data.
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Table 3 The results of analysis of variance (one-way ANOVA) of Coverage percentage family. Family
11 Year exclosure
8 Year exclosure
Moderate grazing
Heavy grazing
Sig.
3. Results
Poaceae
8.1033 c
4.8183 c
Lamiaceae
4.5574 a
3.1550 b
Euphorbiaceae Fabaceae
0.9350 a 6.2017 a
1.5750 a 3.6950 b
Chenopodiaceae Cruciferae Liliaceae Geraniaceae Caryophylaceae Asteraceae Brassicaceae Asteraceae Iridaceae Umbeliferae Zygophylaceae
3.0700 a 0.5867 b 0.1933 a 0.1333 a 2.7333 a 5.0667 a 0.0000 a 0.0000 a 0.0000 a 0.7500 a 0.0000 b
1.3049 a 5.3377 ab 0.9689 bc 0.6721 b 0.1820 a 0.0000 a 1.3852 b 5.8525 a 0.0000 a 0.0000 a 0.0820 a 0.0000 a 0.0000 b
26.3333 a 2.1667 ab 1.5333 a 0.9167 c
0.000⁎⁎
3.1. Characteristic of plant species
14.7967 b 4.4683 a
1.9833 ab 1.7833a 0.0000 a 0.0000 a 1.1167 bc 9.3167 a 0.0833 a 0.0333 a 0.0000 a 0.0000 a 0.0000 b
0.1167 c 0.0000 b 0.0000 a 0.6667 a 0.0000 c 6.9167 a 0.0000 a 0.0000 a 0.0000 a 0.0000 a 8.6167 a
0.000⁎⁎ 0.005⁎⁎ 0.227ns 0.054ns 0.000⁎⁎ 0.143ns 0.108ns 0.108ns 0.401ns 0.112ns 0.000⁎⁎
A total of 37 plant species were observed from 15 families in the studied regions. Some registered species such as Stipa barbata،salvia (sp) ، Euphorbia virgata، Noaea Mucronata، Poa bulbosa، launaea acanthodes، Cousinia verba scifolia bunge، Artemisia sieberi، Scariola orientalis،Hordeum murinum, had a wide sociological and ecological distribution (Table 1). 3.2. Physical and chemical properties of soil the results showed that among chemical properties of the studied soil, electrical conductivity, organic matter percentage and organic carbon showed significant differences at 5% level between the areas, and also the bulk density of the studied areas showed a significant difference at 1% level, significant difference was found between organic matter content of the studied area with mean grazing and other areas, significant difference was found between grazed and exclosure areas (Table 2). 3.3. Coverage percentage of plant species According to Table 3 in the studied area, 15 plant species family were identified. The results showed that exclosure has caused significant increase between the percentage of coverage of Lamiaceae in different areas of exclosure and livestock grazing in at 5% level and a significant difference was found between the percentage of coverage of Poaceae, Fabaceae, Chenopodiaceae, Crucifereae, Caryophyllaceae and Zygophyllaceae in exclosure and livestock grazing areas at 1% level. The mean coverage percentage of plant species showed that livestock grazing affected coverage of plant species so that the majority of plant species are affected by livestock grazing, but some plant species such as Poaceae and Zygophyllaceae increased due to livestock grazing (Table 3). 3.4. Litter percentage According to Table 4, the percentage of litter in 11 and 8-year exclosure areas was 12.3% and 11.79%, respectively, with mean and high grazing areas and with a mean of 6.18% and 5.61% had a significant difference at 1% level.
0.047⁎ 0.724ns 0.000⁎⁎
The mean comparison using the Duncan test at 5% level. Means in a column with different letters are significantly different. ⁎⁎ The different letters indicate a significant difference in the level of 0.01. ⁎ Significant difference at the level of 0.05 ns; is no significant difference.
3.5. Indices of plant species diversity In this research, in order to determine the suitable index in from indicators, among the indicators sensitivity was examined [24]. In order to compare plant species diversity indicators, mean of different indicators was used. According to Fig. 2, among studied diversity indicators the Equally of common species, Reciprocal Simpsons and Shannon-Wiener are more sensitive than other indicators to species' change and variation against livestock grazing intensity, therefore, these are suitable indicators for the study of plant species diversity under the same conditions and can be used to estimate vegetation diversity under similar study conditions. 3.6. Indicators of plant species' similarity The mean of different indicators was used to compare similarity indicators of plant species. According to Fig. 3, among the studied similarity indicators Baroni-Urbani and Buser and the index of Simple Matching Coefficient are more sensitive than other indicators. Therefore, they can better represent environmental changes and can be used as indicators for estimating similarity under similar study conditions. 4. Discussion
Table 2 The results of analysis of variance (one-way ANOVA) of soil properties. Soil properties
11 year exclosure
8 year exclosure
Moderate grazing
Heavy grazing
Sig.
Acidity(pH) EC(mho) Organic carbon
7.8000 a 0.5000 b 0.1833 b
7.8000 a 0.4700 b 0.1833 b
7.7667 a 0.5400 b 0.5100 a
0.219ns 0.039⁎ 0.038⁎
Nitrogen (%) Organic matter (%)
0.0233 a 0.3167 b
0.0233 a 0.3167 b
0.0533 a 0.8533 a
Phosphorus (%)
9.3333 a
9.3333 a
10.0667 a
7.7333 a 0.7667 a 0.4567 ab 0.0467 a 0.7667 ab 10.3333 a 1.5933 b
Bulk density (gr/cm3)
1.6267 a
1.6267 a
1.5900 b
(a, ab and b) The mean comparison using the Duncan test at 5% level. Means in a column with different letters are significantly different. ⁎ The different letters indicate a significant difference in the level of 0.01. ⁎⁎ Significant difference at the level of 0.05 ns; is no significant difference.
0.052ns 0.037⁎ 0.062ns
The results showed that rangeland exclosure reduced electrical conductivity, organic matter percentage, organic carbon percentage and increased bulk density of the soil (Table 2). However, it had no significant effect on acidity, nitrogen and phosphorus. In this regard, Moghimi Nejad et al. [27] stated that exclosure had significant effects on nitrogen and phosphorus content, but no significant difference was found Table 4 The results of analysis of variance (one-way ANOVA) of Litter percentage. Parameter
11 Year exclosure
8 Year exclosure
Moderate grazing
Heavy grazing
Litter percentage
12.3 a
11.79 a
6.18 b
5.61 b
0.000⁎⁎
Sig 0.000⁎⁎
(a and b) The mean comparison using the Duncan test at 5% level. Means in a column with different letters are significantly different. ⁎⁎ The different letters indicate a significant difference in the level of 0.01.
Please cite this article as: J. Bakhshi, S.A. Javadi, A. Tavili, et al., Study on the effects of different levels of grazing and exclosure on vegetation and soil properties ..., Acta Ecologica Sinica, https://doi.org/10.1016/j.chnaes.2019.07.003
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J. Bakhshi et al. / Acta Ecologica Sinica xxx (2019) xxx
Fig. 2. Changes of diversity indices.
between the two grazing and exclosure areas in terms of acidity and organic matter. Steffens et al. [35] by examining the effect of livestock grazing on physical and chemical properties of soil in semi-arid steppes in Chinese Mongolian areas indicated that due to the increase in bulk density, organic matter and nitrogen content of the soil reduced, and pH was not changed. Shifang et al. [33] in desert steppes of Alexa of domestic Mongolia in China showed that changes in soil and plant properties in three areas with common management practices including grazing for a long time, 2 and 6-year exclosure increased organic carbon and storing nitrogen and reduced pH and particulate density of the soil. Tavakoli et al. [36] stated that in the studied areas no significant difference was seen in the amount of organic carbon due to the lack of high grazing in the area as well as the return of organic matter as manure and better mixing of plant remains due to livestock movement to the soil, so no significant difference was found between exclosure and grazing areas. The results showed that exclosure, despite increasing the diversity of plant species in the area over time, has been adapted to all of the studied diversity indicators in the study (Fig. 2). However, according to the results increasing diversity does not increase top species of the area, as well as poor species increased in the composition of vegetation. Therefore, it can be said that increasing diversity does not always improve rangeland plants' vegetation. Jiao Tanga et al. [21] by studying the effects of exclosure on vegetation and soil degradation in sandy rangelands in China concluded that the species' diversity increased due to exclosure. Jimin Cheng et al. [22] by studying the effects of long-term exclosure on vegetation properties in semi-arid rangelands of China concluded that exclosure significantly increased the diversity and percentage of coverage in the area. Mesdaghi and Sadeghnejad [24] compared variance indicators at three levels of exploitation of
semi-steppe rangelands in northeastern Iran. They concluded that the number of species was exaggerated than usual and did not show acceptable standards. Moreover, it continuously leads to a reduction in plant diversity and vegetation due to livestock grazing [32]. This may be due to changes in the composition and abundance of species created in exclosure area. The results diversity plant species to using different indicators showed that in areas with moderate grazing and 8 year exclosure is no difference or fluctuation in these indicators. The reason for this is the elimination of plant species and the replacement of new species in the area due to enclosure. In the 17 plant families in the areas (Table 2), 8 plant families Euphorbiaceae, Liliaceae, Geraniaceae, Asteraceae, Brassicaceae, Asteraceae, Iridaceae and Umbeliferae did not have significant effects in Cover percentage family in this area Which suggests that these plant families are not Patability to be livestock. Also the result showed that plant families as Lamiaceae, Fabaceae, Chenopodiaceae and Caryophylaceae increased in exclosure areas. Its causes can be explained by the presence of Patability species in these plant families as Bromus tecturum, Bromus tumentellus and etc. Plant families as poaceae and Zygophylaceae increase in areas under grazing. The reason for it can be the result that livestock grazing increased plant species such as Poaceae, Zygophyllacea and Poa bulbosa in the area due to the increase of plant species such as Peganum harmala (non-pleasant species of class III), Hordeum murinum and Poa bulbosa (Table 1). In this regard, it can be said that the reason is due to the large number of seeds produced in this species (Hordeum murinum), which, when it reaches the ease, falls into the soil bed, as well as Poa bulbosa that increased resistance of these species to livestock grazing in the area with high grazing intensity and non-use of livestock from these plants during grazing (during the season of livestock grazing due to being non-pleasant), highest coverage of the plant species was in exclosure areas. Tavakoli et al. [36] stated that the percentage of vegetation in exclosure area was greater than the adjacent area under grazing. The composition and vegetation of the two areas also differed, but the amount of plant changes in the type of species and percentage of vegetation in exclosure area was low due to the spent time. Mligo [29] stated that excessive use of rangeland species would weaken the rangeland, reduce the percentage of vegetation and change the composition and plant diversity. The results showed that exclosure increased the percentage of litter in the area (Table 3). In this regard, Brooks et al. [8] reported that litter significantly increased in the enclosure. In this regard, Wahabi [38] reported that in Friden rangelands after 5 years, litter has been observed on the surface of the soil. Bugalho [9] found that litter is significantly higher in non-grazed areas. Asadian et al. [4] Investigation of vegetation changes in Gian Nahavand rangelands under grazing and exclosure
Fig. 3. Changes of similarity indices references.
Please cite this article as: J. Bakhshi, S.A. Javadi, A. Tavili, et al., Study on the effects of different levels of grazing and exclosure on vegetation and soil properties ..., Acta Ecologica Sinica, https://doi.org/10.1016/j.chnaes.2019.07.003
J. Bakhshi et al. / Acta Ecologica Sinica xxx (2019) xxx
conditions concluded that exclosure has increased the amount of litter in the area. 5. Conclusions From the point of view ecologically and land use And also preserving plant diversity is one of the most sustainable one of the sustainable options for manage natural resources in these ranges, it should be noted that pasture grazing in different habitats To restore vegetation and prevent rangeland degradation, because. 1. Exclusion can be considered a suitable method for protecting natural resources. 2. 2-With the exclusion management have less soil degradation and vegetation cover. 3. Exclusion increases the plant diversity in the area. 4. Exclusion has improved the plant composition and increased palatability species in the area. 5. In general, the exclusion increases the perennial species and grazing livestock increases the annual grazes in the area. References [1] M. Aghasi, M. Bahmaniar, M. Akbarzadeh, Comparison of the effects of water exclosure and spread on vegetation and soil parameters in Kiasar rangelands, Mazandaran Province, Agri. Nat. Res. 4 (54) (2006) 73–101. [2] T. Ahmadi, B. Malekpour, S. Kazemi Mazandarani, Investigation of the effect of exclosure on physical and chemical properties of soil in Kajur, Mazandaran Province, Plant Ecophysiol. 3 (8) (2011) 89–100. [3] H. Arzani, H. Mirdavoodi, J. Abdollahi, M. Borhani, M. Farahpour, M. Azimi, H. Kaboli, M. Moalemi, Designing a national evaluation system to investigate changes in rangelands in markazi, Isfahan and Yazd Provinces. Summary of the Papers of the Third Rangeland and Rangeland Management Conferences in Iran, Rangeland Association 2003, p. 15. [4] Q. Asadian, M. Akbarzadeh, M. Sadeghi Manesh, Investigation of vegetation changes in Gian Nahavand rangelands under grazing and exclosure conditions, Iran. J. Range Desert Res. 16 (3) (2009) 343–352. [5] A. Angassa, G. Oba, Effects of grazing pressure, age of enclosures and seasonality on bush coverage dynamics and vegetation composition in southern Ethiopia, J. Arid Environ. 74 (2010) 111–112. [6] H. Azarnivand, M.A. Zare Chahuki, Rangeland Modification, Tehran University Press, Tehran, 2008. [7] M. Basiri, M. Iravani, Vegetation changes after 19 years of experimental exclosure in central Zagros, Rangelands 3 (2) (2009) 155–170. [8] M.L. Brooks, J.R. Matchett, K. Berry, Effects of livestock watering sites on plant communities in the Mojave Desert, USA, J. Arid Environ. 67 (2006) 125–147. [9] M.N. Bugalho, X. Lecomte, M. Goncalves, M.C. Caldeira, M. Branco, Establishing grazing and grazing-excluded patches increases plant and invertebrate diversity in a mediterranean oak woodland, For. Ecol. Manag. 261 (2011) 2133–2139. [10] F. Dehghan, The Effect of Biological Regeneration Operations on Vegetation and Soil Properties (Case Study: Kabir River, Savadkooh), Graduate Thesis Mazandaran University, 2010. [11] A. Fakhimi Abarghouie, A. Javadi, Response of vegetation and soil chemical properties to different grazing intensities in the steppe nodoshan rangelands of yazd, Q. J. Iran. Derby Desert Res. 21 (1) (2014) 109–118. [12] P. Gholami, J. Ghorbani, M. Shokri, Investigation of changes in species diversity of Sorpa and soil seed bank in exclosure areas in Mahoor Rangelands Of Fars Province, Sci. Res. J. Iran. Rangel. Desert Res. (4) (2014) 745–755. [13] P. Gholami, J. Ghorbani, M. Shokri, Changes in vegetation diversity and richness during land use change, National Conference on Protection of Biodiversity and Indigenous Knowledge, International Center for Advanced Science and Technology and Environmental Sciences, Kerman, 2012. [14] H. Guodong, H. Xiying, Z. Mengli, W. Mingjun, H.E. Ben, W. Walter, W. Mingjiu, Effect of grazing intensity on carbon and nitrogen in soil and vegetation in a meadow steppe in inner mongolia, Agric. Ecosyst. Environ. 125 (2008) 21–32. [15] J.A. Harris, R.V. Diggelen, Ecological restoration as a project for global society, in: J.V. Andel, J. Arowson (Eds.), Restoration Ecology, Black Well Publishing Company 2006, pp. 3–28. [16] G. Hosseinzadeh, R. Jalilvand, Tamartash, Changes in vegetation and some chemical properties of soil in rangelands with different intensities of grazing, Q. J. Rangel. Desert Res. Iran. (2007) 500–512.
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Environ. 235 (2016) (2016) 340–348. [22] Jimin Cheng, Guanghua Jing, Lin Wei, Zhaobin Jing, Long-term grazing exclusion effects on vegetation characteristics, soilproperties and bacterial communities in the semi-arid grasslands of China, Ecol. Eng. 97 (2016) (2016) 170–178. [23] M. Khazaeipour, A. Javadi, H. Arzani, Comparison of long-term and short-term exclosures on vegetation of kajur rangelands in Mazandaran, Biomed. J. Res. 8 (31) (2012) 85–97. [24] M. Mesdaghi, R. Sadeghnejad, Comparison of species diversity indicators under three exploitations in semi-steppe meadow northeast of Iran, J. Agric. Sci. Nat. Res. 3 (2000) 63–76. [25] M. Mesdaghi, Range Management in Iran, Astane Ghodse Razavi Press, 2007 334 (In Persian). [26] M.R. Moghaddam, Range and Range Management, Tehran University Press, 2000 470 (In Persian). [27] F. Moghimi Nejad, M. Jafari, M. Zare Chahuki, Y. Ghasemi Arian, A. Kohandel, Comparison of physical and chemical properties of soils between two exclosure and grazing areas (case study: Nazarabad, Karaj), Q. J. Res. Iran's Range Desert (4) (2014) 643–650. [28] A. Moradi, M. Mofidi, The effect of exclosure on vegetation properties in semi-strip rangelands of Semirom, Isfahan (case study: henna exclosure), Rangelands 6 (3) (2012) 272–281. [29] C. Mligo, Effect of grazing pressure on plant species composition and diversity in the semi-arid rangelands of Mbulu district, Tanzania, Agric. J. 1 (4) (2006) 277–283. [30] S.R. Olsen, C.V. Cole, F.S. Watanabe, C.A. Dean, Estimation of Available Phosphorous in Soils by Extraction with Sodium Bicarbonate, vol. 19, U. S. Department of Agricultural Circular. No. 939, 1954 1945. [31] S. Pei, H. Fu, C. Wan, Changes in soil properties and vegetation following exclosure and grazing in degraded alxa desert steppe of inner Mongolia, China, Agric. Ecosyst. Environ. 124 (2008) 33–39. [32] B.C. Ring, M.K. Victor, B. Silver, Vegetation traits of patch-grazed rangeland in west Central Kansas, J. Range Manag. 38 (1985) 51–55. [33] P. Shifang, F. Hua, W. Changgui, Changes in properties and vegetation following exclosure and grazing in degraded Alxa desert steppe of Inner Mongolia, China, Agric. Ecosyst. Environ. 124 (2008) 33–39. [34] R. Siah Mansour, M. Akbarzadeh, A. Zandi Isfahan, K. Khademi, A. Javadi, Investigation of the effect of exclosure on vegetation and soil conservation in rangelands of Zagheh, J. Res. Rangel. Desert Iran. (3) (2015) 417–425. [35] M. Steffens, A. Kolbi, K. Totsch, Grazing effects on soil chemical and physical properties in a semiarid steppe of Inner Mongolia (P.R. China), Geoderma 143 (2008) 63–72. [36] H. Tavakoli, H. Yashty, A. Khodashenas, Comparison of plant properties and organic soil matter under exclosure and grazing condition (case study: Mashhad suburbs), Q. J. Iran. Rangel. Desert Res. 21 (3) (2012) 416–423. [37] M. Tatian, R. Tamartash, Q. Qordoei, H. 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Contents lists available at ScienceDirect
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Study on the effects of different levels of grazing and exclosure on vegetation and soil properties in semi-arid rangelands of Iran Jamal Bakhshi a,⁎, Seyed Akbar Javadi a, Ali Tavili b, Hossein Arzani b a b
Department of range management, Science and Research Branch, Islamic Azad University, Tehran, Iran College of Natural Resource, University of Tehran, Tehran, Iran
a r t i c l e
i n f o
Article history: Received 18 June 2019 Received in revised form 25 July 2019 Accepted 26 July 2019 Available online xxxx Keywords: Grazing Diversity Similarity Rangeland Vegetation Semi-arid
a b s t r a c t Livestock grazing is one of the main factors of vegetation and soil degradation in arid and semi-arid rangelands of Iran and causes changes in diversity, vegetation, litter and soil characteristics. Therefore, this study has been conducted aimed to examine the effects of exclosure and livestock grazing on vegetation and soil. For this purpose, two grazing areas of medium and high grazing intensity and two exclosure areas (Non-grazing livestock) with duration of 8 and 11 years were selected for sampling. Then, we identified plant species, percentage of coverage of each species, measurement of diversity indices, species similarity and soil chemical properties including electrical conductivity (mho), acidity, organic matter(%), organic carbon (%), nitrogen (%), phosphorus (mg/L) and bulk density (gr/cm3) in each area and they were compared using variance analysis. The results showed that exclosure significantly at 5% level reduced organic matter percentage, electrical conductivity and organic carbon percentage, but it caused a significant increase in soil bulk density at 1% level. Similarity of plant species due to the reduction of livestock grazing intensity and increasing exclosure duration. The results also indicate Livestock grazing increased Coverage of plant family such as Poaceae, Zygophyllacea in the area due to the increase of plant species such as Peganum harmala and Poa bulbosa (non-pleasant species of class III). Based on the results, despite increasing the diversity of plant species in the area over time, increasing diversity does not increase dominant species of the area, as well as companion species increased in the composition of vegetation. It concluded that exclusion has a significant effect on vegetation improvement, vegetation cover percentage, diversity, palatability and litter percentage in the region. © 2019 Ecological Society of China. Published by Elsevier B.V. All rights reserved.
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Introduction . . . . . . . . . . . . . . . . . . . Materials and methods . . . . . . . . . . . . . . 2.1. Study area. . . . . . . . . . . . . . . . . 2.2. Identification of the study area . . . . . . . 2.3. Visit the field and select homogeneous stands 2.4. Sampling of the studied areas . . . . . . . . 2.5. Vegetation sampling . . . . . . . . . . . . 2.6. Coefficient of Jaccard . . . . . . . . . . . . 2.7. Soil sampling . . . . . . . . . . . . . . . 2.8. Data analysis . . . . . . . . . . . . . . . Results . . . . . . . . . . . . . . . . . . . . . 3.1. Characteristic of plant species . . . . . . . . 3.2. Physical and chemical properties of soil . . . 3.3. Coverage percentage of plant species. . . . . 3.4. Litter percentage . . . . . . . . . . . . . . 3.5. Indices of plant species diversity. . . . . . . 3.6. Indicators of plant species' similarity . . . . .
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⁎ Corresponding author. E-mail addresses: [email protected] (J. Bakhshi), [email protected] (S.A. Javadi), [email protected] (A. Tavili), [email protected] (H. Arzani).
https://doi.org/10.1016/j.chnaes.2019.07.003 1872-2032/© 2019 Ecological Society of China. Published by Elsevier B.V. All rights reserved.
Please cite this article as: J. Bakhshi, S.A. Javadi, A. Tavili, et al., Study on the effects of different levels of grazing and exclosure on vegetation and soil properties ..., Acta Ecologica Sinica, https://doi.org/10.1016/j.chnaes.2019.07.003
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4. Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5. Conclusions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1. Introduction Despite the importance of vegetation in supplying livestock and protein needed, unfortunately, the potential for production in natural areas is reducing [37]. The comprehensive protection of rangeland ecosystem depends on management based on quantitative development and maintenance of the largest number of indigenous species in this population. Therefore, one of the ways of recognizing and evaluating rangelands is the recognition of biodiversity and its measurement and estimation. Livestock and plants in natural ecosystems always interact with each other, and as long as livestock population in each ecosystem is proportional to its capacity with no damage to its resources, such as water, soil and plant [19]. Inappropriate exploitation reduces the biological capacity and non-establishment of valuable rangeland species [19]. Identification of the process and the amount of changes caused by grazing is one of the factors affecting vegetation changes in rangeland [3]. Human activities (such as livestock grazing) in natural ecosystems in the last century have caused disruption and changes in their structure and function [15]. Preventing further degradation of these natural ecosystems and regeneration of degraded rangelands is an important part of the activities of rangeland managers. Regeneration refers to a set of activities that return ecosystems to conditions prior to destruction. In this regard, regeneration is one of the methods currently being used in rangelands and watersheds to protect water, soil and vegetation, with exclosure as one of the most commonly used methods of doing so [25,26]. Exclosure is the easiest and least costly method of regenerating rangelands, which increases the Coverage natural vegetation [26]. In other words, exclosure provides conditions for the natural regeneration of rangelands through the creation of opportunities for plant species' seeding. Execution of exclosure in the presence of rare and pleasant (palatable) plants causes changes in the replacement of high quality and perennial forage species and has a direct effect on increasing the rate of water permeability in the soil and reducing soil erosion [6]. The purpose of the regeneration projects is to improve the composition and quantity of high-quality vegetation in the area in order to preserve water and soil, reduce soil erosion, and finally increase forage production and improve the economic and social conditions of the exploiters [20]. Such an intervention in rangeland ecosystems can have effects on different components of the ecosystem. Evaluating such changes in the components of the regenerating ecosystem can show the success rate or positive effects of regeneration operations, operational difficulties and efficiency of the treatments used [20]. Some studies show the effect of exclosure regeneration operation, positive changes in vegetation indicators such as species diversity and richness [5,13,33], and improvement of soil qualitative properties [1,10]. Other studies show negative changes in vegetation indicators (species composition, variety, and richness) that lead to degradation of the rangeland. The regeneration operation that works in the direction of the above changes is very important. Moradi and Mofidi [28] believe that, in addition to resources' loss, in the case of exclosure, diversity reduced and the rangeland plants lose their vitality. Zare Chahuki et al. [41] showed that highest distribution frequency was related to the species of Bromus tomentellus, Hypericum perforatum and Thymus kotschyanus. Siah Mansour et al. [34] found that coverage outside exclosure increased significantly in relation to the inside of exclosure. The amount of unprotected soil is also higher outside of exclosure than inside and rock and gravel coverage had a contrast ratio with coverage and litter. Fakhimi Abarghouie and Javadi [11] the amount of soil nitrogen and organic carbon reduced but the amount of
0 0 0
soil phosphorus, potassium, electrical conductivity, and saturation acidity increased. Gholami et al. [12] concluded that with increasing grazing intensity, the amount of nitrogen and organic matter reduced, but the amount of phosphorus, potassium, electrical conductivity and saturation acidity increased. Moghimi Nejad et al. [27] showed that exclosure had positive effects on the physical and chemical properties of the studied rangelands' soil. Tavakoli et al. [36] in such areas, exclosure alone does not change much the composition and percentage of vegetation for the production of forage and the creation of green space. Khazaeipour et al. [23] concluded that exclosure reduced soil EC significantly and increased nitrogen, but had no significant effect on pH and organic matter of soil. Ahmadi et al. [2] concluded that exclosure increased soil organic matter, organic carbon, phosphorus and EC, reduced the amount of limestone and conceptual weight of soil and had no no effect on soil texture, pH, calcium and magnesium. Heydarian Aghakhani et al. [17] concluded that exclosure increased the amount of soil carbon, nitrogen, organic matter and electrical conductivity, but reduced soil acidity. Also, no significant change was seen in the amount of phosphorus and carbon to nitrogen ratio in the area. Studies on the effect of different grazing intensities on soil physical and chemical properties are more than the negative impact of livestock grazing on soil properties and reduction in quantities of qualitative properties such as organic matter, nitrogen and phosphorus [14,17,33,40]. Hosseinzadeh et al. [16] concluded that the soil of the reference area, which had high vegetation, compared to the soil of the grazed area had higher organic matter, total nitrogen, phosphorus and potassium and less acidity in the surface horizons. The result showed that short-term exclosure was very effective on maintaining and improving vegetation and soil due to desired rainfall and climate of the area, indicating the high production capacity of the area. Exclosure reduced acidity and electrical conductivity, and increased nitrogen, phosphorus and potassium absorption [16,33,42]. He et al. [18] concluded that the lack of livestock grazing significantly increased soil carbon at depths of 0–10 cm compared to grazed rangelands. Exclosure studies in different areas show a change in physical and chemical properties of soil [31]. There are some reports on the effects of livestock grazing on acidity, nitrate release and alkaline cations from soil, and changes in potassium and phosphorus intake in rangeland soils affected by different grazing intensities [35]. However, we attempted to investigate the effects of livestock grazing with two mean and high intensities on some of vegetation and soil properties to determine how grazing livestock changes vegetation over time as well as on soil chemical properties. In this study, the following hypotheses are proposed: 1. Livestock grazing has a significant effect on diversity and similarity of plant species. 2. Livestock grazing causes changes in rangeland vegetation and soil. 2. Materials and methods 2.1. Study area The climate study areas on the method of Domarten have a cold dry. This area is located in the southern rangelands of Markazi Province, which is considered as a part of the semi-steppe areas of Iran due to special climate conditions. Geographic coordinates were between longitude 50°, 30΄, 0.4΄΄ to 50°, 44΄, 59.7΄΄ and latitude 33°, 37΄, 29.2΄΄ to 33°, 49΄, 47.7΄΄ The highest altitude point is Dogol with a height of 2519
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J. Bakhshi et al. / Acta Ecologica Sinica xxx (2019) xxx
meters above sea level and in the east of the area and lowest point is 1754 meters above sea level, the mean height is 1971.5 m, and the mean slope is 7.03 percent. The average rainfall in this region is 185 mm, the average rainfall minimum is 1.3 mm in August and the average rainfall maximum is 38.6 mm in April. The average annual relative humidity of the region is 33.53%, The average annual temperature of the study area is 16.66 °C. The minimum absolute temperature is 26.2 °C and the maximum absolute temperature is 8.8 °C respectively in January and July. The location of the area is shown in Fig. 1.
2.2. Identification of the study area First, we collected basic statistics and information including meteorology, and topography (mapping slope) related to the area. Then, the study areas were identified. For this purpose, four areas were identified high grazing area about 730 ha (The grazing pressure of livestock is more than about 2.5 equal to the rangeland capacity), medium grazing area about 200 ha (The grazing pressure of livestock is more than about 1.5 equal to the rangeland capacity), 8-year exclosure area about 365 ha and 11-year exclosure area about 300 ha. The characteristics by which they were identified are as follows. - They are as close as possible to each other. - They have the same climate.
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2.3. Visit the field and select homogeneous stands In order to determine homogeneous stands representing each area for sampling, different types of exclosure and grazed areas were visited and these stands were identified for sampling. 2.4. Sampling of the studied areas In this study, the minimum sample area was obtained to determine the plot size using the screw plot method. In this regard, the plot size of 1*1 m was obtained regarding the appearance and unsteady structure of the rangeland. Since the study area is under two different types of management, the exclosure areas since 2005 and 2008, and livestock grazing areas (control) by sheep and goats, for this purpose, after specifying the range of areas by the cumulative mean of dominant species. Plot count was calculated using the drawing method and for ease in all area, 60 plots per unit were used, sampling method systematic random was carried out in 2016, and in each plot, species were identified and counted. Sampling consists of two groups: sampling of vegetation and soil of the study area. Vegetation sampling involves identification of existing species, litter percentage; coverage percentage of plant species, variety and similarity of plant species in the studied areas. 2.5. Vegetation sampling
Since the slope has a significant effect on the soil and vegetation in the natural environment, therefore, in order to ensure the selection of areas for studying the slope map of the area was prepared. In order to obtain the area slope map and distribution of slope to area, the area slope map was prepared according to the slope classes, which were determined based on the precision required in the area topography. According to the slope map, the study area has a slope of less than 5%, which shows the same topographic conditions of the studied areas.
We identified plant species, percentage of coverage of each species, measurement of diversity indicators, species similarity. This study was conducted the diversity and similarity of plant species Using the formulas and equations below: D¼
X
p2i
1 1 ¼P 2 D Pi
Fig. 1. Location of the study area.
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J. Bakhshi et al. / Acta Ecologica Sinica xxx (2019) xxx
Hˊ ¼
s X ðP i Þð log2 P i Þ
SB ¼
i¼1
pffiffiffiffiffiffi ad þ a pffiffiffiffiffiffi a þ b þ c þ ad
S j: Jaccard's similarity coefficient. a, b, c: As defined above in presenceabsence matrix.SS: Sorensens similarity coefficient.SSM: Simple matching similarity coefficient.SB: Baroni-Urbani and Buser similarity coefficient.
N1 ¼ eHˊ N! ^ ¼ 1 log H N n1 !n2 !n3 !…
2.7. Soil sampling D: Simpson's index, 1/D: Simpson's reciprocal index, Hˊ: Shannon-Wiener index, N1: Equally of common species, Hˆ: Brillouin's indexs: Number of species, Pi: Proportion of species in the community, N: Total number of individuals in entire collection, e: 2.71828 (base of natural logs), n1: Number of individuals belonging to species 1, n2: Number of individuals belonging to species 2. 2.6. Coefficient of Jaccard
In this study, given that the main roots of the area plants are on surface, soil sampling was performed at a depth of 0–30 cm randomly with a combination of the studied plots, and after transferring to the laboratory soil chemical variables were measured including electrical conductivity (EC meter), acidity (pH meter), %organic matter [39], % organic carbon (Dry combustion method),%nitrogen [43], phosphorus [30] and bulk density (gr/cm3). 2.8. Data analysis
Sj ¼
a aþbþc
Ss ¼
2a 2a þ b þ c
Ssm ¼
Diversity indicators including and similarity indicators were estimated using Ecological Methodology 6.2 software (charles j. krebs) for inside and outside of exclosure in all studied areas. Before analyzing the data, first of all, first normality should be considered. For this purpose, several methods have been proposed, one of which is Kolmogorov-Smirnov test. Using this test, the data normality was controlled. Then statistical analysis was done about them (oneway ANOVA) and because the study groups were more than two used
aþb aþbþcþd
Table 1 Descriptive statistics of different variety in the studied area. Species
Stipa barbata Salvia officinalis Euphorbia virgata Astragalus pseudo becki Eremopyrum confusum Noaea mucronata Nepeta racemosa Alyssum desertorum Gagea (sp) Ziziphora tenuior Bromus tomentellus Allium scabriscapum Bromus tectorum Erodium cicutarium Poa bulbosa launaea acanthodes Silene campion Astragalus gossypinus Peganum harmala Agropyron desertorum Cousinia verbascifolia bunge Erysimum capitatum Scorzonera humilis Secale montanum Saussurea sp Acantholimon litvinovii Salsola baryosma Crocus haussknechtii Artemisia sieberi Scariola orientalis Ajuga chmacistus Eryngium bungei Hordeum murinum Bossiera (sp) Echinops robustus Centaurea virgata Alhagi camelorum
Family
Poaceae Lamiaceae Euphorbiaceae Fabaceae Poaceae Chenopodiaceae Lamiaceae Cruciferae Liliaceae Lamiaceae Poaceae Liliaceae Poaceae Geraniaceae Poaceae Fabaceae Caryophyllaceae Fabaceae Zygophylaceae Poaceae Asteraceae Brassicaceae Asteraceae Poaceae Asteraceae Caryophylaceae Chenopodiaceae Iridaceae Asteraceae Asteraceae Lamiaceae Umbeliferae Poaceae Poaceae Asteraceae Asteraceae Fabaceae
11-Year exclosure
1.7869 ± 0.53261 2.9426 ± 0.55145 1.3049 ± 0.27675 3.2984 ± 0.36676 1.52 ± 0.297 3.07 ± 0.4509 0.0067 ± 0.0066 0.5867 ± 0.1982 0.16 ± 0.1202 1.7783 ± 0.4003 4.2333 ± 1.1885 0.033 ± 0.0262 1.2750 ± 0.5239 0.1333 ± 0.0964 4.3333 ± 0.9810 0.8933 ± 0.4382 2.5833 ± 0.6126 1.1 ± 0.6164 0 0 0.750 ± 0.4874 0 0 0 0 0.1058 ± 0.15 0 0 3.3833 ± 1.0311 0.65 ± 0.3897 0 0.75 ± 0.5291 0.3567 ± 0.1498 0.7617 ± 0.1796 0.25 ± 0.185 0.033 ± 0.0333 0
8-Year exclosure
2.3167 ± 0.68126 6.6833 ± 0.77002 0.9350 ± 0.36788 4.2083 ± 0.63291 0.4475 ± 0.1392 0.9689 ± 0.2814 0 0.6721 ± 0.3168 0.082 ± 0.0673 1.0082 ± 0.2186 3.5246 ± 0.9866 0.1 ± 0.0836 0.4098 ± 0.1904 0 1.1803 ± 0.4099 0.9836 ± 0.5459 0.9754 ± 0.2098 1.0557 ± 0.5113 0 0.41 ± 0.02293 0.7869 ± 0.329 0 0 0 0 0.4098 ± 0.3366 0 0.082 ± 0.0819 4.1639 ± 1.0357 0.082 ± 0.0819 0.6066 ± 0.3793 0 0.3115 ± 0.1393 0.4016 ± 0.1305 0.8197 ± 0.4243 0 0
Moderate
Heavy
Grazing
Grazing
0.3767 ± 0.18469 3.0367 ± 0.53297 1.5750 ± 0.30643 2.2133 ± 0.31827 1.1167 ± 0.34432 1.0667 ± 0.30217 0 1.7833 ± 0.60183 0 0.1183 ± 0.0463 0 0 0 0 0.2917 ± 0.1184 0.0833 ± 0.0833 0.4 ± 0.2222 1.3983 ± 0.4686 0 0 1.8 ± 0.692 0.833 ± 0.584 0.0167 ± 0.0166 0.05 ± 0.035 0.0167 ± 0.0166 0.7167 ± 0.295 0.9167 ± 0.6454 0 6.9833 ± 1.314 0.5333 ± 0.2944 0 0 2.7167 ± 0.4621 0.2667 ± 0.1299 0 0 0
0.9333 ± 0.51082 2.1667 ± 0.72648 1.5333 ± 0.68827 0 0 0.1167 ± 0.08923 0 0 0 0 0 0 0 0.6667 ± 0.3844 13.75 ± 1.3377 0.8667 ± 0.5391 0 0 8.6167 ± 1.5535 0 2.8333 ± 0.934 0 0 0 0 0 0 0 0.7 ± 0.4267 0.75 ± 0.3086 0 0 11.65 ± 1.43 0 2.6333 ± 0.6279 0 0.05 ± 0.3873
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the analysis of variance and using Duncan's test, means were compared to obtain the difference between different treatments [7]. Software SPSS (v24.0) was used to analyze the data.
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Table 3 The results of analysis of variance (one-way ANOVA) of Coverage percentage family. Family
11 Year exclosure
8 Year exclosure
Moderate grazing
Heavy grazing
Sig.
3. Results
Poaceae
8.1033 c
4.8183 c
Lamiaceae
4.5574 a
3.1550 b
Euphorbiaceae Fabaceae
0.9350 a 6.2017 a
1.5750 a 3.6950 b
Chenopodiaceae Cruciferae Liliaceae Geraniaceae Caryophylaceae Asteraceae Brassicaceae Asteraceae Iridaceae Umbeliferae Zygophylaceae
3.0700 a 0.5867 b 0.1933 a 0.1333 a 2.7333 a 5.0667 a 0.0000 a 0.0000 a 0.0000 a 0.7500 a 0.0000 b
1.3049 a 5.3377 ab 0.9689 bc 0.6721 b 0.1820 a 0.0000 a 1.3852 b 5.8525 a 0.0000 a 0.0000 a 0.0820 a 0.0000 a 0.0000 b
26.3333 a 2.1667 ab 1.5333 a 0.9167 c
0.000⁎⁎
3.1. Characteristic of plant species
14.7967 b 4.4683 a
1.9833 ab 1.7833a 0.0000 a 0.0000 a 1.1167 bc 9.3167 a 0.0833 a 0.0333 a 0.0000 a 0.0000 a 0.0000 b
0.1167 c 0.0000 b 0.0000 a 0.6667 a 0.0000 c 6.9167 a 0.0000 a 0.0000 a 0.0000 a 0.0000 a 8.6167 a
0.000⁎⁎ 0.005⁎⁎ 0.227ns 0.054ns 0.000⁎⁎ 0.143ns 0.108ns 0.108ns 0.401ns 0.112ns 0.000⁎⁎
A total of 37 plant species were observed from 15 families in the studied regions. Some registered species such as Stipa barbata،salvia (sp) ، Euphorbia virgata، Noaea Mucronata، Poa bulbosa، launaea acanthodes، Cousinia verba scifolia bunge، Artemisia sieberi، Scariola orientalis،Hordeum murinum, had a wide sociological and ecological distribution (Table 1). 3.2. Physical and chemical properties of soil the results showed that among chemical properties of the studied soil, electrical conductivity, organic matter percentage and organic carbon showed significant differences at 5% level between the areas, and also the bulk density of the studied areas showed a significant difference at 1% level, significant difference was found between organic matter content of the studied area with mean grazing and other areas, significant difference was found between grazed and exclosure areas (Table 2). 3.3. Coverage percentage of plant species According to Table 3 in the studied area, 15 plant species family were identified. The results showed that exclosure has caused significant increase between the percentage of coverage of Lamiaceae in different areas of exclosure and livestock grazing in at 5% level and a significant difference was found between the percentage of coverage of Poaceae, Fabaceae, Chenopodiaceae, Crucifereae, Caryophyllaceae and Zygophyllaceae in exclosure and livestock grazing areas at 1% level. The mean coverage percentage of plant species showed that livestock grazing affected coverage of plant species so that the majority of plant species are affected by livestock grazing, but some plant species such as Poaceae and Zygophyllaceae increased due to livestock grazing (Table 3). 3.4. Litter percentage According to Table 4, the percentage of litter in 11 and 8-year exclosure areas was 12.3% and 11.79%, respectively, with mean and high grazing areas and with a mean of 6.18% and 5.61% had a significant difference at 1% level.
0.047⁎ 0.724ns 0.000⁎⁎
The mean comparison using the Duncan test at 5% level. Means in a column with different letters are significantly different. ⁎⁎ The different letters indicate a significant difference in the level of 0.01. ⁎ Significant difference at the level of 0.05 ns; is no significant difference.
3.5. Indices of plant species diversity In this research, in order to determine the suitable index in from indicators, among the indicators sensitivity was examined [24]. In order to compare plant species diversity indicators, mean of different indicators was used. According to Fig. 2, among studied diversity indicators the Equally of common species, Reciprocal Simpsons and Shannon-Wiener are more sensitive than other indicators to species' change and variation against livestock grazing intensity, therefore, these are suitable indicators for the study of plant species diversity under the same conditions and can be used to estimate vegetation diversity under similar study conditions. 3.6. Indicators of plant species' similarity The mean of different indicators was used to compare similarity indicators of plant species. According to Fig. 3, among the studied similarity indicators Baroni-Urbani and Buser and the index of Simple Matching Coefficient are more sensitive than other indicators. Therefore, they can better represent environmental changes and can be used as indicators for estimating similarity under similar study conditions. 4. Discussion
Table 2 The results of analysis of variance (one-way ANOVA) of soil properties. Soil properties
11 year exclosure
8 year exclosure
Moderate grazing
Heavy grazing
Sig.
Acidity(pH) EC(mho) Organic carbon
7.8000 a 0.5000 b 0.1833 b
7.8000 a 0.4700 b 0.1833 b
7.7667 a 0.5400 b 0.5100 a
0.219ns 0.039⁎ 0.038⁎
Nitrogen (%) Organic matter (%)
0.0233 a 0.3167 b
0.0233 a 0.3167 b
0.0533 a 0.8533 a
Phosphorus (%)
9.3333 a
9.3333 a
10.0667 a
7.7333 a 0.7667 a 0.4567 ab 0.0467 a 0.7667 ab 10.3333 a 1.5933 b
Bulk density (gr/cm3)
1.6267 a
1.6267 a
1.5900 b
(a, ab and b) The mean comparison using the Duncan test at 5% level. Means in a column with different letters are significantly different. ⁎ The different letters indicate a significant difference in the level of 0.01. ⁎⁎ Significant difference at the level of 0.05 ns; is no significant difference.
0.052ns 0.037⁎ 0.062ns
The results showed that rangeland exclosure reduced electrical conductivity, organic matter percentage, organic carbon percentage and increased bulk density of the soil (Table 2). However, it had no significant effect on acidity, nitrogen and phosphorus. In this regard, Moghimi Nejad et al. [27] stated that exclosure had significant effects on nitrogen and phosphorus content, but no significant difference was found Table 4 The results of analysis of variance (one-way ANOVA) of Litter percentage. Parameter
11 Year exclosure
8 Year exclosure
Moderate grazing
Heavy grazing
Litter percentage
12.3 a
11.79 a
6.18 b
5.61 b
0.000⁎⁎
Sig 0.000⁎⁎
(a and b) The mean comparison using the Duncan test at 5% level. Means in a column with different letters are significantly different. ⁎⁎ The different letters indicate a significant difference in the level of 0.01.
Please cite this article as: J. Bakhshi, S.A. Javadi, A. Tavili, et al., Study on the effects of different levels of grazing and exclosure on vegetation and soil properties ..., Acta Ecologica Sinica, https://doi.org/10.1016/j.chnaes.2019.07.003
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J. Bakhshi et al. / Acta Ecologica Sinica xxx (2019) xxx
Fig. 2. Changes of diversity indices.
between the two grazing and exclosure areas in terms of acidity and organic matter. Steffens et al. [35] by examining the effect of livestock grazing on physical and chemical properties of soil in semi-arid steppes in Chinese Mongolian areas indicated that due to the increase in bulk density, organic matter and nitrogen content of the soil reduced, and pH was not changed. Shifang et al. [33] in desert steppes of Alexa of domestic Mongolia in China showed that changes in soil and plant properties in three areas with common management practices including grazing for a long time, 2 and 6-year exclosure increased organic carbon and storing nitrogen and reduced pH and particulate density of the soil. Tavakoli et al. [36] stated that in the studied areas no significant difference was seen in the amount of organic carbon due to the lack of high grazing in the area as well as the return of organic matter as manure and better mixing of plant remains due to livestock movement to the soil, so no significant difference was found between exclosure and grazing areas. The results showed that exclosure, despite increasing the diversity of plant species in the area over time, has been adapted to all of the studied diversity indicators in the study (Fig. 2). However, according to the results increasing diversity does not increase top species of the area, as well as poor species increased in the composition of vegetation. Therefore, it can be said that increasing diversity does not always improve rangeland plants' vegetation. Jiao Tanga et al. [21] by studying the effects of exclosure on vegetation and soil degradation in sandy rangelands in China concluded that the species' diversity increased due to exclosure. Jimin Cheng et al. [22] by studying the effects of long-term exclosure on vegetation properties in semi-arid rangelands of China concluded that exclosure significantly increased the diversity and percentage of coverage in the area. Mesdaghi and Sadeghnejad [24] compared variance indicators at three levels of exploitation of
semi-steppe rangelands in northeastern Iran. They concluded that the number of species was exaggerated than usual and did not show acceptable standards. Moreover, it continuously leads to a reduction in plant diversity and vegetation due to livestock grazing [32]. This may be due to changes in the composition and abundance of species created in exclosure area. The results diversity plant species to using different indicators showed that in areas with moderate grazing and 8 year exclosure is no difference or fluctuation in these indicators. The reason for this is the elimination of plant species and the replacement of new species in the area due to enclosure. In the 17 plant families in the areas (Table 2), 8 plant families Euphorbiaceae, Liliaceae, Geraniaceae, Asteraceae, Brassicaceae, Asteraceae, Iridaceae and Umbeliferae did not have significant effects in Cover percentage family in this area Which suggests that these plant families are not Patability to be livestock. Also the result showed that plant families as Lamiaceae, Fabaceae, Chenopodiaceae and Caryophylaceae increased in exclosure areas. Its causes can be explained by the presence of Patability species in these plant families as Bromus tecturum, Bromus tumentellus and etc. Plant families as poaceae and Zygophylaceae increase in areas under grazing. The reason for it can be the result that livestock grazing increased plant species such as Poaceae, Zygophyllacea and Poa bulbosa in the area due to the increase of plant species such as Peganum harmala (non-pleasant species of class III), Hordeum murinum and Poa bulbosa (Table 1). In this regard, it can be said that the reason is due to the large number of seeds produced in this species (Hordeum murinum), which, when it reaches the ease, falls into the soil bed, as well as Poa bulbosa that increased resistance of these species to livestock grazing in the area with high grazing intensity and non-use of livestock from these plants during grazing (during the season of livestock grazing due to being non-pleasant), highest coverage of the plant species was in exclosure areas. Tavakoli et al. [36] stated that the percentage of vegetation in exclosure area was greater than the adjacent area under grazing. The composition and vegetation of the two areas also differed, but the amount of plant changes in the type of species and percentage of vegetation in exclosure area was low due to the spent time. Mligo [29] stated that excessive use of rangeland species would weaken the rangeland, reduce the percentage of vegetation and change the composition and plant diversity. The results showed that exclosure increased the percentage of litter in the area (Table 3). In this regard, Brooks et al. [8] reported that litter significantly increased in the enclosure. In this regard, Wahabi [38] reported that in Friden rangelands after 5 years, litter has been observed on the surface of the soil. Bugalho [9] found that litter is significantly higher in non-grazed areas. Asadian et al. [4] Investigation of vegetation changes in Gian Nahavand rangelands under grazing and exclosure
Fig. 3. Changes of similarity indices references.
Please cite this article as: J. Bakhshi, S.A. Javadi, A. Tavili, et al., Study on the effects of different levels of grazing and exclosure on vegetation and soil properties ..., Acta Ecologica Sinica, https://doi.org/10.1016/j.chnaes.2019.07.003
J. Bakhshi et al. / Acta Ecologica Sinica xxx (2019) xxx
conditions concluded that exclosure has increased the amount of litter in the area. 5. Conclusions From the point of view ecologically and land use And also preserving plant diversity is one of the most sustainable one of the sustainable options for manage natural resources in these ranges, it should be noted that pasture grazing in different habitats To restore vegetation and prevent rangeland degradation, because. 1. Exclusion can be considered a suitable method for protecting natural resources. 2. 2-With the exclusion management have less soil degradation and vegetation cover. 3. Exclusion increases the plant diversity in the area. 4. Exclusion has improved the plant composition and increased palatability species in the area. 5. In general, the exclusion increases the perennial species and grazing livestock increases the annual grazes in the area. References [1] M. Aghasi, M. Bahmaniar, M. Akbarzadeh, Comparison of the effects of water exclosure and spread on vegetation and soil parameters in Kiasar rangelands, Mazandaran Province, Agri. Nat. Res. 4 (54) (2006) 73–101. [2] T. Ahmadi, B. Malekpour, S. Kazemi Mazandarani, Investigation of the effect of exclosure on physical and chemical properties of soil in Kajur, Mazandaran Province, Plant Ecophysiol. 3 (8) (2011) 89–100. [3] H. Arzani, H. Mirdavoodi, J. Abdollahi, M. Borhani, M. Farahpour, M. Azimi, H. Kaboli, M. Moalemi, Designing a national evaluation system to investigate changes in rangelands in markazi, Isfahan and Yazd Provinces. Summary of the Papers of the Third Rangeland and Rangeland Management Conferences in Iran, Rangeland Association 2003, p. 15. [4] Q. Asadian, M. Akbarzadeh, M. Sadeghi Manesh, Investigation of vegetation changes in Gian Nahavand rangelands under grazing and exclosure conditions, Iran. J. Range Desert Res. 16 (3) (2009) 343–352. [5] A. Angassa, G. Oba, Effects of grazing pressure, age of enclosures and seasonality on bush coverage dynamics and vegetation composition in southern Ethiopia, J. Arid Environ. 74 (2010) 111–112. [6] H. Azarnivand, M.A. Zare Chahuki, Rangeland Modification, Tehran University Press, Tehran, 2008. [7] M. Basiri, M. Iravani, Vegetation changes after 19 years of experimental exclosure in central Zagros, Rangelands 3 (2) (2009) 155–170. [8] M.L. Brooks, J.R. Matchett, K. Berry, Effects of livestock watering sites on plant communities in the Mojave Desert, USA, J. Arid Environ. 67 (2006) 125–147. [9] M.N. Bugalho, X. Lecomte, M. Goncalves, M.C. Caldeira, M. Branco, Establishing grazing and grazing-excluded patches increases plant and invertebrate diversity in a mediterranean oak woodland, For. Ecol. Manag. 261 (2011) 2133–2139. [10] F. Dehghan, The Effect of Biological Regeneration Operations on Vegetation and Soil Properties (Case Study: Kabir River, Savadkooh), Graduate Thesis Mazandaran University, 2010. [11] A. Fakhimi Abarghouie, A. Javadi, Response of vegetation and soil chemical properties to different grazing intensities in the steppe nodoshan rangelands of yazd, Q. J. Iran. Derby Desert Res. 21 (1) (2014) 109–118. [12] P. Gholami, J. Ghorbani, M. Shokri, Investigation of changes in species diversity of Sorpa and soil seed bank in exclosure areas in Mahoor Rangelands Of Fars Province, Sci. Res. J. Iran. Rangel. Desert Res. (4) (2014) 745–755. [13] P. Gholami, J. Ghorbani, M. Shokri, Changes in vegetation diversity and richness during land use change, National Conference on Protection of Biodiversity and Indigenous Knowledge, International Center for Advanced Science and Technology and Environmental Sciences, Kerman, 2012. [14] H. Guodong, H. Xiying, Z. Mengli, W. Mingjun, H.E. Ben, W. Walter, W. Mingjiu, Effect of grazing intensity on carbon and nitrogen in soil and vegetation in a meadow steppe in inner mongolia, Agric. Ecosyst. Environ. 125 (2008) 21–32. [15] J.A. Harris, R.V. Diggelen, Ecological restoration as a project for global society, in: J.V. Andel, J. Arowson (Eds.), Restoration Ecology, Black Well Publishing Company 2006, pp. 3–28. [16] G. Hosseinzadeh, R. Jalilvand, Tamartash, Changes in vegetation and some chemical properties of soil in rangelands with different intensities of grazing, Q. J. Rangel. Desert Res. Iran. (2007) 500–512.
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Please cite this article as: J. Bakhshi, S.A. Javadi, A. Tavili, et al., Study on the effects of different levels of grazing and exclosure on vegetation and soil properties ..., Acta Ecologica Sinica, https://doi.org/10.1016/j.chnaes.2019.07.003