Silvicultural opportunities for increasing carbon stock in restoration of Atlantic forests in Brazil

Forest Ecology and Management 350 (2015) 40–45

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Silvicultural opportunities for increasing carbon stock in restoration of Atlantic forests in Brazil Ana Paula C. Ferez a, Otávio C. Campoe b,⇑, João Carlos T. Mendes c, José Luiz Stape d a

Instituto Centro de Vida, Cuiabá, MT 78043-055, Brazil Forestry Science and Research Institute – IPEF, Piracicaba, SP 13418-260, Brazil c Departamento de Ciências Florestais, Universidade de São Paulo, USP-ESALQ, Piracicaba, SP 13418-260, Brazil d Department Forestry and Environmental Resources, North Carolina State University, Raleigh, NC 27695-8008, USA b

a r t i c l e

i n f o

Article history: Received 22 January 2015 Received in revised form 9 April 2015 Accepted 10 April 2015 Available online 5 May 2015 Keywords: Restoration plantation Silviculture Carbon stock Atlantic forest

a b s t r a c t Deforestation for urbanization and agriculture expansion drastically reduced the area of the Atlantic forest biome in Brazil. To reverse this process, rehabilitating degraded lands, restoration plantations with native tree species show significant potential to rebuild the forest habitat and promoting carbon sequestration. High input silviculture (intensive fertilization and weed control), similar to those applied in commercial production forest plantations can increase productivity, accelerating forest restoration process. We evaluated the effects of two contrasting silvicultural systems, ‘‘traditional’’ (based on common silviculture of forest reforestation in Brazil – low input) and ‘‘intensive’’ (based on commercial plantations – high input) on carbon (C) stocks of a restoration plantation. We also compared the plantations with a mature forest remnant. Six years after planting, forest C stock (coarse roots and aboveground biomass) under intensive silviculture reached 23.3 Mg C ha1, more than 3-fold the stock under traditional silviculture (6.9 Mg C ha1). Under both silvicultural systems, soil showed constant C stock (average of 33 Mg C ha1). The C accumulation in biomass with intensive silviculture reached 12.8% of that stored in the mature forest (181.5 Mg C ha1), compared with just 3.8% for traditional silviculture. Intensive silviculture provided nutrients and reduced competition with weeds, increasing growth and carbon sequestration. Forest plantations aiming at restoration and also carbon sequestration are practicable, and are highly responsive to intensive silviculture. Ó 2015 Elsevier B.V. All rights reserved.

1. Introduction The Brazilian Atlantic Forest originally spanned from 4° to 32°S, with 1.2 million km2 of evergreen forests, seasonally deciduous forests, and widely spaced gallery woodlands (Morellato and Haddad, 2000). The biome is considered a hot-spot for plant species richness and endemism, supporting over 20,000 species of vascular plants (Myers et al., 2000). Due to deforestation for urbanization and agriculture expansion, the biome has been reduced to less than 12% of its original cover, with remnant patches highly fragmented across the region (Ribeiro et al., 2009). To overcome this situation, forest restoration has a significant potential and has been successfully used (Chazdon, 2008; Ciccarese et al., 2012). Some methodologies of forest restoration use the natural resilience of the degraded ecosystem with minimum human interference in the process ⇑ Corresponding author at: Forestry Science and Research Institute – IPEF, Via Comendador Pedro Morgante, 3500 Piracicaba, SP 13418-260, Brazil. Tel.: +55 19 2105 8694; fax: +55 2105 8666. E-mail address: [email protected] (O.C. Campoe). http://dx.doi.org/10.1016/j.foreco.2015.04.015 0378-1127/Ó 2015 Elsevier B.V. All rights reserved.

(Holl et al., 2003; Rodrigues et al., 2009). Others speed recovery by planting native tree species (Lamb et al., 2005). Forest restoration plantations on degraded areas can provide several benefits, such as soil and water conservation, biodiversity habitat and carbon sequestration (Benayas et al., 2009; Campoe et al., 2010; Kanowski and Catterall, 2010). Severely disturbed sites with depleted soils and no seed bank or nearby sources of seeds may benefit from the inputs of forest restoration plantations to catalyze forest regeneration (Parrotta et al., 1997). Restoration plantations on degraded sites typically receive low-input silviculture, with little or no soil preparation, nutrient application and weed control. Weed control may be particularly important, as native tree species suffer severe competition from non-native invasive C4 grasses (Eyles et al., 2012). Intensive silvicultural systems that have been developed for monoculture plantations might also enhance forest restoration plantations (Gonçalves et al., 2008; Campoe et al., 2010). Our objective was to compare the effect of two silvicultural systems (traditional with minimal inputs; and intensive with fertilization and weed control) on carbon stock and sequestration of a

A.P.C. Ferez et al. / Forest Ecology and Management 350 (2015) 40–45

forest restoration plantation in degraded areas in Sao Paulo State, Brazil. We also compared the carbon stock of the planted forest ecosystem under both silvicultural systems with a typical mature Atlantic forest remnant as a representative reference of the regional biome. Our hypothesis is that intensive silviculture will increase carbon stock and sequestration of the forest plantation, compared to traditional, showing carbon stock closer to the Atlantic forest remnant amount. 2. Methods 2.1. Site description The experiment was installed in riparian areas of Tiete River at Anhembi Forest Research Station, University of São Paulo (22°430 2200 S, 48°100 3200 W, 455 m of elevation, <2% slope). The native Atlantic Forests in this area were semi-deciduous seasonal forests (Morellato and Haddad, 2000). The climate is mesothermal Cwa (Alvares et al., 2013), with hot rainy summers and dry cool winters. The mean annual temperature is 23 °C and mean cumulated annual rainfall 1100 mm with annual water deficit of 20 mm during the dry season (May–August). The predominant soil is a deep acidic (pH of 4.0) Typic Hapludox (Soil Survey Staff, 1999), with 5% silt, 13% clay and 82% sand, with low organic matter (1.5%, in the top 45 cm, Cook et al., 2013). 2.2. Experimental design In March, 2004, 20 native tree species were planted on an abandoned and degraded pasture (Campoe et al., 2010). Before planting, the site was dominated by the African signal grass (Urochloa decumbens) which was eliminated by applying 5 L ha1 of glyphosate (0.2%). Leaf-cutting ants (Atta sp. and Acromyrmex sp.) were controlled systematically with baits placed (sulfluramide 0.3%) throughout the experimental area. The experimental design is a complete 23 factorial, with eight treatments in randomized blocks with four replications (32 plots of 36 m  22 m each). The two levels of each factor were: (i) Proportion of pioneer and non-pioneer species: 50%:50% and 67%:33%; (ii) planting spacing: 3 m  1 m (3333 plants ha1) and 3 m  2 m (1667 plants ha1) and (iii) traditional and intensive silviculture (Campoe et al., 2010). Four additional plots (50%:50% pioneer and non-pioneer species, 3 m  2 m, with intensive silviculture) were established to provide material for destructive sampling. We focused our study on evaluating the effect of the factor silviculture, fixing the proportion of pioneers: non-pioneers in 50%:50%, and planting spacing of 3 m  2 m. These proportion and spacing are widely used on restoration plantations on Atlantic forest biome. Thus, we evaluated only two treatments (traditional and intensive silviculture) in four replicates per treatment, totaling 8 plots monitored. Traditional silviculture for the establishment of tree seedlings on abandoned pastures include hand row weeding (25 cm on each side) combined with mechanical mowing between rows (at 6, 12, 18 and 24 months after planting) and addition of moderate amounts of inorganic fertilizer, totaling 27 kg N ha1, 21 kg P ha1, 11 kg K ha1 and 24 kg Ca ha1 (Busato et al., 2007; Furtini Neto et al., 2004). The intensive silviculture was based on Eucalyptus plantations in Brazil (Stape et al., 2010; Gonçalves, 2013), providing total weed removal and high fertilization to alleviate any competition for water and nutrient limitation. Weed control was carried out chemically by the application of 5 L ha1 of glyphosate (0.2%) across the entire plot, every three months until canopy closure and inhibition of weed growth (approximately 2 years after planting). After canopy closure, herbicide was spot applied as necessary,

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allowing natural regeneration. Fertilization was performed annually since planting time (March, 2004), totaling 81 kg N ha1, 62 kg P ha1, 33 kg K ha1, 452 kg Ca ha1 and 180 kg Mg ha1. 2.3. Soil carbon stock Total mineral soil carbon was determined from samples collected during experiment establishment and 6 years after planting. Soil bulk density was measured on samples collected using 100 cm3 steel cylinders in the middle of each studied plot, at 0–15 cm and 15–30 cm soil depths, two between rows and two between plants in the row. The soil C content was measured from samples collected with an auger, on two rows and two inter-rows at 0–15 cm and 15–30 cm. On each of these 4 locations, ten fixed positions were sampled and combined, totaling 4 samples per plot. Soil C contents were converted to an area basis by multiplying concentrations by average bulk density and sampling depth and summing the two depths. The C content on the top 30 cm of the soil profile represented 80% of the total C down to 45 cm depth, strongly decreasing below this depth (Cook et al., 2013). 2.4. Carbon stock 2.4.1. Tree measurements Total height and bole diameter (0.3 m above ground level) were measured on all trees inside the measurable plot at 6 years after planting. 2.4.2. Biomass equations Above and belowground biomass were estimated by allometric equations developed from destructive sampling. We selected 4 trees for each species comprising the range of sectional area, based on the inventory performed at 5 years after planting. The equations were developed by pooling all 80 trees (from 20 species) into a single group. On destructive additional plots, we identified the 80 selected trees, measured total height and diameter, harvested and divided the tree into the following components: Bole–stem and bark from ground level to the point of morphological change from bole to branch; branch–woody material after the point of morphological change between bole and branch until the diameter of 10 mm; crown–foliage and branches thinner than 10 mm; and coarse roots until the diameter of 10 mm. Each component of each tree, above and below ground, was weighed on site individually. Representative samples were collected and dried at 65 °C until constant weight for dry mass determination. Based on the 80 harvested trees, we generated specific equations to three different components: (i) aboveground woody biomass (AGBw) as a function of diameter, total height and wood density (see Ferez, 2012 for details on wood density determination); (ii) Coarse roots (CR) as a function of AWB; and (iii) crown biomass as a function of AWB and CR (Table 1). Bole sectional area of the sampled trees ranged from 3.8 cm2 (Cariniana estrellensisi) to 432 cm2 (Erythrina mulungu), total height from 1.30 m (Cedrela fissilis) to 10.55 m (Jacaranda cuspidifolia) and wood density from 220 kg m3 (Erythrina mulungu) to 700 kg m3 (Acacia polyphylla). The biomass equations were generated in R (R Development Core Team, 2008) using the linearized model of Schumacher and Hall (Chave et al., 2005). The data used to generate the equations passed on tests of normality and homoscedasticity of variance. 2.4.3. O horizon and herbaceous strata The dry matter of the O horizon (litter layer above mineral soil) and herbaceous vegetation were quantified just before planting (degraded pasture) and 6 years after planting on all studied plots using a 0.5 m2 (0.71  0.71 m) steel frame, on three positions on

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Table 1 Biomass equations for different components for the restoration plantation and the mature forest. P-value for all equations were <0.0001. SA = sectional area; Ht = total height; q = wood density; AGBW = woody aboveground biomass; CR = coarse roots biomass; C = crown biomass; DBH = diameter at breast height (1.3 m above ground level); AGB = aboveground biomass; BGB = belowground biomass.

a b

Location

Component

Equation

r2

Standard Error kg tree1

Min–Max value kg tree1

Restoration plantation

Woody aboveground Coarse roots Crown

ln(AGBW) = 6.039 + 0.945  ln(SA) + 0.961  ln(Ht) + 1.022  ln(q) ln(CR) = 0.288 + 0.742  ln(AGBW) C = 0.384 + 0.123  AGBW  0.086  CR

0.94 0.87 0.62

1.45 1.54 1.13

0.18–67.02 0.16–35.92 <0.01–9.87

Mature forest

Abovegrounda Belowgroundb

AGB = 0.0673  (q  DBH2  Ht)0.976 BGB = exp(1.085 + 0.926  ln(AGB))

– –

– –

– –

Equation developed by Chave et al. (2014). Equation developed by Cairns et al. (1997).

two rows and two inter-rows, totaling 3 m2 per plot. Each sample was separated into O horizon and herbaceous vegetation and weighted in the field. Representative samples of each component were collected and dried at 65 °C until constant weight for dry mass determination. 2.4.4. Carbon content Carbon content on woody (bole and branches) and non-woody (crow) material were analyzed on three samples per species (covering the range of tree size and species), and in each sample of the mineral soil, O horizon and herbaceous vegetation. All samples were analyzed using a LECO C-144 equipment (Leco Corp. St. Joseph, MI, USA). The average values were 0.46 g g1 for woody material, 0.50 g g1 for non-woody material, 0.71 g g1 for mineral soil, 0.32 g g1 for O horizon and 0.50 g g1 for herbaceous vegetation. The values of carbon content were used to convert the studied variables from dry biomass into carbon. 2.5. Carbon stock and sequestration Carbon stock was assessed by summing the following components: aboveground woody, coarse roots and crown, O horizon, herbaceous vegetation and soil, for each studied system (degraded pasture at planting time, restoration forest plantation and the mature forest). Mean annual carbon sequestration was assessed by calculating the change in C stocks between experiment establishment (degraded pasture) and the stock of the forest restoration divided by the age of 6 years. 2.6. Mature forest Aiming at comparing the carbon stock of the restoration plantation with a natural forest, we selected a mature fragment of Atlantic forest (semi-deciduous seasonal forest) with 1400 ha, 5 km from the experimental area, within same soil characteristics and climatic conditions. Ten transects of 500 m2 (10 m  50 m) were randomly distributed across the patch, where we measured DBH and total height of all trees above 5 cm of DBH (first half of the transect) and 10 cm of DBH (second half of the transect). Understory vegetation below 5 cm in DBH was not considered on our study due to its low contribution to total C carbon stock (Clark et al., 2001). Soil carbon content was quantified by collecting three samples of the 0–15 cm and 3 samples 15–30 cm soil layers every 20 m along the transect (5, 25 and 45 m from the beginning). Soil bulk density samples were collected on both depths at middle of the transect. Soil C contents were converted to area basis by multiplying concentrations by average bulk density and sampling depth and pooling the two depths. Aboveground biomass was calculated using the equation developed by Chave et al. (2014) based on DBH, total height and wood

density. This is the most suitable equation to estimate mature forest biomass within the Atlantic forest biome (Vieira et al., 2008). We used the wood density list provided by Chave et al. (2006). Belowground biomass was calculated using the equation developed for tropical forests by Cairns et al. (1997), with aboveground biomass as the independent variable. The dry matter of the O horizon was quantified on all transects using a 0.5 m2 (0.71  0.71 m) steel frame, on the same three positions used to collect soil samples. Each sample was weighted in the field. Representative samples were collected and dried at 65 °C until constant weight for dry mass determination. Carbon content on soil and O horizon was analyzed using the same methodology applied to the plantation. 2.7. Statistical analysis One-way analysis of variance (GLM procedure) was used to evaluate the effect of treatments (traditional and intensive silviculture) on carbon stock and sequestration, with the level of significance set to 0.05. The analyses were performed using SAS 9.1 (SAS Institute Inc., Cary, NC, USA). 3. Results 3.1. Carbon stock At planting time, the carbon stock of the system was composed by 90.9% of soil C and 9.1% of herbaceous vegetation, summing 34 Mg C ha1 (Fig. 1). After six years, intensive silviculture significantly affected carbon stocks (Fig. 2). The total carbon stored (planted forest + O horizon + soil) under intensive silviculture was 32% higher (60.7 Mg C ha1) than under traditional silviculture (46.1 Mg C ha1). The forest C stock (coarse roots, wood and crown) under intensive silviculture reached 23.3 Mg C ha1, more than 3-fold the stock under traditional silviculture (6.9 Mg C ha1), with all the components showing significant higher values for the intensive silviculture (except for understory vegetation), compared to the traditional silviculture (Table 2). Herbaceous vegetation carbon stock, which was 3.1 Mg C ha1, at planting time, decreased to half of that value at 6 years after planting on traditional silviculture (1.5 Mg C ha1), and it represented only 13% on intensive silviculture (0.2 Mg C ha1). Intensive silviculture increased the O horizon by 40% (5.3 Mg C ha1) compared to traditional silviculture (3.7 Mg C ha1). Mineral soil C showed no significant change over time with either level of silviculture. Under both silvicultural systems, soil showed the same amount of C, on average 33 Mg C ha1 (Table 2). Soil C stock was the dominant component on both silvicultural systems (Table 2), showing higher contribution on traditional (73.7%) than in the intensive silvicultural system (52.5%). Tree

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for traditional silviculture (24.6%) compared to intensive silviculture (21.9%). Wood showed the opposite pattern, with higher contribution to C stock on intensive (69.1%) compared to traditional silviculture (65.2%, Fig. 3)

3.2. Mature forest

Fig. 1. Carbon stock relative distribution among the components of the studied systems.

biomass (coarse roots, wood and crown) represented 15% followed by O horizon (8%) and herbaceous (3.3%) components on traditional silviculture. On intensive silviculture, forest showed higher contribution (38.4%), followed by O horizon (8.8%), with very low contribution of the herbaceous component (only 0.3%). Focusing only on the tree biomass, crown showed similar contribution to C stock (9.6%), coarse roots showed higher contribution

The mature forest remnant contained 61 tree species from 31 families (see Ferez, 2012 for the complete list of trees species and families), with trees ranging from 6.4 kg to 3200 kg of total biomass (Fig. 2). Carbon stock on the mature forest system was 221 Mg C ha1, with aboveground biomass (148.7 Mg C ha1) comprising 67% of the total. The O horizon contained only 4 Mg C ha1, similar to the restoration plantation. No herbaceous vegetation was found in the mature forest (Table 2). Soil showed very similar C stock (from planting time, through the traditional silviculture, intensive silviculture, and the mature forest), ranging from 30.9 ± 5.9 Mg C ha1 to 35.5 ± 10.9 Mg C ha1, suggesting that the soil is a fairly stable component of the C stock. Six years after planting, the forest restoration system under intensive silviculture showed 30% of the carbon stock of the mature forest (60.7 Mg C ha1 versus 221 Mg C ha1), and 21% for the forest system under traditional silviculture (46.1 Mg C ha1).

Fig. 2. Degraded land dominated by invasive C4 grasses at the beginning of the experiment (A), forest plantation under traditional (B) and intensive (C) silviculture after 6 years and the mature Atlantic Forest remnant (D).

Table 2 Carbon stocks on different components at planting time, six years after planting, on both silviculture systems (traditional and intensive) and on the mature forest. Values are means with standard deviation (n = 4 plots). Values followed by different letters for each component differ at p = 0.05.

a

Components

Planting time (Mg C ha1)

Traditional (Mg C ha1)

Intensive (Mg C ha1)

Mature forest (Mg C ha1)

Crown Wood (Stem + branch) Coarse roots Herbaceous O horizon Mineral soil (0–30 cm) Total

– – – 3.1 ± 0.9 – 30.9 ± 5.9 34.0 ± 5.9

0.7 ± 0.2 b 4.5 ± 1.8 b 1.7 ± 0.5 b 1.5 ± 0.6 a 3.7 ± 0.9 b 34.0 ± 6.7 a 46.1 ± 5.6 b

2.1 ± 0.4 a 16.1 ± 3.7 a 5.1 ± 0.8 a 0.2 ± 0.1 b 5.3 ± 1.3 a 31.9 ± 3.4 a 60.7 ± 7.7 a

– 148.7 ± 71.9a 32.8 ± 7.3 – 4.0 ± 1.4 35.5 ± 10.9 221.0 ± 45.0

Total aboveground C stock.

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Fig. 3. Carbon stock relative distribution for the components of traditional and intensive silvicultural systems, excluding soil.

Fig. 4. Mean annual variation of carbon between the degraded pasture at planting time and the forest system under traditional and intensive silvicultural systems, 6 years after planting. Group of bars for the same component with ⁄ differ at P = 0.05.

Considering only wood, coarse roots and crown carbon stock, the intensive silviculture reached 12.8% (23.3 Mg C ha1) while the traditional silviculture showed 3.8% (6.9 Mg C ha1), comparing to the mature forest carbon stock (181.5 Mg C ha1). 3.3. Carbon sequestration Carbon sequestration under intensive silviculture was almost twice as large as under traditional silviculture (Fig. 4). The largest component of carbon sequestration was wood for both silvicultural systems, however, 3.5 times higher on intensive compared to traditional silviculture (2.68 Mg ha1 year1 versus 0.75 Mg ha1 year1). O horizon increased at a higher rate on intensive managed forest (0.88 Mg ha1 year1) than on traditional (0.62 Mg ha1 year1). Herbaceous vegetation decreased on both silvicultural systems, showing larger loss of carbon on intensive silviculture (0.48 Mg ha1 year1 versus 0.27 Mg ha1 year1). Soil C showed no significant variation. 4. Discussion The intensive silvicultural management, with extra fertilization and chemical weed control, alleviated the competition between

planted trees and the aggressive C4 grass for water, nutrients and light. The higher level of available resources under the intensively managed plantation, leaded the trees to sequester carbon (above and belowground) more than three times faster (3.9 Mg ha1 year1), compared to the traditional (1.2 Mg ha1 year1). The herbaceous vegetation before the plantation was established represented approximately 30% of the carbon stock that accumulated in 6 years with traditional silviculture, contrasting with approximately 1% under intensive silviculture (Table 2). In Brazil, abandoned pasture lands represent a significant landscape cover within the original Atlantic Forest Biome area, resulting in depleted soils highly infested by aggressive C4 grasses. Additionally, 80% of the remnants are highly fragmented, with less than 50 hectares and with an average distance of approximately 1500 m from each other (Ribeiro et al., 2009). Therefore, the combination of intensive fertilization and chemical weed control is crucial to the survival and growth of planted trees aiming at restoration. The low effectiveness of limited mechanical weed control and low levels of available nutrients of the traditional treatment allowed substantial understory competition, retarding growth and C accumulation by the planted trees. During establishment and early stages, the root system of new planted seedlings and weeds explore the same soil layers. Due to the C4 photosynthetic cycle characteristic of the dominant grass on our experimental site, the competition for resources (water and nutrients) is unbalanced. Therefore, effective weed control is mandatory to increase carbon sequestration on planted trees (Fig. 4). In the same site, Campoe et al. (2010, 2014) found that growth was highly responsive to the weed control, with the planted tree species showing 20% higher photosynthesis with intensive silviculture. In Australia, during the initial 18 months after planting, the productivity of Eucalyptus seedlings was two-fold higher on stands with intensive weed control, compared to stands with no weed control (Adams et al., 2003). Early weed control on Eucalyptus plantation (until 18 months) allowed the trees to increase investment in leaf area growth, increasing productivity (Eyles et al., 2012). Extra fertilization is equally important, especially under conditions of tropical depleted abandoned pasture lands (Furtini Neto et al., 2004). The successional status of the tree species result in a wide range of nutrient demand, however all tree species respond positively to the increase in nutrient availability (Santos Jr. et al., 2006). Davidson et al. (2004) studying tree biomass growth in a secondary forest in Brazil observed that all species showed higher productivity after the application of nitrogen and phosphorus, otherwise limited by lack of nutrient. Scarce information related to native tree species demand for nutrients limits precise fertilization recommendation, leading foresters to rely on fertilization rates of forest plantations for wood production. Substantial studies focusing on Brazilian tree species demand for nutrients are needed. Two years after planting, canopy closure of the intensive treatment provided enough shading to inhibit weed growth; therefore, broadcasted chemical weed control was replaced by limited spotted application of herbicide, allowing natural regeneration of native tree species from the planted species and from surrounding remnants. Evaluation of natural regeneration had been performed at our experimental site, showing significant saplings recruitment of both planted and not planted tree species growing and forming an understory, with significantly higher recruitment on intensive management (data not shown). Carbon stock and sequestration on mineral soil was constant in space (for both silvicultural systems) and time (between planting time and after 6 years, Fig. 4). These results were similar to several forest or grassland systems, showing that despite a significant stock, soil C sequestration was uncertain to be accounted as a carbon sink of a forest plantation (Post and Kwon, 2000).

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As observed in our results (Table 2, Fig. 4), forest restoration plantations on tropical regions have actual potential to be a carbon sequestration mechanism on both above- and belowground for long periods of time (Silver et al., 2001). Restoration of forest plantations with multiple tree species (20 for this study), from different succession classes may show double benefits in terms of carbon sequestration. Early-succession fast-growing species (pioneers) are able to capture carbon fast, and late-succession long-lived species (non-pioneers) maintain the carbon fixed in the forest system for long periods of time (Redondo-Brenes and Montagnini, 2006). Especially under conditions of degraded abandoned pasture lands, dominated by C4 grasses, fast initial development of pioneer species are crucial to reach canopy closure as soon as possible to prevent establishment of competing vegetation. Intensive silviculture, especially during the early stages of a forest plantation, provide nutrients and absence of weed competition, changing physical and biological site conditions, facilitating the forest restoration process (Lugo, 1997; Parrotta et al., 1997). The intensive silviculture increased growth and carbon sequestration, resulting in a carbon stock closer to the one of the native mature forest, comparing with traditional silviculture. Forest plantations aiming at restoration and also carbon sequestration are feasible, and highly responsive to intensive silviculture to achieve high rates of carbon stocks. Acknowledgements This research was supported by Petrobras Company, Forestry Science and Research Institute (IPEF), the University of São Paulo (USP) and Coordination for the Improvement of Higher Education Personnel (CAPES). We thank to Flávio Gandara, Eduardo Gusson, João D. Santos, Monte Olimpo Forest Group (ESALQ – USP) and Anhembi Research Station (ESALQ - USP) staff for their contribution in field and laboratory work. We also thank to Dan Binkley for insightful contributions. References Adams, P.R., Beadle, C.L., Mendham, N.J., Smethurst, P.J., 2003. The impact of timing and duration of grass control on growth of young Eucalyptus globulus Labill. Plant. New For. 26, 147–165. Alvares, C.A., Stape, J.L., Sentelhas, P.C., Gonçalves, J.L.M., Sparovek, G., 2013. Köppen’s climate classification map for Brazil. Meteorol. Z. 22, 711–728. Benayas, J.M.R., Newton, A.C., Diaz, A., Bullock, J.M., 2009. Enhancement of biodiversity and ecosystem services by ecological restoration: a meta-analysis. Science 325, 1121–1124. Busato, L.C., Gobbo, P.R.S., Nave, A.G., Rodrigues, R.R., 2007. Intermontes project in the context of Brazilian field works and researches on restoration. In: Rodrigues, R.R., Martins, S.V., Gandolfi, S. (Eds.), High Diversity Forest Restoration in Degraded Areas: Methods and Projects in Brazil. Nova Science, Hauppauge, pp. 223–245. Cairns, M.A., Brown, S., Helmer, E.H., Baumgardner, G.A., 1997. Root biomass allocation in the world’s upland forests. Oecologia 111, 1–11. Campoe, O.C., Stape, J.L., Mendes, J.C.T., 2010. Can intensive management accelerate the restoration of Brazil’s Atlantic forests? For. Ecol. Manage. 259, 1808–1814. Campoe, O.C., Iannelli, C., Stape, J.L., Cook, R.L., Mendes, J.C.T., Vivian, R., 2014. Atlantic forest tree species responses to silvicultural practices in a degraded pasture restoration plantation: from leaf physiology to survival and initial growth. For. Ecol. Manage. 313, 233–242. Chave, J. et al., 2005. Tree allometry and improved estimation of carbon stocks and balance in tropical forests. Oecologia 145, 87–99. Chave, J., Muller-Landau, H.C., Baker, T.R., Easdale, T.A., Ter Steege, H., Webb, C.O., 2006. Regional and phylogenetic variation of wood density across 2456 neotropical tree species. Ecol. Appl. 16, 2356–2367.

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