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1.
In the context of global carbon cycle management, accurate knowledge of carbon content in forests is a relevant issue in contemporary forest ecology. We measured the above-ground and soil carbon pools in the darkconiferous boreal taiga. We compared measured carbon pools to those calculated from the forest inventory records containing volume stock and species composition data. The inventory data heavily underestimated the pools in the study area(Stolby State Nature Reserve, central Krasnoyarsk Territory, Russian Federation). The carbon pool estimated from the forest inventory data varied from 25(t ha-1)(low-density stands) to 73(t ha-1)(highly stocked stands). Our estimates ranged from 59(t ha-1)(lowdensity stands) to 147(t ha-1)(highly stocked stands). Our values included living trees, standing deadwood, living cover, brushwood and litter. We found that the proportion of biomass carbon(living trees): soil carbon varied from99:1 to 8:2 for fully stocked and low-density forest stands,respectively. This contradicts the common understanding that the biomass in the boreal forests represents only16–20 % of the total carbon pool, with the balance being the soil carbon pool.  相似文献   

2.
India launched National Agroforestry Policy on 10th February, 2014 which has the potential to substantially reduce poverty in rural India and revive wood based industry, besides integrating food production with environmental services. The policy is not only crucial to India’s ambitious goal of achieving 33 per cent forest and tree cover but also to mitigate GHG emissions from agriculture sector. Dynamic CO2FIX-v3.1 model has been used to estimate the carbon sequestration potential (CSP) of existing agroforestry systems (AFS) for simulation period of 30 years in twenty six districts from ten selected states of India. The observed number of trees on farmers’ field in these districts varied from 1.81 to 204 per hectare with an average value of 19.44 trees per hectare. The biomass in the tree component varied from 0.58 to 48.50 Mg DM ha?1, whereas, the total biomass (tree and crop) ranged from 4.96 to 58.96 Mg DM ha?1. The soil organic carbon ranged from 4.28 to 24.13 Mg C ha?1. The average estimated carbon sequestration potential of the AFS, representing varying edapho-climatic conditions, on farmers field at country level was 0.21 Mg C ha?1yr?1. At national level, existing AFS are estimated to mitigate 109.34 million tons CO2 annually, which may offsets one-third (33 %) of the total GHG emissions from agriculture sector.  相似文献   

3.
In the Northern and Baltic countries, grey alder is a prospective tree species for short-rotation forestry. Hence, knowledge about the functioning of such forest ecosystems is critical in order to manage them in a sustainable and environmentally sound way. The 17-year-long continuous time series study is conducted in a grey alder plantation growing on abandoned agricultural land. The results of above- and below-ground biomass and production of the 17-year-old stand are compared to the earlier published respective data from the same stand at the ages of 5 and 10 years. The objectives of the current study were to assess (1) above-ground biomass (AGB) and production; (2) below-ground biomass: coarse root biomass (CRB), fine root biomass (FRB) and fine root production (FRP); (3) carbon (C) and nitrogen (N) accumulation dynamics in grey alder stand growing on former arable land. The main results of the 17-year-old stand were as follows: AGB 120.8 t ha?1; current annual increment of the stem mass 5.7 t ha year?1; calculated CRB 22.3 t ha?1; FRB 81 ± 10 g m?2; nodule biomass 31 ± 19 g m?2; fine root necromass 11 ± 2 g m?2; FRP 53 g DM m?2 year?1; fine root turnover rate 0.54 year?1; and fine root longevity 1.9 years. FRB was strongly correlated with the stand basal area and stem mass. Fine root efficiency was the highest at the age of 10 years; at the age of 17 years, it had slightly reduced. Grey alder stand significantly increased N and Corg content in topsoil. The role of fine roots for the sequestration of C is quite modest compared to leaf litter C flux.  相似文献   

4.
In tropical areas of Mexico, Leucaena leucocephala is widely used in silvopastoral systems. However, little information exists on other native woody species of high forage potential, such as Guazuma ulmifolia. The aim of this study was to evaluate the components of biomass, forage yield and quality, and availability of N in fodder banks of L. leucocephala, G. ulmifolia, and a mixture of both species during dry and rainy seasons, under sub-humid tropical conditions. The experimental unit was a 5 × 10 m plot, containing three rows with 2 m between rows; each row had 20 plant positions with 0.50 m between plants. Within each plant position there was either a single plant, in the case of pure-crop, or two plants, in the case of mixed of both species. A complete randomized block design with three repetitions was used. In both seasons, there were a significantly greater proportion of leaves in the G. ulmifolia fodder banks (71 %) and in mixed fodder banks (69 %) than in L. leucocephala fodder banks (64 %). Consequently, these systems had leaf-to-stem ratios of 2.4, 2.2 and 1.9, respectively. The forage yield of fodder banks was not influenced by season. The mixed fodder bank had greater forage yield (5.1 t DM ha?1) than the L. leucocephala fodder bank (3.4 t DM ha?1) in each season. Additionally, the mixed fodder bank accumulated more forage yield during the experimental period (10.2 t DM ha?1 year?1) than G. ulmifolia (9.0 t DM ha?1 year?1) or L. leucocephala (6.9 t DM ha?1 year?1). The concentrations of CP, C and C:N were not influenced by season. Forage NDF and ADF concentrations were greater in the rainy season (476 g kg?1 DM) compared with the dry season (325 g kg?1 DM). Mixed fodder banks had the greatest N yield (185.9 kg ha?1) and consequently the greatest availability of N (371.8 kg N ha?1 year?1). We conclude that mixed fodder banks of L. leucocephala and G. ulmifolia are a better option for improving productivity and forage quality in comparison with pure fodder banks in Yucatan, Mexico.  相似文献   

5.
Changes in coffee economics are leading producers to reduce agrochemical use and increase the use of shade. Research is needed on how to balance the competition from shade trees with the provision of ecological services to the coffee. In 2000, long-term coffee experiments were established in Costa Rica and Nicaragua to compare coffee agroecosystem performance under full sun, legume and non-legume shade types, and intensive and moderate conventional and organic inputs. Coffee yield from intensive organic production was not significantly different from intensive conventional in Nicaragua, but in Costa Rica it was lower during three of the six harvests. Full sun coffee production over 6 years was greater than shaded coffee in Costa Rica (61.8 vs. 44.7 t ha?1, P = 0.0002). In Nicaragua, full sun coffee production over 5 years (32.1 t ha?1) was equal to coffee with shade that included Tabebuia rosea (Bertol.) DC., (27?C30 t ha?1) and both were more productive (P = 0.03) than coffee shaded with Inga laurina (Sw.) Willd. (21.6 t ha?1). Moderate input organic production was significantly lower than other managements under all shade types, except in the presence of Erythrina poepiggina (Walp.) O.F. Cook. Inga and Erythrina had greater basal area and nutrient recycling from prunings than other shade species. Intensive organic production increased soil pH and P, and had higher K compared to moderate conventional. Although legume shade trees potentially provide ecological services to associated coffee, this depends on management of the competition from those same trees.  相似文献   

6.
Aboveground biomass and carbon stock in the largest sacred grove of Manipur was estimated for trees with diameter [10 cm at 1.37 m height.The aboveground biomass,carbon stock,tree density and basal area of the sacred grove ranged from 962.94 to 1130.79 Mg ha~(-1),481.47 to 565.40 Mg ha~(-1) C,1240 to 1320 stem ha~(-1) and79.43 to 90.64 m~2 ha~(-1),respectively.Trees in diameter class of 30–40 cm contributed the highest proportion of aboveground biomass(22.50–33.73%).The aboveground biomass and carbon stock in research area were higher than reported for many tropical and temperate forests,suggesting a role of spiritual forest conservation for carbon sink management.  相似文献   

7.
Replantation of degraded forest using rapidgrowth trees can play a significant role in global carbon budget by storing large quantities of carbon in live biomass,forest floor,and soil organic matter.We assessed the potential of 20-year old stands of three rapid-growth tree species,including Alnus subcordata,Populus deltoides and Taxodium distichum,for carbon(C) storage at ecosystem level.In September 2013,48 replicate plots(16 m × 16 m) in 8 stands of three plantations were established.36 trees were felled down and fresh biomass of different components was weighed in the field.Biomass equations were fitted using data based on the 36 felled trees.The biomass of understory vegetation and litter were measured by harvesting all the components.The C fraction of understory,litter,and soil were measured.The ecosystem C storage was as follows: A.subcordata(626.5 Mg ha~(-1)) [ P.deltoides(542.9Mg ha~(-1)) [ T.distichum(486.8 Mg ha~(-1))(P \ 0.001),of which78.1–87.4% was in the soil.P.deltoides plantation reached the highest tree biomass(206.6 Mg ha~(-1)),followed by A.subcordata(134.5 Mg ha~(-1)) and T.distichum(123.3 Mg ha~(-1)).The highest soil C was stored in theplantation of A.subcordata(555.5 Mg ha~(-1)).The C storage and sequestration of the plantations after 20 years were considerable(25–30 Mg ha~(-1) year~(-1)) and broadleaves species had higher potential.Native species had a higher soil C storage while the potential of introduced species for live biomass production was higher.  相似文献   

8.
Afforestation and ecological restoration have often been carried out with fast-growing exotic tree species because of their high apparent growth and yield. Moreover, fast-growing forest plantations have become an important component of mitigation measures to offset greenhouse gas emissions. However, information on the long-term performance of exotic and fast-growing species is often lacking especially with respect to their vulnerability to disturbance compared to native species. We compared carbon (C) storage and C accumulation rates in vegetation (above- and belowground) and soil in 21-year-old exotic slash pine (Pinus elliottii Engelm.) and native Masson pine (Pinus massoniana Lamb.) plantations, as well as their responses to a severe ice storm in 2008. Our results showed that mean C storage was 116.77 ± 7.49 t C ha?1 in slash pine plantation and 117.89 ± 8.27 t C ha?1 in Masson pine plantation. The aboveground C increased at a rate of 2.18 t C ha?1 year?1 in Masson pine and 2.23 t C ha?1 year?1 in slash pine plantation, and there was no significant difference in C storage accumulation between the two plantation types. However, we observed significant differences in ice storm damage with nearly 7.5 % of aboveground biomass loss in slash pine plantation compared with only 0.3 % loss in Masson pine plantation. Our findings indicated that the native pine species was more resistant to ice storm because of their adaptive biological traits (tree shape, crown structure, and leaf surface area). Overall, the native pine species might be a safer choice for both afforestation and ecological restoration in our study region.  相似文献   

9.
Grewia optiva Drummond is one of important agroforestry tree species grown by the farmers in the lower and mid-hills of western Himalaya. Different models viz., monomolicular, logistic, gompetz, allometric, rechards, chapman and linear were fitted to the relationship between total biomass and diameter at breast height (DBH) as independent variable. The adjusted R2 values were more than 0.924 for all the seven models implying that all models are apparently equally efficient. Out of the six non-linear models, allometric model (Y = a × DBH b ) fulfils the validation criterion to the best possible extent and is thus considered as best performing. Biomass in different tree components was fitted to allometric models using DBH as explanatory variable, the adjusted R2 for fitted functions varied from 0.872 to 0.965 for different biomass components. The t values for all the components were found non-significant (p > 0.05), thereby indicating that model is valid. Using the developed model, the estimated total biomass varied from 6.62 Mg ha?1 in 4 year to 46.64 Mg ha?1 in 23 year old plantation. MAI in biomass varied from 1.66–2.05 Mg ha?1 yr?1. The total biomass carbon stocks varied from 1.99 Mg ha?1 in 4 year to 15.27 Mg ha?1 in 23 year old plantation. Rate of carbon sequestration varied from 0.63–0.81 Mg ha?1 yr?1. Carbon storage in the soil up to 30 cm soil depth varied from 25.4 to 33.6 Mg ha?1.  相似文献   

10.
Allometric equations are routinely used in the estimation of biomass stocks for carbon accounting within forest ecosystems. However, generic equations may not reflect the growth trajectories of afforestation species that are introduced to degraded farmland characterized by water and nutrient limitations. Using sequential measurements of the height, basal diameter, and above- and belowground biomass of juvenile trees, we developed allometric equations for five woody species (Moringa oleifera Lam., Leucaena leucocephala Lam., Jatropha curcas L., Anacardium occidentale L. and Parkia biglobosa Jacq.) subjected to a gradient of water and nutrient availability in an afforestation trial on degraded cropland in the semi-arid zone of Benin, West Africa. For three of the species studied, the allometric relationships between basal diameter and biomass components (i.e. leaves, stems and roots) were described best by a simple power-law model (R2 > 0.93). The incorporation of species-specific height–diameter relationships and total height as additional predictors in the power-law function also produced reasonable estimates of biomass. Fifteen months after planting, roots accounted for 10–58% of the total biomass while the root-to-shoot ratio ranged between 0.16 and 0.73. The total biomass of the saplings ranged between 1.4 and 10.3 Mg ha?1, yielding 0.6–4.3 Mg C ha?1, far exceeding the biomass in the traditional fallow system. The rate of stem carbon sequestration measured ca. 0.62 Mg C ha?1 year?1. Overall, the allometric equations developed in this study are generally useful for assessing the standing shoot and root biomass of the five afforestation species during the juvenile growth stage and can help in reporting and verifying carbon stocks in young forests.  相似文献   

11.
The present study was conducted in five forest types of subtropical zone in the Northwestern Himalaya, India. Three forest stands of 0.1 ha were laid down in each forest type to study the variation in vegetation carbon pool, stem density, and ecosystem carbon density. The stem density in the present study ranged from (483 to 417 trees ha?1) and stem biomass from (262.40 to 39.97 tha?1). Highest carbon storage (209.95 t ha?1) was recorded in dry Shiwalik sal forest followed by Himalayan chir forest > chir pine plantation > lower Shiwalik pine forest > northern mixed dry deciduous forest. Maximum tree above ground biomass is observed in dry Shiwalik sal forests (301.78 t ha?1), followed by upper Himalayan chir pine forests (194 t ha?1) and lower in Shiwalik pine forests (138.73 t ha?1). The relationship with stem volume showed the maximum adjusted r2 (0.873), followed by total density (0.55) and average DBH (0.528). The regression equation of different parameters with shrub biomass showed highest r2 (0.812) and relationship between ecosystem carbon with other parameters of different forest types, where cubic function with stem volume showed highest r2 value of 0.873 through cubic functions. Our results suggest that biomass and carbon stocks in these subtropical forests vary greatly with forest type and species density. This variation among forests can be used as a tool for carbon credit claims under ongoing international conventions and protocols.  相似文献   

12.
Carbon (C) sequestration potential was quantified for five tree species, commonly used in tree-based intercropping (TBI) and for conventional agricultural systems in southern Ontario, Canada. In the 25-year-old TBI system, hybrid poplar (Populus deltoides × Populus nigra clone DN-177), Norway spruce (Picae abies), red oak (Quercus rubra), black walnut (Juglans nigra), and white cedar (Thuja occidentalis) were intercropped with soybean (Glycine max). In the conventional agricultural system, soybean was grown as a sole crop. Above- and belowground tree C Content, soil organic C, soil respiration, litterfall and litter decomposition were quantified for each tree species in each system. Total C pools for hybrid poplar, white cedar, red oak, black walnut, Norway spruce and a soybean sole-cropping system were 113.4, 99.4, 99.2, 91.5, 91.3, and 71.1 t C ha?1, respectively at a tree density of 111 trees ha?1, including mean tree C content and soil organic C stocks. Net C flux for hybrid poplar, white cedar, red oak, black walnut, Norway spruce and soybean sole-crop were 2.1, 1.4, 0.8, 1.8, 1.6 and ?1.2 t C ha?1 year?1, respectively. Results presented suggest greater atmospheric CO2 sequestration potential for all five tree species when compared to a conventional agricultural system.  相似文献   

13.
We studied variations in tree biomass and carbon sequestration rates of Chir Pine(Pinus roxburghii. Sarg.) forest in three categories of forest disturbance, protected, moderately disturbed, and highly disturbed. In the first year, total biomass was 14.7 t?ha-1 in highly disturbed site, 94.46 t?ha-1 in moderately disturbed forest, and 112.0 t?ha-1 in protected forest. The soil organic carbon in the top 20 cm of soil ranged from 0.63 to 1.2%. The total rate of carbon sequestration was 0.60(t/ha)·a-1on the highly disturbed site, 1.03(t/ha)·a-1 on the moderately disturbed site, and 4.3(t/ha)·a-1 on the protected site.  相似文献   

14.
This study provides the first complete framework for the valuation of ecosystem services of agroforestry and uses a tree-based intercropping (TBI) system in southern Québec, Canada, as a case study. Ten ecosystem services were estimated, all of which were of interest and directly applicable to most agricultural systems worldwide: nutrient mineralization, water quality, soil quality, pollination, biological control, air quality, windbreak, timber provisioning, agriculture provisioning, and climate regulation. A mix of mathematical models for the quantification and economic valuation of various ecosystem services were used. The results revealed a total annual margin of $2,645 ha?1 y?1 (averaged over 40 years). The economic value of combined non-market services was $1,634 ha?1 y?1, which was higher than the value of marketable products (i.e. timber and agricultural products). An analysis of the present value suggested that agricultural products ranked highest among the ecosystem services taken singularly, followed by water quality, air quality, climate regulation, and soil quality maintenance. Total economic value of all ecosystem services for the rotation period was $54,782 ha?1, only one third of which was contributed by agricultural products. Although the total value of the ecosystem services provided by TBI was high, farmers only benefited from agricultural and timber products. Thus, government incentives are needed to interest farmers in adopting practices that benefit society as a whole.  相似文献   

15.
A major challenge for cocoa producers in Côte d’Ivoire is to seek alternative shade trees or crop associations to adapt their planting devices and techniques to the shortage of forests. The recent tendency developed by farmers is to plant simplified orchards combining cacao and fruit trees. An on-farm trial was set up in a 5-year-old cocoa farm to compare a cacao monocrop planted at densities of 1,115 trees ha?1 with cacao intercropped with orange or avocado trees, both at 44 trees ha?1. Observations were done on incident light received by the cacao, vigour, growth and cocoa yields. On average, the cacaos received 100 % light in the monocrop, 89.6 % under orange trees and 80.6 % of incident light under avocado trees. They yielded 64.0 pods tree?1 year?1 in the monocrop (equivalent to 2.54 kg dry cocoa beans tree?1), 30.3 pods tree?1 when combined with orange trees and 28.3 pods tree?1 with avocado trees. The two combinations allowed cocoa yields equivalent to those observed in the region (0.58 kg dry cocoa beans tree?1). Vigour and yield were very highly correlated with the incident light received. Both the yield and the incident light are a logistic function of the planting distance from the shade tree. The inflexion point of the logistic functions corresponds to the minimum planting distance between the cacao and the intercropped fruit trees. On this basis, we suggest that the cacaos should not be planted closer than 6.50 ± 0.2 m to the orange or avocado trees.  相似文献   

16.
The effect of different planting densities (100,000 and 167,000 plants ha?1) and levels of nitrogen fertilization (0, 261, 521, and 782 kg N ha?1 year?1) on biomass production and chemical composition of Moringa oleifera was studied in a split-plot design with four randomized complete blocks over 2 years with eight cuts year?1 at the National Agrarian University farm in Managua, Nicaragua (12°09′30.65″N, 86°10′06.32″W, altitude 50 m above sea level). Density 167,000 plants ha?1 produced significantly higher total dry matter yield (TDMY) and fine fraction yield (FFDM), 21.2 and 19.2 ton ha?1 respectively, compared with 11.6 and 11 ton ha?1 for 100,000 plants ha?1. Growth rate in 167,000 plants ha?1 was higher than in 100,000 plants ha?1 (0.06 compared with 0.03 ton ha?1 day?1). Average plant height was 119 cm irrespective of planting density. Fertilization at the 521 and 782 kg N ha?1 year?1 levels produced the highest TDMY and FFDM in both years of the study and along all cuts. The interaction between cut and year was significant, with the highest TDMY and FFDM during the rainy season in the second year. Chemical composition of fractions showed no significant differences between planting densities. Significantly higher crude protein content was found in the coarse fraction at fertilizer levels 521 and 782 kg N ha?1 year?1 (87.9 and 93.7 g kg?1 DM) compared with lower levels. The results indicate that Moringa can maintain up to 27 ton ha?1 dry matter yield under dry tropical forest conditions over time at a planting density of 167,000 plants ha?1 if the soil is regularly supplied with N at a level of approximately 521 kg ha year?1 in conditions where phosphorus and potassium are not limiting.  相似文献   

17.
Afforestation of degraded croplands by planting N2-fixing trees in arid regions is highly recognized. However, fixation of atmospheric nitrogen gas (N2) by woody perennials is often limited on phosphorus (P) poor soils, while any factor limiting N nutrition inhibits tree growth. In a two-factorial field experiment, the effect of three P amendments was examined during 2006–2008 on N2 fixation, biomass production, and foliage feed quality of actinorhizal Elaeagnus angustifolia L. and leguminous Robinia pseudoacacia L. With the 15N natural abundance method, N2 fixation was quantified based on foliar and whole-tree sampling against three non-N2-fixing reference species: Gleditsia triacanthos L., Populus euphratica Oliv., and Ulmus pumila L. The P applications, in March 2006 and April 2007 only, included (i) high-P (90 kg P ha?1), (ii) low-P (45 kg P ha?1), and (iii) 0-P. After 3 years, the average proportion of N derived from atmosphere (Ndfa, %) increased from 78 % with 0-P to 87 % with high P when confounded over both N2-fixing species. With the used density of 5,714 trees ha?1, the total amount of N2 fixed (Ndfa, kg N ha?1) with high-P increased from 64 kg N ha?1 (year 1) to 807 kg N ha?1 (year 3) in E. angustifolia and from 9 kg N ha?1 (year 1) to 155 kg N ha?1 (year 3) in R. pseudoacacia. Total above-ground biomass increases were too variable to be significant. Leaf N content and therewith also leaf crude protein content, which is an indicator for feed quality, increased significantly (24 %) with high-P when compared to 0-P for E. angustifolia. Overall findings indicated the suitability of the two N2-fixing species for afforestating salt-affected croplands, low in soil P. With P-applications as low as 90 kg P ha?1, the production potential of E. angustifolia and R. pseudoacacia, including the supply of protein-rich feed, could be increased on salt-affected croplands.  相似文献   

18.
Diverse kinds of fast growing multipurpose trees are traditionally grown as support trees (standards) for trailing black pepper vines in the humid tropics of India. Apart from differential black pepper yields, such trees exhibit considerable variability to accumulate biomass, carbon and nutrients. An attempt was made to assess the biomass production, carbon sequestration potential (tree + soil) and nutrient stocks of six multipurpose tree species (age: 22 years) used for trailing black pepper vines (Acacia auriculiformis, Artocarpus heterophyllus, Grevillea robusta, Macaranga peltata, Ailanthus triphysa and Casuarina equisetifolia). Results indicate that G. robusta showed the highest total biomass production (365.72 Mg ha?1), with A. triphysa having the least value (155.13 Mg ha?1). Biomass allocation among tissue types followed the order stemwood > roots > branchwood > twigs > leaves. Total C stocks were also highest for G. robusta (169 Mg C ha?1), followed by A. auriculiformis (155 Mg C ha?1). Mean annual carbon increment also followed a similar trend. Among the various tissue fractions, stemwood accounted for the highest N, P and K stocks, implying the potential for nutrient export from the site through wood harvest. All the support trees showed significantly higher soil carbon content compared to the treeless control. Soil N, P and K contents were higher under A. auriculiformis than other species. Nitrogen fixation potential, successional stage of the species, stand age and tree management practices such as lopping may modify the biomass allocation patterns and system productivity.  相似文献   

19.
We construct dry weight equations for hybrid aspen growing on former farmland in Sweden. Dry weight equations for fractions of hybrid aspen trees were also made. We estimated biomass production in 24 stands. The stands were located in Sweden at latitudes ranging from 55 to 60o N. The mean age was 18 years (range 15-23), the mean stand density 1090 stems·ha-1 (range 378 2374), and the mean diameter at breast height (over bark) 178 mm (range 85 244 mm). Soil types in the hybrid aspen stands were mainly clay (21 stands), tills (2 stands) and other (1 stand). The mean total standing dry weight above stump level (≈ 200 mm) for the hybrid aspen stands was 135±53 t·ha-1 with a range of 42 219 t·ha-1 . In addition to estimating conventional dry weights of trees and tree components, basic density, specific leaf area (SLA), projected leaf area (PLA) and leaf area index (LAI) were estimated and were in agreement with published figures.  相似文献   

20.
Although agrosystems are recognized for their socio-economic value, few works have been conducted to assign its sequestration potential and ecological services. Accordingly, this study aimed to evaluate the ecological services of the eucalyptus stands in order to permit to small producers the access in carbon credit market. Three stands were selected according to age. Data were compared to that of a savannah (control). In total, 12,817 individuals belonging to 30 families, 53 genera and 70 species were identified in the plantations against 7107 individuals belonging to 24 families, 36 genera and 42 species in the savannah. Gmelina, Annona, Hymenocardia, Allophyllus, Daniellia, Terminalia and Piliostigma were the most represented genera. There was no significant difference between Savannah and plantations in terms of diversity (p > 0.05). The largest stock of carbon was found in oldest stands (108.51 ± 26.46 t C/ha) against 13.62 ± 3.03 t C/ha in Savannah. Eucalyptus saligna stored 39.66 t C/ha (4 t C ha?1year?1) in young stands; 57.28 t C/ha (6 t C ha?1year?1) in medium stands and 85.46 t C/ha (9 t C ha?1year?1) in old stands. The sequestration potential was higher in eucalyptus stands (398.25 t CO2eq/ha) than savannah (50.05 t CO2eq/ha). In total 956.82 t CO2eq/ha were sequestered for an economic value of $9568.45/ha against 50.05 t CO2eq/ha corresponding to $500.56/ha in Savannah. Eucalyptus stands are carbon sinks and could be an opportunity for financial benefits in the event of payment for environmental services in the context of the CDM process.  相似文献   

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