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Copyright of Bulletin of Soil & Water Conservation is the property of Bulletin of Soil & Water Conservation Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

[Objective] Sustainable Development Goal 15.3.1 (SDG 15.3.1) is one of the important indicators to characterize land degradation.Exploring the impact of land use change and ecosystem service values (ESVs) on SDG 15.3.1 is a key factor to improve land degradation. [Methods] Based on land use and carbon stock changes, a new evaluation rule was established for SDG15.3.1 index, and the completion of SDG 15.3.1 was evaluated. The equivalent factor method was used to calculate the value of ecosystem services to quantitatively analyse the impact of land use change on ESV. [Results] (1) The land use type change was frequent in the study area, which mainly showed that high forest land, water body and construction land increased, cultivated land, grassland and shrub decreased, and unused land remained basically unchanged; (2) The spatial distribution pattern of ESV was high in the middle, low arround, high in the west and low in the east; From 2000 to 2020, the total ESV loss was 7.32×108 yuan. From 2000 to 2010, the ESV loss of land degradation area was 3.03×109 yuan. From 2010 to 2020, the ESV loss in land degradation areas was 2.28×109 yuan. (3) According to the evaluation results of SDG15.3.1, the indicators of SDG15.3.1 for 2000—2010 and 2010—2020 are 5.22 percent and 4.77 percent, respectively, while the net land restoration area was -1.62×105 hm2 and -2.4×105 hm2. The SDG15.3.1 target had improved, but the zero land degradation growed target is still not achieved. [Conclusion] The research results provided a reference for the impact of land use change on ecosystem services in the process of achieving SDG 15.3.1 in plateau urban agglomerations.

[Objective]In an attempt to increase carbon stock in the agricultural sector, the marginalized and unstable lands were identified as the fallow plots, carbon sinks due to ecological fallowing under future multi-gradient fallowing scenarios were explored to provide an crucial basis for arranging the fallow of marginalised cropland and enriching the theory of carbon sequestration in the northeast black soil region. [Methods]Based on the 2005 and 2020 land use data in the central black soil area of Jilin Province, a multi-gradient fallow scenario was simulated by the PLUS-Markov coupled model and the InVEST model, and the carbon stock and the potential for carbon sequestration and sink enhancement due to ecological fallow in the study area were measured. [Results](1)The natural development scenario and three fallowing scenarios A, B, and C with increasing intensity were set in this study. The marginal unstable farmland fallow in scenarios A, B, and C were 1. 5 × 104 hm², 2. 65 × 104 hm², and 3. 8 × 104 hm², respectively. These scenarios were mainly driv-en by socio-economic factors, accounting for about 30％of the total contribution. In terms of fallow types, the returning-to-forest areas widely distributed, mainly concentrated in the places such as Siping, Dongliao, and Changchun, while the returning-to-grass areas were smaller but exhibited spatial aggregation features, which were mainly located in the places such as Shuangliao and Nong'an. (2)As the simulated fallow intensi-ty increased, the carbon stock in the study area also indicated an increasing trend. Under fallow scenarios A, B, and C, the estimated carbon storage would reach up to 7. 26 × 106 Mg, 7. 27 × 106 Mg和7. 27 × 106 Mg, respectively, which decreased from the southeast and the northwest. The areas with high carbon sinks concentrated mainly in areas such as Shulan, Yongji, and Huadian. (3)Under different fallow scenarios, the carbon sink pattern in the study area remained stable, mainly concentrated in the eastern and southern parts. Considering the factors of food security and agricultural carbon sequestration demand, it is recommended to refer to the fallowing scenario B, and Siping, Dongliao, and Changchun will become the key agricultural carbon sink units in the black soil area of central Jilin Province. It is estimated that carbon stock will increase to 1963. 4 Mg, 806. 48 Mg and 703. 06 Mg, respectively. [Conclusion]The carbon stock increase from the agricultural sector in the black soil region of central Jilin Province depends on the fallow of marginalized croplands in a rolling hilly region. The productivity and the ecological effects arising from cropland use should be balanced in the layout and priority of the fallow projects. Meanwhile, the food production capacity needs to be adjusted in conjunc-tion with comprehensive land reclamation in the entire region in order to achieve the aims of improving the spatial suitability of cropland and the sustainability of the agricultural system in the black soil area. [ABSTRACT FROM AUTHOR]

Copyright of Arid Land Geography is the property of Chinese Academy of Sciences, Xinjiang Institute of Ecology & Geography and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To explore the impact of land use change on ecosystem carbon storage in Hohhot City, this paper simulates and predicts the land use and carbon stock of Hohhot City under four scenarios, namely, natural development, ecological protection, arable land protection, and urban development based on the InVEST and PLUS models. The results showed that the area of land use types, such as impervious surface, forest land, grassland, and water bodies in Hohhot City increased from 1990 to 2020. The area of land types, such as cultivated land, bare land, and shrubs decreased, with shrubs and bare land having the highest land turn-out rate of 93.63% and 98.24%, respectively. The estimation results of the InVEST model indicated that the continuous expansion of anthropogenic ground, erosion of arable land, and other land use high carbon density land types that resulted in a decreasing trend of carbon storage in Hohhot City from 1990 to 2020. The carbon stocks in Hohhot City in 2030 under the abovementioned scenarios are predicted to decrease compared with those in 2020. Carbon stocks in the arable land protection scenario are predicted to decrease the least, followed by the ecological protection scenario, indicating that reasonable protection measures can effectively reduce the decrease of carbon stocks. The arable land conservation scenario can effectively slow down the expansion of urban buildings, while the ecological conservation scenario can effectively increase ecological land such as water bodies and grasslands. The study shows that the implementation of arable land and ecological protection policies, optimization of land use structure, and improvement of land use efficiency are all important for the sustainable development of Hohhot City. [ABSTRACT FROM AUTHOR]

Land use change is the main factor driving the change of carbon stock, and assessing the impact of land use change on carbon stock is of great significance for carbon balance. Taking Jiangxi Province as an example, based on the InVEST-PLUS model, we explore the spatial and temporal evolution characteristics of land use change and carbon stock in Jiangxi Province from 1990 to 2020, and measure the evolution of carbon stock under various scenarios in Jiangxi Province in 2030. (1) The carbon stocks in Jiangxi Province in 1990, 2000, 2010 and 2020 were 1275.94×106 t, 1276.00×106 t, 1269.12×106 t and 1258.00×106 t, respectively, with an overall decreasing trend. The decrease of forest land was the main factor for the loss of carbon stock. Above-ground biomass carbon pool and soil carbon pool had the most carbon stock, accounting for 88.82% of the total carbon stock. (2) By 2030, the carbon stock of the natural development scenario, ecological protection scenario, and urban development scenario will decrease by 3.8×106 t, increase by 1.25×106 t, and decrease by 13.3×106 t, respectively, compared with 2020. it shows that the adoption of ecological protection measures and optimization of land-use structure can effectively control the decrease of carbon stock. (3) The areas with significantly higher carbon stocks are located in the mountainous areas of Gannan where ecological land use is continuous, while the areas with significantly lower carbon stocks are located in the northern regions of Gannan where carbon density values are low and construction land use is distributed in patches. The results of the study will provide a scientific basis for making reasonable ecological decisions for the construction of ecological civilization in Jiangxi Province and for realizing high-quality development. [ABSTRACT FROM AUTHOR]

The growth of trees generates a huge carbon sink, which is of great significance in alleviating environmental problems such as global warming caused by carbon emissions. To accurately assess the carbon sink of forests, a model of the annual growth rate of tree diameter at breast height (DBH) in 4 forms for 13 main tree species (groups) in Beijing was established based on the data from the 6th to 9th National Forest Inventory. This model predicted the future trend of DBH changes, thereby provided a computational basis for calculating carbon storage using the continuous function method of biomass conversion factors. Ultimately, it estimated the carbon storage and carbon density of deciduous forests in Beijing by 2050. The results showed that: 8 of the tree species (groups) had a DBH annual growth rate model R2 greater than 0.900, with the highest R2 of 0.960 for linden; except willow and Fraxinus mandshurica/Juglans mandshurica/Phellodendron amurense the RMSE of 11 tree species (groups) was less than 0.5 cm; except for poplars, other hard broad-leaved forests and elms, Bias was less than 1.0 cm. The overall R2 in the validation of DBH prediction accuracy was high, with the highest for black locusts (0.951) and the lowest for other hard broad-leaved forests (0.766). It was predicted the carbon stock of arbor forests in Beijing in 2050 was 42.71 TgC, and the carbon density is 43.35 MgC · hm-2. The study found that the tree growth simulation method based on the annual growth rate at breast height model could effectively improve the overall accuracy of future carbon sink potential assessment of tree forests in Beijing, which could provide a theoretical basis for formulating greenhouse gas reduction policies and achieving the 2060 carbon neutrality target. [ABSTRACT FROM AUTHOR]

Copyright of Mountain Research (10082786) is the property of Mountain Research Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Land use change has a significant impact on the carbon balance in urban ecosystems. Based on the law of land use change in Taiyuan City from 2000 to 2020, this study uses the CA-Markov model to predict the spatial pattern of land use in different scenarios in 2030, and uses the InVEST model to evaluate the carbon storage of Taiyuan City from 2000 to 2030. The results show that from 2000 to 2020, the construction land increased significantly, an increase of 339.265 km², and the area of forest land increased by 96.707 km²; the area of water, cultivated land, grassland and unused land decreased by 13.333 km², 275.037 km², 146.073 km² and 1.223 km², respectively. From 2000 to 2020, the carbon storage in Taiyuan has decreased by 2 312 591.65 t. Different from the natural development scenario, under the ecological protection scenario, the forest land will increase slightly in 2030 compared with 2020, and the construction land will be effectively limited and expanded, both of which facilitated the generation of ecological effects under the ecological protection scenario. In 2030, the carbon storage under the ecological protection scenario is 1 760 959.397 t more than that under the natural development scenario. From the perspective of land use changes, the increase in forest area is the main reason for the increase in carbon storage in the study area, and the carbon sequestration capacity is enhanced under the ecological protection scenario. This study will provide a scientific basis for land use structure adjustment and management in Taiyuan. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Applied Ecology / Yingyong Shengtai Xuebao is the property of Chinese Journal of Applied Ecology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

As a key ecosystem for climate change mitigation, wetlands play an irreplaceable role in carbon capture and sequestration. The analysis of wetland carbon stocks and their influencing factors, as well as the prediction of carbon sequestration potential, are of great significance to the conservation and management of wetlands and the achievement of the national "double carbon" target.This study employed ArcGIS 10.8 to vectorize the wetland distribution map of the Wetland Protection and Development Plan of Guizhou Province (hereinafter referred to as the Plan) for three periods (1999-2009, 2010-2018, and 2018-present, respectively) by means of remote sensing visual interpretation and zoned them according to the intensity of karst development in Guizhou Province. The changes in wetland area and carbon stock in Guizhou Province were estimated and analyzed using the life belt research method and biomass estimation method, and the total carbon stock and carbon stock per unit area of key wetlands were estimated and compared with those of all wetlands in Guizhou Province. A calculation model was used to estimate the carbon sequestration potential of the key wetlands in Guizhou Province.The Origin software was applied to analyze the data on all relevant impact factors. The results showed that: ①The area of wetlands in Guizhou Province was 216, 526.95 hm2, 209, 726.85 hm2, and 255, 440.53 hm2 in the pre-, mid-, and late-planning periods, respectively, with an overall decrease and then increase, and the total area increased by 38, 913.58 hm2; ② The wetland carbon stock in Guizhou Province was 3.78×106 t in the late stage of planning, increasing significantly to more than 6 times of that in the early stage of planning(5.97×105 t), among which the carbon stock of the key wetlands was 3.24×106 t, accounting for 85.71% of the province's wetland carbon stock; ③ The carbon sequestration potential of the keywetlands in Guizhou Provincewas 1.14×104 t C/a, and the total carbon sequestration of wetlands is expected to reach 7.99×106 t C and 8.34×106 t C by 2030 and 2060, respectively; and ④ The carbon stock of the key wetlands was positively correlated with DIC concentration, organic carbon content and wetland area and negatively correlated with temperature, indicating thattemperature, DIC concentration, organic carbon content and wetland area had a strong influence on the carbon stock of the key wetlands in Guizhou Province.The results of this study will not only facilitate the understanding of the current status of wetland carbon sequestration in Guizhou Province but also provide a theoretical reference for the contribution of regional wetland ecosystems to the "3060" dual carbon target.

Mangroves occur in coastal intertidal zones and play an important role in terrestrial and marine carbon cycles. Accurate estimations of mangrove carbon stocks and sequestration potential can help quantify the contribution of mangroves to addressing climate change and achieving carbon neutrality goals. The carbon stocks and burial rates of different mangrove communities and regions in Guangdong Province were studied through literature collection and data integration. The soil carbon densities of the Rhizophora stylosa and Bruguiera gymnorhiza communities were 0.27 and 0.23 Gg C/hm2, respectively, while the soil carbon density of the Kandelia obovata community was the lowest at only 0.13 Gg C/hm2. The area of mangroves in Guangdong Province is 9,106.2 hm2, the total carbon stock is 1,542.02 Gg C, and the soil carbon density is 0.23 Gg C/hm2. The total carbon reserves of mangroves in thirteen regions are in the following order: Zhanjiang (894.5 Gg C) > Yangjiang (195.4 Gg C) > Jiangmen (97.7 Gg C) > Zhuhai (91.0 Gg C) > Maoming (59.6 Gg C) > Shantou (51.4 Gg C) > Zhongshan (49.2 Gg C) > Huizhou (36.1 Gg C) > Guangzhou (35.1 Gg C) > Shenzhen (18.3 Gg C) > Shanwei (10.8 Gg C) > Dongguan (2.83 Gg C) > Chaozhou (0.11 Gg C). Using the 210Pb method, the sediment accretion rate was found to be 13.47 mm/a. Qi'ao Island had the highest sediment compaction rate of 31.5 mm/a, followed by Zhenhai Bay, with 16.5 mm/a, Shenzhen Futian, with 15.9 mm/a, and Leizhou Bay, with the lowest sediment compaction rate of 7.3 mm/a. The carbon sequestration capacity of Guangdong province is approximately 2.96 Gg C/a, with the Leizhou Peninsula having the highest (6.05 Gg C/a) and Futian, Shenzhen having the lowest (0.66 Gg C/a) capacities. The carbon storage of mangroves in Guangdong Province was 1,542.02 Gg C, which was higher than that in other regions. The carbon sequestration capacity of the mangroves was relatively strong. Therefore, the protection and restoration of local mangroves may substantially contribute to the mitigation of climate change while providing additional benefits. This assessment, on a provincial scale, provides insights into blue carbon sequestration capacity, thus contributing to the synchronous progression of blue carbon management.

Mangroves occur in coastal intertidal zones and play an important role in terrestrial and marine carbon cycles. Accurate estimations of mangrove carbon stocks and sequestration potential can help quantify the contribution of mangroves to addressing climate change and achieving carbon neutrality goals. The carbon stocks and burial rates of different mangrove communities and regions in Guangdong Province were studied through literature collection and data integration. The soil carbon densities of the Rhizophora stylosa and Bruguiera gymnorhiza communities were 0.27 and 0.23 Gg C/hm2, respectively, while the soil carbon density of the Kandelia obovata community was the lowest at only 0.13 Gg C/hm2. The area of mangroves in Guangdong Province is 9,106.2 hm2, the total carbon stock is 1,542.02 Gg C, and the soil carbon density is 0.23 Gg C/hm2. The total carbon reserves of mangroves in thirteen regions are in the following order: Zhanjiang (894.5 Gg C) > Yangjiang (195.4 Gg C) > Jiangmen (97.7 Gg C) > Zhuhai (91.0 Gg C) > Maoming (59.6 Gg C) > Shantou (51.4 Gg C) > Zhongshan (49.2 Gg C) > Huizhou (36.1 Gg C) > Guangzhou (35.1 Gg C) > Shenzhen (18.3 Gg C) > Shanwei (10.8 Gg C) > Dongguan (2.83 Gg C) > Chaozhou (0.11 Gg C). Using the 210Pb method, the sediment accretion rate was found to be 13.47 mm/a. Qi'ao Island had the highest sediment compaction rate of 31.5 mm/a, followed by Zhenhai Bay, with 16.5 mm/a, Shenzhen Futian, with 15.9 mm/a, and Leizhou Bay, with the lowest sediment compaction rate of 7.3 mm/a. The carbon sequestration capacity of Guangdong province is approximately 2.96 Gg C/a, with the Leizhou Peninsula having the highest (6.05 Gg C/a) and Futian, Shenzhen having the lowest (0.66 Gg C/a) capacities. The carbon storage of mangroves in Guangdong Province was 1,542.02 Gg C, which was higher than that in other regions. The carbon sequestration capacity of the mangroves was relatively strong. Therefore, the protection and restoration of local mangroves may substantially contribute to the mitigation of climate change while providing additional benefits. This assessment, on a provincial scale, provides insights into blue carbon sequestration capacity, thus contributing to the synchronous progression of blue carbon management. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Applied Ecology / Yingyong Shengtai Xuebao is the property of Chinese Journal of Applied Ecology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

It is important to study the impact of land use change on terrestrial ecosystem carbon stocks in urban agglomerations for the optimization of land use structure and sustainable development in urban agglomerations. Based on the patch-generating land use simulation (PLUS) model and integrated valuation of ecosystem services and trade-offs (InVEST) model, a simulation was developed that predicted the land use change and carbon stock of the Guanzhong Plain urban agglomeration in 2040 under different scenarios and further analyzed the impact of land use change on carbon stock. The results showed that:① The land use types of the Guanzhong Plain urban agglomeration were mainly cultivated land, forest land, and grassland, which accounted for more than 90 % of the total study area. ② From 2000 to 2020, the carbon stock in the Guanzhong Plain showed a continuous downward trend, with cropland, woodland, and grassland being the main sources of carbon stock in the Guanzhong Plain, and the overall carbon stock declined by 15.12×10 6 t, with the spatial distribution presenting the distribution characteristics of "high in the north and south and low in the middle." ③ By 2040, the carbon stock would decrease the most under the urban development scenario, with a total reduction of 27.08×10 6 t, and the least under the ecological development scenario, with a total reduction of 4.14×10 6 t. The research results can provide data support for the high-quality development and rational land use planning of the Guanzhong Plain urban agglomeration.

Copyright of Chinese Journal of Applied Ecology / Yingyong Shengtai Xuebao is the property of Chinese Journal of Applied Ecology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

As a dominant part of terrestrial ecosystems, forest ecosystem plays an important role in absorbing atmospheric CO2 and global climate change mitigation. From the aspects of zonal climate and geographical distribution, the present carbon stocks and carbon sequestration capacity of forest ecosystem were comprehensively examined based on the review of the latest literatures. The influences of land use change on forest carbon sequestration were analyzed, and factors that leading to the uncertainty of carbon sequestration assessment in forest ecosystem were also discussed. It was estimated that the current forest carbon stock was in the range of 652 to 927 Pg C and the carbon sequestration capacity was approximately 4.02 Pg C·a–1. In terms of zonal climate, the carbon stock and carbon sequestration capacity of tropical forest were the maximum, about 471 Pg C and 1.02–1.3 Pg C·a–1 respectively; then the carbon stock of boreal forest was about 272 Pg C, while its carbon sequestration capacity was the minimum, approximately 0.5 Pg C·a–1; for temperate forest, the carbon stock was minimal, around 113 to 159 Pg C and its carbon sequestration capacity was 0.8 Pg C·a–1. From the aspect of geographical distribution, the carbon stock of forest ecosystem in South America was the largest (187.7–290 Pg C), then followed by European (162.6 Pg C), North America (106.7 Pg C), Africa (98.2 Pg C) and Asia (74.5 Pg C), and Oceania (21.7 Pg C). In addition, carbon sequestration capacity of regional forest ecosystem was summed up as listed below: Tropical South America forest was the maximum (1276 Tg C·a–1), then were Tropical Africa (753 Tg C · a–1), North America (248 Tg C · a–1) and European (239 Tg C·a–1), and East Asia (98.8–136.5 Tg C·a–1) was minimum. To further reduce the uncertainty in the estimations of the carbon stock and carbon sequestration capacity of forest ecosystem, comprehensive application of long-term observation, inventories, remote sensing and modeling method should be required. [ABSTRACT FROM AUTHOR]

A four-year (2008-2012) field experiment was conducted to investigate the effects of different straw-returning regimes on soil total organic carbon (TOC), labile organic carbon (LOC) and the ratio of LOC to TOC (LOC/TOC) as well as TOC stock (SCS) and soil carbon pool management index (CPMI) in a farmland with maize-wheat double cropping system in Guanzhong Plain area, Shaanxi Province, China. The results indicated that soil TOC and LOC contents and SCS were significantly increased when wheat or maize straw was returned to field, and the increasing extent showed the rising order as follows: double straw-returning > single straw-returning > no straw-returning. Compared to no straw returning, a significant increase of TOC and LOC contents and SCS was found in the treatment of wheat straw chopping retention combined with maize straw chopping sub soiling retention (WC-MM), and CPMI of WC-MM was significantly higher than in the other treatments in 0-20 cm soil layer. Compared to no wheat straw returning, soil CPMIs in 0-10 cm and 10-20 cm soil layer increased by 19.1% and 67.9% for the wheat straw chopping returning treatment, and by 22.6% and 32.4% for the maize straw chopping subsoiling treatment, respectively. Correlation analysis showed that soil CPMI was a more effective index reflecting the sequestration of soil organic carbon in 0-30 cm soil layer than the ratio of LOC to TOC. This study thus suggested that WC-MM regime is the best straw-returning regime for soil organic carbon sequestration. [ABSTRACT FROM AUTHOR]

Based on datasets from plot survey and bibliographic of Larix olgensis plantations in Maoer Mountain, the CO 2 FIX model was used to quantitatively simulate the effects of different rotations (30, 40, 50, 60 years), site indices (12, 16, 20 m), and initial densities (2500, 3333, 4444 trees·hm -2 ) on the stand level carbon flows among different carbon pools ( i.e. , biomass carbon pool, soil carbon pool, and product carbon pool). The results showed that the CO 2 FIX model had high reliability for simulating the processes of L. olgensis plantation, with the average relative errors of stand biomass and volume between analog and measured values being 6.4% and 3.7%. Under the baseline conditions of initial density of 3333 trees·hm -2 , site index of 16 m and rotation of 40 years, the carbon stock of total and sub-pool of L. olgensis plantation changed periodically with rotation. The total stand carbon stock and volume for L. olgensis plantation increased with the extension of rotation, the improvement of site index, and the increase of initial density. The stand carbon stock and volume would be increased by 12.2% and 31.2%, 36.7% and 67.8%, respectively, when the reference rotation was correspondingly extended by 10 and 20 years. However, if the reference rotation was shortened by 10 years, stand carbon stock and volume would be correspondingly decreased by 20.9% and 40.4%, respectively. When the initial density was set as 3333 and 4444 trees·hm -2 , stand carbon stock and volume were increased by 27.8% and 50.9%, 27.4% and 49.1%, respectively. When the site index was under the range of 12 to 20 m, stand carbon stock and volume could be increased by 36.0% and 40.3%, 39.3% and 44.2%, respectively, with each increase of 4 m in site index. During one rotation, 271.57 t C per hectare could be fixed into L. olgensis plantation. At the end round of the rotation, 27.47 and 56.75 t C were transferred to soil and wood product carbon pools. Therefore, when the site condition was good, the management model with a higher initial density (4444 trees·hm -2 ) and longer rotation (60 years) would be more beneficial to maximizing the carbon sink and timber benefits of L. olgensis plantation.

Based on the forest carbon budget model for China FORCCHN, which had been improved through adding variables and modules of precipitation (rainfall and snowfall) intercepted by tree crown and of understory and litter, the spatiotemporal distribution pattern of carbon stocks of forest ecosystems in Northeast China from 1981 to 2002 were simulated. The results showed that from 1981 to 2002, the forest ecosystems in Northeast China played a role of carbon sink, and the total carbon stock was about 1237 Pg C·a-1, of which, the stock of vegetation and soil was 401 Pg C·a-1 and 836 Pg C·a-1, respectively. During the study period, the carbon stock of both vegetation and soil all had an increasing trend, and the increase of air temperature contributed more than the change of precipitation. Spatially, the carbon density of vegetation had the characteristics of high in southeast part and low in northwest part, with an average of 1045 kg C·m-2. Most of the forest ecosystems in Northeast China had a higher soil carbon density, with a mean value of 2178 kg C·m-2 and the maximum in part regions of Daxing'anling, Xiaoxing'anling, and Changbai mountains. The forest area in Northeast China accounted for 314 % of that in the whole country, possessing an important position in China forest carbon pool. The carbon stock of vegetation and soil in the forests of Northeast China occupied 7423 % and 6388 %, and the carbon density of vegetation and soil was 270 and 122 times of that in the forests of the whole country, respectively. [ABSTRACT FROM AUTHOR]

We measured the annual net biomass growth, carbon content of each component and soil heterotrophic respiration in four low-efficiency interplanting patterns, i.e ., Pinus massoniana stands interplanting Myrica rubra , Sapindus mukurossi , Camellia oleifera and Gardenia jasminoides in Changting County, Fujian Province, with the aim to analyze the effects of interplanting patterns on carbon storage pattern and carbon balance of low-efficiency P. massoniana stand. The ranges of carbon content in different organs of M. rubra , S. mukurossi , C. oleifera , G. jasminoides and P. massoniana were 41.1%-50.1%, 42.2%-50.6%, 45.1%-48.9%, 44.7%-49.6% and 46.1%-51.9%, respectively. Carbon content of the same organ significantly differed among tree species. The pattern of P. massoniana interplanting M. rubra and S. mukurossi had the highest carbon stock and annual net carbon increase reserves, with values of 67.62-68.42 t·hm -2 and 9.21-9.45 t·hm -2 ·a -1 , respectively. Followed by the lower pattern of C. oleifera , G. jasminoides , with values of 31.96-36.24 t·hm -2 and 4.09-4.16 t·hm -2 ·a -1 , respectively. The P. massoniana pure forest was the lowest, with values of 17.01 t·hm -2 and 2.00 t·hm -2 ·a -1 , respectively. Annual flux of soil heterotrophic respiration was following the order of P. massoniana interplanting M. rubra pattern (7.41 t·hm -2 ·a -1 ) > P. massoniana interplanting C. oleifera pattern (5.89 t·hm -2 ·a -1 )> P. massoniana interplanting S. mukurossi pattern (5.86 t·hm -2 ·a -1 ) > P. massoniana interplanting G. jasminoides pattern (4.95 t·hm -2 ·a -1 ) > P. massoniana pure forest (2.45 t·hm -2 ·a -1 ). Annual net ecosystem carbon balance of P. massoniana interplanting M. rubra and S. mukurossi patterns were 2.04 and 3.27 t C·hm -2 ·a -1 , showing a "carbon sink" pattern. The net carbon balance in the patterns of P. massoniana interplanting C. oleifera and G. jasminoides along with P. massoniana pure forest were -1.80, -0.80 and -0.45 t C·hm -2 ·a -1 , which expressed a "carbon source" pattern. In the short-term, interplanting with M. rubra or S. mukurossi could improve the carbon income of the low-efficiency P. massoniana stand ecosystem.

Mangroves are the most important coastal blue carbon sinks. The accurate estimation on the carbon sequestration capacity of plant communities would guide the mangrove conservation, afforestation and management. This study investigated the vegetation carbon stocks of dominant mangrove communities, which were Avicennia marina, Kandelia obovata, Sonneratia caseolaris, and Sonneratia apetala in Futian Nature Mangrove Reserve in Shenzhen, Guangdong Province of China. Vegetation carbon stock consisted of living trees (aboveground and belowground biomass), understory, pneumatophore, standing dead trees, fallen dead trees and litter in these communities. The net primary productivity (NPP) was calculated from the litterfall and incremental growth in the same year of each community. Our results showed that the vegetation carbon stocks for A. marina, K. obovata, S. caseolaris, and S. apetala communities were 28.7, 127.6, 100.1, and 73.6 t C·hm -2 , and the NPP were 8.75, 7.67, 9.60, and 11.8 t C·hm -2 ·a -1 , respectively. Therefore, acting as urban forests, Futian mangroves in Shenzhen assimilated about 4000 t CO 2 ·a -1 . These results provided guidance for mangrove blue carbon assessment, and theoretical basis for the construction of coastal carbon sequestration forests in China.