scholarly journals Relative contribution of stand characteristics on carbon stocks in subtropical secondary forests in Eastern China

2016 ◽  
Author(s):  
Arshad Ali ◽  
En-Rong Yan ◽  
Han Y. H. Chen ◽  
Yan-Tao Zhao ◽  
Xiao-Dong Yang ◽  
...  
Keyword(s):  
Species Diversity ◽  
Eastern China ◽  
Structural Diversity ◽  
Stand Age ◽  
Site Productivity ◽  
Organic C ◽  
C Stocks ◽  
C Stock ◽  
Stand Structural Diversity ◽  
Stand Characteristics

Abstract. Stand structural diversity, which is characterized by species diversity, variances in tree diameter at breast height (DBH) and height, plays an important role in influencing forest carbon (C) stocks. However, the relative contribution of stand structural diversity in contrast to other stand characteristics on the variation in C stocks in subtropical forests have not been fully explored. In this study, aboveground C stock, soil organic C stock, tree species, DBH and height diversities, stand age, and stand density, and site productivity were determined across 80 subtropical forest plots in Eastern China. Using simple regression analysis, we found that DBH and height diversities, site productivity, and stand age explained 49 %, 13 %, 41 %, and 50 % of the variation in aboveground C stock, respectively, whereas species diversity and stand density did not explained any variation (i.e., < 1 %). Multiple regression analysis indicated that variation in aboveground C stock was explained to a higher degree (83 %) by the joint effects of DBH diversity, stand age, site productivity, species diversity and height diversity than by stand structural diversity (54 %), and the other three stand characteristics (79 %) alone. The structural equation modelling (SEM) showed that the effect of stand age on aboveground C stock was stronger directly (beta = 0.59) than indirectly (beta = 0.11). Stand age has also significant and strong effect on DBH (beta = 0.63) and height (beta = 0.55) diversities. Six stand characteristics did not explain any variation in soil organic C stock (i.e., < 2 %), based on both simple and multiple regressions analyses, as well as SEM analysis. Our analyses suggest that, rather than species and height diversities, DBH diversity, stand age and site productivity cumulatively contributed to variation in aboveground C stock during stand development in subtropical secondary forests in Eastern China. Therefore, improving tree DBH diversity and stand condition could be an effective approach for enhancing C storage in subtropical forests.

scholarly journals Stand structural diversity rather than species diversity enhances aboveground carbon storage in secondary subtropical forests in Eastern China

2016 ◽  
Vol 13 (16) ◽  
pp. 4627-4635 ◽  
Author(s):  
Arshad Ali ◽  
En-Rong Yan ◽  
Han Y. H. Chen ◽  
Scott X. Chang ◽  
Yan-Tao Zhao ◽  
...  
Keyword(s):  
Species Diversity ◽  
Direct Effect ◽  
Indirect Effect ◽  
Eastern China ◽  
Structural Diversity ◽  
Total Effect ◽  
Stand Age ◽  
C Storage ◽  
Stand Structural Diversity ◽  
Positive Direct

Abstract. Stand structural diversity, typically characterized by variances in tree diameter at breast height (DBH) and total height, plays a critical role in influencing aboveground carbon (C) storage. However, few studies have considered the multivariate relationships of aboveground C storage with stand age, stand structural diversity, and species diversity in natural forests. In this study, aboveground C storage, stand age, tree species, DBH and height diversity indices, were determined across 80 subtropical forest plots in Eastern China. We employed structural equation modelling (SEM) to test for the direct and indirect effects of stand structural diversity, species diversity, and stand age on aboveground C storage. The three final SEMs with different directions for the path between species diversity and stand structural diversity had a similar goodness of fit to the data. They accounted for 82 % of the variation in aboveground C storage, 55–59 % of the variation in stand structural diversity, and 0.1 to 9 % of the variation in species diversity. Stand age demonstrated strong positive total effects, including a positive direct effect (β =  0.41), and a positive indirect effect via stand structural diversity (β =  0.41) on aboveground C storage. Stand structural diversity had a positive direct effect on aboveground C storage (β =  0.56), whereas there was little total effect of species diversity as it had a negative direct association with, but had a positive indirect effect, via stand structural diversity, on aboveground C storage. The negligible total effect of species diversity on aboveground C storage in the forests under study may have been attributable to competitive exclusion with high aboveground biomass, or a historical logging preference for productive species. Our analyses suggested that stand structural diversity was a major determinant for variations in aboveground C storage in the secondary subtropical forests in Eastern China. Hence, maintaining tree DBH and height diversity through silvicultural operations might constitute an effective approach for enhancing aboveground C storage in these forests.

scholarly journals Carbon stocks of homestead forests have a mitigation potential to climate change in Bangladesh

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tarit Kumar Baul ◽  
Tajkera Akhter Peuly ◽  
Rajasree Nandi ◽  
Lars Holger Schmidt ◽  
Shyamal Karmakar
Keyword(s):  
Species Diversity ◽  
Stand Structure ◽  
Diversity Index ◽  
Carbon Stocks ◽  
Small Scale ◽  
Species Diversity Index ◽  
C Stocks ◽  
Homestead Forests ◽  
C Stock ◽  
Low Altitude

AbstractA total of 176 homestead forests at three altitudes in the Chittagong Hill Tracts, Bangladesh were randomly surveyed to estimate carbon (C) stocks and how stand structure affects the biomass C. All woody vegetations were measured, and litter and soil (0–30 cm depth) were sampled. The tree biomass C stock in the top two altitude forests was up to 37–48% higher than in low altitude, owing to significantly higher tree density and species diversity. An increase in species diversity index by one unit increased the biomass stock by 23 Mg C ha−1. The C stock of litterfall in low altitude forests was 22–28% higher than in the top two altitude due to the deposition of litters downslope and deliberate use of mulch for soil improvement and conservation, resulting in up to 5% higher total soil C. The topsoil C was 10–25% higher than the deeper soil, depending on the altitude. The forest stored 89 Mg C ha−1, indicating a potential for C sequestration in trees outside forest. This study would help policymakers to strengthen the recognition of small-scale forests for mitigation in REDD + (reducing emissions from deforestation and forest degradation, the role of conservation, sustainable management of forests, and enhancement of forest carbon stocks) and support owners through C credits from sustainably managed forests.

scholarly journals Tree species richness increases ecosystem carbon storage in subtropical forests

2018 ◽  
Vol 285 (1885) ◽  
pp. 20181240 ◽  
Author(s):  
Xiaojuan Liu ◽  
Stefan Trogisch ◽  
Jin-Sheng He ◽  
Pascal A. Niklaus ◽  
Helge Bruelheide ◽  
...  
Keyword(s):  
Species Richness ◽  
Tree Species ◽  
C Sequestration ◽  
Stand Age ◽  
Southeast China ◽  
Subtropical Forests ◽  
C Stocks ◽  
C Stock ◽  
Below Ground ◽  
Time Periods

Forest ecosystems are an integral component of the global carbon cycle as they take up and release large amounts of C over short time periods (C flux) or accumulate it over longer time periods (C stock). However, there remains uncertainty about whether and in which direction C fluxes and in particular C stocks may differ between forests of high versus low species richness. Based on a comprehensive dataset derived from field-based measurements, we tested the effect of species richness (3–20 tree species) and stand age (22–116 years) on six compartments of above- and below-ground C stocks and four components of C fluxes in subtropical forests in southeast China. Across forest stands, total C stock was 149 ± 12 Mg ha −1 with richness explaining 28.5% and age explaining 29.4% of variation in this measure. Species-rich stands had higher C stocks and fluxes than stands with low richness; and, in addition, old stands had higher C stocks than young ones. Overall, for each additional tree species, the total C stock increased by 6.4%. Our results provide comprehensive evidence for diversity-mediated above- and below-ground C sequestration in species-rich subtropical forests in southeast China. Therefore, afforestation policies in this region and elsewhere should consider a change from the current focus on monocultures to multi-species plantations to increase C fixation and thus slow increasing atmospheric CO 2 concentrations and global warming.

scholarly journals Variability in above- and belowground carbon stocks in a Siberian larch watershed

2017 ◽  
Vol 14 (18) ◽  
pp. 4279-4294 ◽  
Author(s):  
Elizabeth E. Webb ◽  
Kathryn Heard ◽  
Susan M. Natali ◽  
Andrew G. Bunn ◽  
Heather D. Alexander ◽  
...  
Keyword(s):  
Aboveground Biomass ◽  
Spatial Scales ◽  
Siberian Larch ◽  
Stand Age ◽  
Permafrost Region ◽  
Organic C ◽  
Soil C ◽  
C Storage ◽  
C Stocks ◽  
Thaw Depth

Abstract. Permafrost soils store between 1330 and 1580 Pg carbon (C), which is 3 times the amount of C in global vegetation, almost twice the amount of C in the atmosphere, and half of the global soil organic C pool. Despite the massive amount of C in permafrost, estimates of soil C storage in the high-latitude permafrost region are highly uncertain, primarily due to undersampling at all spatial scales; circumpolar soil C estimates lack sufficient continental spatial diversity, regional intensity, and replication at the field-site level. Siberian forests are particularly undersampled, yet the larch forests that dominate this region may store more than twice as much soil C as all other boreal forest types in the continuous permafrost zone combined. Here we present above- and belowground C stocks from 20 sites representing a gradient of stand age and structure in a larch watershed of the Kolyma River, near Chersky, Sakha Republic, Russia. We found that the majority of C stored in the top 1 m of the watershed was stored belowground (92 %), with 19 % in the top 10 cm of soil and 40 % in the top 30 cm. Carbon was more variable in surface soils (10 cm; coefficient of variation (CV)  =  0.35 between stands) than in the top 30 cm (CV  =  0.14) or soil profile to 1 m (CV  =  0.20). Combined active-layer and deep frozen deposits (surface – 15 m) contained 205 kg C m−2 (yedoma, non-ice wedge) and 331 kg C m−2 (alas), which, even when accounting for landscape-level ice content, is an order of magnitude more C than that stored in the top meter of soil and 2 orders of magnitude more C than in aboveground biomass. Aboveground biomass was composed of primarily larch (53 %) but also included understory vegetation (30 %), woody debris (11 %) and snag (6 %) biomass. While aboveground biomass contained relatively little (8 %) of the C stocks in the watershed, aboveground processes were linked to thaw depth and belowground C storage. Thaw depth was negatively related to stand age, and soil C density (top 10 cm) was positively related to soil moisture and negatively related to moss and lichen cover. These results suggest that, as the climate warms, changes in stand age and structure may be as important as direct climate effects on belowground environmental conditions and permafrost C vulnerability.

scholarly journals Assessment of the Carbon Stock in Pine Plantations in Southern Spain through ALS Data and K-Nearest Neighbor Algorithm Based Models

Geosciences ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 442 ◽  
Author(s):  
Miguel A. Navarrete-Poyatos ◽  
Rafael M. Navarro-Cerrillo ◽  
Miguel A. Lara-Gómez ◽  
Joaquín Duque-Lazo ◽  
Maria de los Angeles Varo ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Nearest Neighbor ◽  
Growth Models ◽  
C Sequestration ◽  
Accurate Estimation ◽  
Biomass Estimation ◽  
K Nearest Neighbor ◽  
Organic C ◽  
C Stocks ◽  
C Stock

Accurate estimation of forest biomass to enable the mapping of forest C stocks over large areas is of considerable interest nowadays. Airborne laser scanning (ALS) systems bring a new perspective to forest inventories and subsequent biomass estimation. The objective of this research was to combine growth models used to update old inventory data to a reference year, low-density ALS data, and k-nearest neighbor (kNN) algorithm Random Forest to conduct biomass inventories aimed at estimating the C sequestration capacity in large Pinus plantations. We obtained a C stock in biomass (Wt-S) of 12.57 Mg ha−1, ranging significantly from 19.93 Mg ha−1 for P. halepensis to 49.05 Mg ha−1 for P. nigra, and a soil organic C stock of the composite soil samples (0–40 cm) ranging from 20.41 Mg ha−1 in P. sylvestris to 37.32 Mg ha−1 in P. halepensis. When generalizing these data to the whole area, we obtained an overall C-stock value of 48.01 Mg C ha−1, ranging from 23.96 Mg C ha−1 for P. halepensis to 58.09 Mg C ha−1 for P. nigra. Considering the mean value of the on-site C stock, the study area sustains 1,289,604 Mg per hectare (corresponding to 4,732,869 Mg CO2), with a net increase of 4.79 Mg ha−1 year−1. Such C cartography can help forest managers to improve forest silviculture with regard to C sequestration and, thus, climate change mitigation.

scholarly journals The role of soil in regulation of climate

2021 ◽  
Vol 376 (1834) ◽  
pp. 20210084 ◽  
Author(s):  
Rattan Lal ◽  
Curtis Monger ◽  
Luke Nave ◽  
Pete Smith
Keyword(s):  
Land Use ◽  
Management Practices ◽  
Ghg Emissions ◽  
Organic C ◽  
Soil C ◽  
C Cycle ◽  
C Stocks ◽  
C Stock ◽  
Land Use And Management

The soil carbon (C) stock, comprising soil organic C (SOC) and soil inorganic C (SIC) and being the largest reservoir of the terrestrial biosphere, is a critical part of the global C cycle. Soil has been a source of greenhouse gases (GHGs) since the dawn of settled agriculture about 10 millenia ago. Soils of agricultural ecosystems are depleted of their SOC stocks and the magnitude of depletion is greater in those prone to accelerated erosion by water and wind and other degradation processes. Adoption of judicious land use and science-based management practices can lead to re-carbonization of depleted soils and make them a sink for atmospheric C. Soils in humid climates have potential to increase storage of SOC and those in arid and semiarid climates have potential to store both SOC and SIC. Payments to land managers for sequestration of C in soil, based on credible measurement of changes in soil C stocks at farm or landscape levels, are also important for promoting adoption of recommended land use and management practices. In conjunction with a rapid and aggressive reduction in GHG emissions across all sectors of the economy, sequestration of C in soil (and vegetation) can be an important negative emissions method for limiting global warming to 1.5 or 2°C This article is part of the theme issue ‘The role of soils in delivering Nature's Contributions to People’.

scholarly journals Effects of Tree Species Diversity and Stand Structure on Carbon Stocks of Homestead Forests in Maheshkhali Island, Southern Bangladesh

2020 ◽  
Author(s):  
Tarit Kumar Baul ◽  
Avinanda Chakraborty ◽  
Rajasree Nandi ◽  
Mohammed Mohiuddin ◽  
Antti Kilpeläinen ◽  
...  
Keyword(s):  
Species Richness ◽  
Species Diversity ◽  
Tree Species ◽  
Forest Ecosystems ◽  
Stand Density ◽  
Tree Species Diversity ◽  
Soil C ◽  
C Stocks ◽  
Homestead Forests ◽  
C Stock

Abstract BackgroundThis study aimed to estimate the carbon (C) stocks in homestead forest ecosystems (trees, litterfall, and soil) of Maheshkhali Island in Bangladesh and how tree species diversity and stand structural variation affected these C stocks. We randomly surveyed a total of 239 homestead forests proportionately allocating in hillside (67), beachside (69), and inland (103) in 2019 for measuring woody plants and sampling litterfall and C in soil at 0-30 cm depth. Tree (above- and below-ground) biomass was estimated by using pan-tropical allometric equations, and carbon of litterfall and soil were analyzed in a laboratory. ResultsWe found a total of 52 tree species, of which, 41, 42, and 48 species were in the hillside, beachside, and inland, respectively, corresponding to the individuals of 840, 540, and 1504 sampled. According to the results, species diversity, richness, stand density, basal area (BA), and tree diameter at breast height (DBH) and height were significantly (p ≤ 0.05) greater in the hillside and inland homestead forests, compared to the beachside. Most abundant species, for example, Mangifera indica, Samanea saman, and Artocarpus heterophyllus in the inland and hillside homestead forests stored most C in biomass, compared to the beachside forest. Tree biomass C stocks were 48-67% greater in the inland and hillside than on beachside forests due to significantly (p ≤ 0.05) greater stand density, BA, and DBH. The overall C stock of litterfall was 0.1% of the total biomass carbon. C stock in soil surface was greatest in the hillside homestead forests due to the greatest litterfall. The total soil C stock was also affected by tree species, stand density and species richness, and their interaction with soil properties. Total soil C stocks across the depths were greatest (51 Mg ha-1) in the inland homestead forests, with the greatest stand density and species richness. ConclusionsHomestead forest ecosystems across the area stored total 96 Mg C ha-1, which thus can contribute to climate change mitigation while generating C credit for small-scale homestead forests owners as well as conserving biodiversity in Bangladesh and countries alike.

scholarly journals Effects of tree species diversity and stand structure on carbon stocks of homestead forests in Maheshkhali Island, Southern Bangladesh

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Tarit Kumar Baul ◽  
Avinanda Chakraborty ◽  
Rajasree Nandi ◽  
Mohammed Mohiuddin ◽  
Antti Kilpeläinen ◽  
...  
Keyword(s):  
Species Richness ◽  
Species Diversity ◽  
Tree Species ◽  
Stand Density ◽  
Tree Species Diversity ◽  
Tree Biomass ◽  
C Stocks ◽  
Homestead Forests ◽  
C Stock ◽  
Below Ground

Abstract Background The homestead forests of Bangladesh occupy 0.27 million hectares (10% of the total forested area) and have potential to store carbon (C) and conserve biodiversity. Small scale forestry practices, however, are lacking reliable estimation of C stocks and tree species diversity. This may hinder successful implementation of REDD + and similar mechanisms as they concentrate on large-scale forests. This study aimed to estimate the above- and below-ground carbon stocks in homestead forests of Maheshkhali Island in Bangladesh and how tree species diversity and stand structural variation affect these C stocks. We randomly surveyed a total of 239 homestead forests in the hillside, beachside, and inland in 2019. Results Tree biomass C stocks were 48–67% greater in the inland and hillside forests than in the beachside due to significantly greater stand density, basal area, tree diameter. In total we found 52 tree species, but most abundant species in the inland and hillside forests, Mangifera indica, Samanea saman, and Artocarpus heterophyllus stored the most C in tree biomass. Greater tree species richness and diversity index in the inland and hillside forests indicated greater above- and below-ground tree biomass C stocks. An increase in tree species richness and diversity index by one unit was found to increase the tree biomass C stock by 22 and 30 Mg C ha−1, respectively. The total soil C stock was also affected by tree species diversity, stand density, and their interaction with soil properties. Total soil C stocks were greatest (51 Mg ha−1) in the inland forests, having also the greatest stand density and tree species richness. C stock in soil surface was greatest in the hillside forests due to the greatest litterfall, but the average share of litterfall from the total biomass C was only 0.1%. Conclusions Homestead forest ecosystems could store 96 Mg C ha−1 in total, which can contribute to climate change mitigation by generating C credits for small-scale homestead forests owners. Above- and below-ground tree biomass C stocks were found to correlate with tree species diversity, which may also contribute to biodiversity conservation in the REDD + in Bangladesh and countries alike.

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