Differences In Carbon Storage Research Articles

Analysis of Spatiotemporal Predictions and Drivers of Carbon Storage in the Pearl River Delta Urban Agglomeration via the PLUS-InVEST-GeoDetector Model

Land use and land cover change (LUCC) significantly influences the dynamics of carbon storage in thin terrestrial ecosystems. Investigating the interplay between land use alterations and carbon sequestration is crucial for refining regional land use configurations, sustaining the regional carbon balance, and augmenting regional carbon storage. Using land use data from the Pearl River Delta Urban Agglomeration (PRDUA) from 2010 to 2020, this study employed PLUS-InVEST models to analyze the spatiotemporal dynamics of land use and carbon storage. Projections for the years 2030, 2040, and 2050 were performed under three distinct developmental scenarios, namely, natural development (ND), city priority development (CPD), and ecological protection development (EPD), to forecast changes in land use and carbon storage. The geographic detector model was leveraged to dissect the determinants of the spatial and temporal variability of carbon storage, offering pertinent recommendations. The results showed that (1) during 2010–2020, the carbon storage in the PRDUA showed a decreasing trend, with a total decrease of 9.52 × 106 Mg, and the spatial distribution of carbon density in the urban agglomeration was imbalanced and showed an overall trend in increasing from the center to the periphery. (2) Clear differences in carbon storage were observed among the three development scenarios of the PRDUA between 2030 and 2050. Only the EPD scenario achieved an increase in carbon storage of 1.10 × 106 Mg, and it was the scenario with the greatest potential for carbon sequestration. (3) Among the drivers of the evolution of spatial land use patterns, population, the normalized difference vegetation index (NDVI), and distance to the railway had the greatest influence on LUCC. (4) The annual average temperature, annual average rainfall, and GDP exerted a significant influence on the spatiotemporal dynamics of carbon storage in the PRDUA, and the interactions between the 15 drivers and changes in carbon storage predominantly manifested as nonlinear and double-factor enhancements. The results provide a theoretical basis for future spatial planning and achieving carbon neutrality in the PRDUA.

Effects of forest type on carbon storage in the hilly region of Loess Plateau, China

The hilly region of the Loess Plateau has lush vegetation and high carbon sequestration potential. However, previous studies have not focused on differences in carbon storage of different forest types and their causes. This study aimed to explore the carbon storage of forest and identify the main influencing factors of carbon storage to provide basis for improving the carbon fixation capacity of planted forest in the region. Broad-leaved, coniferous, and mixed forests at different altitudes were selected from the Ziwuling Mountains in the Loess hilly region. The carbon storage as well as physical and chemical characteristics of the vegetation and soil samples from different soil layers were measured. The vegetation factor, terrain factor, and soil factor of the sample plot were evaluated by Mantel test and redundancy analysis (RDA). The carbon storage of the mixed forest (138.87 MgC hm−2) showed the highest carbon storage compared to broad-leaved forest (131.97 MgC hm−2) and coniferous forest (113.62 MgC hm−2) in the loess hilly region. The carbon storage of different components followed the order of soil carbon storage, vegetation carbon storage, and litter carbon storage. The soil organic carbon content and forest type had the highest explanations for total carbon storage, accounting for 57 and 26.9% of the variance, respectively. This indicates that forest type is an important factor affecting carbon storage, and selecting mixed forests can achieve better results when creating and transforming carbon sink forests.

Carbon storage estimation and strategy optimization under low carbon objectives for urban attached green spaces

In the context of rapid urbanization, scarce land resources have highlighted the importance of attached green spaces (AGS), which have received limited attention despite their critical importance in the urban carbon cycle. Analyzing the differences in carbon storage of different AGS types and proposing different optimization strategies can provide a reference for urban managers to scientifically enhance the carbon sinks of greenfield. This study estimated the carbon storage of AGS in central Shanghai using a series of detailed field survey data and remote sensing data. The results showed that AGS stored 296 Gg (1Gg = 109 g) of carbon, accounting for 56 % of the total carbon storage in all urban green spaces. While carbon density in AGS is lower than that in other green space types due to the dominance of small trees, simple vegetation structures and poor maintenance in some areas. Significant differences in carbon storage capacity were also found among different types of AGS, related to individual vegetation attributes and vegetation structure. Our findings emphasized that optimal design strategies should be different for various green space types, and proposed corresponding optimization strategies for different AGS types. Furthermore, the dual role of multi-layered planting structures in carbon sinks and biodiversity was also emphasized.

Comparison of the CASA and InVEST models’ effects for estimating spatiotemporal differences in carbon storage of green spaces in megacities

Urban green space is a direct way to improve the carbon sink capacity of urban ecosystems. The carbon storage assessment of megacity green spaces is of great significance to the service function of urban ecosystems and the management of urban carbon zoning in the future. Based on multi-period remote sensing image data, this paper used the CASA model and the InVEST model to analyze the spatio-temporal variation and driving mechanism of carbon storage in Shenzhen green space and discussed the applicability of the two models to the estimation of carbon storage in urban green space. The research results showed that, from 2008 to 2022, in addition to the rapid expansion of construction land, the area of green space and other land types in Shenzhen showed a significant decrease trend. The estimation results of the carbon storage model showed that the carbon storage of green space shows a significant trend of reduction from 2008 to 2022, and the reduction amounts are 0.8 × 106 t (CASA model) and 0.64 × 106 t (InVEST model), respectively. The evaluation results of the model show that, in megacities, the spatial applicability of InVEST model is lower than that of CASA model, and the CASA model is more accurate in estimating the carbon storage of urban green space. The research results can provide a scientific basis for the assessment of the carbon sink capacity of megacity ecosystems with the goal of "dual carbon".

Evaluation and Tradeoff of Ecosystem Services in Jiaozuo

With the continuous development of the economy and society, the demand for land space for human survival has also increased, which means that the pressure on ecosystem services has also been unprecedentedly high, leading to serious problems such as ecological environment deterioration and system function decline, resulting in fierce conflicts between ecological environment protection and human social development. Therefore, the relationship between ecosystem services and economic and social development has become a hot research topic in the field of land ecology. Jiaozuo City is also facing the problem of ecological degradation. In order to achieve coordinated development of ecology, society, and economy, this article analyzes the spatiotemporal changes in land use/cover in Jiaozuo City from 1995 to 2020. The InVEST model is used to evaluate four types of ecosystem services in Jiaozuo City: water production, carbon storage, soil conservation, and nutrient output; Summarize and summarize the spatiotemporal distribution characteristics and evolution laws of ecosystem services, and explore the trade-off and synergistic relationships between ecosystem service functions and their driving factors. The research results indicate that: (1) The main types of land use/cover in Jiaozuo City are arable land (64.5%), forest land (approximately 9.9%), grassland (1.1%), water area (0.6%), and construction land (23.8%). The changes in land use types are relatively small. (2) From 1995 to 2020, the biomass and spatial distribution evolution of the four ecosystem services in Jiaozuo City varied. There are significant interannual differences in water production services, and the spatial distribution of water production in the western region is lower than that in the eastern region. The southern region is lower than the northern region. The interannual variation of nutrient (phosphorus) output is relatively small, and the spatial distribution pattern varies greatly, showing a high and low value clustering distribution pattern. The interannual difference in soil conservation is relatively small. The interannual differences in carbon storage are small, and the annual spatial distribution is irregular. (3) Each ecosystem service is influenced by different natural and social influencing factors, and the contribution rate of natural factors is higher than that of social factors. There is a significant difference in the output capacity of ecosystem services among different land uses/covers, which directly affects the total amount and spatial distribution of ecosystem services. The ecological status of Jiaozuo City is worrying. In the future socio-economic development process, reasonable planning of land use should be carried out to vigorously ensure the parallel and healthy development of social economy and ecological environment.

Soil and vegetation factors affecting carbon storage in a coastal forest in NE Germany

A large part of carbon in forest ecosystems is stored in the soil. Large-scale inventories of soil C stocks in European forests have been published. Nevertheless, detailed site-specific studies are still necessary, because C storage is spatially highly variable and depends on site specific soil, ecological and management factors, which cannot be captured by large scale studies.Here, we assess C stocks in a coastal forest at the Baltic Sea with different tree species, stand ages, management, and soils, to elucidate possible causes for differences in carbon storage. Soil samples were taken down to 1 m depth both from soil profile pits with 250 cm3 cores and by auger cores in the years 2017–2019 in forest treatment plots which varied with respect to forest management, tree species (beech, birch, oak), and tree age. Although the abiotic parameters soil type (mainly gleysol and podsol), soil texture (mainly sandy), pH value, groundwater depth and distance to the coast were not part of the treatment design, these factors were – along with the biotic factors – evaluated to foster our understanding of the importance of possible drivers of carbon storage in forests. Soil carbon stocks were evaluated for 0–1 m soil depth using measured C concentrations in the soil samples and bulk densities. Carbon stocks in the vegetation were determined by detailed stand inventories of the trees on the forest plots.Total ecosystem carbon stocks were on average 50 kg C m−2, i.e., about threefold higher than the reported average values for forest ecosystems worldwide in temperate climates. Soil C stocks were on average 32 kg C m−2 (0–1 m depth). This is distinctly higher than soil C stocks reported for most other forest sites in similar climatic conditions, and is likely caused by widespread occurrence of anaerobic conditions in the soil, but also by high bioproductivity due to good water availability and low drought stress. Variability of soil carbon stocks at this site is predominantly governed by soil factors (soil type, soil texture, soil pH), whereas tree carbon stocks are mainly determined by tree species and tree age.

Assessing protected area’s carbon stocks and ecological structure at regional-scale using GEDI lidar

Protected areas (PAs) serve as a critical strategy for protecting natural resources, conserving biodiversity, and mitigating climate change. While there is a critical need to guide area-based conservation efforts, a systematic assessment of PA effectiveness for storing carbon stocks has not been possible due to the lack of globally consistent forest biomass data. In this study, we present a new methodology utilizing forest structural information and aboveground biomass density (AGBD) obtained from the Global Ecosystem Dynamics Investigation (GEDI) mission. We compare PAs with similar, unprotected forests obtained through statistical matching to assess differences in carbon storage and forest structure. We also assess matching outcomes for a robust and minimally biased way to quantify PA efficacy. We find that all analyzed PAs in Tanzania possess higher biomass densities than their unprotected counterfactuals (24.4% higher on average). This is also true for other forest structure metrics, including tree height, canopy cover, and plant area index (PAI). We also find that community-governed PAs are the most effective category of PAs at preserving forest structure and AGBD – often outperforming those managed by international or national entities. In addition, PAs designated under more than one entity perform better than the PAs with a single designation, especially those with multiple international designations. Finally, our findings suggest that smaller PAs may be more effective for conservation, depending on levels of connectivity. Taken together, these findings support the designation of PAs as an effective means for forest management with considerable potential to protect forest ecosystems and achieve long-term climate goals.

Can seasonal fire management reduce the risk of carbon loss from wildfires in a protected Guinea savanna?

AbstractFire is fundamental to the functioning of tropical savannas and routinely used as a management tool. Shifting prescribed burning from later to earlier in the growing season has the potential to reduce greenhouse gas emissions. However, large uncertainties surround the impact of seasonal burning on longer term plant and soil carbon sequestration. In this study, we quantify ecosystem carbon storage across burn seasons and histories in a wet‐to‐mesic Guinea tropical savanna in Mole National Park, Ghana. Aboveground (plant and litter) and belowground (soil plus roots) carbon storage was quantified across four burning seasons and histories: recent (<3 years) early‐season burns, recent late‐season burns, old (>4 years) late‐season burns, and long‐unburned (>15 years) sites. We found that recent late‐season burns significantly lowered belowground carbon storage to a depth of 17 cm compared with all other burn seasons and histories. Belowground carbon was 1.2 kg C m−2, or 27% lower, for recent late‐season burns compared with prescribed early‐season burns. However, in older late‐season burns sites, belowground carbon “recovered” after 4–13 burn years to comparable storage as long‐unburned and early‐season burn sites. For most aboveground carbon pools, there was no significant difference in carbon storage across burn seasons and histories, except higher aboveground tree carbon in long‐unburned sites. We suggest that observed changes in belowground carbon are likely due to the turnover and production of root carbon. Prescribed early‐season burning is promoted to reduce greenhouse gas emissions and our findings affirm that early‐season burning has limited impact on plant and soil carbon stocks compared with long‐unburned sites. While early‐season burning regimes will have some patches that become late‐season wildfires, our results suggest on balance early‐season burning regimes are a low‐risk land management practice in reducing plant and soil carbon storage losses and sustaining a patch‐mosaicked landscape with multiple other ecosystem service benefits for savannas.

Bright spots of carbon storage in temperate forests

Abstract Mitigating climate change is an urgent challenge for society. Increasing carbon storage in forests, which cover more than 30% of the global land surface, presents a key opportunity to meet this challenge. Although the biophysical and ecological factors that affect carbon storage have been well studied, the relative importance of social factors in privately owned forests, such as people's goals and management actions, is less well understood. We examine how well typical biophysical and ecological variables can explain differences in above‐ground carbon storage across 1,561 plots in temperate forests of southern Quebec, Canada. We then identify bright spots and dark spots of above‐ground carbon storage, where forests are performing much better or worse than predicted based on biophysical and ecological conditions alone. We conducted surveys with forest owners to assess whether their individual goals, values and management actions explain the differences in carbon storage between bright and dark spots. Biophysical and ecological variables collectively explained a substantial fraction of the variation in carbon storage between forest plots (R2 = 0.42). The ecological variables of stand age, species richness and functional diversity within the plots were the most important variables in explaining carbon storage. Surveys showed that bright spots (plots that stored more carbon than predicted) were often managed by forest owners who expressed a strong connection to, or dependence on, their forested property. Dark spots were often associated with forest harvesting and hunting. Synthesis and applications. Ecologically based policies that aim to increase the average forest age, species richness and functional diversity—and socially based policies that incentivise long‐term forest ownership, stronger connections between people and their properties, and maple syrup production—could help increase carbon storage over multidecadal time‐scales and thereby reduce the harmful effects of climate change.

Spatial and temporal dynamics of 20th century carbon storage and emissions after wildfire in an old-growth forest landscape

Both fire exclusion and subsequent wildfires have strongly affected carbon storage in fire-prone dry forests, with implications for how carbon storage will change in the future. Using a reconstruction of forest structure in 1899 and pre- and post-fire field data, we quantified changes in carbon stocks in a 2125-ha old-growth mixed conifer forest landscape over a century of fire exclusion and emissions due to a 2013 wildfire. From 1899 to 2002 aboveground carbon storage in live trees increased 2.5-fold from 97 Mg/ha to 263 Mg/ha. Despite burning in an uncharacteristically severe wildfire, the forest still contained 169 Mg/ha of live aboveground tree carbon in 2014. Direct fire emissions were 72 Mg/ha and did not vary with canopy cover loss because emissions were largely driven by consumption of accumulated surface fuels. Areas that burned at low, moderate and high severity in the wildfire contained similar amounts of carbon in 1899, when the forest was still experiencing frequent low severity fire. By 2002 the low severity areas contained 80 and 86 Mg/ha more aboveground live tree carbon than moderate and high severity areas respectively. The wildfire reinforced and amplified these differences in carbon storage that arose during fire exclusion, such that carbon storage following the wildfire was more variable across the landscape. Additionally, the proportion of carbon stored in shade-intolerant, more fire-sensitive species increased. These changes in where and in what tree species carbon is stored, due to the combination of fire exclusion and wildfire, have implications for the potential future stability of these carbon stocks.

Biomass and carbon budgeting of land use types along elevation gradient in Central Himalayas

Biomass of vegetation is a crucial variable for understanding the potential future changes of the climate system. In the present study dominant land use types i.e. agroforestry (AF), banjoak forest (BF), chirpine forest (CF), mixed forest (MF) and grasslands (GL) of Himalayan region was investigated for biomass production and carbon stock budgeting in vegetation as well as in soil. Among land use type's highest aboveground biomass was recorded in banjoak forest (BF), 0.69%, 9.42% and 40.16% more than chirpine forest (CF), mixed forest (MF) and agroforestry (AF). However it was more than 16 times higher than grasslands (GL). Herbage and/or crops aboveground biomass was 3.73%, 4.05%, 4.42% and 29.34% of the aboveground biomass of trees in BF, CF, MF and AF. Herbage aboveground biomass was 76.01% of total aboveground biomass in grasslands. Our results revealed that in AF crops biomass accounted for 19.41–26.60% and trees contributed 73.40–80.59% biomass in total biomass of land use. Likewise, similar contributions were recorded for belowground biomass and total biomass in land uses. Irrespective of land use types along elevation the total biomass including aboveground and belowground biomass significantly (P < 0.01) increased. Among land use types and along the elevation similar trend was recorded for vegetation carbon stock as it is the manifestation of biomass. Soil carbon density differed significantly in land use types with highest in BF and increased significantly along the elevation with highest at elevation E5. Forest land uses stored 26.22% and 53.79% more total (vegetation + soil) carbon in than agroforestry and grasslands. The difference in carbon storage among land use types can be related to land use type, vegetation composition, their structural and functional characteristics viz., density, age and soil type. Thus, tree based land use types are more efficient for biomass production and carbon storage in changing climatic pattern.

Carbon storage implications of active management in mature Pseudotsuga menziesii forests of western Oregon

Mature stands, mid-successional communities in which large live trees are the dominant structural feature, are a major component of forested landscapes across North America. Despite this prominence at regional scales, mature stands have rarely been the focus of research on forest carbon dynamics. We utilized an observational study design to (i) examine the medium-term impact of active management on carbon storage in live and dead vegetation in mature Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco)–dominated stands in western Oregon, and (ii) provide baseline estimates of total non-soil carbon storage during the mature phase of stand development for this forest type. Stands aged 106–193 years at the time of sampling were selected to represent a gradient in harvest intensity, from passive (reserve-based) management, to low-intensity (commercial thinning) and high-intensity (regeneration harvest with structural retention) active management. Active management treatments were implemented following the onset of maturity in stands with no prior management history, and sampling was conducted an average of 38 years and 22 years following treatment (mean for thinned and retention harvest conditions, respectively). Total non-soil carbon storage was significantly greater in stands managed using a reserve-based approach (mean of 575 Mg C ha−1) than those subject to retention harvest (mean 257 Mg C ha−1) 17 to –34 years previously, but was not different from stands managed over extended rotations with commercial thinning (mean 546 Mg C ha−1). A similar trend was evident for carbon storage in live overstory trees, which were also the dominant component of total non-soil carbon in all management conditions. Dead wood pools varied greatly among stands, but estimates did not indicate any systematic differences in carbon storage in dead wood between management conditions. Our results suggest that shifting from passive management to a high-intensity harvest regime in mature Douglas-fir stands will entail substantial reductions in carbon storage. By contrast, managing stands over extended rotations with light thinning may enable the provision of wood products while maintaining relatively high carbon storage in the forest ecosystem. In absolute terms, mean carbon storage across our full sample of unmanaged, low-intensity and high-intensity harvest conditions exceeded previously reported values from inventories of mature plots across a similarly broad range of site conditions, but remains below the potential upper bounds to carbon storage in Douglas-fir-dominated forests. However, total aboveground carbon stocks in excess of 700 Mg ha−1 in individual mature stands in our dataset implies that, under certain conditions, forest biomass approaches its maximum by the close of the mature phase of stand development in Douglas-fir-dominated forests.

Sources of Uncertainty in Modeled Land Carbon Storage within and across Three MIPs: Diagnosis with Three New Techniques

Terrestrial carbon cycle models have incorporated increasingly more processes as a means to achieve more-realistic representations of ecosystem carbon cycling. Despite this, there are large across-model variations in the simulation and projection of carbon cycling. Several model intercomparison projects (MIPs), for example, the fifth phase of the Coupled Model Intercomparison Project (CMIP5) (historical simulations), Trends in Net Land–Atmosphere Carbon Exchange (TRENDY), and Multiscale Synthesis and Terrestrial Model Intercomparison Project (MsTMIP), have sought to understand intermodel differences. In this study, the authors developed a suite of new techniques to conduct post-MIP analysis to gain insights into uncertainty sources across 25 models in the three MIPs. First, terrestrial carbon storage dynamics were characterized by a three-dimensional (3D) model output space with coordinates of carbon residence time, net primary productivity (NPP), and carbon storage potential. The latter represents the potential of an ecosystem to lose or gain carbon. This space can be used to measure how and why model output differs. Models with a nitrogen cycle generally exhibit lower annual NPP in comparison with other models, and mostly negative carbon storage potential. Second, a transient traceability framework was used to decompose any given carbon cycle model into traceable components and identify the sources of model differences. The carbon residence time (or NPP) was traced to baseline carbon residence time (or baseline NPP related to the maximum carbon input), environmental scalars, and climate forcing. Third, by applying a variance decomposition method, the authors show that the intermodel differences in carbon storage can be mainly attributed to the baseline carbon residence time and baseline NPP (&gt;90% in the three MIPs). The three techniques developed in this study offer a novel approach to gain more insight from existing MIPs and can point out directions for future MIPs. Since this study is conducted at the global scale for an overview on intermodel differences, future studies should focus more on regional analysis to identify the sources of uncertainties and improve models at the specified mechanism level.

The role of traditional coffee management in forest conservation and carbon storage in the Jimma Highlands, Ethiopia

Ethiopia has lost 90% of its forest extent. Remnant patches in the southwest are often semi-forest coffee (SFC), a system whereby coffee is managed beneath the canopy. Here, we (1) quantify aboveground live carbon (AGC) stored by trees in SFC and other land use types in the Jimma Highlands; and (2) determine coffee farmers’ preference for canopy shade trees, and the resulting differences in carbon storage. We surveyed twenty coffee farmers and assessed thirty-one 1-ha vegetation plots across a 23.6-km transect. The most preferred shade species were Albizia gummifera, Acacia abyssinica, Millettia ferruginea and Cordia africana, which together accounted for 42% AGC in SFC and 12% in natural forests. These species had broad size class distributions, while the least preferred had scant representation in lower size classes. SFC stores significantly more AGC (61.5 ± 25.0 t ha−1, mean ± SE) than woodland, pasture and cropland, significantly less than plantation and slightly less than natural forest (82.0 ± 32.1 t ha−1). If SFC was converted to cropland, then 59.5 t ha−1 would be released, at a social cost of US$2892–4225 ha−1. Carbon-payment schemes (e.g. REDD+) may, therefore, play a role in conserving these forests and associated biodiversity and livelihoods into the future.

Soil carbon storage, respiration potential, and organic matter quality across an age and climate gradient in southwestern Greenland

Geological factors influence biological cycling of organic carbon in soils but are not well represented in our understanding of Arctic carbon dynamics. Landscape age, for instance, directly affects quantity and quality of soil carbon, which are two strong controls of the temperature sensitivity of soil organic matter. We investigated soil carbon storage, respiration potential, and organic matter quality for microbial decomposition across a climate and landscape age gradient in southwest Greenland that deglaciated during the Holocene. We measured soil respiration during a 370-day laboratory incubations of active layer soils collected from four study areas across this gradient (ages 1.8 × 102, 6.8 × 103, and 1.0 × 104, coinciding with a climate gradient from drier inland to wetter coastal terrain) and used a soil respiration model comparison approach to assess the substrate quality of stored organic matter for microbial decomposers. Soils store more than three times greater organic carbon at the 10,000-year-old, maritime climate study areas than the 180-year-old, continental climate study areas. Respiration rates were highest in the surface soils of the coastal areas. Model comparisons reveal important heterogeneity in the quality of organic matter for microbial decomposition between areas: coastal soils were best modeled by both one- and two-pooled models, and inland soils were best represented by one-pooled respiration models. Together, the measures of carbon quality (C:N, CO2 production, and model parameters estimating initial CO2 production rates from different organic matter pools) show that shallow soils at the southern coastal area, Kobbefjord, had the highest respiration rates from the recalcitrant carbon pool. This study reveals differences in carbon storage and turnover associated with landscape age and climate factors in western Greenland. When applied to thermodynamic theory, which predicts that temperature sensitivity increases with carbon recalcitrance, our findings suggest that carbon stored in coastal soils may be more sensitive to climate warming than inland soils.

Structure and floristic composition of mangroves in the Bahía de Cispatá, Colombian Caribbean

&lt;p&gt;Los manglares son asociaciones de plantas que se adaptan fácilmente a las condiciones salinas y los niveles fluctuantes de inundación. Estos ecosistemas suministran gran cantidad de bienes y servicios tales como el almacenamiento de carbono. Diferencias estructurales, de composición de especies y de características micro-ambientales entre tipos fisiográficos implican diferencias en el almacenamiento de carbono en sus suelos. La presente investigación tuvo como objetivo identificar la variación de las especies de mangle a través de los cambios en las variables físico-bióticas de bosques de manglar de la bahía Cispatá, Colombia. Se realizaron mediciones de variables estructurales del bosque (&lt;em&gt;D, H, &lt;/em&gt;densidad de individuos) y medición de variables físico-bióticas (nivel de inundación, cobertura de &lt;em&gt;A. aureum&lt;/em&gt;, salinidad del agua intersticial, pH del suelo, % N, % limo, % arena, % COs, raíces y densidad aparente en el suelo) en 12 parcelas establecidas aleatoriamente. Con un CCA identificaron tres manglares: cuenca, borde en buen estado de conservación y borde con intervención antropogénica. El primero dominado por &lt;em&gt;A. germinans&lt;/em&gt; y los otros por &lt;em&gt;R. mangle&lt;/em&gt;. El manglar de cuenca se diferencia de los de borde en términos estructurales y en variables físico-bióticas, presentó los valores más altos de COs, salinidad, densidad aparente y pH. Aunque los dos manglares de borde presentan características físico-bióticas similares, la alteración antropogénica cambia fuertemente la estructura de uno de ellos. Se ha concluido que la distribución de las especies de manglar de la bahía responde a la variación espacial de las características ambientales. Sin embargo, la intervención antropogénica es una variable determinante en la estructura de los manglares lo cual afecta las estimaciones del papel de diferentes tipos de manglar como sumideros de carbono.&lt;/p&gt;

Quantifying the sampling error in tree census measurements by volunteers and its effect on carbon stock estimates

A typical way to quantify aboveground carbon in forests is to measure tree diameters and use species-specific allometric equations to estimate biomass and carbon stocks. Using "citizen scientists" to collect data that are usually time-consuming and labor-intensive can play a valuable role in ecological research. However, data validation, such as establishing the sampling error in volunteer measurements, is a crucial, but little studied, part of utilizing citizen science data. The aims of this study were to (1) evaluate the quality of tree diameter and height measurements carried out by volunteers compared to expert scientists and (2) estimate how sensitive carbon stock estimates are to these measurement sampling errors. Using all diameter data measured with a diameter tape, the volunteer mean sampling error (difference between repeated measurements of the same stem) was 9.9 mm, and the expert sampling error was 1.8 mm. Excluding those sampling errors > 1 cm, the mean sampling errors were 2.3 mm (volunteers) and 1.4 mm (experts) (this excluded 14% [volunteer] and 3% [expert] of the data). The sampling error in diameter measurements had a small effect on the biomass estimates of the plots: a volunteer (expert) diameter sampling error of 2.3 mm (1.4 mm) translated into 1.7% (0.9%) change in the biomass estimates calculated from species-specific allometric equations based upon diameter. Height sampling error had a dependent relationship with tree height. Including height measurements in biomass calculations compounded the sampling error markedly; the impact of volunteer sampling error on biomass estimates was +/- 15%, and the expert range was +/- 9%. Using dendrometer bands, used to measure growth rates, we calculated that the volunteer (vs. expert) sampling error was 0.6 mm (vs. 0.3 mm), which is equivalent to a difference in carbon storage of +/- 0.011 kg C/yr (vs. +/- 0.002 kg C/yr) per stem. Using a citizen science model for monitoring carbon stocks not only has benefits in educating and engaging the public in science, but as demonstrated here, can also provide accurate estimates of biomass or forest carbon stocks.

Role of vegetation change in future climate under the A1B scenario and a climate stabilisation scenario, using the HadCM3C Earth system model

Abstract. The aim of our study was to use the coupled climate-carbon cycle model HadCM3C to quantify climate impact of ecosystem changes over recent decades and under future scenarios, due to changes in both atmospheric CO2 and surface albedo. We use two future scenarios – the IPCC SRES A1B scenario, and a climate stabilisation scenario (2C20), allowing us to assess the impact of climate mitigation on results. We performed a pair of simulations under each scenario – one in which vegetation was fixed at the initial state and one in which vegetation changes dynamically in response to climate change, as determined by the interactive vegetation model within HadCM3C. In our simulations with interactive vegetation, relatively small changes in global vegetation coverage were found, mainly dominated by increases in shrub and needleleaf trees at high latitudes and losses of broadleaf trees and grasses across the Amazon. Globally this led to a loss of terrestrial carbon, mainly from the soil. Global changes in carbon storage were related to the regional losses from the Amazon and gains at high latitude. Regional differences in carbon storage between the two scenarios were largely driven by the balance between warming-enhanced decomposition and altered vegetation growth. Globally, interactive vegetation reduced albedo acting to enhance albedo changes due to climate change. This was mainly related to the darker land surface over high latitudes (due to vegetation expansion, particularly during December–January and March–May); small increases in albedo occurred over the Amazon. As a result, there was a relatively small impact of vegetation change on most global annual mean climate variables, which was generally greater under A1B than 2C20, with markedly stronger local-to-regional and seasonal impacts. Globally, vegetation change amplified future annual temperature increases by 0.24 and 0.15 K (under A1B and 2C20, respectively) and increased global precipitation, with reductions in precipitation over the Amazon and increases over high latitudes. In general, changes were stronger over land – for example, global temperature changes due to interactive vegetation of 0.43 and 0.28 K under A1B and 2C20, respectively. Regionally, the warming influence of future vegetation change in our simulations was driven by the balance between driving factors. For instance, reduced tree cover over the Amazon reduced evaporation (particularly during June–August), outweighing the cooling influence of any small albedo changes. In contrast, at high latitudes the warming impact of reduced albedo (particularly during December–February and March–May) due to increased vegetation cover appears to have offset any cooling due to small evaporation increases. Climate mitigation generally reduced the impact of vegetation change on future global and regional climate in our simulations. Our study therefore suggests that there is a need to consider both biogeochemical and biophysical effects in climate adaptation and mitigation decision making.

Restoring ecosystem carbon sequestration through afforestation: A sub-tropic restoration case study

The long-term Forest Restoration Experimental Project (FREP) was established in 1991 on a sub-tropical, barren, degraded, red soil with a rolling terrain located in Taihe County, Jianxi province, China. The objective of the FREP was to evaluate the effects of restoration, through afforestation of various local climax species, on ecological functions to provide guidance for future restoration projects on severely deteriorated landscapes, which are very common in southern China. In this study, we selected five restoration forests: Chinese sweetgum (Liquidamber formosana), schima (Schima superb), masson’s pine (Pinus massoniana), slash pine (Pinus elliottii), Chinese sweetgum×slash pine mixtures, and one experimental control (natural recovery) to evaluate the differences in carbon storage and pool structures, including above- and below-ground carbon pools, forest floor litter, woody debris, and soil organic carbon (SOC). A similar assessment was also conducted on the species functional groups (coniferous forest, broad-leaved forest, and mixed-species forest – broad-leaved×coniferous species mixture) based on groupings of studied species. We also evaluated the recovery trajectory of FREP’s evergreen broad-leaved forest by comparing it with local ecosystems.Over the 19-year study period, the Total Ecosystem Carbon (TEC) stocks in the five restoration types were significantly higher than that in the control sites, but there were no significant differences in the TEC stock among the restoration types. The TEC was 119MgCha−1 for Chinese sweetgum, 118MgCha−1 for schima, 105MgCha−1 for masson’s pine, 104MgCha−1 for slash pine, and 124MgCha−1 for the mixture. However, there was a significant variation in the carbon pool structure among restoration functional groups. The SOC pool sizes of broad-leaved and mixed-species forest were 25% and 16% significantly higher than the coniferous forest, respectively. This difference may be explained by the recovery trajectory, which suggests that the evergreen forest (schima) in FREP is still in the early developmental stage, and its projected rate of growth is much slower than the average growth rate in the region. This study clearly demonstrated that active restoration can enhance ecosystem carbon sequestration. Clearly, a long-term monitoring program is critical for obtaining more information that will enable us to extrapolate our findings for broader restoration plans and to increase the carbon sequestration strength of restored forests.

Mathematical modeling of soil carbon turnover in natural Podocarpus forest and Eucalyptus plantation in Ethiopia using compound specific δ13C analysis

AbstractForest soils exhibit huge potential in storing carbon, but may also release large amounts of it if they undergo major changes in land use and environmental conditions. Biogeochemical processes controlling accumulation and release of soil organic carbon (SOC) are not yet sufficiently understood. We investigate the dynamics of SOC depending on its chemical composition below a natural forest (Podocarpus falcatus dominated) and a plantation (Eucalyptus saligna) growing on Nitisols in southern Ethiopia. Soils at the study‐site show a huge shift to less negative δ13C values at a depth of 20–30 cm, indicating a change from C4 savanna to C3 forest during the late Holocene. Total organic carbon (TOC), black carbon (BC), and sugars from microbial (rhamnose, fucose) and plant origin (xylose, arabinose) are subjected to compound‐specific stable isotope analysis. Turnover characteristics are calculated using a numerical advection–diffusion–decomposition model. Our measurements show significant differences in carbon storage (P&lt;0.05) for both sites (Podocarpus 23.5 ± 3.2 kg SOC m−3; Eucalyptus 18.6 ± 2.7 kg SOC m−3). These differences can be explained with an initial loss of 15–26% of TOC about 50 years ago, induced by clearing the natural forest. After canopy closure, the carbon input below Eucalyptus is 15–34% less than below natural forest. At present, mean residence times (MRTs) of the investigated compounds do not differ between both stands. Sugars show the shortest MRTs in the topsoil with 2–7 years (xylose) and 5–13 years (arabinose) and have been affected the most by clear‐cutting. TOC and BC show MRTs of 13–25 years and 20–34 years, respectively. Old C4 carbon below 20 cm has merely been affected by the land use change. Contrary to expectation, our study does not indicate a pronounced recalcitrance of BC.