Aboveground Carbon Pools Research Articles

Independent effects of tree diversity on aboveground and soil carbon pools after six years of experimental afforestation.

Planting diverse forests has been proposed as a means to increase long-term carbon (C) sequestration while providing many co-benefits. Positive tree diversity-productivity relationships are well established, suggesting more diverse forests will lead to greater aboveground C sequestration. However, the effects of tree diversity on belowground C storage have the potential to either complement or offset aboveground gains, especially during early stages of afforestation when potential exists for large losses in soil C due to soil decomposition. Thus, experimental tests of the effects of planted tree biodiversity on changes in whole-ecosystem C balance are needed. Here, we present changes in above- and belowground C pools 6 years after the initiation of the Forests and Biodiversity experiment (FAB1), consisting of high-density plots of one, two, five, or 12 tree species planted in a common garden. The trees included a diverse range of native species, including both needle-leaf conifer and broadleaf angiosperm species, and both ectomycorrhizal and arbuscular mycorrhizal species. We quantified the effects of species richness, phylogenetic diversity, and functional diversity on aboveground woody C, as well as on mineral soil C accumulation, fine root C, and soil aggregation. Surprisingly, changes in aboveground woody C pools were uncorrelated to changes in mineral soil C pools, suggesting that variation in soil C accumulation was not driven by the quantity of plant litter inputs. Aboveground woody C accumulation was strongly driven by species and functional identity; however, plots with higher species richness and functional diversity accumulated more C in aboveground wood than expected based on monocultures. We also found weak but significant effects of tree species richness, identity, and mycorrhizal type on soil C accumulation. To assess the role of the microbial community in mediating these effects, we further compared changes in soil C pools to phospholipid fatty acid (PLFA) profiles. Soil C pools and accumulation were more strongly correlated with specific microbial clades than with total microbial biomass or plant diversity. Our results highlight rapidly emerging and microbially mediated effects of tree biodiversity on soil C storage in the early years of afforestation that are independent of gains in aboveground woody biomass.

Site-specific additionality in aboveground carbon sequestration in set-aside forests in Flanders (northern Belgium)

IntroductionIn situ carbon sequestration in forests is important in the context of climate change mitigation, and setting aside managed forests has been proposed as an option for increased carbon sequestration. Comparing set-aside and managed forests may provide insights and rules of thumb on the potential for additional in situ carbon sequestration in set-aside forest.MethodsIn an observational study, we compared re-inventory data from the network of set-aside forest reserves in Flanders, which have been unmanaged for 17–66 years (2 surveys with a 10 years interval), with re-inventory data from the regional forest inventory, representing the overall forest area in Flanders (2 surveys with a 15 years interval).ResultsThe aboveground carbon pools and sequestration rates were higher in the set-aside forests compared to the average forest in Flanders. In the average Flemish forest, the aboveground carbon pool increased from 64.7 to 85.1 tC ha−1, over a period of 15 years. In the set-aside forests, the mean pool was higher at the first measurement and further increased from 84.8 to 102.4 tC ha−1, over a period of 10 years. The mean aboveground annual carbon sequestration rate was 1.3 tC ha−1 year−1 in the average forest in Flanders and 1.8 tC ha−1 year−1 in the set-aside forests. The stocks and fluxes depended on the soil conditions and were higher in set-aside forests on silt and sandy silt sites compared to wet and sand sites. The set-aside forests on dry sites showed additionality in in situ aboveground carbon sequestration. We saw no indication of approaching a culmination point in the first decades following set-aside: plots with high carbon pools did not show lower carbon sequestration. In conclusion, set-aside forests can combine high carbon pools with high sequestration rates on suitable sites. Under the current management policy, we expect Flemish forests—regular and set-aside—to further increase their carbon pools in the coming decades.

FLORISTICS, CARBON STOCK QUANTIFICATION AND SEQUESTRATION ABILITY OF AN ENCROACHED FOREST IN AKWA IBOM STATE UNIVERSITY, IKOT AKPADEN, SOUTHERN NIGERIA

This study assessed the floristics, carbon stock and sequestration ability of an encroached forest in Akwa Ibom State, Southern Nigeria. Ten plots within the forest were chosen and ten belt transects were established. Trees species were identified in each plot. Litter boxes were placed in each plot at 10 m for litter collection. Soils were collected from the plots at different depths. AGB (aboveground biomass), BGB (belowground biomass), AGC (aboveground carbon) and BGC (belowground carbon) were calculated using appropriate allometric equations. Twenty-two woody species were present in the forest. The values for AGB, AGC, BGM and BGC were 119.31 Mg ha-1, 59.65 Mg C.ha-1, 24.46 Mg ha-1 and 12.23 Mg C.ha-1, each. The total carbon stock (TCS) and biomass in the litter were 9.37 MgCha-1 and 20 Mg ha-1, respectively. The carbon stock in the litter followed this order: leaf (4.10±0.08 Mg C.ha-1) > twigs (3.02±0.04 Mg C.ha-1) > fine root (2.25±0.01 Mg C.ha-1). The TCS in the soil was 33.73 MgCha-1 and followed this decreasing trend: 0-15 cm (23.80±2.65 MgCha-1) > 0 – 30 cm (9.93±1.02 MgCha-1). The TCS and carbon sequestration ability (CSA) of this forest were 125.61 Mg C.ha-1 and 458.31 Mg CO2ha-1. The CSA of this forest followed this decreasing order: AGC pool (218.92 Mg CO2ha-1) > soil (121.11 Mg CO2ha-1) > litter (73.40 Mg CO2ha-1) > BGC pool (44.88 Mg CO2ha-1). These results validate this forest as having a considerable carbon sequestration ability, though, this ability is threatened by human disturbances.

Fighting climate change with bamboo in Africa: The case of Kyela, Rungwe and Mufindi districts – Tanzania

Responding to the African Forest Landscape Restoration Initiative (AFR100), 32 countries have committed to restoring more than 100 million hectares of land across Africa by 2030. Bamboo is being discussed as one of the nature-based solutions to achieve this ambitious target in the face of climate change. Major advantages are that it is a fast-growing versatile woody grass that can prosper in degraded lands. So far, landscape restoration strategies are driven by climate policy debates where bamboo is largely neglected. Most empirical research on the potential of bamboo for fighting climate change has been conducted in Asia, leaving open questions on the transferability of results to the African context. In this paper, we contribute to the debate by investigating how bamboo can contribute to climate change mitigation, especially in degraded ecosystems. Taking Tanzania as an example, we lay a special focus on bamboo carbon sequestration and storage potential and assess the dynamics of carbon stocks: (i) across an elevation gradient, (ii) between indigenous and exotic bamboo species, and (iii) between intensively and extensively managed bamboo ecosystems. We collected data from 60 destructive sample plots and estimated biomass carbon stocks in the aboveground carbon pool. The weighted average biomass, carbon stocks, and sequestration rates obtained were 52.4 t ha−1, 26.2 t C ha−1, and 19 t C ha−1yr−1, respectively. The ANOVA revealed a significant variation in carbon stocks across an elevation gradient and between bamboo species (P < 0.05), which explained 22% and 11% of the total variation. We also observed a significant two-way-factors interaction between elevation versus species and silvicultural management options (P < 0.05), explaining 12% and 5% of the total variation, respectively. Similarly, a three-way interaction between all factors was significant, accounting for 4% of the total aboveground carbon variation. Our results contribute to developing a more nuanced picture of the advantages and disadvantages of incorporating bamboo in landscape restoration efforts. The novel findings may be a first step toward unlocking future climate finance in Africa.

Large-scale high-resolution yearly modeling of forest growing stock volume and above-ground carbon pool

Within the Paris Agreement's Enhanced Transparency Framework, consistent data collections are the prerequisite for a successful reporting of GHG emissions. For such purposes, NFIs are usually the primary source of information, even if they are frequently not designed for producing estimations on a yearly basis and in the form of wall-to-wall high-resolution maps. In this framework, we present a new spatial model to produce yearly growing stock volume (GSV), above-ground biomass (AGB), and carbon stock wall-to-wall estimates. We tested the model in Italy for the period 2005–2018, obtaining a time-series of yearly maps at 23 m spatial resolution. Results were validated against the 2015 Italian NFI reaching an average RMSE% of 19% for aggregated areas. Results were also compared against data reported by the Italian GHG inventory, reaching an RMSE% of 28% and 20% for GSV and carbon stock respectively.We demonstrated that the modeling approach can be successfully used for setting up a forest monitoring system to meet the interests of governments in inventories of GHG emissions and private entities in carbon offset investments.

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 (&lt;3 years) early‐season burns, recent late‐season burns, old (&gt;4 years) late‐season burns, and long‐unburned (&gt;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.

Estimation of carbon pool at mangrove forest of Kudat, Sabah, Malaysia

Abstract. Hatta SM, Salleh E, Suhaili NS, Besar NA. 2022. Estimation of carbon pool at mangrove forest of Kudat, Sabah, Malaysia. Biodiversitas 23: 4601-4608. Mangroves play a significant role in reducing tropical carbon emissions and preventing climate change. This study was carried out in Kudat's Tun Mustapha Park mangrove forest. This research aims to quantify the aboveground, belowground, and soil carbon pools. Nine 125-meter-long transect lines were set up, and every 25 meters, a 7-meter-diameter circle was placed. A forest inventory was conducted to determine the diameter at the breast height of standing trees. For soil analysis and bulk density, soil samples were collected at four different depths (0-15 cm, 15-30 cm, 30-50 cm, and 50-100 cm). An ICP-OES analyzer was used to determine the value of soil nutrients, and a CHNS analyzer was used to determine the soil carbon concentration. The aboveground and belowground biomass was calculated using the allometric equation, and the carbon stock was estimated at 50% of the total biomass. The outcome showed a 455.87 MgCha-1 total carbon pool. The soil carbon has the highest value with 273.76 MgCha-1, followed by aboveground carbon (living trees) with 136.58 MgCha-1 and belowground carbon (roots) with 45.53 MgCha-1. This study found that soil carbon stock made up almost 60% of the total carbon stock in the mangrove forest.

A comprehensive assessment of mangrove species and carbon stock on Pohnpei, Micronesia.

Mangrove forests are the most important ecosystems on Pohnpei Island, Federated States of Micronesia, as the island communities of the central Pacific rely on the forests for many essential services including protection from sea-level rise that is occurring at a greater pace than the global average. As part of a multi-component assessment to evaluate vulnerabilities of mangrove forests on Pohnpei, mangrove forests were mapped at two points in time: 1983 and 2018. In 2018, the island had 6,426 ha of mangrove forest. Change analysis indicated a slight (0.76%) increase of mangrove area between 1983 and 2018, contrasting with global mangrove area declines. Forest structure and aboveground carbon (AGC) stocks were inventoried using a systematic sampling of field survey plots and extrapolated to the island using k-nearest neighbor and random forest species models. A gridded or wall to wall approach is suggested when possible for defining carbon stocks of a large area due to high variability seen in our data. The k-nearest neighbor model performed better than random forest models to map species dominance in these forests. Mean AGC was 167 ± 11 MgC ha-1, which is greater than the global average of mangroves (115 ± 7 MgC ha-1) but within their global range (37–255 MgC ha-1) Kauffman et al. (2020). In 2018, Pohnpei mangroves contained over 1.07 million MgC in AGC pools. By assigning the mean AGC stock per species per area to the map, carbon stock distributions were visualized spatially, allowing future conservation efforts to be directed to carbon dense stands.

Improving the Contribution of Forests to Carbon Neutrality under Different Policies—A Case Study from the Hamburg Metropolitan Area

As various political initiatives have set goals to reach net-zero emissions by the mid-21st century, forests will play an important role as a carbon sink for sequestering unavoidable emissions. Forest management can take two approaches by either decreasing harvest and enlarging the forest carbon stock or increasing harvest to increase carbon uptake and create harvested wood products (HWPs). Currently, these two management options seem at odds with seemingly conflicting policy directives being written. We used the BEKLIFUH model to assess six management scenarios based on carbon offset potential taking into consideration forest carbon, HWPs and the material and energetic substitution effects. The results show that while conservation leads to a higher above-ground carbon pool, including HWPs, material and energetic substitution leads to more overall carbon offsets for management scenarios with more timber harvesting. With compromise being possible by selectively conserving old growth forests with a high biodiversity value. In conclusion, if the forest sector decouples GHG reporting from forest management and includes all the secondary effects of timber harvest, this new approach can lead to a different cost–benefit analysis for the choice between harvest vs. conservation. This could result in a paradigm shift to a future where biodiversity and carbon neutrality can coexist.

Active forest management accelerates carbon storage in plantation forests in Lishui, southern China

China has committed to achieving peak CO2 emissions before 2030 and carbon neutrality before 2060; therefore, accelerated efforts are needed to better understand carbon accounting in industry and energy fields as well as terrestrial ecosystems. The carbon sink capacity of plantation forests contributes to the mitigation of climate change. Plantation forests throughout the world are intensively managed, and there is an urgent need to evaluate the effects of such management on long-term carbon dynamics. We assessed the carbon cycling patterns of ecosystems characterized by three typical plantation species (Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.), oak (Cyclobalanopsis glauca (Thunb.) Oerst.), and pine (Pinus massoniana Lamb.)) in Lishui, southern China, by using an integrated biosphere simulator (IBIS) tuned with localized parameters. Then, we used the state-and-transition simulation model (STSM) to study the effects of active forest management (AFM) on carbon storage by combining forest disturbance history and carbon cycle regimes. 1) The carbon stock of the oak plantation was lower at an early age (<50 years) but higher at an advanced age (>50 years) than that of the Chinese fir and pine plantations. 2) The carbon densities of the pine and Chinese fir plantations peaked at 70 years (223.36 ​Mg·ha‒1) and 64 years (232.04 ​Mg·ha‒1), respectively, while the carbon density in the oak plantation continued increasing (>100 years). 3) From 1989 to 2019, the total carbon pools of the three plantation ecosystems followed an upward trend (an annual increase of 0.16–0.22 ​Tg ​C), with the largest proportional increase in the aboveground biomass carbon pool. 4) AFM increased the recovery of carbon storage after 1996 and 2009 in the pine and Chinese fir plantations, respectively, but did not result in higher growth in the oak plantation. 5) The proposed harvest planning is reasonable and conducive to maximizing the carbon sequestration capacity of the forest. This study provides an example of a carbon cycle coupling model that is potentially suitable for simulating China's plantation forest ecosystems and supporting carbon accounting to monitor peak CO2 emissions and reach carbon neutrality.

Resistance and change in a High Arctic ecosystem, NW Greenland: Differential sensitivity of ecosystem metrics to 15 years of experimental warming and wetting

Dramatic increases in air temperature and precipitation are occurring in the High Arctic (>70°N), yet few studies have characterized the long-term responses of High Arctic ecosystems to the interactive effects of experimental warming and increased rain. Beginning in 2003, we applied a factorial summer warming and wetting experiment to a polar semidesert in northwest Greenland. In summer 2018, we assessed several metrics of ecosystem structure and function, including plant cover, greenness, ecosystem CO2 exchange, aboveground (leaf, stem) and belowground (litter, root, soil) carbon (C) and nitrogen (N) concentrations (%) and pools, as well as leaf and soil stable isotopes (δ13 C and δ15 N). Wetting induced the most pronounced changes in ecosystem structure, accelerating the expansion of Salix arctica cover by 370% and increasing aboveground C, N, and biomass pools by 94%-101% and root C, N, and biomass pools by 60%-122%, increases which coincided with enhanced net ecosystem CO2 uptake. Further, wetting combined with warming enhanced plot-level greenness, whereas in isolation neither wetting nor warming had an effect. At the plant level, the effects of warming and wetting differed among species and included warming-linked decreases in leaf N and δ15 N in S. arctica, whereas leaf N and δ15 N in Dryas integrifolia did not respond to the climate treatments. Finally, neither plant- nor plot-level C and N allocation patterns nor soil C, N, δ13 C, or δ15 N concentrations changed in response to our manipulations, indicating that these ecosystem metrics may resist climate change, even in the longer term. In sum, our results highlight the importance of summer precipitation in regulating ecosystem structure and function in arid parts of the High Arctic, but they do not completely refute previous findings of resistance in some High Arctic ecosystem properties to climate change.

Temporally variable parameters simulate asymmetrical interannual variation of aboveground and belowground carbon pools in an alpine meadow

Exploring interannual variation (IAV) of terrestrial carbon cycle is crucial for understanding the climate-carbon cycle feedback. However, model simulations of IAV in carbon pools are highly sensitive to parameterization. Although researches indicate that parameters vary as environment changes, most terrestrial carbon cycle models apply time-invariant parameters, leading to uncertainty in reproducing IAV. We compared the IAV simulation accuracy of carbon pools between constant and temporally variable parameters, generated by a piecewise model-data fusion framework based on long-term multi-observations in an alpine meadow over the Tibetan Plateau. Piecewise assimilation showed that key parameters involved in photosynthesis and allocation processes exhibited significant temporal variation under warming and nitrogen deposition. Specifically, day length threshold for leaf senescence was postponed, while allocation to autotrophic respiration, allocation to root, leaf nitrogen content, and nitrogen use efficiency increased. Compared with constant parameters, temporally variable parameters captured the observed asymmetrical response of aboveground and belowground carbon pools to climate fluctuations, improved modeled magnitude of IAV in carbon pools by 34% on average, and advanced carbon sink estimation accuracy by 43.15%. Therefore, fitting parameter dynamics to climatic conditions can provide a benchmark for future simulation in the Tibetan Plateau. Our research suggests that IAV in different carbon pools is crucial in determining carbon sinks. Temporal variations of parameters present how ecosystems adapt to a changing environment and should be incorporated to terrestrial carbon cycle models to reduce uncertainty in model prediction.

Above ground biomass carbon assessment using field, satellite data and model based integrated approach to predict the carbon sequestration potential of major land use sector of Arunachal Himalaya, India

The land-use sector needs special importance owing to its ability to store and emit carbon back to the atmosphere. Land-use changes and their correlations could elucidate conditions that put forests at risk of conversion to other land uses. The impact of rapid forest cover change tends to reduce the percentage of forest cover, thereby reducing the potential for carbon storage in woody biomass. The study was conducted in the state of Arunachal Pradesh to estimate the above-ground biomass, carbon pool and sequestration potential of major land-use sectors. The above-ground biomass of selected land-uses viz. dense forest, moderately dense forest, open forest, plantations, Jhum >5 years, Jhum <5 years and current jhum are 332.28 t ha−1, 246.63 t ha−1, 145.36 t ha−1, 179.31 t ha−1, 149.63 t ha−1, 55.40 t ha−1, 16.84 t ha−1 respectively. The developed model is derived from Soil Adjusted Vegetation Index (SAVI) and Atmospherically Resistant Vegetation Index (ARVI) for prediction of above-ground biomass (AGB) (R 2 = 0.85, p < 0.05). The resultant R 2 value of 85% predicts that 79% of accuracy could be assumed by the model. The RMSE of the model was 53.21 t ha−1, having no multicollinearity problem keeping tolerance (0.49) and VIF (2.80). The spatial AGB density map was predicted using a step-wise linear regression model which used AGB, SAVI and ARVI of the corresponding sample plot location. The implication of the land-use change revealed that about 84% carbon will be lost from dense forest once it is converted to Jhum (Jhum is the alternate name of Shifting cultivation in India) followed by Jhum <5 years (65%). It is pertinent to mention here that, the present analysis will help the policymakers in visualizing a proper developmental goal to regulate land-use changes for achieving the higher carbon stock and maintaining balance in the global climate scenario.

Aboveground Biomass Allocation of Boreal Shrubs and Short-Stature Trees in Northwestern Canada

In this follow-on study on aboveground biomass of shrubs and short-stature trees, we provide plant component aboveground biomass (herein ‘AGB’) as well as plant component AGB allometric models for five common boreal shrub and four common boreal short-stature tree genera/species. The analyzed plant components consist of stem, branch, and leaf organs. We found similar ratios of component biomass to total AGB for stems, branches, and leaves amongst shrubs and deciduous tree genera/species across the southern Northwest Territories, while the evergreen Picea genus differed in the biomass allocation to aboveground plant organs compared to the deciduous genera/species. Shrub component AGB allometric models were derived using the three-dimensional variable volume as predictor, determined as the sum of line-intercept cover, upper foliage width, and maximum height above ground. Tree component AGB was modeled using the cross-sectional area of the stem diameter as predictor variable, measured at 0.30 m along the stem length. For shrub component AGB, we achieved better model fits for stem biomass (60.33 g ≤ RMSE ≤ 163.59 g; 0.651 ≤ R2 ≤ 0.885) compared to leaf biomass (12.62 g ≤ RMSE ≤ 35.04 g; 0.380 ≤ R2 ≤ 0.735), as has been reported by others. For short-stature trees, leaf biomass predictions resulted in similar model fits (18.21 g ≤ RMSE ≤ 70.0 g; 0.702 ≤ R2 ≤ 0.882) compared to branch biomass (6.88 g ≤ RMSE ≤ 45.08 g; 0.736 ≤ R2 ≤ 0.923) and only slightly better model fits for stem biomass (30.87 g ≤ RMSE ≤ 11.72 g; 0.887 ≤ R2 ≤ 0.960), which suggests that leaf AGB of short-stature trees (&lt;4.5 m) can be more accurately predicted using cross-sectional area as opposed to diameter at breast height for tall-stature trees. Our multi-species shrub and short-stature tree allometric models showed promising results for predicting plant component AGB, which can be utilized for remote sensing applications where plant functional types cannot always be distinguished. This study provides critical information on plant AGB allocation as well as component AGB modeling, required for understanding boreal AGB and aboveground carbon pools within the dynamic and rapidly changing Taiga Plains and Taiga Shield ecozones. In addition, the structural information and component AGB equations are important for integrating shrubs and short-stature tree AGB into carbon accounting strategies in order to improve our understanding of the rapidly changing boreal ecosystem function.

Identifying and addressing knowledge gaps for improving greenhouse gas emissions estimates from tropical peat forest fires

Tropical peatlands are areas of high carbon density that are important in biosphere-atmosphere interactions. Drainage and burning of tropical peatlands releases about 5% of global greenhouse gas (GHG) emissions, yet there is great uncertainty in these estimates. Our comprehensive literature review of parameters required to calculate GHG emissions from burnt peat forests, following the international guidelines, revealed many gaps in knowledge of carbon pools and few recent supporting studies. To improve future estimates of the total ecosystem carbon balance and peatfire emissions this study aimed to account for all carbon pools: aboveground, deadwood, pyrogenic carbon (PyC) and peat of single and repeatedly burnt peat forests. A further aim was to identify the minimum sampling intensity required to detect with 80% power significant differences in these carbon pools among long unburnt, recently burnt and repeatedly burnt peat swamp forests.About 90 Mg C ha−1 remains aboveground as deadwood after a single fire and half of this remains after a second fire. One fire produces 4.5 ± 0.6 Mg C ha−1 of PyC, with a second fire increasing this to 7.1 ± 0.8 Mg C ha−1. For peat swamp forests these aboveground carbon pools are rarely accounted in estimates of emissions following multiple fires, while PyC has not been included in the total peat carbon mass balance. Peat bulk density and peat carbon content change with fire frequency, yet these parameters often remain constant in the published emission estimates following a single and multiple fires. Our power analysis indicated that as few as 12 plots are required to detect meaningful differences between fire treatments for the major carbon pools. Further field studies directed at improving the parameters for calculating carbon balance of disturbed peat forest ecosystems are required to better constrain peatfire GHG emission estimates.

Thinned northern German Scots pine forests have a low carbon storage and uptake potential in comparison to naturally developing beech forests

In Europe, production forests with conifers widely replace native broadleaf trees. In the Pleistocene lowlands of northern Germany, > 1.7 million hectares of pine forests (Pinus spp., mostly P. sylvestris) have replaced natural broadleaf forests. We compared aboveground biomass carbon (C) pools and net primary productivity (ANPP) of broadleaf forests with natural development (ND; mostly Fagus sylvatica or Quercus petraea forests; 146 years old on average) to nearby young pine forests (YP; 65 years old on average) and old pine forests (OP; > 90 years) in northern Germany. Study aims where (i) to estimate the aboveground biomass C loss resulting from forest transformation, (ii) to compare the ANPP of broadleaf and pine forests, and (iii) to identify the main factors causing differences in biomass C storage and ANPP between forest types. YP forests stored only half of the biomass C of the ND forests (means: 72 vs. 147 MgCha−1); OP stands exceeded YP stands only by ~20% (87 vs. 72 MgCha−1). The main factor driving the biomass C pool differences was tree species identity, while stand age was not influential. Mean ANPP was 1.1 MgCha−1year−1 higher in ND forests than in YP stands due to higher litter production, while wood production was similar. We conclude that large-scale forest conversion to Scots pine forests has decreased the aboveground biomass carbon storage by half and the C sequestration potential with aboveground productivity by ~25%; this effect must be assessed together with changes in soil organic carbon stocks.

Total carbon and nitrogen stocks under different land use/land cover types in the Southwestern region of Nigeria

Land use systems play a vital role in the storage of soil total nitrogen (STN) and terrestrial carbon stocks and offset of the atmospheric CO2 concentration. In this study, we estimated the overall-ecosystem carbon stocks under different land cover types in some parts of Southwestern Nigeria, sub-Saharan Africa (SSA). Soil carbon and total nitrogen concentrations were measured at 0–10, 10–20 and 20–30 cm soil depths for four land covers (forests (FOR), plantations (TP), woodlands (WD) and croplands (CP)). The aboveground biomass carbon (Mg C ha−1) followed the order: FOR (118.19 Mg C ha−1) > TP (64.57 Mg C ha−1) > WD (31.09 Mg C ha−1) > CP (17.31 Mg C ha−1). Soil organic carbon (SOC) and STN concentration in all land uses decreased significantly (p < 0.05) with depth increment. Total SOC stock in 0–30 cm soil layer follows the order: FOR land use (93.62 Mg C ha−1) > TP (60.87 Mg C ha−1) > WD (55.21 Mg C ha−1) > CP (50.23 Mg C ha−1). The majority of carbon stocks in our study area were concentrated in the aboveground and soil carbon pool. Overall, the total carbon stock (TCS) of FOR was 163.67 Mg C ha−1, 152.86 Mg C ha−1 and 107.98 Mg C ha−1, respectively, greater than that of CP, WD and TP, respectively. This result indicated that forests stored larger amount of TCS compared to croplands and woodlands. As such, agroforestry, forest plantations and forestry should be given serious considerations as strategies to sequester carbon. Land use management practices and disturbance history are major factors impacting changes in carbon storage among land use systems. Improved knowledge of these and their spatial and temporal variability is very important in understanding the global change in soil carbon stocks and in enhancing human capacity to implement mitigation and adaptation strategies.

First report on carbon storage in a warm-temperate mangrove forest in South Africa

Carbon (C) storage by vegetated coastal habitats (mangroves, salt marshes and seagrasses) is globally recognized as a critical ecosystem service. Research efforts have therefore focused on quantifying C stored in these “blue carbon” ecosystems but a notable knowledge gap still exists for certain geographical regions. This study aimed to provide the first comprehensive assessment of C storage in South African warm temperate mangroves by quantifying the C storage in aboveground biomass and soil C pools associated with the mangrove forest at the Nxaxo Estuary. C storage variability was also related to mangrove forest structure and soil environmental variables. C storage was quantified using standardized protocols for aboveground (live trees, leaf litter, pneumatophores) and soil C pools at five Avicennia marina sites. The results showed soil C storage to be spatially variable while aboveground C pools were similar between intertidal zones within the sites. The soil C pool made the largest contribution to total C storage at each site and ranged from 176.91 ± 4.5MgC.ha−1 to 262.53 ± 18.8 MgC.ha−1. Of the aboveground carbon pools, live trees made the largest contribution and ranged from 2.25 ± 1.0 MgC.ha−1 to 9.56 ± 3.6 MgC.ha−1. Across all sites, average C storage for all pools was 234.9 ± 39.16 MgC.ha−1, which falls within the range reported for mangroves at other southern hemisphere range limits. Variability in soil C was linearly related to soil organic matter but this relationship was inconsistent between different soil depth intervals that were sampled. Total C storage was inversely related to mangrove tree density. This study confirms the need for more blue carbon studies to quantify C storage in under-represented geographical areas and to investigate factors that drive variability in C storage at different spatial scales.

ESTIMASI CADANGAN KARBON DI ATAS PERMUKAAN PADA HUTAN DESA BUNTOI KABUPATEN PULANG PISAU KALIMANTAN TENGAH (Above-Ground Carbon Pool Estimation at the Buntoi Village, Pulang Pisau District, Central Kalimantan Province)

ABSTRACTVillage forest program is one of the breakthroughs of the Ministry of Forestry for community-based forest management. In order to manage the village forest, needing the data and information about the biomassa at the site. The research was aimed to estimate the above-ground carbon pool at the Buntoi Village Forest that located at the protection forest in the form of deep peat areas. This site is administratively located at the Pulang Pisau District, Central Kalimantan Province. Research result showed that above-ground carbon pool at the peat-swamp scrub of Buntoi Village Forest is predictively namely 16.510 ton, whereas above-ground carbon pool at peat-swamp secondary forest of Buntoi Village Forest is predictively namely 176.059 ton. These data are lower than Central Kalimantan REL standard, with the result the Buntoi Village Forest is suitable for carbon trade purpose at the future.Keywords: Buntoi, carbon pool, peat-swamp areas, village forest

Aboveground biomass and carbon pool estimates of Portulacaria afra (spekboom)-rich subtropical thicket with species-specific allometric models

Accurate biomass and carbon flux estimations are essential for global carbon cycle modeling and are useful for setting and evaluating ecological restoration goals. Estimates derived from remote sensing can only be as good as the field data with which they are calibrated. Biomass estimates derived from allometric models are widely used to extrapolate from a plot to a landscape or regional scale, but both species- and/or site- specific models are scarce, and the model development procedure destructive and labour-intensive. Here we present allometric models that estimate biomass for 40 species common in Spekboom Thicket (ST), an arid South African Subtropical Thicket type, and its ecotones. Portulacaria afra (spekboom) is a canopy cover dominant in intact states of ST. Using these simple regression models, based on plant height and canopy diameter parameters, we estimate the aboveground biomass carbon (ABC) and with litter, the total aboveground carbon (AGC) of five sites situated across the Subtropical Thicket biome in South Africa. On each site, adjacent stands were selected that compared two management histories, intact and livestock-degraded, divided by a fence line boundary. Our estimates compared well with results from other studies. The highest AGC for stands in both intact and degraded states were estimated at 43.0 t C ha−1 and 13.0 t C ha−1 respectively, and the lowest at 26.3 t C ha−1 and 2.5 t C ha−1. Large canopy dominant (LCD) species contributed the largest AGC portion at three intact stands. The second largest portion was recorded for spekboom. Overall, the sites to the northeast of the biome recorded the highest AGC pools, consistent with a higher incidence of rainfall, especially in the summer months. In contrast, sites to the west of the biome showed higher mean litter carbon pools. Should intact sites be applied as reference, livestock-degraded subtropical thicket can potentially recover 22 – 27 t C ha−1 in AGC through restoration action.