Belowground Carbon Research Articles

Phosphorus regulates ectomycorrhizal fungi biomass production in a Norway spruce forest

Abstract. Ectomycorrhizal fungi (EMF) are important components of soil microbial communities, and EMF biomass can potentially increase carbon (C) stocks by accumulating in the soils as necromass and producing recalcitrant structures. EMF growth depends on the C allocated belowground by the host trees, and the nutrient limitation on tree growth is expected to influence this allocation. Therefore, studying EMF production and understanding the factors that regulates it in natural soils are important to understand C cycling in forests. Fungal mycelium collected from ingrowth mesh bags is commonly used to estimate EMF biomass, but these measurements might not reflect the total EMF production since turnover rates of the hyphae are not considered. Here we estimated EMF production and turnover in response to P fertilization (applied as superphosphate) in a Norway spruce forest where nitrogen (N) deposition has resulted in phosphorus (P) limitation of plant production by using a combination of mesh bags with different incubation periods and with Bayesian inferences. To test how localized patches of N and P influence EMF production and turnover we amended some bags with a nitrogen source (methylene urea) or P source (apatite). Additionally, the Bayesian model tested the effect of seasonality (time of mesh-bag harvesting) on EMF production and turnover. We found that turnover of EMF was not affected by P fertilization or mesh-bag amendment. P fertilization had a negative effect on EMF production in all the mesh-bag amendments, suggesting a reduced belowground C allocation to the EMF when P limitation is alleviated. Apatite amendment significantly increased EMF biomass production in comparison with the pure quartz bags in the control plots but not in the P-fertilized plots. This indicates that P-rich patches enhance EMF production in P-limited forests, but not when P is not limiting. Urea amendment had a generally positive effect on EMF production, but this was significantly reduced by P fertilization, suggesting that a decrease in EMF production due to the alleviated P limitation will affect N foraging. Seasonality had a significant effect on EMF production, and the differences registered between the treatments were higher during the warmer months and disappeared at the end of the growing season. Many studies highlight the importance of N for regulating belowground C allocation to EMF in northern coniferous forests, but here we show that the P status of the forest can be equally important for belowground carbon allocation to EMF production in areas with high N deposition.

How fine root turnover functions during mangrove root zone expansion and affects belowground carbon processes

How fine root turnover functions during mangrove root zone expansion and affects belowground carbon processes

How biotic, abiotic, and functional variables drive belowground soil carbon stocks along stress gradient in the Sundarbans Mangrove Forest?

Mangrove forests, some of the most carbon-dense ecosystems on Earth, play an important role in climate change mitigation through storing carbon in the soil. However, increasing anthropogenic pressures and sea level rise are likely to alter mangrove forest structure and functions, including the major source of carbon in mangrove ecosystems — below-ground soil carbon stocks (BSCS). Although estimating soil carbon stocks has been a popular practice in the mangroves, but poorly understood the (I) the linkage between BSCS and key ecosystem drivers (i.e., biotic, abiotic, and functional) and in (II) determining the pathways of how BSCS and multiple forest variables interact along stress gradients. This lack of understanding limits our ability to predict ecosystem carbon dynamics under future changes in climate. Here, we aimed to understand how abiotic factors (such as salinity, canopy gap fraction, nutrients, and soil pH), biotic factors (e.g., structural parameters, canopy packing, and leaf area index, LAI), and forest functional variables (e.g., growth and aboveground biomass stocks, AGB) affect BSCS (i.e., soil organic carbon, SOC, and root carbon, RC) using spatiotemporal data collected from the Sundarbans Mangrove Forest (SMF) in Bangladesh. We observed that BSCS decreased significantly with increasing salinity (e.g., from 70.6 Mg C ha−1 in the low-saline zone to 44.6 Mg C ha−1 in the high-saline zone). In contrast, the availability of several macronutrients (such as nitrogen, phosphorous, and potassium), LAI, species diversity, AGB, and growth showed a significant positive effect on SOC and RC. Stand properties, including tree height, basal area, density, canopy packing, and structural diversity, had a non-significant but positive impact on RC, while tree height and basal area significantly influenced SOC. Pathway analysis showed that salinity affects BSCS variability directly and indirectly by regulating stand structure and restricting nutrients and forest functions, although basal area, nutrients, and LAI directly enhance RC stocks. Our results indicate that an increase in nutrient content, canopy density, species diversity, and leaf area index can enhance BSCS, as they improve forest functions and contribute to a better understanding of the underlying mechanisms.

Effects of fertilisation and understory removal on aboveground and belowground carbon stocks in wet and dry moorlands in south-western France

Effects of fertilisation and understory removal on aboveground and belowground carbon stocks in wet and dry moorlands in south-western France

Do Managed Hill Sal (Shorea robusta) Community Forests of Nepal Sequester and Conserve More Carbon than Unmanaged Ones?

Nepalese community forests are globally recognized for sustainable forest management and improving the livelihoods of forest-dependent communities, but their contribution to carbon sequestration in trees and soil is rarely studied. This study was performed to understand the effect of management practices on carbon stock of two community forests (CFs) - Taldanda (managed) and Dangdunge (unmanaged) - dominated by Sal (Shorea robusta) in the mid-hills of Nepal. Twenty-one concentric sample plots, each of 250 m2, were laid out in each forest to estimate different carbon pools and a stratified random sampling intensity of 0.5% used to collect data. Results showed significant (p<0.05) differences in above and below-ground biomass and carbon sequestration potential between the two CFs. The managed and unmanaged forests had total carbon stock of 269.3±27.4 and 150.0±22.7 ton/ha, respectively, demonstrating 1.79 times higher carbon stock in the former than the latter. The managed forest had significantly (p<0.05) greater mean soil organic carbon (SOC) stock than the unmanaged forest. The SOC was highest in the upper soil layer (0-10 cm), with a steady decrease as the soil depth increased. All other measured carbon pools values were higher in managed compared to unmanaged forest. The difference in carbon stock was due to the manipulation of different forest management activities, including thinning, timber extraction, fire control, grazing, and fuel wood/fodder extraction. The study suggests that the implementation of proper forest management would be necessary for enhancing carbon stock in forest trees and soils.

Root traits in response to frequent fires: Implications for belowground carbon dynamics in fire-prone savannas.

Predicting how belowground carbon storage reflects changes in aboveground vegetation biomass is an unresolved challenge in most ecosystems. This is especially true for fire-prone savannas, where frequent fires shape the fraction of carbon allocated to root traits for post-fire vegetation recovery. Here I review evidence on how root traits may respond to frequent fires and propose to leverage root traits to infer belowground carbon dynamics in fire-prone savannas. Evidently, we still lack an understanding of trade-offs in root acquisitive vs. conservative traits in response to frequent fires, nor have we determined which root traits are functionally important to mediate belowground carbon dynamics in a frequently burned environment. Focusing research efforts along these topics should improve our understanding of savanna carbon cycling under future changes in fire regimes.

Estimation of carbon sequestration by some selected dominant tree species of Chandigarh University, Gharuan, Mohali

The purpose of this study was to determine the carbon in selected tree species at Chandigarh University to analysis carbon stock by measuring their aboveground and belowground biomass for sequestering carbon. Distinct Count's tree species have a total biomass of 113. There are a total of 701 trees of 54 different kinds growing in a particular region of the Chandigarh University campus in Punjab. Non-destructive methods have been used to measure the total biomass and carbon sequestered by the tree species. Each species' above and belowground organic carbon (tones/tree) and total organic carbon was determined. The overall total of carbon that may be found in different tree species is 17474.22.

Woody species diversity, composition, structure and carbon storage of a dry evergreen montane forest of Essimingor Nature Forest Reserve in Tanzania

Abstract. Mwakalukwa EE, Mwakisu A, Maliondo SMS. 2023. Woody species diversity, composition, structure and carbon storage of a dry evergreen montane forest of Essimingor Nature Forest Reserve in Tanzania. Intl J Trop Drylands 7: 26-36. The biodiversity status of flora and fauna of many forests found on small protruding and isolated hills in most parts of dry areas in Tanzania is largely less studied. Their contribution to climate mitigation options also remains largely unknown. This study assessed the woody species diversity, composition, structure and carbon stocks potential of a dry evergreen montane forest of Essimingor Nature Forest Reserve in Tanzania. The vegetation data were collected from 23 concentric sample plots of 5m, 15m, and 20m radius laid systematically across the entire forest area of 6,100 ha. A total of 54 trees and shrubs species belonging to 29 families were identified. Diversity indices indicated the forest to have a high diversity of woody species. The most important species were Cassipourea malosana, Diospyros abyssinica and Drypetes natalensis. Stand structure comprised 288±173 stems ha-1, basal area of 11.47±7.23 m2ha-1 and standing volume of 27.3±16.3 m3ha-1. The mean above-ground and below-ground carbon stocks were 56.93±34.60 Mg C ha-1 and 34.71±19.72 Mg C ha-1, respectively. The observed high species diversity and carbon density signify the importance of conservation efforts bestowed in this reserve. Quantification of other carbon pools for estimation of the total carbon stock potential of this forest is recommended.

Spatial and seasonal variations in soil respiration in a subtropical forest in Okinawa, Japan

AbstractTo clarify soil respiration (soil CO2 efflux, Rs) characteristics in a subtropical evergreen broad‐leaved natural forest in Yambaru, Okinawa, Japan, we examined spatiotemporal variation in Rs and its determining factors. We then compared yearly Rs with the value in other forests. The spatial variation in Rs (coefficient of variation [CV] = 38.9%) was not significantly related to temperature or soil water content but was evidently dependent on ground surface litter coverage. Rs was greater in summer (ca. 7–10 μmol m−2 s−1), and its seasonal variation was exponentially related to soil temperature (Q10 = 2.16). As a function of soil temperature, we estimated a yearly mean stand‐scale Rs of 5.17 μmol m−2 s−1, and a total carbon efflux from the soil of 1959 g C m−2 year−1 for 2014. Despite showing similar seasonal patterns as those in temporal forests, the Rs in this ecosystem is very high throughout the year, and the yearly value is much higher for natural mature forests. A mass balance approach suggests that the large amount of belowground carbon allocation of plants contributed to the high CO2 emissions from the soils.

Mapping global nitrogen deposition impacts on soil respiration

Soil respiration (Rs) is a key indicator of belowground biological activities of terrestrial ecosystems. Despite ongoing atmospheric nitrogen (N) deposition due to anthropogenic activities, it remains uncertain how Rs responds to globally varied atmospheric N deposition. Based on a meta-analysis of 340 simulated experimental nitrogen addition studies, we aimed to identify the key factors altering the responses of Rs to N deposition and extrapolate these results to the global mapping of Rs changes under N deposition. We found the overall experimental N addition effect on Rs was insignificant, but the responses of Rs significantly shifted from positive to negative with increasing accumulated N addition amount and lower soil pH, and the negative responses to increasing N amounts were significantly intensified in acid soils. Also, the response of heterotrophic respiration to N addition significantly increased with a lower N amount, and both responses of heterotrophic and autotrophic respiration were significantly more negative in soils with lower pH. Our mapping efforts showed that global Rs overall increased by 2.8 % in response to the accumulated N deposition from 2000 to 2020. Regions with combined characteristics of high accumulated N deposition amounts and low soil pH, including Eastern U.S., Europe, and Eastern Asia, were hotspots of Rs declines under current and future atmospheric N deposition. Our findings challenge the long-held notion that N deposition has universal negative impacts on Rs, and suggest the spatial heterogeneity in the impacts of N deposition on belowground activities and carbon release across the globe.

Experimental drought increased the belowground sink strength towards higher topsoil organic carbon stocks in a temperate mature forest

Reduced carbon assimilation by trees is often considered to lower the overall carbon sink function of drought-stressed forests. However, soil organic carbon (SOC) stocks may respond differently to drought than ecosystem carbon flux dynamics, leading to imprecise predictions of soil carbon sequestration when one value is inferred from the other. As a major component of soil organic matter, SOC is the largest actively cycling terrestrial carbon reservoir, and thus fulfills various important ecosystem services. Yet, there is uncertainty about how SOC quantity and quality respond to drought in temperate forests. This study addressed the depth distribution of SOC stocks and soil organic matter stability in a forest exposed to artificial drought for five consecutive growing seasons below clusters of temperate mature deciduous beech (Fagus sylvatica L.) and coniferous spruce (Picea abies (L.) Karst.). In addition to SOC stock determination, we measured concentrations of water-extractable organic carbon (WEOC), performed density fractionation, and determined beta values of SOC (slopes of linear regressions between δ13C of soil and log-transformed SOC content throughout soil depth profiles). Following drought, SOC stocks down to 30 cm depth increased by a factor of 1.5 under P. abies while they did not change with drought under F. sylvatica. Under both species, SOC stocks in the mineral topsoil (0–5 cm soil depth) increased by >80 % with drought, increasing the relative contribution of this thin depth section to total SOC from 5 % to >30 %. At 5–15 cm soil depth, SOC stocks decreased with drought under F. sylvatica but not under P. abies. With drought, carbon in the free light fraction (fLF) increased under F. sylvatica but declined marginally under P. abies. Results from density fractionation and beta values suggest decreased soil organic matter stability under F. sylvatica and increased stability under P. abies. Greater SOC accumulation suggests that the belowground carbon sink strength of drought-stressed forests increases, which contrasts with reduced ecosystem carbon uptake under drought.

Carbon pool dynamics after variable retention harvesting in Nothofagus pumilio forests of Tierra del Fuego

BackgroundIt is necessary to determine the implications for managing forest stands using variable retention harvesting for maintaining carbon and for calculating the effects of different harvesting practices on above- and below-ground carbon balance in forest ecosystems. In this context, forest carbon management has gained more attention among managers and policy-makers during recent years. The aim of this study was to determine carbon pool dynamics in different forest ecosystem components after variable retention harvesting (VRH) to characterize the ecological stability and quantify the recovery rate through the years-after-harvesting (YAH).MethodsCarbon pool compartmentalization of 14 different components was determined in 60 harvested and primary unmanaged forests during the first 18 YAH in Tierra del Fuego (Argentina). We compared them using uni- and multi-variate methods, relativizing the outputs with primary unmanaged forests.ResultsWe determined the effectiveness to retain carbon components in post-harvested stands under different retention strategies (aggregated vs. dispersed). The balance among carbon pool components changed between managed and unmanaged stands across the YAH, and was directly related to the impact magnitude. Aggregated retention improved the ecological stability of the harvested areas, where the below-ground components were more stable than the above-ground components. The recovery rate was directly related to the post-harvesting natural dynamics of the stands. The studied period was not enough to fully recover the C levels of primary unmanaged forests, but VRH showed advantages to increase the C pools in the managed stands.ConclusionsPromoting VRH can improve sustainable forestry at the landscape level and in the long term, generating positive synergies with biodiversity and the provision of ecosystem services. This study provides important new insights into forest carbon management, in particular to setting standards in carbon projects and sets the groundwork for analysing the economics of the mentioned harvesting systems.

Belowground carbon allocation, root trait plasticity, and productivity during drought and warming in a pasture grass.

Sustaining grassland production in a changing climate requires an understanding of plant adaptation strategies, including trait plasticity under warmer and drier conditions. However, our knowledge to date disproportionately relies on aboveground responses, despite the importance of belowground traits in maintaining aboveground growth, especially in grazed systems. We subjected a perennial pasture grass, Festuca arundinacea, to year-round warming (+3 °C) and cool-season drought (60% rainfall reduction) in a factorial field experiment to test the hypotheses that: (i) drought and warming increase carbon allocation belowground and shift root traits towards greater resource acquisition and (ii) increased belowground carbon reserves support post-drought aboveground recovery. Drought and warming reduced plant production and biomass allocation belowground. Drought increased specific root length and reduced root diameter in warmed plots but increased root starch concentrations under ambient temperature. Higher diameter and soluble sugar concentrations of roots and starch storage in crowns explained aboveground production under climate extremes. However, the lack of association between post-drought aboveground biomass and belowground carbon and nitrogen reserves contrasted with our predictions. These findings demonstrate that root trait plasticity and belowground carbon reserves play a key role in aboveground production during climate stress, helping predict pasture responses and inform management decisions under future climates.

Carbon sequestration potential of different forest types in Pakistan and its role in regulating services for public health.

A high amount of CO2 causes numerous health effects, including headaches, restlessness, difficulty in breathing, increased heart rate, high blood pressure, asphyxia, and dizziness. This issue of increasing atmospheric CO2 can only be solved via above-ground and below-ground carbon sequestration (CS). This study was designed to determine the relationship between CS with the crown area (CA), diameter at breast height (DBH), height (H), species richness (SR), and elevation in different forest types of Pakistan with the following specific objectives: (1) to quantify the direct and indirect relationship of carbon sequestration with CA, DBH, H, and SR in various natural forest types and (2) to evaluate the effect of elevation on the trees functional traits and resultant CS. We used the linear structural equation model (SEM) for each conceptual model. Our results confirmed that the highest CS potential was recorded for dry temperate conifer forests (DTCF) i.e., 52.67%, followed by moist temperate mix forests (MTMF) and sub-tropical broad-leaved forests (STBLF). The SEM further described the carbon sequestration variation, i.e., 57, 32, 19, and 16% under the influence of CA (β = 0.90 and P-value < 0.001), H (β = 0.13 and p-value = 0.05), DBH (β = 0.07 and p-value = 0.005), and SR (β = -0.55 and p-value = 0.001), respectively. The individual direct effect of SR on carbon sequestration has been negative and significant. At the same time, the separate effect of CA, DBH, and H had a positive and significant effect on carbon sequestration. The remaining 20% of CS variations are indirectly influenced by elevation. This means that elevation affects carbon sequestration indirectly through CA, DBH, H, and SR, i.e., β = 0.133 and P-value < 0.166, followed by β = 0.531 and P-value < 0.001, β = 0.007 and P-value < 0.399, and β = -0.32 and P-value < 0.001, respectively. It is concluded that abiotic factors mainly determined carbon sequestration in forest ecosystems along with the elevation gradients in Pakistan. Quantifying the role of various forest types in carbon dioxide (CO2) reduction leads to improved air quality, which positively impacts human health. This is an imperative and novel study that links the dynamics of the biosphere and atmosphere.

Drought reduces invasive grass performance by disrupting plant-microbe interactions that enhance plant nitrogen supply.

Non-native invasive plants can promote their dominance in novel ecosystems by accelerating soil nutrient cycling via interactions with decomposer microbes. Changes in abiotic conditions associated with frequent or prolonged drought may disrupt these interactions, but the effects of disruption on invasive plant performance and the underpinning mechanisms are poorly understood. Here, we used rainout shelters in an experimental field setting to test the hypothesis that drought reduces invasive plant performance by reducing microbial metabolic activity, resulting in decreased nitrogen flow to plants. We imposed growing season drought on populations of the exotic grass Microstegium vimineum, a widespread invasive plant in eastern deciduous forests, and quantified effects on aboveground and belowground biomass, and carbon (C) and nitrogen (N) cycling among plants, decomposers, and soil. Drought resulted in a 24% decrease in soil respiration, a 16% decrease in phenol oxidase enzyme activity, a 12% decrease in dissolved organic N concentration, and a decrease in the C:N ratio of particulate organic matter, suggesting reduced microbial metabolic activity and nutrient mining of soil organic matter. Drought also reduced aboveground Microstegium biomass 33% and increased Microstegium leaf C:N ratio, consistent with a decline in plant N uptake. We conclude that drought can reduce the performance of existing invasive species populations by suppressing plant-microbe interactions that increase nitrogen supply to plants, which may have consequences for the persistence of invasive plants under hydrologic change.

The inverted forest: Aboveground and notably large belowground carbon stocks and their drivers in Brazilian savannas

Savannas contribute to ca. 30 % of the total terrestrial net primary productivity and are responsible for significant carbon storage. Savannas in South America are mostly found within the Cerrado Domain, which is very threatened and presents remarkable carbon pools. Herein, we used a unique dataset of 21 Cerrado sites spanning 144 permanent field plots in Southeastern Brazil to assess the general patterns of above and belowground carbon stocks. We identified the main environmental and tree diversity drivers of aboveground wood carbon and productivity, belowground carbon stocks (roots and soil), carbon ratios (root:shoot and above:below) and total carbon stocks in the Cerrado through a combination of climatic estimates, fire frequency data, field measurements of vegetation, roots, soil carbon, nutrients and texture, and assessment of different components of diversity (species, functional and phylogenetic). Our findings reveal average aboveground, root, and soil carbon stocks of 20.4, 14.24, and 123.13 Mg.ha−1, respectively. Average Root:Shoot and Above:Below confirm the “inverted forest” concept with values of 1.58 and 0.21, respectively. Total carbon was 145.62 Mg.ha−1, reinforcing the great amount of carbon storage in the Cerrado and its role in the carbon cycle and dynamics. Tree diversity variables (mainly species diversity and functional composition variables) had more significant effects over aboveground variables, whereas environmental variables had more significant effects over belowground variables. Ratios and total carbon mixed up these effects. The impressive values of carbon storage, especially belowground, point out the need to better manage and protect the Cerrado. Moreover, our findings might be particularly relevant for discussions on restoration programs focused on the trees-for‑carbon idea that do not consider species diversity and belowground carbon stocks.

黄河源园区高寒草地碳储量估算及其影响因素

PDF HTML阅读 XML下载 导出引用 引用提醒 黄河源园区高寒草地碳储量估算及其影响因素 DOI: 10.5846/stxb202207152024 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 2021年度全国草原资源调查项目(DD20211601);国家自然科学基金项目(41371125) Estimated carbon storage and influencing factors of alpine grassland in the source region of the Yellow River Author: Affiliation: Fund Project: The National Natural Science Foundation of China (General Program, Key Program, Major Research Plan) 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:高寒草地碳储量及其影响因素研究是认识青藏高原草地生态系统乃至陆地生态系统碳循环和气候变化的关键之一。利用2021年8月上旬地面调查数据与同期高分6号遥感数据建立回归关系,在反演研究区植被地上、地下生物量碳密度和0-40cm土壤层有机碳密度基础上,估算了黄河源园区高寒草地有机碳储量,并通过路径分析探讨了土壤理化性质对碳密度的影响驱动机制。结果表明:(1)2021年黄河源园区地上生物量、地下生物量、0-40cm土壤层碳密度分别为37.65g/m2、1305.28g/m2、4769.11g/m2;总碳储量为100.44Tg(1Tg=1012g),植被层和土壤层碳储量分别分为22.06Tg、78.38Tg,占总碳密度的21.96%、78.04%。(2)黄河源园区高寒草甸和高寒草原两种草地类型地上生物量碳密度分别为41.27g/m2、30.76g/m2;地下生物量碳密度分别为1661.41g/m2、618.74g/m2;0-40cm土壤层有机碳密度分别为5790.99g/m2、2804.04g/m2;研究区碳密度总体呈现南高北低的空间分布现状,分布格局与地表植被类型分布特点较为吻合;(3)路径分析表明,研究区土壤理化性质与草地碳密度关系密切,其中地上生物量碳密度主要受土壤全磷含量和土壤含水率驱动,地下生物量碳密度主要受土壤全氮含量和容重驱动,土壤有机碳密度主要受地下生物量碳密度、土壤容重和pH值驱动。 Abstract:The study of alpine grassland carbon storage and its influencing factors is one of the keys to understand the carbon cycle and climate change of grassland ecosystem and even terrestrial ecosystem on the Qinghai Tibet Plateau. In this paper, the regression relationship between the ground survey data in early August 2021 and the remote sensing data of Gaofen-6 in the same period was established. Based on the inversion of the above-ground and below-ground biomass carbon density of vegetation and the organic carbon density of 0-40 cm soil layer in the study area, the organic carbon storage of alpine grassland in the source region of the Yellow River was estimated, and the driving mechanism of the impact of soil physical and chemical properties on carbon density was discussed through path analysis. The results showed that: (1) In 2021, the above-ground biomass, below-ground biomass and carbon density of 0-40 cm soil layer in the source region of the Yellow River were 37.65 g/m2, 1305.28 g/m2 and 4769.11 g/m2, respectively. The total carbon storage was 100.44 Tg (1 Tg=1012 g). The carbon storage of vegetation layer and soil layer was 22.06 Tg and 78.38 Tg, accounting for 21.96% and 78.04% of the total carbon density respectively. (2) The above-ground biomass carbon density of alpine meadow and alpine steppe in the source region of the Yellow River was 41.27 g/m2 and 30.76 g/m2 respectively; The below-ground biomass carbon density was 1661.41 g/m2 and 618.74 g/m2 respectively; The organic carbon density of 0-40 cm soil layer was 5790.99 g/m2 and 2804.04 g/m2 respectively; The spatial distribution of carbon density in the study area was generally high in the south and low in the north, and the distribution pattern was consistent with the distribution characteristics of surface vegetation types. (3) Path analysis showed that the physical and chemical properties of soil in the study area were closely related to the carbon density of grassland. The above-ground biomass carbon density was mainly driven by soil total phosphorus content and soil moisture, the below-ground biomass carbon density was mainly driven by soil total nitrogen content and soil bulk, and the soil organic carbon density was mainly driven by the below-ground biomass carbon density, soil bulk and pH. 参考文献 相似文献 引证文献

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) &gt; twigs (3.02±0.04 Mg C.ha-1) &gt; 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) &gt; 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) &gt; soil (121.11 Mg CO2ha-1) &gt; litter (73.40 Mg CO2ha-1) &gt; 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.

Assessment of aboveground, belowground, and total biomass carbon storage potential of Bambusa vulgaris in a tropical moist forest in Ghana, West Africa

This article reports on a study conducted to assess the carbon storage potential of Bambusa vulgaris, the predominant bamboo species in Ghana. The study aimed to fill a knowledge gap on the potential of bamboo to sequester carbon for climate change mitigation in Ghana. Unlike previous studies that only focused on aboveground biomass, this study assessed belowground, litter, and coarse wood carbon pools. Allometric parameters and models were used to measure the aboveground biomass, while other carbon pools were directly measured. The results showed that the aboveground biomass of B. vulgaris had a carbon stock of 42.85 ± 9.32 Mg C ha−1, which was 73% of the total biomass carbon stock. The carbon stocks of belowground, coarse wood and litter were 8.57, 3.02, and 4.25 Mg C ha−1, respectively. The study also found that B. vulgaris had a high carbon dioxide sequestration potential of 215.39 Mg CO2e ha−1 compared to 147–275 Mg CO2e ha−1 for trees in general. The findings suggest that B. vulgaris could contribute to Ghana's transition to a low-carbon economy through carbon stock monitoring, reporting, and policy development to minimise the impact of climate change. Moreover, the inclusion of relevant carbon pools, including coarse wood and litter, in forest carbon estimates should be encouraged to provide a comprehensive understanding of the plant carbon cycle.

A Conceptual Framework on the Fate of Rhizodeposits in Forming Mineral-Associated Organic Matter or Encapsulating Into Microaggreagtes

Rhizodeposition, as transported from photosynthates and exudated in soils via fine roots, is the pivot linking above- and belowground carbon (C) cycling pathways. Meanwhile, rhizodeposit C serves as “currency” for plant nutrient acquisition because of its critical roles in priming soil microorganisms, maintaining plant-mycorrhizal symbionts, and elongating plant roots. Therefore, a conceptual framework integrating knowledge on the biogeochemical fate of rhizodeposit C can help understand plant nutrient economics and soil C sink function. However, it still remains a great challenge to efficiently delineate the dynamics of rhizodeposit C in soils. In the framework, we present the possible stabilization pathways of rhizodeposit C via formation of mineral-associated organic matter (MAOM) or encapsulation by microaggregates. We further propose that continuous and pulse 13CO2 labeling are powerful techniques to track the fate of rhizodeposit C and to quantify how much C could eventually be sequestrated in soils as the component of MAOM or microaggregates. This framework would provide future research possibilities to better optimize plant C allocation and productivity and preserve soil C stocks.