Carbon Balance and Management最新文献

{"title":"Degradation-driven changes in fine root carbon stocks, productivity, mortality, and decomposition rates in a palm swamp peat forest of the Peruvian Amazon","authors":"Nelda Dezzeo,&nbsp;Julio Grandez-Rios,&nbsp;Christopher Martius,&nbsp;Kristell Hergoualc’h","doi":"10.1186/s13021-021-00197-0","DOIUrl":"10.1186/s13021-021-00197-0","url":null,"abstract":"<div><h3>Background</h3><p>Amazon palm swamp peatlands are major carbon (C) sinks and reservoirs. In Peru, this ecosystem is widely threatened owing to the recurrent practice of cutting <i>Mauritia flexuosa</i> palms for fruit harvesting. Such degradation could significantly damage peat deposits by altering C fluxes through fine root productivity, mortality, and decomposition rates which contribute to and regulate peat accumulation. Along a same peat formation, we studied an undegraded site (Intact), a moderately degraded site (mDeg) and a heavily degraded site (hDeg) over 11 months. Fine root C stocks and fluxes were monthly sampled by sequential coring. Concomitantly, fine root decomposition was investigated using litter bags. In the experimental design, fine root stocks and dynamics were assessed separately according to vegetation type (<i>M. flexuosa</i> palm and other tree species) and <i>M. flexuosa</i> age class. Furthermore, results obtained from individual palms and trees were site-scaled by using forest composition and structure.</p><h3>Results</h3><p>At the scale of individuals, fine root C biomass in <i>M. flexuosa</i> adults was higher at the mDeg site than at the Intact and hDeg sites, while in trees it was lowest at the hDeg site. Site-scale fine root biomass (Mg C ha⁻¹) was higher at the mDeg site (0.58 ± 0.05) than at the Intact (0.48 ± 0.05) and hDeg sites (0.32 ± 0.03). Site-scale annual fine root mortality rate was not significantly different between sites (3.4 ± 1.3, 2.0 ± 0.8, 1.5 ± 0.7 Mg C ha⁻¹ yr⁻¹ at the Intact, mDeg, and hDeg sites) while productivity (same unit) was lower at the hDeg site (1.5 ± 0.8) than at the Intact site (3.7 ± 1.2), the mDeg site being intermediate (2.3 ± 0.9). Decomposition was slow with 63.5−74.4% of mass remaining after 300 days and it was similar among sites and vegetation types.</p><h3>Conclusions</h3><p>The significant lower fine root C stock and annual productivity rate at the hDeg site than at the Intact site suggests a potential for strong degradation to disrupt peat accretion. These results stress the need for a sustainable management of these forests to maintain their C sink function.</p></div>","PeriodicalId":505,"journal":{"name":"Carbon Balance and Management","volume":"16 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2021-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8555211/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39573732","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multi-predictor mapping of soil organic carbon in the alpine tundra: a case study for the central Ecuadorian páramo","authors":"Johanna Elizabeth Ayala Izurieta,&nbsp;Carmen Omaira Márquez,&nbsp;Víctor Julio García,&nbsp;Carlos Arturo Jara Santillán,&nbsp;Jorge Marcelo Sisti,&nbsp;Nieves Pasqualotto,&nbsp;Shari Van Wittenberghe,&nbsp;Jesús Delegido","doi":"10.1186/s13021-021-00195-2","DOIUrl":"10.1186/s13021-021-00195-2","url":null,"abstract":"<div><h3>Background</h3><p>Soil organic carbon (SOC) affects essential biological, biochemical, and physical soil functions such as nutrient cycling, water retention, water distribution, and soil structure stability. The Andean páramo known as such a high carbon and water storage capacity ecosystem is a complex, heterogeneous and remote ecosystem complicating field studies to collect SOC data. Here, we propose a multi-predictor remote quantification of SOC using Random Forest Regression to map SOC stock in the herbaceous páramo of the Chimborazo province, Ecuador.</p><h3>Results</h3><p>Spectral indices derived from the Landsat-8 (L8) sensors, OLI and TIRS, topographic, geological, soil taxonomy and climate variables were used in combination with 500 in situ SOC sampling data for training and calibrating a suitable predictive SOC model. The final predictive model selected uses nine predictors with a RMSE of 1.72% and a R² of 0.82 for SOC expressed in weight %, a RMSE of 25.8 Mg/ha and a R² of 0.77 for the model in units of Mg/ha. Satellite-derived indices such as VARIG, SLP, NDVI, NDWI, SAVI, EVI2, WDRVI, NDSI, NDMI, NBR and NBR2 were not found to be strong SOC predictors. Relevant predictors instead were in order of importance: geological unit, soil taxonomy, precipitation, elevation, orientation, slope length and steepness (LS Factor), Bare Soil Index (BI), average annual temperature and TOA Brightness Temperature.</p><h3>Conclusions</h3><p>Variables such as the BI index derived from satellite images and the LS factor from the DEM increase the SOC mapping accuracy. The mapping results show that over 57% of the study area contains high concentrations of SOC, between 150 and 205 Mg/ha, positioning the herbaceous páramo as an ecosystem of global importance. The results obtained with this study can be used to extent the SOC mapping in the whole herbaceous ecosystem of Ecuador offering an efficient and accurate methodology without the need for intensive in situ sampling.</p></div>","PeriodicalId":505,"journal":{"name":"Carbon Balance and Management","volume":"16 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2021-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8543914/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39554369","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of rising temperatures on the biomass of humid old-growth forests of the world","authors":"Markku Larjavaara,&nbsp;Xiancheng Lu,&nbsp;Xia Chen,&nbsp;Mikko Vastaranta","doi":"10.1186/s13021-021-00194-3","DOIUrl":"10.1186/s13021-021-00194-3","url":null,"abstract":"<div><h3>Background</h3><p>Understanding how warming influence above-ground biomass in the world’s forests is necessary for quantifying future global carbon budgets. A climate-driven decrease in future carbon stocks could dangerously strengthen climate change. Empirical methods for studying the temperature response of forests have important limitations, and modelling is needed to provide another perspective. Here we evaluate the impact of rising air temperature on the future above-ground biomass of old-growth forests using a model that explains well the observed current variation in the above-ground biomass over the humid lowland areas of the world based on monthly air temperature.</p><h3>Results</h3><p>Applying this model to the monthly air temperature data for 1970–2000 and monthly air temperature projections for 2081–2100, we found that the above-ground biomass of old-growth forests is expected to decrease everywhere in the humid lowland areas except boreal regions. The temperature-driven decrease is estimated at 41% in the tropics and at 29% globally.</p><h3>Conclusions</h3><p>Our findings suggest that rising temperatures impact the above-ground biomass of old-growth forests dramatically. However, this impact could be mitigated by fertilization effects of increasing carbon dioxide concentration in the atmosphere and nitrogen deposition.</p></div>","PeriodicalId":505,"journal":{"name":"Carbon Balance and Management","volume":"16 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2021-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8513374/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39515585","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Inward- versus outward-focused bioeconomy strategies for British Columbia’s forest products industry: a harvested wood products carbon storage and emission perspective","authors":"Sheng H. Xie,&nbsp;Werner A. Kurz,&nbsp;Paul N. McFarlane","doi":"10.1186/s13021-021-00193-4","DOIUrl":"10.1186/s13021-021-00193-4","url":null,"abstract":"<div><h3>Background</h3><p>British Columbia’s (BC) extensive forest resources provide climate change mitigation opportunities that are available to few other jurisdictions. However, as a consequence of the Mountain Pine Beetle outbreak and large-scale wildfires, BC is anticipating reduced roundwood harvest for the next decades. Progress towards more climatically efficient utilization of forest resources is needed. This research quantitatively compared the greenhouse gas emission consequences of nine harvested wood products trade and consumption strategies. Inward-focused strategies use wood products within Canada to achieve emission reduction objectives, while outward-focused strategies encourage exports of wood products.</p><h3>Results</h3><p>In the business-as-usual baseline scenario, average emissions arising from BC-originated harvested wood products between 2016 and 2050 were 40 MtCO₂e yr⁻¹. The estimated theoretical boundaries were 11 MtCO₂e yr⁻¹ and 54 MtCO₂e yr⁻¹, under the scenarios of using all harvests for either construction purposes or biofuel production, respectively. Due to the constrained domestic market size, inward-focused scenarios that were based on population and market capacity achieved 0.3–10% emission reductions compared to the baseline. The international markets were larger, however the emissions varied substantially between 68% reduction and 25% increase depending on wood products’ end uses.</p><h3>Conclusions</h3><p>Future bioeconomy strategies can have a substantial impact on emissions. This analysis revealed that from a carbon storage and emission perspective, it was better to consume BC’s harvests within Canada and only export those products that would be used for long-lived construction applications, provided that construction market access beyond the US was available. However, restricting export of wood products destined for short-lived uses such as pulp and wood pellets would have significant economic and social impacts. On the other hand, inward-focused strategies had a small but politically and environmentally meaningful contribution to BC’s climate action plan. This study also revealed the conflicts between a demand-driven bioeconomy and targeted environmental outcomes. A hierarchical incentive system that could co-exist with other market drivers may help achieve emission reduction goals, but this would require a better quantitative understanding of wood products’ substitution effects. While the analyses were conducted for BC, other regions that are net exporters of wood products may face similar issues.</p></div>","PeriodicalId":505,"journal":{"name":"Carbon Balance and Management","volume":"16 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2021-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8466961/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39447483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Changes of lake organic carbon sinks from closed basins since the Last Glacial Maximum and quantitative evaluation of human impacts","authors":"Yu Li,&nbsp;Xinzhong Zhang,&nbsp;Lingmei Xu,&nbsp;Yuxin Zhang,&nbsp;Wangting Ye,&nbsp;Yichan Li","doi":"10.1186/s13021-021-00191-6","DOIUrl":"10.1186/s13021-021-00191-6","url":null,"abstract":"<div><h3>Background</h3><p>Closed basins occupy 21% of the world’s land area and can substantially affect global carbon budgets. Conventional understanding suggests that the terminal areas of closed basins collect water and carbon from throughout the entire basin, and changes in lake organic carbon sinks are indicative of basin-wide organic carbon storages. However, this hypothesis lacks regional and global validation. Here, we first validate the depositional process of organic carbon in a typical closed-basin region of northwest China using organic geochemical proxies of both soil and lake sediments. Then we estimate the organic carbon sinks and human impacts in extant closed-basin lakes since the Last Glacial Maximum (LGM).</p><h3>Results</h3><p>Results show that 80.56 Pg organic carbon is stored in extant closed-basin lakes mainly found in the northern mid-latitudes. Carbon accumulation rates vary from 17.54 g C m⁻² yr⁻¹ during modern times, 6.36 g C m⁻² yr⁻¹ during the mid-Holocene and 2.25 g C m⁻² yr⁻¹ during the LGM. Then, we evaluated the influence by human activities during the late Holocene (in the past three thousand years). The ratio of human impacts on lake organic carbon storage in above closed basins is estimated to be 22.79%, and human-induced soil organic carbon emissions in the past three thousand years amounted to 207 Pg.</p><h3>Conclusions</h3><p>While the magnitude of carbon storage is not comparable to those in peatland, vegetation and soil, lake organic carbon sinks from closed basins are significant to long-term terrestrial carbon budget and contain information of climate change and human impact from the whole basins. These observations improve our understanding of carbon sinks in closed basins at various time scales, and provide a basis for the future mitigation policies to global climate change.</p></div>","PeriodicalId":505,"journal":{"name":"Carbon Balance and Management","volume":"16 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2021-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8447695/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39445916","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Biomass, carbon stock and sequestration potential of Oxytenanthera abyssinica forests in Lower Beles River Basin, Northwestern Ethiopia","authors":"Shiferaw Abebe,&nbsp;Amare Sewnet Minale,&nbsp;Demel Teketay,&nbsp;Durai Jayaraman,&nbsp;Trinh Thang Long","doi":"10.1186/s13021-021-00192-5","DOIUrl":"10.1186/s13021-021-00192-5","url":null,"abstract":"<div><h3>Background</h3><p>Given the large bamboo resource base with considerable potential to act as an important carbon sink, Ethiopia has included bamboo in the national Reducing Emissions from Deforestation and Forest Degradation and enhancing forest carbon stocks (REDD+) and Clean Development Mechanisms (CDM) programs. However, little is known about the carbon stock and sequestration potential of bamboo forests. As a result, this research was conducted to quantify the carbon sequestration and storage capacity of <i>Oxytenanthera abyssinica</i> forests in the Lower Beles River Basin, northwestern Ethiopia. To this end, a total of 54 circular plots, each measuring 100 m² with a radius of 5.64 m, were established to conduct the inventory in Assitsa and Eddida bamboo forests, the typical bamboo sites in Lower Beles River Basin. Biomass accumulation of bamboo was estimated using an allometric equation based on diameter at breast height (DBH) and age. Soil samples were taken from two different soil depths (0–15 and 15–30 cm) to determine soil organic carbon.</p><h3>Results</h3><p>Results indicate that the mean biomass of the bamboo forests in the study area accounted for about 177.1 <span>(pm)</span> 3.1 Mg ha⁻¹. The mean biomass carbon and soil organic carbon stock of the bamboo forests were 83.2 <span>(pm)</span> 1.5 Mg C ha⁻¹ and 70 <span>(pm)</span> 1.7 Mg C ha⁻¹, respectively. Therefore, the mean carbon stock of the <i>O. abyssinica</i> bamboo forests was 152.5 <span>(pm)</span> 2.5 Mg C ha⁻¹ to 559.8 <span>(pm)</span> 9.0 ton CO₂ ha⁻¹.</p><h3>Conclusion</h3><p>This study highlights the importance of assessing bamboo’s carbon stock and sequestration potential for enhancing its role in climate change mitigation and sustainable resource management. The <i>O. abyssinica</i> bamboo forests of the study area have significant carbon stock and sequestration potential. Therefore, sustainable management of these crucial vegetation resources will enhance their role in providing ecosystem services, including climate change mitigation.</p></div>","PeriodicalId":505,"journal":{"name":"Carbon Balance and Management","volume":"16 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2021-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8447768/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39425284","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Changes in soil carbon sequestration and emission in different succession stages of biological soil crusts in a sand-binding area","authors":"Bo Wang,&nbsp;Jing Liu,&nbsp;Xin Zhang,&nbsp;Chenglong Wang","doi":"10.1186/s13021-021-00190-7","DOIUrl":"10.1186/s13021-021-00190-7","url":null,"abstract":"<div><h3>Background</h3><p>We investigated the spatio-temporal dynamics of soil carbon dioxide (CO₂)- and soil methane (CH₄)-flux during biological soil crust (BSCs) deposition in a sand-binding area in the eastern Chinese Hobq Desert. The trends in soil organic carbon (C) content and density were analyzed during this process. The sampling sites comprised a mobile dune (control) and those with algal, lichen, and moss crust-fixed sands. The desert soil CO₂- and CH₄-flux, temperature, and water content were measured from May to October in 2017 and 2018. Simultaneously, organic C content and density were measured and analyzed by stratification.</p><h3>Results</h3><p>The spatio-temporal variation in desert soil CO₂-flux was apparent. The average CO₂- fluxes in the control, algal, lichen, and moss sites were 1.67, 2.61, 5.83, and 6.84 mmol m⁻² h⁻¹, respectively, during the growing season, and the average CH₄-fluxes in the four sites were − 1.13, − 1.67, − 3.66, and − 3.77 µmol m⁻² h⁻¹, respectively. Soil temperature was significantly positively correlated with CO₂-flux but could not influence CH₄ absorption, and C flux had minimal correlation with soil water content. The soil total organic C density at all sites was significantly different and decreased as follows: moss &gt; lichen &gt; algal &gt; control; moreover, it decreased with soil depth at all sites. The accumulation of desert soil organic C could enhance soil C emissions.</p><h3>Conclusion</h3><p>In a semi-arid desert, artificial planting could promote sand fixation and BSCs succession; therefore, increasing the C storage capacity of desert soils and decreasing soil C emissions could alter the C cycle pattern in desert ecosystems. Soil temperature is the major factor controlling desert soil CO₂ flux and vegetation restoration, and BSCs development could alter the response patterns of C emissions to moisture conditions in desert soils. The results provide a scientific basis for studying the C cycle in desert ecosystems.</p></div>","PeriodicalId":505,"journal":{"name":"Carbon Balance and Management","volume":"16 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2021-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8439077/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39413622","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Carbon emissions from a temperate coastal peatland wildfire: contributions from natural plant communities and organic soils","authors":"Robert A. Mickler","doi":"10.1186/s13021-021-00189-0","DOIUrl":"10.1186/s13021-021-00189-0","url":null,"abstract":"<div><h3>Background</h3><p>One of the scientific challenges of understanding climate change has been determining the important drivers and metrics of global carbon (C) emissions and C cycling in tropical, subtropical, boreal, subarctic, and temperate peatlands. Peatlands account for 3% of global land cover, yet contain a major reservoir of 550 gigatons (Gt) of soil C, and serve as C sinks for 0.37 Gt of carbon dioxide (CO₂) a year. In the United States, temperate peatlands are estimated to store 455 petagrams of C (PgC). There has been increasing interest in the role of wildfires in C cycling and altering peatlands from C sinks to major C sources. We estimated above- and below-ground C emissions from the Pains Bay Fire, a long-duration wildfire (112 days; 18,329 ha) that burned a coastal peatland in eastern North Carolina, USA.</p><h3>Results</h3><p>Soil C emissions were estimated from pre- and post-burn Light Detection and Ranging (LIDAR) soil elevation data, soils series and C content mapping, remotely sensed soil burn severity, and post-burn field surveys of soil elevation. Total above-ground C emissions from the fire were 2,89,579 t C and 214 t C ha⁻¹ for the 10 vegetation associations within the burn area perimeter. Above-ground sources of C emissions were comprised of litter (69,656 t C), shrub (1,68,983 t C), and foliage (50,940 t C). Total mean below-ground C emissions were 5,237,521 t C, and ranged from 2,630,529 to 8,287,900 t C, depending on organic matter content of different soil horizons within each of the 7 soil series. The mean below-ground C emissions within the burn area were 1,595.6 t C ha⁻¹ and ranged from 629.3 to 2511.3 t C ha⁻¹.</p><h3>Conclusions</h3><p>In contrast to undisturbed temperate peatlands, human induced disturbances of the natural elevation gradient of the peatland has resulted in increased heterogeneity of floristic variation and assemblages that are a product of the spatial and temporal patterns of the water table level and the surface wetness across peatlands. Human induced changes in surface hydrology and land use influenced the fuel characteristics of natural vegetation and associated soils, thus influencing wildfire risk, behavior, and the resulting C emissions.</p></div>","PeriodicalId":505,"journal":{"name":"Carbon Balance and Management","volume":"16 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8408986/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39373920","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Two large-scale forest scenario modelling approaches for reporting CO2 removal: a comparison for the Romanian forests","authors":"Viorel N. B. Blujdea,&nbsp;Richard Sikkema,&nbsp;Ioan Dutca,&nbsp;Gert-Jan Nabuurs","doi":"10.1186/s13021-021-00188-1","DOIUrl":"10.1186/s13021-021-00188-1","url":null,"abstract":"<div><h3>Background</h3><p>Forest carbon models are recognized as suitable tools for the reporting and verification of forest carbon stock and stock change, as well as for evaluating the forest management options to enhance the carbon sink provided by sustainable forestry. However, given their increased complexity and data availability, different models may simulate different estimates. Here, we compare carbon estimates for Romanian forests as simulated by two models (CBM and EFISCEN) that are often used for evaluating the mitigation options given the forest-management choices.</p><h3>Results</h3><p>The models, calibrated and parameterized with identical or harmonized data, derived from two successive national forest inventories, produced similar estimates of carbon accumulation in tree biomass. According to CBM simulations of carbon stocks in Romanian forests, by 2060, the merchantable standing stock volume will reach an average of 377 m³ ha⁻¹, while the carbon stock in tree biomass will reach 76.5 tC ha⁻¹. The EFISCEN simulations produced estimates that are about 5% and 10%, respectively, lower. In addition, 10% stronger biomass sink was simulated by CBM, whereby the difference reduced over time, amounting to only 3% toward 2060.</p><h3>Conclusions</h3><p>This model comparison provided valuable insights on both the conceptual and modelling algorithms, as well as how the quality of the input data may affect calibration and projections of the stock and stock change in the living biomass pool. In our judgement, both models performed well, providing internally consistent results. Therefore, we underline the importance of the input data quality and the need for further data sampling and model improvements, while the preference for one model or the other should be based on the availability and suitability of the required data, on preferred output variables and ease of use.</p></div>","PeriodicalId":505,"journal":{"name":"Carbon Balance and Management","volume":"16 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2021-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8379742/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39330978","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Projected soil organic carbon loss in response to climate warming and soil water content in a loess watershed","authors":"Fubo Zhao,&nbsp;Yiping Wu,&nbsp;Jinyu Hui,&nbsp;Bellie Sivakumar,&nbsp;Xianyong Meng,&nbsp;Shuguang Liu","doi":"10.1186/s13021-021-00187-2","DOIUrl":"10.1186/s13021-021-00187-2","url":null,"abstract":"<div><h3>Background</h3><p>Soil organic carbon (SOC) plays a crucial role in the global carbon cycle and terrestrial ecosystem functions. It is widely known that climate change and soil water content (SWC) could influence the SOC dynamics; however, there are still debates about how climate change, especially climate warming, and SWC impact SOC. We investigated the spatiotemporal changes in SOC and its responses to climate warming and root-zone SWC change using the coupled hydro-biogeochemical model (SWAT-DayCent) and climate scenarios data derived under the three Representative Concentration Pathways (RCPs2.6, 4.5, and 8.5) from five downscaled Global Climate Models (GCMs) in a typical loess watershed––the Jinghe River Basin (JRB) on the Chinese Loess Plateau.</p><h3>Results</h3><p>The air temperature would increase significantly during the future period (2017–2099), while the annual precipitation would increase by 2.0–13.1% relative to the baseline period (1976–2016), indicating a warmer and wetter future in the JRB. Driven by the precipitation variation, the root-zone SWC would also increase (by up to 27.9% relative to the baseline under RCP4.5); however, the SOC was projected to decrease significantly under the future warming climate. The combined effects of climate warming and SWC change could more reasonably explain the SOC loss, and this formed hump-shaped response surfaces between SOC loss and warming-SWC interactions under both RCP2.6 and 8.5, which can help explain diverse warming effects on SOC with changing SWC.</p><h3>Conclusions</h3><p>The study showed a significant potential carbon source under the future warmer and wetter climate in the JRB, and the SOC loss was largely controlled by future climate warming and the root-zone SWC as well. The hump-shaped responses of the SOC loss to climate warming and SWC change demonstrated that the SWC could mediate the warming effects on SOC loss, but this mediation largely depended on the SWC changing magnitude (drier or wetter soil conditions). This mediation mechanism about the effect of SWC on SOC would be valuable for enhancing soil carbon sequestration in a warming climate on the Loess Plateau.</p></div>","PeriodicalId":505,"journal":{"name":"Carbon Balance and Management","volume":"16 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2021-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8369727/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39316422","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}