Carbon Balance and Management最新文献

{"title":"Substitution impacts of Nordic wood-based multi-story building types: influence of the decarbonization of the energy sector and increased recycling of construction materials","authors":"Tanja Myllyviita,&nbsp;Elias Hurmekoski,&nbsp;Janni Kunttu","doi":"10.1186/s13021-022-00205-x","DOIUrl":"10.1186/s13021-022-00205-x","url":null,"abstract":"<div><h3>Background</h3><p>The building and construction sectors represent a major source of greenhouse gas (GHG) emissions. Replacing concrete and steel with wood is one potential strategy to decrease emissions. On product level, the difference in fossil emissions per functional unit can be quantified with displacement factors (DFs), i.e., the amount of fossil emission reduction achieved per unit of wood use when replacing a functionally equivalent product. We developed DFs for substitution cases representative of typical wood-frame and non-wood frame multi-story buildings in the Nordic countries, considering the expected decarbonization of the energy sector and increased recycling of construction products.</p><h3>Results</h3><p>Most of the DFs were positive, implying lower fossil emissions, if wood construction is favored. However, variation in the DFs was substantial and negative DFs implying higher emissions were also detected. All DFs showed a decreasing trend, i.e., the GHG mitigation potential of wood construction significantly decreases under future decarbonization and increased recycling assumptions. If only the decarbonization of the energy sector was considered, the decrease was less dramatic compared to the isolated impact of the recycling of construction materials. The mitigation potential of wood construction appears to be the most sensitive to the GHG emissions of concrete, whereas the emissions of steel seem less influential, and the emissions of wood have only minor influence.</p><h3>Conclusions</h3><p>The emission reduction due to the decarbonization of the energy sector and the recycling of construction materials is a favorable outcome but one that reduces the relative environmental benefit of wood construction, which ought to be considered in forest-based mitigation strategies. Broadening the system boundary is required to assess the overall substitution impacts of increased use of wood in construction, including biogenic carbon stock changes in forest ecosystems and in wood products over time, as well as price-mediated market responses.</p></div>","PeriodicalId":505,"journal":{"name":"Carbon Balance and Management","volume":"17 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2022-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://cbmjournal.biomedcentral.com/counter/pdf/10.1186/s13021-022-00205-x","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43365814","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":"Spatiotemporal variations in urban CO2 flux with land-use types in Seoul","authors":"Chaerin Park,&nbsp;Sujong Jeong,&nbsp;Moon-Soo Park,&nbsp;Hoonyoung Park,&nbsp;Jeongmin Yun,&nbsp;Sang-Sam Lee,&nbsp;Sung-Hwa Park","doi":"10.1186/s13021-022-00206-w","DOIUrl":"10.1186/s13021-022-00206-w","url":null,"abstract":"<div><h3>Background</h3><p>Cities are a major source of atmospheric CO₂; however, understanding the surface CO₂ exchange processes that determine the net CO₂ flux emitted from each city is challenging owing to the high heterogeneity of urban land use. Therefore, this study investigates the spatiotemporal variations of urban CO₂ flux over the Seoul Capital Area, South Korea from 2017 to 2018, using CO₂ flux measurements at nine sites with different urban land-use types (baseline, residential, old town residential, commercial, and vegetation areas).</p><h3>Results</h3><p>Annual CO₂ flux significantly varied from 1.09 kg C m^− 2 year^− 1 at the baseline site to 16.28 kg C m^− 2 year^− 1 at the old town residential site in the Seoul Capital Area. Monthly CO₂ flux variations were closely correlated with the vegetation activity (r = − 0.61) at all sites; however, its correlation with building energy usage differed for each land-use type (r = 0.72 at residential sites and r = 0.34 at commercial sites). Diurnal CO₂ flux variations were mostly correlated with traffic volume at all sites (r = 0.8); however, its correlation with the floating population was the opposite at residential (r = − 0.44) and commercial (r = 0.80) sites. Additionally, the hourly CO₂ flux was highly related to temperature. At the vegetation site, as the temperature exceeded 24 ℃, the sensitivity of CO₂ absorption to temperature increased 7.44-fold than that at the previous temperature. Conversely, the CO₂ flux of non-vegetation sites increased when the temperature was less than or exceeded the 18 ℃ baseline, being three-times more sensitive to cold temperatures than hot ones. On average, non-vegetation urban sites emitted 0.45 g C m^− 2 h^− 1 of CO₂ throughout the year, regardless of the temperature.</p><h3>Conclusions</h3><p>Our results demonstrated that most urban areas acted as CO₂ emission sources in all time zones; however, the CO₂ flux characteristics varied extensively based on urban land-use types, even within cities. Therefore, multiple observations from various land-use types are essential for identifying the comprehensive CO₂ cycle of each city to develop effective urban CO₂ reduction policies.</p></div>","PeriodicalId":505,"journal":{"name":"Carbon Balance and Management","volume":"17 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2022-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://cbmjournal.biomedcentral.com/counter/pdf/10.1186/s13021-022-00206-w","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41753963","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":"Wood Vault: remove atmospheric CO2 with trees, store wood for carbon sequestration for now and as biomass, bioenergy and carbon reserve for the future","authors":"Ning Zeng,&nbsp;Henry Hausmann","doi":"10.1186/s13021-022-00202-0","DOIUrl":"10.1186/s13021-022-00202-0","url":null,"abstract":"&lt;div&gt;&lt;h3&gt;Background&lt;/h3&gt;&lt;p&gt;Wood harvesting and storage (WHS) is a hybrid Nature-Engineering combination method to combat climate change by harvesting wood sustainably and storing it semi-permanently for carbon sequestration. To date, the technology has only been purposefully tested in small-scale demonstration projects. This study aims to develop a concrete way to carry out WHS at large-scale.&lt;/p&gt;&lt;h3&gt;Results&lt;/h3&gt;&lt;p&gt;We describe a method of constructing a wood storage facility, named Wood Vault, that can bury woody biomass on a mega-tonne scale in specially engineered enclosures to ensure anaerobic environments, thus preventing wood decay. The buried wood enters a quasi-geological reservoir that is expected to stay intact semi-permanently. Storing wood in many environments is possible, leading to seven versions of Wood Vault: (1) Burial Mound (Tumulus or Barrow), (2) Underground (Pit, Quarry, or Mine), (3) Super Vault, (4) Shelter, (5) AquaOpen or AquaVault with wood submerged under water, (6) DesertOpen or DesertVault in dry regions, (7) FreezeVault in cold regions such as Antarctica. Smaller sizes are also possible, named Baby Vault. A prototype Wood Vault Unit (WVU) occupies 1 hectare (ha, 100 m by 100 m) of surface land, 20 m tall, stores up to 100,000 m&lt;sup&gt;3&lt;/sup&gt; of wood, sequestering 0.1 MtCO&lt;sub&gt;2&lt;/sub&gt;. A 1 MtCO&lt;sub&gt;2&lt;/sub&gt; y&lt;sup&gt;−1&lt;/sup&gt; sequestration rate can be achieved by collecting currently unused wood residuals (WR) on an area of 25,000 km&lt;sup&gt;2&lt;/sup&gt;, the size of 10 typical counties in the eastern US, corresponding to an average transportation distance of less than 100 km. After 30 years of operation, such a Wood Vault facility would have sequestered 30 MtCO&lt;sub&gt;2&lt;/sub&gt;, stored in 300 WVUs, occupying a land surface of 300 ha. The cost is estimated at $10–50/tCO&lt;sub&gt;2&lt;/sub&gt; with a mid-point price of $30/tCO&lt;sub&gt;2&lt;/sub&gt;. To sequester 1 GtCO&lt;sub&gt;2&lt;/sub&gt; y&lt;sup&gt;−1&lt;/sup&gt;, wood can be sourced from currently unexploited wood residuals on an area of 9 Mkm&lt;sup&gt;2&lt;/sup&gt; forested land (9 million square kilometers, size of the US), corresponding to a low areal harvesting intensity of 1.1 tCO&lt;sub&gt;2&lt;/sub&gt; ha&lt;sup&gt;−1&lt;/sup&gt; y&lt;sup&gt;−1&lt;/sup&gt;. Alternatively, giga-tonne scale carbon removal can be achieved by harvesting wood at a medium harvesting intensity of 4 tCO&lt;sub&gt;2&lt;/sub&gt; ha&lt;sup&gt;−1&lt;/sup&gt; y&lt;sup&gt;−1&lt;/sup&gt; on 3 Mkm&lt;sup&gt;2&lt;/sup&gt; of forest (equivalent to increasing current world wood harvest rate by 25%), or harvest on 0.8 Mkm&lt;sup&gt;2&lt;/sup&gt; forest restored from past Amazon deforestation at high harvest intensity, or many combinations of these and other possibilities. It takes 1000 facilities as discussed above to store 1 GtCO&lt;sub&gt;2&lt;/sub&gt; y&lt;sup&gt;−1&lt;/sup&gt;, compared to more than 6000 landfills currently in operation in the US. After full closure of a Wood Vault, the land can be utilized for recreation, agriculture, solar farm, or agrivoltaics. A more distributed small operator model (Baby Vault) has somewhat different operation and economic constraints. A 10 gi","PeriodicalId":505,"journal":{"name":"Carbon Balance and Management","volume":"17 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://cbmjournal.biomedcentral.com/counter/pdf/10.1186/s13021-022-00202-0","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4002423","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":"Operational assessment tool for forest carbon dynamics for the United States: a new spatially explicit approach linking the LUCAS and CBM-CFS3 models","authors":"Benjamin M. Sleeter,&nbsp;Leonardo Frid,&nbsp;Bronwyn Rayfield,&nbsp;Colin Daniel,&nbsp;Zhiliang Zhu,&nbsp;David C. Marvin","doi":"10.1186/s13021-022-00201-1","DOIUrl":"10.1186/s13021-022-00201-1","url":null,"abstract":"<div><h3>Background</h3><p>Quantifying the carbon balance of forested ecosystems has been the subject of intense study involving the development of numerous methodological approaches. Forest inventories, processes-based biogeochemical models, and inversion methods have all been used to estimate the contribution of U.S. forests to the global terrestrial carbon sink. However, estimates have ranged widely, largely based on the approach used, and no single system is appropriate for operational carbon quantification and forecasting. We present estimates obtained using a new spatially explicit modeling framework utilizing a “gain–loss” approach, by linking the LUCAS model of land-use and land-cover change with the Carbon Budget Model of the Canadian Forest Sector (CBM-CFS3).</p><h3>Results</h3><p>We estimated forest ecosystems in the conterminous United States stored 52.0 Pg C across all pools. Between 2001 and 2020, carbon storage increased by 2.4 Pg C at an annualized rate of 126 Tg C year⁻¹. Our results broadly agree with other studies using a variety of other methods to estimate the forest carbon sink. Climate variability and change was the primary driver of annual variability in the size of the net carbon sink, while land-use and land-cover change and disturbance were the primary drivers of the magnitude, reducing annual sink strength by 39%. Projections of carbon change under climate scenarios for the western U.S. find diverging estimates of carbon balance depending on the scenario. Under a moderate emissions scenario we estimated a 38% increase in the net sink of carbon, while under a high emissions scenario we estimated a reversal from a net sink to net source.</p><h3>Conclusions</h3><p>The new approach provides a fully coupled modeling framework capable of producing spatially explicit estimates of carbon stocks and fluxes under a range of historical and/or future socioeconomic, climate, and land management futures.</p></div>","PeriodicalId":505,"journal":{"name":"Carbon Balance and Management","volume":"17 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2022-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://cbmjournal.biomedcentral.com/counter/pdf/10.1186/s13021-022-00201-1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4424936","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":"The default methods in the 2019 Refinement drastically reduce estimates of global carbon sinks of harvested wood products","authors":"Chihiro Kayo,&nbsp;Gerald Kalt,&nbsp;Yuko Tsunetsugu,&nbsp;Seiji Hashimoto,&nbsp;Hirotaka Komata,&nbsp;Ryu Noda,&nbsp;Hiroyasu Oka","doi":"10.1186/s13021-021-00200-8","DOIUrl":"10.1186/s13021-021-00200-8","url":null,"abstract":"<div><h3>Background</h3><p>The stock dynamics of harvested wood products (HWPs) are a relevant component of anthropogenic carbon cycles. Generally, HWP stock increases are treated as carbon removals from the atmosphere, while stock decreases are considered emissions. Among the different approaches suggested by the Intergovernmental Panel on Climate Change (IPCC) for accounting HWPs in national greenhouse gas inventories, the production approach has been established as the common approach under the Kyoto Protocol and Paris Agreement. However, the 24th session of the Conference of the Parties to the United Nations Framework Convention on Climate Change decided that alternative approaches can also be used. The IPCC has published guidelines for estimating HWP carbon stocks and default parameters for the various approaches in the 2006 Guidelines, 2013 Guidance, and 2019 Refinement. Although there are significant differences among the default methods in the three IPCC guidelines, no studies have systematically quantified or compared the results from the different guidelines on a global scale. This study quantifies the HWP stock dynamics and corresponding carbon removals/emissions under each approach based on the default methods presented in each guideline for 235 individual countries/regions.</p><h3>Results</h3><p>We identified relatively good consistency in carbon stocks/removals between the stock-change and the atmospheric flow approaches at a global level. Under both approaches, the methodological and parameter updates in the 2019 Refinement (e.g., considered HWPs, starting year for carbon stocks, and conversion factors) resulted in one-third reduction in carbon removals compared to the 2006 Guidelines. The production approach leads to a systematic underestimation of global carbon stocks and removals because it confines accounting to products derived from domestic harvests and uses the share of domestic feedstock for accounting. The 2013 Guidance and the 2019 Refinement reduce the estimated global carbon removals under the production approach by 15% and 45% (2018), respectively, compared to the 2006 Guidelines.</p><h3>Conclusions</h3><p>Gradual refinements in the IPCC default methods have a considerably higher impact on global estimates of HWP carbon stocks and removals than the differences in accounting approaches. The methodological improvements in the 2019 Refinement halve the global HWP carbon removals estimated in the former version, the 2006 Guidelines.</p></div>","PeriodicalId":505,"journal":{"name":"Carbon Balance and Management","volume":"16 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2021-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8666044/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39717313","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":"Modelling the disappearance of coarse woody debris, following a land clearing event","authors":"Matthew J. Pringle,&nbsp;Steven G. Bray,&nbsp;John O. Carter","doi":"10.1186/s13021-021-00199-y","DOIUrl":"10.1186/s13021-021-00199-y","url":null,"abstract":"<div><h3>Background</h3><p>Land clearing generates coarse woody debris (CWD), much of which ultimately becomes atmospheric CO₂. Schemes for greenhouse gas accounting must consider the contribution from land clearing, but the timing of the contribution will have large uncertainty, due to a paucity of knowledge about the rate of CWD disappearance. To better understand above-ground CWD disappearance following a land clearing event—through the actions of microorganisms, invertebrates, wildfire, or deliberate burning—we combined statistical modelling with an archive of semi-quantitative observations (units of CWD %), made within Queensland, Australia.</p><h3>Results</h3><p>Using a generalised additive mixed-effects model (median absolute error = 14.7%), we found that CWD disappearance was strongly influenced by the: (i) number of years elapsed since clearing; (ii) clearing method; (iii) bioregion (effectively a climate-by-tree species interaction); and (iv) the number of times burned. Years-since-clearing had a strongly non-linear effect on the rate of CWD disappearance. The data suggested that disappearance was reverse-sigmoidal, with little change in CWD apparent for the first three years after clearing. In typical conditions for Queensland, the model predicted that it will take 38 years for 95% of CWD to disappear, following a land clearing event; however, accounting for uncertainty in the data and model, this value could be as few as 5 years, or &gt; 100 years. In contrast, due to an assumption about the propensity of land managers to burn CWD, the official method used to assess Australia’s greenhouse gas emissions predicted that 95% of CWD will disappear in &lt; 1 year.</p><h3>Conclusions</h3><p>In Queensland, the CWD generated by land clearing typically takes 38 years to disappear. This ultimately implies that a key assumption of Australia’s official greenhouse gas reporting—i.e. that 98% of CWD is burned soon after a clearing event—does not adequately account for delayed CO₂ emissions.</p></div>","PeriodicalId":505,"journal":{"name":"Carbon Balance and Management","volume":"16 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2021-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8650528/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39576737","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":"Correction to: 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/s13021-021-00198-z","DOIUrl":"10.1186/s13021-021-00198-z","url":null,"abstract":"","PeriodicalId":505,"journal":{"name":"Carbon Balance and Management","volume":"16 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2021-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8594098/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39892600","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":"Allometric equations for selected Acacia species (Vachellia and Senegalia genera) of Ethiopia","authors":"Abreham Berta Aneseyee,&nbsp;Teshome Soromessa,&nbsp;Eyasu Elias,&nbsp;Gudina Legese Feyisa","doi":"10.1186/s13021-021-00196-1","DOIUrl":"10.1186/s13021-021-00196-1","url":null,"abstract":"<div><h3>Background</h3><p>Allometric equations are used to estimate biomass and carbon stock of forests. In Ethiopia, despite the presence of large floral diversity, only a few site-specific allometric equations have been developed so far. This study was conducted in the Omo-Gibe woodland of south-western Ethiopia to develop an allometric equation to estimate the Above-ground Biomass (AGB) of the four <i>Acacia</i> species (<i>Senegalia polyacantha</i>, <i> Vachellia seyal, Vachellia etbaica</i> and <i>Vachellia tortilis</i>)<i>.</i> Fifty-four (54) <i>Acacia</i> trees were sampled and measured within 35 temporarily established square plots. In each plot, dendrometric variables were measured to derive the models based on combinations of Diameter at Breast Height (DBH), height, and wood density as predictor variables. Model performance was evaluated using goodness-of-fit statistics. The biomass was compared using four allometric biomass models that have been widely used in the tropics.</p><h3>Results</h3><p>The model containing DBH alone was more accurate to estimate AGB compared to the use of multiple predictor variables. This study, therefore, substantiated the importance of site-specific allometric equations in estimating the AGB of <i>Acacia</i> woodlands. This is because a site-specific allometric equation recognizes the environmental factors, vegetation types and management practices.</p><h3>Conclusions</h3><p>The results of this study contribute to a better understanding of allometric equations and an accurate estimate of AGB of <i>Acacia</i> woodlands in Ethiopia and similar ecosystems elsewhere.</p></div>","PeriodicalId":505,"journal":{"name":"Carbon Balance and Management","volume":"16 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2021-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8561847/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39672436","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":"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}