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Soil organic carbon (SOC) and nitrogen (N) are two of the most important indicators for agricultural productivity. The primary objective of this study was to investigate the changes in SOC and N in the deep soil profile (up to 100 cm) and their relationships with crop productivity under the influence of long-term (since 1990) fertilization in the wheat-maize cropping system. Treatments included CK (control), NP (inorganic N and phosphorus (P) fertilizers), NPK (inorganic N, P and potassium fertilizers), NPKM (NPK plus manure), and M (manure). Crop yield and the properties of topsoil were measured yearly from 2001 to 2009. C and N contents were measured at five different depths in 2001 and 2009. The results showed that wheat and maize yields decreased between 2001 and 2009 under the inorganic fertilizer (NP and NPK) treatments. The average yield between 2001 and 2009 under the NP, NPK, NPKM, and M treatments (compared with the CK treatment) increased by 38, 115, 383, and 381%, respectively, for wheat and 348, 891, 2 738, and 1 845%, respectively, for maize. Different long-term fertilization treatments significantly changed coarse free particulate (cfPOC), fine free particulate (ffPOC), intramicroaggregate particulate (iPOC), and mineral-associated (mSOC) organic carbon fractions. In the experimental years of 2001 and 2009, soil fractions occurred in the following order for all treatments: mSOC>cfPOC>iPOC>ffPOC. All fractions were higher under the manure application treatments than under the inorganic fertilization treatments. Compared to the inorganic fertilization treatments, manure input enhanced the stocks of SOC and total N in the surface layer (0–20 cm) but decreased SOC and N in the deep soil layer (80–100 cm). This reveals the efficiency of manure in increasing yield productivity and decreasing risk of vertical loss of nutrients, especially N, compared to inorganic fertilization treatments. The findings provide opportunities for understanding deep soil C and N dynamics, which could help mitigate climate change impact on agricultural production and maintain soil health.

The Qilian Mountain National Nature Reserve is an important ecological barrier in northwestern China; therefore, it is of great importance to accurately evaluate the carbon storage of its main arbor forest. In this study, the Tianlaochi Basin of Qilian Mountain Nature Reserve was used as the research area to measure the carbon storage of the main arbor forests and determine the relationship between neglect of understory vegetation and errors in estimated carbon storages. The results showed that: (1) The total carbon storages of Picea crassifolia and Sabina przewalskii in Qilian Mountain Nature Reserve were 6.05 × 107 and 9.48 × 106 Mg and the carbon density were 426.07 Mg/hm2 and 338.72 Mg/hm2, respectively. (2) The understory carbon storage of Picea crassifolia and Sabina przewalskii accounted for 7.03% and 5.5% of the total carbon storage, respectively (6.81% combined). When the understory vegetation was neglected, the carbon storage in Qilian Mountain Nature Reserve was estimated to be less than 9.72 × 105 Mg. (3) There are large areas of Picea and Sabina forests worldwide; therefore, ignoring understory vegetation in these systems when estimating the carbon stock will lead to underestimations. Our research can provide a reference when estimating the carbon storage of similar tree species.

This study aims at estimating the carbon emission from biomass carbon stock change in tropical forests of Sarawak, Malaysia, within the years 2005–2014 as a consequence of wood harvesting. Emission inventory has been developed in the study, based on Tier 1 methodology of 2006 IPCC (Intergovernmental Panel on Climate Change). To the best of our knowledge, this paper is among the first papers to utilize 2006 IPCC Guidelines for computing change in biomass carbon stocks. From the results obtained, it was found that overall carbon emission was a net gain for Sarawak. During the period of 2005–2014 net gain in biomass carbon stocks was observed with values ranging from 28.76 Mt C or 105.44 CO2 equivalent to 39.03 Mt C or 143.11 CO2 equivalent. Whereas emission from wood removal has started to decrease since 2008 from 6.28 Mt C to 2013 at 4.64 Mt C due to lesser wood removed resulting from global economic crisis. Rapid changes in areas of tropical forests was and varying evaluation method were identified to be the major problem. High uncertainty of data currently in existence for this tropic region highlights the need for additional field investigations in the effort of evaluating future biomass carbon stock. Keywords: Biomass carbon stock, Gain-loss method, Forest remain forest, Tier 1, Wood removal

Tropical forests play a key role in climate change mitigation by sequestering and storing carbon from the atmosphere. In Ethiopia, there are inadequate data in the form of carbon accumulation records or databank to assess the carbon sequestration potential of different forests. This study intended to estimate the living biomass and carbon stocks of woody plants in Chilimo-Gaji Forest. Totally, 10 circular plots with 20 m radius each having 1,256 m2, estimated the biomass of 17 tree species using the nondestructive allometric equation. The total woody biomass of the study area estimated to be 1013.3 t ha-1, of which, about 83.3 % (844.4 t ha-1) was aboveground, and 16.7% (168.9 t ha-1) was below ground biomass. The total carbon stocks and total carbon sequestration potential of the study area was about 506.7 t C ha-1 and 1859.45 t ha-1, respectively. The result indicates that the Chilimo-Gaji Forest has huge potential for carbon stock compared to research conducted on other remnant forests in Ethiopia. This is mainly due to the improvement in the forest stocks as a result of participatory forest management practices in the area. Generally, Chilimo-Gaji Forest is playing a vital role in carbon sequestration, thereby contributing to climate change mitigation. Therefore, in the future, the forest can generate carbon credits as financial benefits to the indigenous population, which could help to strengthen the conservation efforts of forest resources in the study area.

The carbon sequestered in harvested wood products (HWP) can contribute to climate change mitigation. As a fast-growing country with abundant forest resources, Indonesia potentially has vast HWP carbon stocks that need to be accurately assessed as a first step towards understanding the extent of their potential contribution in climate change mitigation. In this study, a dynamic materials stock and flow analysis for carbon in wood-based products in Indonesia was conducted, covering six end-use sectors. In general, only around 30.3% of the harvested wood (carbon mass) was converted into end-use materials in 2014, indicating a significantly low harvested wood conversion rate in Indonesia. There was a significant increase of wood-based products’ carbon stocks in Indonesia from 1961 to 2016. There were 72 (-17/+15) Mt-C of wood stocks in Indonesian society in 2016, or equivalent to 0.28 t-C/capita. Buildings (42%) and infrastructure (31%) were the largest contributors to in-use carbon stocks. The product lifetime uncertainty had a significant influence on the estimate of total society’s wood-based carbon stock. Indonesia’s in-use stock of wood-based products in 2008 was below its stock level of steel (1.2 times smaller) and cement (5.3 times smaller). Both wood-steel and wood-cement stock ratios showed declining trends, indicating a shifting trend to non-renewable materials use over the past decades. This is the first study that accounts for the in-use wood-based carbon stocks in a developing country. Its results can facilitate further quantitative environmental assessments of non-renewable materials substitution and could help framing materials use policies for climate change mitigation.

Biomass of vegetation is a crucial variable for understanding the potential future changes of the climate system. In the present study dominant land use types i.e. agroforestry (AF), banjoak forest (BF), chirpine forest (CF), mixed forest (MF) and grasslands (GL) of Himalayan region was investigated for biomass production and carbon stock budgeting in vegetation as well as in soil. Among land use type's highest aboveground biomass was recorded in banjoak forest (BF), 0.69%, 9.42% and 40.16% more than chirpine forest (CF), mixed forest (MF) and agroforestry (AF). However it was more than 16 times higher than grasslands (GL). Herbage and/or crops aboveground biomass was 3.73%, 4.05%, 4.42% and 29.34% of the aboveground biomass of trees in BF, CF, MF and AF. Herbage aboveground biomass was 76.01% of total aboveground biomass in grasslands. Our results revealed that in AF crops biomass accounted for 19.41–26.60% and trees contributed 73.40–80.59% biomass in total biomass of land use. Likewise, similar contributions were recorded for belowground biomass and total biomass in land uses. Irrespective of land use types along elevation the total biomass including aboveground and belowground biomass significantly (P

Natural forest comprises approximately 78% of New Zealand’s total forest area and their dead wood carbon pools contribute to the national carbon balance reported under the United Nations Framework Convention on Climate Change. We investigate the accuracy of coarse woody debris (CWD) carbon stock estimates obtained from periodic inventories of New Zealand’s natural forest. Dimensions and decay classes of standing-dead spars, fallen logs and stumps over 10 cm diameter were assessed in permanent plots during two inventory cycles (2002–07 and 2009–14). Carbon in CWD was estimated by multiplying CWD volume with species-specific mean wood and bark density, a density modifier based on decay class, and the carbon fraction. The measured change in CWD between inventories was obtained by subtracting 2002–07 from 2009–14 mean CWD carbon stocks. This measured change in CWD carbon stocks was compared with the modelled change derived by applying a decay model to 2002–07 stocks to determine the losses from decay and adding inputs from the tree mortality recorded between the two measurement cycles. Estimates of CWD carbon stocks from field measurements were 19.9 and 19.5 tC ha−1 in 2002–07 and 2009–14 respectively, with a statistically non-significant change of −0.4 ± 0.6 tC ha−1 (95% C.I.) over the period between measurements implying that CWD carbon is in a steady state. However, the modelling approach gave a significant increase of 2.5 ± 0.7 tC ha−1, implying that CWD stocks are increasing. It appears likely that the primary reason for the discrepancy between the direct measurement and modelling approaches is that CWD carbon stocks are substantially underestimated using current measurement protocols used in the inventory of New Zealand’s natural forest. If CWD carbon stocks in New Zealand’s natural forests are approximately in balance as implied by the direct measurement of CWD stocks, CWD inputs from mortality would have to be balanced by losses from decay. For this to be true, the CWD pool would have to approximate 35.4 tC ha−1 which is 78% higher than its measured value.

Forests are among the most important land ecosystems both in term of their contribution to the global carbon cycle and for their prominence in hosting large biodiversity. Under a changing world, both in terms of land use and climate scenarios, it is pivotal to understand the matter and energy flows in complex ecosystems such as forests, in order to infer potential relationships at different levels, i.e. from soil to bird community within the forest stands. In this context, soil organic matter is main source of carbon and energy for heterotrophic soil organisms, which are a main component of the whole food web all the way up to bird communities. Even though many studies have investigated factors affecting C cycle and bird communities in forest ecosystems separately, an integrated approach that links soil to bird community was never attempted. Accordingly, we have used an innovative Two-block Partial Least Squares analysis to investigate patterns of covariance between soil and nesting bird communities in a relatively small wooded area surrounded by the urban area of Naples (southern Italy). Our research revealed that, in spite of the small extent and the surrounding urban context, the area of the Astroni hosts a substantial C stock and has a diversified bird nesting community. The abundance of species such as blue tit, jay, green woodpecker and great tit had a direct covariance with C stock in litter, while sampling sites that were characterized by greater C stocks in the soil and higher microbial activity were correlated with abundance of other bird species, most noticeably short-toed treecreeper and blackbird. Despite the limited extent of our research area, our study showed, for the first time, patterns of covariance between some forest species and different soil variables, linking forest ecological compartments whose connections are not immediately detectable and that could open new perspectives in land use management, both in terms of C stock and biodiversity evaluations.

Woody-biomass is an important indicator for good vegetation cover, and a healthy environment that provides ecosystems services such as supplying, provisioning, regulating, esthetic, and cultural values. Moreover, woody-biomass stores a very good amount of carbon dioxide as about fifty percent of living organisms are built from carbon. The objective of this study is to estimate the above and belowground woody biomass and carbon stock of Kunzila watershed, Northwest Ethiopia as a piece of baseline information so as to gage the changes after the intervention. The watershed covers about 11,200 ha of land with undulating topographic landscapes. More than 230 sample plots of 30 m by 30 m were surveyed and every woody plant (shrub/bush and tree) was measured. Allometric equations were applied to calculate biomass and carbon stock potential at the plot level. The Random forest algorithm was applied to upscale plot values to watershed level. The results indicate that Kunzila watershed offers maximum biomass of 1,756(±249) Mt year−1/watershed and corresponding carbon dioxide equivalent (CO2e) of 3,022(±429) Mt C year−1 /watershed with the current vegetation status; while the average woody biomass and CO2e were estimated about 244(±249) Mt ha−1 year−1 and 425(±429) Mt C ha−1 year−1, respectively. These results indicate that there are high variabilities among different ecosystem types and also the watershed generally offers below its potential. However, there is a high potential to achieve up to triples of biomass and CO2e by implementing recommended intervention plans developed out of the current study. The current approach using machine learning algorithm to upscale from sample plot-level to watershed scale is a very good one and can be applied to other watersheds at scale.

Accurate quantification of fine fuel loads (e.g. foliage and twigs) in forests is required for many fire behaviour models, and for assessing post-fire changes in carbon stocks and modelling smoke emissions. Fine fuels burn readily and are thus often targeted for fuel load assessments. Estimates of fine live fuel loads often rely on visual assessments or utilise allometric equations that relate stem diameter of plants to total above-ground biomass. Here, we develop allometric equations for shrubs that relate stem diameter to the portion of above-ground biomass comprised of fine fuel. Our study area is within the temperate eucalypt forests of south-eastern Australia. We present equations for (i) foliage; (ii) all biomass

We measured total carbon stocks of three marshes: Two formed in association with a developing spit along the Gulf of St. Lawrence coast of New Brunswick, Canada, and another with a lagoon on the coast of Maine, USA. Overall, 46 cores and 157 depth recordings were collected to determine depth of the marsh deposits. Total marsh soil volume was estimated by interpolation. In all marshes soil depth varied in a predictable pattern based upon marsh developmental history. In spit marshes deposit age and thickness increased towards the oldest portion of the spit. In the lagoonal marsh, soil depth was greatest in the center and declined towards both the upland and seaward margins. This same pattern held on axes perpendicular to the primary, age axis of the spit marshes. In each marsh C density did not significantly vary with depth so that marsh depth was an acceptable estimator of C stock, and therefore driven by the geomorphic context of the marshes we studied. There were major differences in C stock estimates produced using GIS interpolation, average C contained in all marsh cores, or cores along a single transect. Our study demonstrates that assuming a soil depth of just 0.5 or 1 m can substantially under- or overestimate marsh carbon stocks and the value of that stock on a carbon market.

Globally, drylands cover large areas, but few models for estimation of biomass are developed for the relatively complicated tree and shrub structures found in this particular environment. A first set of general aboveground biomass models for exclosures in the drylands of the Tigray region, northern Ethiopia were developed from a large dataset with 305 destructively sampled trees and shrubs covering 50 different species and distinct growing conditions. Since biomass revealed nonlinear relationships to the independent tree variables, we used a nonlinear least square modelling technique when fitting models. Selection of models was based on Pseudo-R2, and root mean square errors and mean prediction errors (MPE) from a leave-one-out-cross-validation procedure. Pseudo-R2 and relative MPE of the models varied from 0.76 to 0.84 and −3.7% to −1.5%, respectively. The large prediction errors observed when testing the “pan-tropical” models on our data, not only demonstrated the importance of developing the new models, but also indicated that careful considerations should done if the “pan-tropical” are planned for application in drylands elsewhere than Ethiopia. The new models may be applied generally for exclosures in Tigray for decision-support in forest management and as basis for reporting changes in carbon stock as required in the REDD + mechanism.

Tree biomass data are essential for developing the biomass allometric models that are necessary for estimating carbon stock and for monitoring changes in forest biomass. In this ‘data article’ biomass records are presented for 240 Norway spruce trees (Picea abies (L.) Karst.). Trees were between 4 and 15 years of age and were sampled from 24 pure plantations located in Eastern Carpathians of Romania. Ten trees were sampled from each plantation using a cluster sampling method. For each tree, diameter at root collar height (D) and tree height (H) are provided as potential predictors for biomass. Oven-dried biomass is also recorded for the following partitions: stem (ST); branches (BR); needles (ND); roots (RT); as well as their combinations representing total aboveground biomass (AGB) and overall tree biomass (TB). Sampled trees were between 0.6 and 10.0 cm in diameter and between 53.0 and 552.0 cm in height. Total tree biomass ranged between 0.019 and 15.53 kg/tree. This dataset is related to the research article entitled “Site-effects on biomass allometric models for early growth plantations of Norway spruce (Picea abies (L.) Karst.)” (Dutca et al., 2018) [1] .

In 2015 New Zealand exported 10.5 Mm3 of logs to China. A model has been developed to quantify the carbon stocks of harvested wood products (HWP) manufactured in China from these logs and the life cycle of the HWP produced. The model allows the aggregate decay curve of the HWP carbon stock to be estimated together with the 95% confidence interval. Overall, the HWP produced in China from New Zealand logs are short-lived with an aggregate half-life of just under two years. Some 46% of the HWP is lumber and plywood used for temporary construction while 13% is used for packaging which is also short-lived. There is a long tail in the carbon decay curve with 10% of HWP still in use after 23 years. Longer lived products are the 9% of HWP used for appearance products including furniture as well as panel products produced from a proportion of sawmill and plymill residues. Logs have been exported to China annually since 1987 and at levels exceeding 5 Mm3/year since 2010. The total HWP carbon stock from historical log exports is estimated to be 22.7 Mt CO2 at the end of 2015 with a 95% confidence interval of 19.1–26.4 Mt CO2. The annual increase for 2015 is estimated to be 1.9 ± 0.5 Mt CO2. The model developed will support New Zealand in meeting UNFCCC carbon reporting and Kyoto Protocol carbon accounting requirements. The analysis highlighted the importance of certain model inputs on which future effort should be focused.

Accurate and reliable soil organic carbon stock estimation is critical in understanding forest role to regional carbon cycles. So far, the total carbon pool in dry Miombo ecosystems is often under-estimated. In that regard this study sought to model the relationship between the aboveground woody carbon pool and the soil carbon pool, using both ground-based and remote sensing methods. To achieve this objective, the Ratio Vegetation Index (RVI), Normalized Difference Vegetation Index (NDVI), and the Soil Adjusted Vegetation Index (SAVI) computed from the newly launched Landsat 8 OLI satellite data were used. Correlation and regression analysis were used to relate Soil Organic Carbon (S.O.C), aboveground woody carbon and remotely sensed vegetation indices. Results showed a soil organic carbon in the upper soil layer (0–15 cm) was positively correlated with aboveground woody carbon and this relationship was significant (r = 0.678; P 0.05) between SOC in the deeper soil layer (15–30 cm) and aboveground woody carbon. These findings imply that (relationship between aboveground woody carbon and S.O.C) aboveground woody carbon stocks can be used as a proxy to estimate S.O.C in the top soil layer (0–15 cm) in dry Miombo ecosystems. Overall, these findings underscore the potential and significance of remote sensing data in understanding savanna ecosystems contribution to the global carbon cycle.

Major infrastructure projects can cause sizeable reduction in the urban tree cover thereby affecting terrestrial carbon sequestration potential of cities. This study investigated the spatio-temporal changes occurred in terrestrial carbon sequestration due to the metro rail project at Kochi city in India during the years 2013 to 2015. Normalized Difference Vegetation Index (NDVI) estimated from IRS-P6 LISS IV satellite sensor data was used to detect the tree cover change and for the quantification of carbon stock. An urban carbon storage equation was used to estimate the carbon content from NDVI values. Stock difference approach was used to estimate the change in carbon sequestration due to the construction of metro rail. Results indicated reduction of 14.51 ha of tree cover area within a distance of 60 m from the center-line of metro rail during the study period. Study found that 2316 tCO2e was emitted as a result of cutting urban trees for the metro rail. Such an emission was overlooked while estimating the emission reduction due to the promotion of public transport. This study points to the need for estimating the impacts of major urban infrastructure projects to the global climate in addition to assessing their mostly localized environmental impacts.

In tropical forests, selective logging generates a significant reduction of above-ground carbon stocks, due to direct removal of a few large merchantable individuals, and the death of smaller injured or smashed trees following harvesting. Several studies have shown a strong correlation between logging intensity and a reduction of biodiversity, wood production, and biomass stocks. However, little is known about the long-term effects of logging on the main forest carbon (C) stocks in above and below-ground tree biomass, deadwood, litter, and soil. In this study we quantified C stocks in 28 0.25-ha plots located in a mixed Dipterocarp forest, Borneo, Indonesia, logged 16 years ago at different intensities ranging from 0 to 57% of initial biomass removed. We investigated the effect of logging intensity, topography, and soil variables on each C stock using linear mixed models. Sixteen years after logging, total C stocks ranged from 218 to 554 Mg C ha−1 with an average of 314 ± 21 Mg C ha−1, of which more than 75% were found in live trees. Logging intensity was found to be the main factor explaining the variability in carbon stored in above- and below- ground biomass of tree DBH >20 cm and deadwood. Simultaneously, the proportion of deadwood increased with logging intensity reaching 13.5% of total C stocks in intensively logged plots (>20% removal of initial biomass). This study confirmed, therefore, the need to limit logging intensity to a threshold of 20% of initial biomass removal in order to limit the long-term accumulation of deadwood after logging, probably due to high post-logging mortality. With more than half of all Bornean forests already logged, accounting for total C post-logging is key to better assess the long-term carbon footprint of commercial logging in the region, and is a necessary step towards the development of C-oriented forest management in the tropics.

Decision-making process, as well as the implementation of future climate change mitigation strategies for mangrove ecosystems, need the availability of reliable base information and tools to estimate the carbon stocks at regional and national levels. We estimated carbon (C) stocks in aboveground biomass (AGB) for mangroves in the Caribbean and Pacific coasts of Colombia. Using available data on AGB density and mangrove area for the whole country (excluding islands) and each coast independently, we estimated a national carbon stock in AGB for Colombian mangroves as 14.95 ± 2.72 TgC (mean ± SE), with 2.20 ± 0.86 TgC in the Caribbean coast and 9.61 ± 2.78 TgC in the Pacific coast. Uncertainty for total carbon in AGB in Colombian mangroves, reported as SE/mean in percentage, was 18% at the national level, 39% in the Caribbean coast, and 29% in the Pacific coast. This uncertainty was more influenced by uncertainties associated with the estimation of mangrove area for the Caribbean coast, while for the Pacific coast it was more influenced by the uncertainties associated with AGB density. This difference is the result of a contrasting availability of AGB density data for both coasts. Comparison between observed AGB density data and predictions from large-scale models showed that these models underestimate AGB density for Colombian mangroves. We reparameterized these models with our data, but found poor goodness-of-fit statistics for these model structures. We propose therefore three new statistical models to predict AGB density in Colombian mangroves based on climatic and vegetation data. In all cases, the best models included the enhanced vegetation index (EVI) and the mean temperature of driest quarter (BIO9).

V. Rolo and P.I. Olivier are supported by post-doctoral grants from the National Research Foundation (NRF) of South Africa. This work was also partly funded by an Ecologists in Africa grant by the British Ecological Society to P.I. Olivier. R.J. van Aarde is supported by Richards Bay Minerals, NRF and the Technology and Human Resources for Industry Programme (THRIP). M. Pfeifer was supported by European Research Council Project number 281986.

Soils are a large reservoir of organic carbon, and plays a significant role in its accumulation and storage. The goal of this study is to provide a generalized estimate of soil organic carbon (SOC) stocks at dominant types of forest soils in the European North-East of Russia. The soil cover of the studied territory is mostly formed by Histic Retisols (HsR), Haplic Retisols (HpR) and Albic Podzols (AP). We used the results of our own SOC estimates and the ones of soil profile descriptions that were published for the region of investigation. The calculation was carried out for organic horizons and depths of 0–30, 0–50 and 0–100 cm including the organic horizon. The literature data lacks bulk density (BD) information. We calculated the mean BD value for soil horizons based on our BD determinations conducted for the studied soil groups in various parts of the region. The obtained BD values differed for separate soil groups. Relatively high BD of mineral horizons was obtained for HsR, low BD – for AP. Larger BD of organic layer for HpR is explained by accumulation of comparatively well-decomposed organic matter on the soil surface. The BD of organic layers was comparable for AP and HsR. The SOC stocks in all soil groups were characterized by a wide variation with differences between minimal and maximal values changing from 4 to 13 times. A closer spread was for HpR. The highest SOC stocks in 1 m depth were calculated for HsR with the mean value of 12.66 ± 0.13 kg m−2. The SOC content in HpR was 7.69 ± 0.12 kg m−2 and in AP – 3.80 ± 0.09 kg m−2. The organic layer share varied from 24 to 35% in SOC stocks of the 1 m profile. The depth of 0–50 cm concentrates 70–78% of SOC of the 1 m soil profile. According to the mean SOC stocks data and the area of the soil groups we estimated SOC stocks concentrated in main soil groups in the Komi Republic.

Forests are the world's largest carbon sink and play a vital role in climate change mitigation through carbon sequestration; thus the assessment of carbon stock in the forests is important for policy prescription and management planning. In view of this, present study is an attempt to assess the biomass and carbon stock of tree species in selected subtropical and temperate forest stands along the vertical elevation gradient (300 m to 2250 m) in the Central Himalaya. Volumetric equations (allometric method) were used for various tree species along with field sampling/ assessment (quadrat method) for biomass and carbon sequestration potentials. The total tree biomass and carbon stock of dominant forest stands varied from 227.23 to 577.16 Mg ha−1 (megagram per hectare), and 107.93 to 274.15 Mg C ha−1 respectively; it was found maximum for Sal (Shorea robusta) dominated forest and minimum for mixed Oak forest (Quercus floribunda, Q. lanuginosa, Q. leucotrichophora etc.). The carbon sequestration was recorded maximum (4.83 Mg C ha−1 yr−1) for Chir-pine stand (Pinus roxburghii) followed by Sal (4.63 Mg C ha−1 yr−1), mixed Oak (4.47 Mg C ha−1 yr−1), and minimum (3.99 Mg C ha−1 yr−1) for temperate Banj-oak forest (Quercus leucotrichophora). The contribution of above and below ground biomass among different forest stands was recorded 82% and 18% respectively. The dominant species contributed maximum biomass and carbon stock (70–82%) in pure Sal, Chir-pine and Banj-oak stand, while the contribution of dominant and co-dominant species in the mixed forest varied depending on forest composition. The results reveal higher carbon stock for subtropical forest as compared to temperate forest; however, it is interesting that there is no significant difference in carbon sequestration among the different forest stands. The study recommended for the assessing biomass and carbon stock of different forests for long-term management of forests and climate change mitigation.

As the rate of forest degradation continues to rise, agroforestry systems may serve as a way of conserving species and carbon sinks. The aim of the study was to assess the contribution of Daniellia oliveri agroforestry parklands to the mitigation of climate change via the estimation of carbon stock in the Sudanian-Sahelian zone of Cameroon. To achieve it, an ecological study was carried out. A total area of 144 ha has been established in Daniellia oliveri agroforestry parklands. To meet this objective, the diameter at breast height of trees in Daniellia oliveri parklands was measured with regard to their age. Thus, allometric equations and the ascending hierarchical classification were used for the assessment of carbon stock and determination of the typology of Daniellia oliveri agroforestry parklands in the study area. The results show that Daniellia oliveri agroforestry parklands harbor 61 species belonging to 48 genera and 45 families. The carbon stored in Daniellia oliveri agroforestry parklands differs according to their age. It varies from 85.44±11.11 tC/ha for 1-10 year in young parklands to 236.55±4.96 tC/ha for those ≥30 years old. Carbon sequestration potential fluctuates from 312.71±40.77 CO2eq/ha for young parklands (1-10 years) to 865.77±18.20 CO2eq/ha in old one (≥30 years). The typology of Daniellia oliveri agroforestry parklands indicates the existence of three categories of parklands among which; type 1, the most representative of the area (52.78%) and capable of generating significant income. This study greatly contributes to the understanding of the usefulness of Daniellia oliveri agroforestry parklands for carbon sequestration. Actions to strengthen the protection of the trees of this ecosystem must be considered to minimize its long-term degradation and so that it can be a more sustainable source of carbon sequestration.

The world’s largest area of tropical peatland ecosystems is found in South-East Asia. These peatlands have globally significant carbon stocks and play an important role in regional and global climate systems. Despite the valuable social and economic services and ecosystem biodiversity these tropical peatlands provide, misguided land use policies have resulted in widespread peatland degradation in the region during the past 20 years. This paper reviews the drivers of peatland degradation in South-East Asia and confirms that logging, conversion to industrial plantations, drainage, and recurrent fires are the principal direct drivers of peatland degradation in South-East Asia, and that these drivers are compounded by a complex mix of indirect socioeconomic, policy- and climate change-related factors. The review concludes by noting that in order to address the problem of peatland degradation, we first need to know more about how to design and assess “successful” peatland restoration initiatives, and what regulatory and policy interventions are likely to improve peatland conservation and restoration outcomes in the South-East Asian region.

To reduce greenhouse gas (GHG) emissions, the Kyoto Protocol identifies several activities that are closely related to land use, included into the category called Agriculture, FOrestry and Land Uses (AFOLU). In this framework, a multidisciplinary study has been performed about the carbon footprint of extra virgin olive (EVO) oil in Italy. This study aims to promote process innovation by implementing eco-friendly techniques and technologies along a more sustainable production chain. Life Cycle Assessment approach was used to quantify the environmental impacts during the entire life cycle, starting from olive cultivation up to transformation processes and packaging. Each operation was monitored in terms of energy and material flows; the data were normalized on the basis of 1 L of olive oil, chosen as functional unit. Forest survey methodologies were applied to estimate the biomass and the respective carbon stocked in olive tree permanent (trunk, branches, twigs and root collar, roots) and non-permanent components (prunings and fruits). Added value of this study was coupling the resulting impacts with carbon sequestrations in order to: i) estimate the net balance between the equivalent carbon dioxide (CO2-eq) emissions and absorptions; ii) identify the break-even point, after which the amount of sequestered carbon exceeds the energy investments linked to human activities. Results from the study give important contributions towards the preliminary assessment of potential benefits in terms of avoided CO2-eq from agriculture.

The soil organic carbon (SOC) and nitrogen (N) stocks in mountainous forests are influenced by the forest diversity, topographic features, and climate change impacts. Role of forest SOC and N stocks in global C cycle has been a subject of great research recently, but the effect of topographic features on their dynamics at the stand level has received less attention especially under temperate conditions. In order to find out how topographic aspect and altitude affect SOC and N budgets, a study was conducted in the Himalayan Mawer Forest Range. We examined SOC and N stocks at two altitude zones (Z1: 1800–2200 masl & Z2: 2200–2500 masl) under North (N) and South (S) aspects at three soil depths (D1: 0–20 cm, D2: 20–40 cm and D3: 40–60 cm). The SOC stock was found to be decreasing with altitude from 105.9 Mg ha− 1 to 78.3 Mg ha− 1 under N aspect and from 81.6 Mg ha− 1 to 74.0 Mg ha− 1 under S aspect. SOC stock was higher by 16.5% under N aspect as compared to S aspect. The results lead to the conclusion that altitude has a negative effect on SOC stabilization and therefore altitude and aspect effect may be included in SOC stock estimation equations.

C-sequestration, as a function of soils, is known to help mitigate climate change. However, the potential of urban soils to be C-sinks or sources, is widely unknown. This study aims to understand the role and significance of urban soils in the C-balance of the region. It reveals several important findings about the C-balance capacities of urban soils and the multiple factors affecting this balance. This two-year study focused on soil organic carbon (SOC) stocks and CO 2 emissions of urban soils in the city of Kursk, located in the Central Chernozemic region of Russia, an area known to have some of the most fertile soils in the world. SOС stocks and emissions were studied in residential, recreational, and industrial functional zones and in comparison to corresponding natural reference soils to analyze the influence of urbanization on C turnover Urban soils were found to store 20 to 50 kg С m − 2 in 1.5 m layer; 10–30% less than in corresponding natural Luvic Chernozems and Chernic Phaeozems, but greater than what has been reported for many other cities. The urban soils with developed cultural layers stored more C in subsoil compared to the natural soils. Emissions of CO 2 in urban soils, however, were higher than from Chernic Phaeozems but comparable to those from Luvic Chernozems. The CO 2 /SOC stocks ratio in urban soils was two–three times higher than in natural soils. These outcomes point to the intensive C turnover and low sustainability of SOC stocks in urban soils. This study found evidence that the recent urbanization of the Chernozemic region has adversely affected the C balance. Natural soils in the region are important C sinks, however they can convert to C sources in result of urbanization.

Forest ecosystems play an important role in the global carbon cycle and with this there is an increasing need for quantifying carbon at large scales. The aim of this research was to develop a system for classifying tropical forests in Brazil into carbon stock classes, applicable to large areas, emphasizing different sets of stand and climate variables. We used data from forests inventoried in two Brazilian biomes: Atlantic Forest and Savanna. We applied discriminant analysis to generate a classification rule by biome. Three types of variables were used: climatic (mean annual temperature and precipitation, or MAT and MAP), geographical (latitude and longitude), and stand variables (density of trees, mean height or h ¯ , mean square diameter or dg, and basal area or G). We combined these into three scenarios for analysis: (1) all variables; (2) all variables, except h ¯ ; (3) all variables, except h ¯ , dg, and G, to determine their contribution to classifying carbon stocks. We also assessed each set of variables in the presence/absence of MAP and MAT, used simultaneously or not. The best classification rules resulted in 83.9% and 98.5% of correct classifications for Atlantic Forest and Savanna biomes, respectively. Stand variables contributed significantly to successful classification; for the Atlantic Forest biome, dg and G contributed from 36% to 42% and h ¯ from 2% to 5%, yet for the Savanna biome the gains ranged from 31% to 42% and 6%–9%, respectively. For the climate variables, the simultaneous use of MAT and MAP played an important role in the classification in all cases in the Atlantic Forest biome, contributing up to 9.2% for the classification. In the Savanna biome, we found significant positive gains by the simultaneous use in the absence of h ¯ , dg, and G, on the other hand, the simultaneous use exerted negative effects when h ¯ was used. We concluded that climate variables are most helpful when stand variables are not included in the analysis. In terms of carbon stock variation, the Atlantic Forest biome tended to be more sensitive to both MAT and MAP, whereas the Savanna biome had no significant climatic dependence in the classification. The variable h ¯ exerted a greater effect in the Savanna biome than in the Atlantic Forest, however, basal area and mean square diameter were the most important in both biomes.

Assessments of forest carbon are available via multiple alternate tools or applications and are in use to address various regulatory and reporting requirements. The various approaches to making such estimates may or may not be entirely comparable. Knowing how the estimates produced by some commonly used approaches vary across forest types and regions allows users of carbon stock estimates to make informed comparisons. Here, we focus on equivalence of alternate estimates of aboveground live tree carbon in eastern U.S. forests derived from the carbon reports output by the Fire and Fuels Extension (FFE) to the Forest Vegetation Simulator (FVS). Three approaches to estimating individual-tree carbon are compared by FVS variant and forest type. There are two approaches available in the FVS Fire and Fuels Extension (labeled FFE and Jenkins) and a third based on the U.S. Forest Service’s forest inventory (component ratio method, labeled CRM). We found that the two volume-based approaches, CRM and FFE, are most often identified as equivalent within forest type group or whole-variant relative to the other two pairs of approaches. Equivalence is common in the Northeast and Southern variants, but relatively infrequent in the Central States and Lake States variants. The underlying volume equations of the FFE and CRM approaches influence the carbon equivalence patterns as indicated by differences in volume estimates between FVS and the U.S. Forest Service’s forest inventory. Aggregation, or expanding forest estimates to include increasingly larger areas, tends to reduce apparent differences between approaches – that is, they become more equivalent. This result is most evident with the CRM-FFE pair or in softwood forest type groups.

Soil surveys for improving carbon (C) stock estimates frequently involve soil sampling by pre-determined regular depth-intervals, in order to enable more convenient computation of soil organic carbon (SOC) stocks. As a result, soil horizons are often neglected in these surveys, although they represent distinct components of the soil profile. When soil-horizon depths and thicknesses vary considerably within the same site, soil sampling by horizon with accompanying depth measurements may be more suitable. The main objective in this study was to investigate the potential differences in current SOC stocks in different afforested mineral soils, with varying horizon depths and thicknesses, and that were sampled by soil horizon, by using the trapezoidal SOC stock computing approach, and comparing it to the spline approach. An adaptation of the trapezoidal rule computation approach, enabling relatively simple crude estimations of the fixed depth-interval SOC stocks from horizon data, was developed. Estimations of SOC stocks for 18 sites located on three different afforested mineral soils (Gleys, Podzols and Cambisols, aged ≥ 20 years) were done for 0–30 cm, 30–60 cm and 0–60 cm fixed depth-intervals, excluding surface organic layers. The results indicate that the trapezoidal approach is likely to provide cruder estimates of SOC stocks than the spline approach, although no statistically significant differences were observed between the fixed depth-interval SOC stocks (for 0–30 cm and 30–60 cm) when computed by the two methods. Both methods showed a significant effect of horizon and soil group on SOC stocks. The soil below the 30 cm depth was estimated to store over 22% of the total SOC stocks to 60 cm depth. Gleys showed significantly greater mineral SOC stocks than Podzols, with differences mainly evident in the upper 30 cm, which was observed regardless of the computing methodology used (trapezoidal or spline). The adapted trapezoidal rule computing approach is hoped to facilitate the use of soil-horizon sampling in studies on SOC stocks.

This work was aimed at providing a sustainable approach in the use of manure in irrigated maize crop under Mediterranean climatic conditions. To this end, the effect of continuous annual applications of dairy cattle manure, combined or not with mineral N fertilizer, on the following parameters was studied: grain yield, grain and plant N concentration, N uptake by plant, N use efficiency, and soil N and organic carbon. The experiment was conducted in a furrow-irrigated sandy soil under dry Mediterranean conditions during seven years. Three different rates of cattle manure (CM): 0, 30 and 60 Mg ha−1, were applied each year before sowing. These CM rates were combined with four mineral N rates (0, 100, 200 and 300 kg N ha−1) applied at sidedress. On average, the highest grain yields during the 7 years were obtained with the combination of CM at 30 Mg ha−1 and mineral fertilizer and with CM at 60 Mg ha−1 without mineral fertilizer. With CM at 30 Mg ha−1, mineral fertilizer increased yields during most of the growing seasons, meanwhile with CM at 60 Mg ha−1, there was not any significant effect of the joint application of mineral fertilizer on yields. Overall, best results were obtained exceeding maximum rates according to present legislation. The mean apparent nitrogen recovery (ANR) fraction during the 7 seasons was 29% for N exclusively applied as CM. Overall, increased N rates applied as CM resulted in decreased ANRs. However, ANR with CM at 30 and 60 Mg ha−1 increased during the first two seasons. This increased ANR ascribed to mineralization of residual organic N applied in previous seasons explained the increasing yields observed in the treatments along the study. The application of CM during 7 years increased the soil organic carbon in the first 30 cm by 5.7 and 9.9 Mg ha−1 with CM at 30 and 60 Mg ha−1, respectively, when compared to the initial stock. Thus, manure-based fertilization could be an alternative to mineral fertilizer in order to achieve high maize yields while improving soil quality under dry Mediterranean conditions.

Mapping of ecosystem services in biophysical environment helps distinguishing the nature’s benefits in our surroundings. Ecosystem services also enable assessing the level of sustainability of the use of the environment. Various methods are being used for mapping them and methods: vary from expert evaluations to complex modelling. All methods: are related with uncertainties and affect to their applicability for different purposes. In this study, two different level biophysical mapping based datasets were tested; 1) data combination of biophysical polygon GIS data (SutiGIS) and statistics, and 2) modelled data of National Forest Inventory were evaluated to compare the differences between the methods: for carbon storages. Our results show that there are differences between results that have been produced in different levels of complexity. However, we also discovered that simpler datasets can also help detecting the shortcomings that may occur in modelling. We discuss also the potential applications of the used datasets in terms of providing information on biodiversity in ES assessments.

Our recent article on the comparative effects of logging and wildfire on carbon stocks in forests with contrasting responses to fire (Wilson et al., 2021) elicited a commentary from Jurskis (2021). While speculating widely about the nature of forests in our study and their management, Jurskis (2021) attempts to cast doubt on our finding that logging affected above ground carbon stocks. Our results showed that Eucalypt forests have substantially lower above ground carbon stocks in recently logged sites, compared to sites logged approximately 80 years ago. Further, none of the sites we sampled had above ground carbon stocks close to the estimated carrying capacity for their respective forest types (Roxburgh et al., 2006; Keith et al., 2014). The effect of logging on above ground carbon stocks was much stronger than the effect of wildfire, which had almost no effect in forests dominated by species capable of resprouting after high severity wildfires. Jurskis (2021) does not accept the findings of our results from the field because they do not conform to his expectations based on silvicultural growth models. He also claims that we should have accounted for ex situ forest carbon storage, based on the false premise that we concluded that logging should cease. We made no such claim.

Previous soil sampling from grazed pastures in New Zealand compared the changes of soil organic carbon (SOC) in adjacent irrigated and unirrigated portions of the same paddocks. It showed that irrigated portions had lower SOC stocks than unirrigated portions, with an average difference of 7.0 tC ha−1 or 0.6 tC ha−1 yr−1. These findings have formed the basis of an assessment for the net effect of conversion of New Zealand's grazed pastures to irrigation. However, since cattle could move freely between irrigated and unirrigated portions of the studied paddocks, there could have been different grazing intensities and/or excreta transfer between the irrigated and unirrigated portions of the same paddocks. Both these factors could have affected SOC stocks. In this study, we used the process-based model, CenW, to simulate the consequences of this possible carbon transfer via animal excreta and different grazing intensities. We found that the observed increase of 0.6 tC ha−1 yr−1 in SOC stock in the unirrigated portions could result from a transfer of 20% excreta from the irrigated to unirrigated portions (with an area ratio of 6:1) of a paddock and with the unirrigated portions being grazed only lightly with 2.0 tDM ha−1 in foliage biomass residuals remaining after grazing. That means that the observed higher SOC stocks in the unirrigated portions could potentially be attributable to the behaviour of grazing animals. We suggest that a realistic extent of carbon transfer and/or differences in grazing intensities could be sufficient to account for the observed differences in SOC stocks even if irrigation per se caused no differences in carbon stocks. It is therefore inappropriate to ascribe the change of SOC to irrigation effects based on experimental findings where SOC changes can be affected by the behaviour of grazing animals.

Tree growth is an important means of capturing and storing atmospheric carbon and is thus a key to mitigating the effects of climate change. Over recent decades, mango (Mangifera indica L.) parklands have expanded in Burkina Faso, due to the species’ fast growth and its compatibility with local agricultural crops. However, the contribution of mango parklands to reducing atmospheric CO2 remains unknown, due to the lack of local tools for aboveground biomass (AGB) estimation. The aim of this study was to develop accurate allometric equations for estimating the AGB and carbon (C) stocks of mango parklands. A field survey was carried out to select mango parklands according to their age. These parklands were then classified into six groups age (0≦y

There is growing interest in plantation forests throughout Africa because of their role in environment, economy and people's livelihoods. However, the contribution of planted forests to climate mitigation is poorly understood, partly due to lack of allometric equations for biomass estimation. This study aimed to determine wood density and biomass fractions in aboveground components, and to develop biomass estimation equations for multispecies plantation forests in the arboretum of Ruhande in Rwanda. Allometric equations were developed by regressing diameter at breast height (DBH) alone or in combination with height or wood density or age of trees against the biomass of 45 trees harvested from a 200-ha site. Biomass estimates obtained from destructively sampled trees were up-scaled to estimate the amount of carbon stocked in the arboretum of Ruhande, assuming a stem density of 250 stems per ha. Wood density varied among the species but not tree size. The greatest fraction of aboveground biomass was allocated to stems (71–77%) compared to branches (19–27%) and leaves (1–8%) and varied by species. Equations developed fit the data well with DBH explaining over 90% of the observed variation in aboveground and stem biomass. Including height or wood density as supporting parameters reduced the relative error for aboveground biomass by 6.4 and 8.0% and improved model fit by 2.1 and 2.9%, respectively. Akaike information criterion (AIC) showed that wood density (AIC=63.6) and height (AIC=48.2) were the most suitable parameters to support DBH as a proxy for aboveground and stem biomass, respectively. Allometric equations developed in this study are useful tool for estimating carbon stocks of plantation forests in Rwanda and can enhance the accuracy of biomass predictions where site-specific equations rather than generalized models are recommended. Further studies focusing on development of allometric equations on belowground biomass in such systems are recommended.

A recent meta-analysis (Zhang et al., 2020) stated that acidification induced by nitrogen (N) (over)fertilization increases soil organic carbon (SOC) accumulation. This Letter disagrees with that statement regarding acidification effects on SOC accumulation. We especially wish to show how processing of large datasets might mislead conclusions, and may have fatal consequences for land management. Another crucial point we wish to raise is that the role of carbonates for carbon stocks and induced CO2 losses to the atmosphere has been completely disregarded in the soil acidification discussion.

Disturbance plays an important role in determining whether forests are carbon sinks or sources. Logging and wildfire are common widespread disturbances known to significantly reduce carbon stocks in carbon rich forests, such as, the tall forests of south-eastern Australia. Most tall forests in south-eastern Australia are dominated by globally unique resprouting Eucalypts that experience limited mortality after high severity wildfire. However, the most carbon dense forests in the region are dominated by non-resprouting Eucalypts that, like many other species associated with carbon dense forests around the world, experience stand replacement after high severity wildfire. We used space-for-time surveys to measure how above ground carbon stocks change with time since logging and time since wildfire in resprouting and non-resprouting Eucalypt forests in south-eastern Australia. Logging reduced above ground carbon stocks much more than wildfire in both forest types. Carbon stock losses caused by wildfire were more substantial in non-resprouting forests than resprouting forests, which experience only minor losses after wildfire. The recovery of carbon stocks after wildfire began to asymptote after approximately 40 years but increased almost continuously with time since logging in both forest types. Carbon stock losses associated with logging represent a much greater departure from natural disturbance in resprouting forests, because wildfire causes relatively little carbon loss in resprouting forests compared to non-resprouting forests. This analysis highlights the need to consider specific biological responses when assessing forest carbon stock losses associated with disturbance. Consideration of these dynamics is essential in addressing carbon stock risk mitigation.

Confusion persists regarding the potential for no-till (NT) farming to accumulate soil organic C (SOC) and mitigate climate change. This uncertainty could be partly due to shallow sampling ( 34 yr). We quantified SOC stock (Mg ha−1) on an equivalent mass basis for the 0–60 or 100 cm soil depths for NT, disk, double disk, chisel plow, and moldboard plow under continuous corn and corn-soybean on silt clay loams after 34 yr and 39 yr in the western US Corn Belt. Results showed that NT did not increase SOC stocks near the surface but it did with cumulative depth relative to moldboard plow. No-till accumulated SOC at a rate of 0.68 Mg ha−1 yr-1 relative to inversion tillage (moldboard plow). However, NT did not store more SOC than common conventional (chisel plow) or reduced (disk) till practices for the whole soil profile. Results indicate that depth of soil sampling can affect conclusions about tillage system impacts on SOC stocks. For example, if we had sampled to 20 cm soil depth only, we would have incompletely concluded that NT does not significantly accumulate more SOC than moldboard plow. Results after 34 and 39 yr of tillage management also indicate that non-inversion tillage, particularly disk, can be as effective as NT for accumulating SOC. Overall, deep soil sampling can tell a different story about NT impacts on SOC stocks from shallow sampling.

The present study was conducted in Doon valley of north western Himalaya to estimate biomass and carbon storage in male bamboo (Dendrocalamus strictus) raised on degraded bouldary land. Different non-linear models (Monomolicular, Logistic, Gompetz, Allometric, Rechards, Chapman) were fitted to the relationship between total biomass as dependent variable and diameter at breast height (DBH) as independent variable. The adjusted R2 values were > 0.85 for all the six models indicating that all models are apparently equally efficient. Allometric model (Y = a × DBHb) was found to be best performing and was used for fitting different biomass components using DBH as explanatory variable. The estimated total aboveground biomass from the developed allometric model was 18.91 Mg ha− 1 in 6 year and 109.30 Mg ha− 1 in 20 years old plantation. Carbon content in different components revealed that it was higher in culm (48.66%) followed by branch (48.09%) and leaf (44.68%). The total biomass carbon stocks mitigated were 8.39 and 49.08 Mg ha− 1 in 6 and 20 year old plantations.

This study aimed to investigate the applicability of dendrochronology for assessing the growth dynamics and response to climate variability and to estimate the aboveground carbon stock and carbon sequestration potential of Vitellaria paradoxa in southern Mali. Twenty stem disks were collected from three land-use types (parklands, fallows and protected areas) in Koutiala and Yanfolila districts. We combined a standard dendrochronological approach with biomass allometric equations to estimate the growth and carbon stocks. The results showed that V. paradoxa forms distinct growth ring boundaries but most of the disks from parklands did not successfully cross-date due to management operations like pruning. The tree-ring width showed a significant standardized coefficient of regression with rainfall (r2 = 0.66, p 0.05) for C-sequestration as well as for carbon stocks in aboveground biomass for both land-use types and sites. Mean values of the amount of C-sequestered in Yanfolila were 0.112 ± 0.0.065 Mg C ha−1 yr−1 in parklands, 0.075 ± 0.018 Mg C ha−1 yr−1 in fallows and 0.064 ± 0.028 Mg C ha−1 yr−1 in protected areas. In Koutiala, the values were 0.068±0.020 Mg C ha−1 yr−1 in the parklands and 0.053 ± 0.017 Mg C ha−1 yr−1 in the fallows. These results clearly indicate that dendrochronology can be applied to assess growth and carbon sequestration potential of V. paradoxa. These results also suggest that climate change could affect the growth and carbon sequestration potential of V. paradoxa. Given the limited size of our sample, figures on the amount of carbon are indicative calling for applying the tested approaches to larger samples and also to other tree species in West Africa.

The microalgae biofuels life cycle assessments (LCA) present in the literature have excluded the effects of direct land use change (DLUC) from facility construction under the assumption that DLUC effects are negligible. This study seeks to model the greenhouse gas (GHG) emissions of microalgae biofuels including DLUC by quantifying the CO2 equivalence of carbon released to the atmosphere through the construction of microalgae facilities. The locations and types of biomass and Soil Organic Carbon that are disturbed through microalgae cultivation facility construction are quantified using geographical models of microalgae productivity potential including consideration of land availability. The results of this study demonstrate that previous LCA of microalgae to biofuel processes have overestimated GHG benefits of microalgae-based biofuels production by failing to include the effect of DLUC. Previous estimations of microalgae biofuel production potential have correspondingly overestimated the volume of biofuels that can be produced in compliance with U.S. environmental goals.

International audience; In France like in many other countries, the soil is monitored at the locations of a regular, square grid thus forming a systematic sample (SY). This sampling design leads to good spatial coverage, enhancing the precision of design based estimates of spatial means and totals. Design-based estimation of the mean or total from SY samples is straightforward. However, an unbiased estimator of the sampling variance of the estimated mean or total does not exist. This paper compares five variance approximations, being the simple random (SI), stratified simple random (STSI), Geary's spatial autocorrelation C index (Geary), Moran's I index (Moran), and the model-based (MB) approximation in a simulation study and a real-world case study. In a simulation study the model distribution of the conditional bias (conditioned on a simulated reality) of the variance approximations is estimated for various variograms and two sample sizes. In the case study the data of the first campaign of the French Soil Monitoring Network are used to estimate the spatial means of six soil variables (C, TI, Cd, Ni, K, Mn) for aggregated soil map units of France, and to approximate their sampling variances. The bias in the approximated variances is explored with MODIS-NDVI data. With variograms with no or a small relative nugget variance approximation STSI and MB are the best choices. In situations with large relative nugget STSI is to be preferred over MB as MB then may somewhat underestimate the variance. Moran and SI should be avoided as approximation methods, as they seriously underestimate (Moran) and overestimate (SI) the variance in many cases. The approximated standard error of total soil organic carbon stock in France as obtained with MB was 0.0335 Pg, which was small compared to the estimated stock of 3.580 Pg.

Reliable and accurate mapping and extraction of key forest indicators of ecosystem development and health, such as aboveground biomass (AGB) and aboveground carbon stocks (AGCS) is critical in understanding forests contribution to the local, regional and global carbon cycle. This information is critical in assessing forest contribution towards ecosystem functioning and services, as well as their conservation status. This work aimed at assessing the applicability of the high resolution 8-band WorldView-2 multispectral dataset together with environmental variables in quantifying AGB and aboveground carbon stocks for three forest plantation species i.e. Eucalyptus dunii (ED), Eucalyptus grandis (EG) and Pinus taeda (PT) in uMgeni Catchment, South Africa. Specifically, the strength of the Worldview-2 sensor in terms of its improved imaging agilities is examined as an independent dataset and in conjunction with selected environmental variables. The results have demonstrated that the integration of high resolution 8-band Worldview-2 multispectral data with environmental variables provide improved AGB and AGCS estimates, when compared to the use of spectral data as an independent dataset. The use of integrated datasets yielded a high R 2 value of 0.88 and RMSEs of 10.05 t ha −1 and 5.03 t C ha −1 for E. dunii AGB and carbon stocks; whereas the use of spectral data as an independent dataset yielded slightly weaker results, producing an R 2 value of 0.73 and an RMSE of 18.57 t ha −1 and 09.29 t C ha −1 . Similarly, high accurate results ( R 2 value of 0.73 and RMSE values of 27.30 t ha −1 and 13.65 t C ha −1 ) were observed from the estimation of inter-species AGB and carbon stocks. Overall, the findings of this work have shown that the integration of new generation multispectral datasets with environmental variables provide a robust toolset required for the accurate and reliable retrieval of forest aboveground biomass and carbon stocks in densely forested terrestrial ecosystems.

Dark coniferous forests with dominating Caucasian fir are basically distributed in West Georgia. They occupy 153.920 ha with the wood substance stock of 61191,5 thousand m3, respectively making 91,3 and 91,0% of fir woods in Georgia. Forests with dominating oriental spruce are distributed comparatively evenly in Georgia; 55,3% (55354 ha) of spruce stands come to West Georgia. Coniferous forests in Svaneti were chosen as the object of the research. Forests with dominating Caucasian fir occupying 60100 ha in Svaneti have absorbed up to 7,85 million tons of carbon from the atmosphere and annually it sequesters up to 189,3 thousand tons of carbon dioxide. In the forest biomass with dominating Caucasian fir occupying 14345 ha has accumulated up to 1,13 million tons of carbon. Spruce stand annually sequesters up to 35,9 thousand tons of CO2. The Article describes distribution of biomass and carbon stock in dark conferous forests according to the stand age groups and single fractions. High indicators of carbon dioxide annually sequestered by dark coniferous forests of Svaneti Region once again emphasize the special role of forests in the process of air exchange on the Earth.

Mangroves provide vital climate change mitigation and adaptation (CCMA) ecosystem services (ES), yet have suffered extensive tropics-wide declines. To mitigate losses, rehabilitation is high on the conservation agenda. However, the relative functionality and ES delivery of rehabilitated mangroves in different intertidal locations is rarely assessed. In a case study from Panay Island, Philippines, using field- and satellite-derived methods, we assess carbon stocks and coastal protection potential of rehabilitated low-intertidal seafront and mid- to upper-intertidal abandoned (leased) fishpond areas, against reference natural mangroves. Due to large sizes and appropriate site conditions, targeted abandoned fishpond reversion to former mangrove was found to be favourable for enhancing CCMA in the coastal zone. In a municipality-specific case study, 96.7% of abandoned fishponds with high potential for effective greenbelt rehabilitation had favourable tenure status for reversion. These findings have implications for coastal zone management in Asia in the face of climate change.

In any given watershed, riparian buffer systems (RBSs) can influence terrestrial carbon (C) sequestration and potentially enhance terrestrial C sinks. This study looked at the effects of soil texture, vegetation type and age on C stock sequestration in eight RBSs located within the Grand River Watershed (GRW), southern Ontario, Canada and compared the C stock with adjacent agricultural fields. Soil organic carbon (SOC) stocks on an equivalent mass basis were significantly higher (p

In Southern Africa there are no local allometric models that can precisely and accurately estimate tree carbon stocks in community managed forests. This study developed the local allometric models for estimating tree carbon stocks in community managed forests and tested predictive performance of existing models when applied on community managed forests. While the developed allometric models are robust in tree carbon estimation, the existing allometric models underestimated the tree carbon stocks in community managed forest. As such, it is recommended that estimation of tree carbon from community managed Miombo woodlands employ locally developed models in order to improve accuracy of forest carbon estimation to protect community members against revenue loss when engaging in carbon trade.

Climate change and human activities have continuously decreased productivity, carbon storage and soil fertility of global plantations under continuous planting. However, this situation can be largely reversed through appropriate planting density and thinning management. We evaluated the effects of initial planting density and selective thinning management on biomass accumulation and carbon stocks in different plantation compartments, on soil carbon stocks in different stand stages of a chronosequence of evergreen (Cunninghamia lanceolata) plantations in typical hilly and mountainous areas of Jiangxi Province, Southeast China. The result showed that biomass components and carbon storage of tree, understory and the whole ecosystem in C. lanceolata plantations were significantly higher with than without selective thinning treatment, in the low (1150 trees ha−1) than in the high (2460 trees ha−1) initial density in our study. Aboveground vegetation biomass and carbon storage in C. lanceolata plantations increased with stand stages. However, carbon storage of 0–10 cm and 20–40 cm soil depth decreased with stand stages, which indicated certain degraded characteristics of soil carbon in the C. lanceolata plantations. Interestingly, low initial density increased the biomass and carbon storage of trees, shrubs, herbs and 0–20 cm soil depth greater in the pre-mature and mature stands compared to high initial density. Furthermore, these positive effects of low density increased with selective thinning. According to regressions and Detrended Correspondence Analysis (DCA), increment in carbon of trees and 0–10 cm soil with the stand age were significantly higher in the low initial density and with selective thinning than in other three treatments. Therefore, selected thinning and relatively appropriate density might have a significantly positive role in carbon storage of the ecosystem in different stand ages, especially showing a increasing trend of soil carbon. Our results provide the important evidence for selective thinning management of C. lanceolata plantations with regeneration, which plays an important role in improving the carbon storage of degraded C. lanceolata plantations.

Reliable estimates of carbon stocks for drylands are constrained by a limited number of biomass models for predicting accurately the biomass of dominant tree and shrub species. In this study, 119 trees with a diameter at breast height (dbh) between 3.82 and 45.48 cm were destructively sampled to evaluate aboveground biomass (AGB) allocation and prediction for four dryland species (Senegalia dudgeonii, Senegalia gourmaensis, Vachellia nilotica and Vachellia tortilis) commonly found in the Sudanian and Sahelian zones of Burkina Faso. Biomass allocation to leaf, branch and stem was examined using a classmometric analysis. Allometric equations relating biomass to dbh alone, and to dbh in combination with height and/or crown area were developed with and without consideration of the additivity property. Branches stored the largest (up to 90%) proportion of AGB. For three of the species, the branch mass fraction increased with increasing tree size at the expense of stem and leaf mass fractions. The statistical evaluations of the selected additive and non-additive models were satisfactory with no severe deficiencies. Diagnostics of model performance revealed that non-additive models performed better than additive models. The biomass models developed can be used for improved quantification of carbon stock and dynamics in dry savanna ecosystems.