Biomass Carbon Sequestration Research Articles

Spatial comparisons of productivity and carbon sequestration for Cupressus lusitanica and macrocarpa within New Zealand

Cupressus lusitanica and C. macrocarpa are two fast growing conifer species with valuable timber that have been widely established throughout New Zealand. Despite the importance of these two species within New Zealand and in many other countries, little research has investigated how volume, height, and carbon productivity are influenced by environment. Volume growth of these two cypress spp. has been recently described using the 300 Index which quantifies the mean annual volume increment at age 30 yrs for a stand density of 300 stems ha−1. Using New Zealand growth data obtained from 290 plots, the objectives of this study were to (i) develop models and fine resolution national maps of 300 Index and site index, (ii) use these two productivity metrics and allometric equations to develop models of carbon stocks for the two species, and (iii) spatially predict carbon across New Zealand for C. lusitanica and macrocarpa grown under a factorial range of stand densities (400, 650 and 900 stems ha−1) and ages (30, 40 and 50 yrs).Plot measurements showed wide variation in 300 Index which reached 26.9 and 29.0 m3 ha−1 yr−1, respectively, for C. lusitanica and C. macrocarpa. Site index (age 30 yrs) reached values of 31.9 and 34.1 m for C. lusitanica and C. macrocarpa, respectively. Models developed for C. lusitanica had high accuracy for both 300 Index (RMSE = 2.48 m3 ha−1 yr−1; R2 = 0.75) and site index (RMSE = 1.78 m; R2 = 0.84) while models developed for C. macrocarpa had similar, but slightly lower, accuracy for 300 Index (RMSE = 2.86 m3 ha−1 yr−1; R2 = 0.72) and site index (RMSE = 1.86 m; R2 = 0.81).Spatial predictions of the two productivity metrics showed distinct differences between species with C. lusitanica being more sensitive to cold, dry, and wet conditions than C. macrocarpa. Under the mid-range scenario (age 40, 650 stems ha−1) mean carbon sequestration in above and below ground biomass, dead wood, and litter pools for C. macrocarpa was higher than C. lusitanica in both the North Island (321 vs. 296 t C ha−1) and South Island (222 vs. 120 t C ha−1). Carbon was higher for C. macrocarpa than C. lusitanica within, respectively, 62 and 94% of the North and South Islands under the mid-range scenario. Carbon markedly increased with stand density and age and gains were greatest between ages 30 and 40 and from the low to moderate stand density for both species.

Research on Biomass Waste Utilization Based on Pollution Reduction and Carbon Sequestration

Biomass waste in agricultural and forestry production has low value, large volume, disordered texture, high water content, and high recycling costs, disturbing its biomass waste treatment. In terms of mainstream treatment methods, incineration directly releases carbon dioxide, dust, and other pollutants, while landfills produce carbon dioxide and methane with stronger greenhouse effects. In response to this problem—taking pollution reduction, carbon sequestration, and the resource utilization of biomass waste as the purpose—a mode of in-situ, harmlessness, homogenization, reduction, automation, inorganic transformation, resource utilization, and carbon sequestration is proposed, which reduces recycling costs and improves economic efficiency and operability with carbonization as the key technique. The carbonization mechanism of biomass waste was first investigated using TGA analysis to obtain the key technical parameters of in-situ carbonization, and then biomass carbonization was divided into two stages: in-situ carbonization and factory carbonization. Thus, a process is constructed for in-situ crushing, carbonization, screening, and recycling, which promotes the recovery efficiency of biomass waste, including domestic waste. Moreover, on the basis of massive experiments, a carbon-based material was invented where, through wide applications in architecture, huge carbon can be stored in building materials; thus, a novel method of biomass waste resource utilization, carbon sequestration, and artificial carbon pool construction was established. Among them, with the convenient collection of biomass waste as the premise, the economic and reasonable carbonization process is a pivotal step to guarantee the wide application of carbon-based materials, and pollution reduction and carbon sequestration are the final purposes. This novel mode is conducive to saving resources and realizing carbon peaking and carbon neutrality goals with significant economic, ecological, and social benefits. The novelty lies in five aspects. Firstly, differing from current research on pollution reduction, carbon reduction, and carbon balance, further research on carbon sequestration was proposed. Secondly, the feasibility of reducing re-emission through carbon transfer was demonstrated. Thirdly, in-situ carbonization to recycle biomass waste was constructed. Fourthly, through carbonization, the inorganic transformation of biomass waste avoided carbon re-emission, especially methane emissions. Last but not the least, carbonization products achieved carbon sequestration and constructed an artificial carbon pool.

Opportunities for blue carbon restoration projects in degraded agricultural land of the coastal zone in Queensland, Australia

Restoring degraded agricultural lands to their original coastal wetland cover is an approach for enhancing blue carbon storage. This approach enhances carbon sequestration in biomass and soils whilst reducing greenhouse gas emissions and delivering other conservation benefits such as enhancing biodiversity, improving water quality, and protecting coastlines from sea level rise. In Queensland, Australia, tens of thousands of hectares of coastal land have been converted to agriculture since the 1900s, often through drainage. We evaluated the characteristics of degraded agricultural land to identify opportunities for blue carbon restoration projects. Degraded agricultural land was identified through visual inspection of satellite imagery. Our analysis revealed degradation was associated with historical Melaleuca-dominated wetland vegetation and current land uses other than intensive agriculture. Field sampling of a subset of paired degraded and non-degraded sites found that water content, organic carbon, and electrical conductivity were significantly higher at degraded sites. We also observed standing water, drainage structures, and dead trees at degraded sites. From our analyses, we inferred land degradation is likely caused by waterlogging, salinisation, and land management choices. Degraded land historically vegetated by Melaleuca-dominated wetlands could be targeted for blue carbon restoration projects that protect remaining soil carbon and enhance carbon storage, restore ecosystem services, and provide new income streams for landowners. Further characterisation of the distribution of degraded lands may contribute to prioritisation of sites suitable for restoration.

Implications of changes in land use on soil and biomass carbon sequestration: a case study from the Owabi reservoir catchment in Ghana

Land use changes affect soil and biomass carbon sequestration potential of the agroecosystems of most Sub-Sahara Africa facing rising temperatures due to global climate change. One such ecosystem is the Owabi reservoir catchment in Ghana, which has undergone extensive changes in land use through urbanization. Our study aimed to determine the impact of the spatial and temporal variability of the different land uses on soil and biomass carbon storage in the Owabi catchment. Land use/cover maps were elaborated using SPOT satellite images of 30 × 30-m resolution and Erdas Imagine and ArcGIS Pro softwares. Soil and vegetation were sampled along three transects in the Y plane in early 2014. Nested plot design and temporary sample plots of 50 × 50 m were demarcated within a 1 ha plot in each of the land uses. Trees, herbs and litter were sampled to assess aboveground carbon, and soil samples were taken at 0–15 cm and 15–30 cm depth. Belowground (root) biomass was calculated using the root:shoot ratio. Seven (7) land use types – dense forest, sparse forest, grassland, cropland, wetland, settlement, and excavated land – were identified and differences in carbon stocks were assessed. Soil carbon stock (0–30 cm) ranged from 51.80 Mg/ha in dense forest to 7.00 Mg/ha in excavated land. Our study showed that the conversion of forest lands to other land uses through excavation resulted in about 30-folds loss in carbon and also a major loss of carbon in the catchment from c. 1.4 × 106 Mg C in 1990 to 0.55 × 106 Mg C in 2014. Enhancing forests or growing trees to sequester carbon seems to be the optimum choice among the seven land uses if the introduction of payment for environmental services options is considered.

Climate change may increase Quebec boreal forest productivity in high latitudes by shifting its current composition

Several recent studies point out that climate change is expected to influence boreal forest succession, disturbances, productivity, and mortality. However, the effect of climate change on those processes and their interactions is poorly understood. We used an ecophysiological-based mechanistic landscape model to study those processes and their interactions and predict the future productivity and composition under climate change scenarios (RCP) for 300 years (2010–2310). The effects of climate change and wildfires on forest composition, biomass carbon sequestration and storage, and mortality were assessed in three management units of Quebec boreal forest, distributed along a longitudinal gradient from west to east: North-of-Quebec (MU1), Saguenay–Lac-Saint-Jean (MU2), and Côte-Nord region (MU3). Coniferous mortality variation was explained by competitive exclusion and wildfires, which are related to climate change. In the studied MU, we found a decrease in coniferous pure occupancy at the landscape scale and an increase in mixed deciduous forests in MU1 and MU2, and an increase in mixed coniferous, mainly black spruce and balsam fir in MU3. On the other hand, for extreme scenarios (RCP4.5 and RCP8.5), in the absence of broadleaves dispersal, the open woodland occupancy could increase to more than 8, 22, and 10% in MU1, MU2, and MU3 respectively. Also, climate change might increase overall biomass carbon stock two times for RCP2.6 and RCP4.5 scenarios compared to the baseline this may be explained by the extension of the growing season and the reduction of potential cold-temperature injuries. Generally, western regions were more sensitive to climate changes than the eastern regions (MU3), in fact under RCP8.5 biomass carbon stock will be decreasing in the long-term for MU1 compared to the current climate. This study provides a good starting point to support future research on the multiple factors affecting forest C budget under global change.

Forest stand factors determine the rainfall pattern of crown allocation of Picea schrenkiana in the northern slope of Mount Bogda, Tianshan Range, China.

The middle elevation forest of the Tianshan Mountains, dominated by the conifer tree Picea schrenkiana, is an important part of the mountain ecosystem of arid Northwestern China, which plays a pivotal role in carbon sequestration and water conservation. As the first interface of water transfer in a forest ecosystem, tree crown allocates precipitation regulating soil water supply and sustaining vegetation growth below the crown. In this study, four 20-m × 20-m sampling quadrats were randomly installed at each of three elevation sites (2,200 m, 1,800 m, and 1,450 m) on the northern slope of Mount Bogda, the main peak of the Eastern Tianshan Range. The effects of forest stand factors and incoming rainfall on forest crown allocation of precipitation were investigated, and the trade-off between water and carbon was also discussed. The results revealed that (1) the interception, throughfall, and stemflow ratio had values of 44.3%-50.0%, 49.6%-55.4%, and<0.5%, respectively; (2) there was a complementary relationship between stemflow ability and threshold rainfall when stemflow emerged, and the crown interception rainfall had a saturation value; and (3) the allocation of crown-intercepted rainfall was controlled by trunk diameter at breast height, crown height-to-width ratio, and leaf area index, which was why differences arose in the allocation of crown precipitation at differing elevations. With greater arbor biological carbon density, the crown interception ratio initially increased rapidly but then remained stable, indicating that once a natural forest stand is mature, its biomass carbon sequestration would not change further allocation of crown precipitation.

Eucalyptus clones respond differentially for heavy-metals phytoextraction and carbon sequestration in tree biomass and soil with distillery effluents irrigation in north-western India

Forest ecology has significant potential for carbon (C) and heavy-metals’ accumulation, and is considered important for mitigating environmental impacts within the ecosystem. Heavy-metals enter the soil–plant system via different anthropogenic activities per se industrialization, which has huge contribution through the discharge of heavy-metals enriched effluents. Although, irrigation with effluents to large biomass producing forestry plantation e.g. Eucalyptus sp. with high net primary production (NPP) are considered ecologically and environmentally safe, yet the information on differential response of diverse clones towards applied effluents is scares. We therefore, performed field evaluation of nine Eucalyptus clones originated from diverse agro-ecological environments irrigated with distillery effluents to investigate their growth attributes, heavy-metals (e.g. As, Cr, Cd and Ni) and micro-nutrients (e.g. Cu, Zn, Fe and Mn) uptake potential, and C storage in above-and below-ground biomass and sequestration in soil C pool. The diameter at breast height (DBH), tree volume, fresh and dry biomass of stems, leaves, branches and roots of C-316 clone was significantly (p < 0.05) higher, lowest for PE-6, whilst the C-411, C-2045, PE-5, PE-7, PE-8, PE-11 and C-413 were in-between. The Cr uptake was significantly higher for PE-8 and C-413, Ni uptake in PE-6 and C-413 and Pb uptake in clone C-2045. Among micro-nutrients, Zn, Mn and Fe uptake was significantly higher for C-316, compared with other clones. However, the metal content in surface (0–15 cm) soil layer was well below the threshold level. The partitioning of NPP among different above-and below-ground biomass components revealed that dry stem biomass comprised ~ 54.8–56.7%, branches ~ 15.8–17.1%, while leaves ~ 5.6–7.5% of total dry tree biomass. Root biomass comprised ~ 21.3% of total tree biomass. Carbon stocks in dry above-ground biomass (stems + branches + leaves) varied between 33.9 and 59.5 kg C tree−1, and were significantly higher for C-316, and lowest for PE-6 clones. The total C sequestration in tree biomass varied between 229.7 and 450.9 Mg C ha−1 in different clones; with significantly higher in C-316 and lowest in PE-6. Carbon sequestration rate varied between 57.4 and 112.7 Mg C ha−1 year−1 for different Eucalyptus clones. Total organic C (TOC) stocks in surface soil layer under C-413, C-411 and C-316 clones were significantly (p < 0.05) higher than others. The discriminant function analysis (DFA) showed that two significant canonical discriminant functions (DFs) viz. DF-1 and DF-2 involving total tree biomass, total uptake of As, Pb, Zn, Mn and Fe in above-ground biomass of Eucalyptus clones distinguished different cones, appropriately grouping 97.5% of the tested clones. These results underpin overwhelming significance of C-316 plantation for increased heavy-metals’ uptake with co-benefits of C sequestration in tree biomass as well as in soils. Therefore, a stringent policy framework for large scale C-316 clone plantation in regions with availability of distillery effluents is required for restoring the forest ecosystem on sustainability basis.

Environmental Aspects of Sustainable Agriculture

Agricultural policy in the European Union at Community level, as well as in the member states, increasingly emphasises the issue of sustainable agriculture. The pursuit of climate neutrality requires a reduction in emissions from agricultural sources. Above all, it is necessary to fully exploit the potential of agricultural and forestry areas to increase carbon sequestration in biomass and soil, optimise systems for the storage, transport and use of livestock manure, and significantly improve energy efficiency and increase the share of renewable energy in plant and livestock production. Rural areas, and in particular agriculture, are also seen as one of the main and important sources of pollution and eutrophication of water. Determining the correct way to assess the degree of sustainability of farms requires objective and feasible to determine measures and indicators of socioeconomic-environmental sustainability and a lot of analysis, methodological and practical research. To date, no uniform set of sustainability indicators has been developed and their selection depends on data availability.

C4 photosynthesis in Paulownia? A case of inaccurate citations

Societal Impact StatementC4 photosynthesis is an ultra‐efficient mode of photosynthesis found in some of our most productive crop species yet is notably rare in trees. Given C4 photosynthesis is associated with high yield in herbaceous species, especially under hot and dry conditions, C4 trees may seem an attractive prospect for biomass production and carbon sequestration in a rapidly changing climate. This may explain why some in the literature have optimistically linked C4 photosynthesis with the exceptionally fast‐growing tree Paulownia. However, this claim is lacking in evidence and represents an example of poor citation practices leading to the spread of misinformation.Summary The rapid growth of trees in genus Paulownia (Paulowniaceae) has been attributed in the literature to their use of C4 photosynthesis, a complex trait that confers increased photosynthetic efficiency under certain environmental conditions. After careful examination of citations used to support the idea that Paulownia species use C4 photosynthesis, we find that there is no data underpinning this claim. Despite this, many investment schemes utilise information about the physiology of Paulownia, including photosynthetic type, to legitimise the use of Paulownia trees for financial investment and carbon offsetting. This study uses leaf physiology, anatomy and stable isotope data to determine whether or not three species in Paulownia (Paulownia tomentosa, Paulownia fortunei and Paulownia kawakamii) use C4 photosynthesis. These data are compared with existing data for C3 and C4 woody species in the literature. We show that the leaf physiology, anatomy and stable isotope phenotypes of the three Paulownia trees considered in the study are not consistent with those of C4 plants. Our findings highlight how inaccurate citation of scientific findings can contribute to the spread of misinformation beyond the scientific community, as some of those promoting investments in Paulownia plantations reference the photosynthetic superiority of Paulownia as a means to legitimise its use in carbon offsetting.

Cotton stubble return and subsoiling alter soil microbial community, carbon and nitrogen in coastal saline cotton fields

Long-term cotton stubble return and subsoiling improve root growth and soil properties and alter microbial colonization in the rhizosphere. However, it is unknown if cotton stubble return and subsoiling would change the soil microbial biomass carbon (MBC) and nitrogen (MBN) sequestration by changing the microbial community in coastal saline soil. We used an experiment to quantify the effects of stubble management (removal or return), tillage (non-subsoiling or subsoiling), and soil compartments (non-rhizosphere or rhizosphere) on the bacterial and fungal communities after 9-year treatments. Soil compartments were the main factor affecting the soil bacterial community. The abundance of Bacillus, Pseudomonas, and Sphingomonas in the rhizosphere soil increased by 63.64%, 20.40%, and 109.24%, respectively, compared to the non-rhizosphere soil. Moreover, Bacillus was increased by both stubble return and subsoiling. The Chao1, Simpson, and Shannon indices in alpha diversity of the bacterial community were increased by rhizosphere soil, stubble return, and subsoiling. The MBC and MBN in the rhizosphere soil was 22.4% and 13.2% higher than in the non-rhizosphere soil. Stubble management was the main factor affecting the fungal community composition. Stubble return significantly increased some fungal abundance, e.g., Cephalotrichum and Fusarium, by 243.11% and 95.24% than stubble removal. The abundance of Cephalotrichum, Fusarium, and Alternaria in the rhizosphere soil was significantly higher than that in the non-rhizosphere soil. The Chao1, Simpson, and Shannon indices of the fungal community were only significantly increased by stubble return. Compared with cotton stubble removal, stubble return increased MBC and MBN by 31.8% and 23.0%, respectively. The effects of the plant growth promoting rhizobacteria (PGPR) (Bacillus and Pseudomonas) on rhizosphere microbial community and MBC and MBN were higher than those of pathogenic fungi (Fusarium and Alternaria) from Structural Equation Models (SEM). Our results suggest that long-term cotton stubble return and subsoiling could play a role in improving soil microbial community and C and N and enhance the sustainability of coastal saline soil.

Woody Species Diversity and Biomass Carbon Sequestration in Private Residential Green Infrastructure of Dilla Town, Southern Ethiopia

Urban forests have an important role in biodiversity conservation, environmental improvement, and ecosystem services including climate change mitigation enhancement. The objectives of the current study were to: assess plant types and management strategies of the owners; woody species’ composition, structure, and diversity; and estimate aboveground biomass of trees and associated carbon stock in private residential green infrastructure (PRGI) at Dilla town. This study was conducted at three kebeles, the lowest administrative unit in Ethiopia. Ninety-four households were randomly selected from a proportional sample size for each kebele. A complete inventory of woody species was done after measuring the area occupied by plants at each household. At plot level, the aboveground biomass of sampled trees was calculated by using an allometric biomass equation developed for agroforestry species. Diversity was described by using different indices The free software EstimateS 9.1.0 was used to generate data for the construction of sample-based rarefaction curves and SPSS version 20 for descriptive statistics. Based on plant types and arrangement, the households manage their PRGI in 15 categories on area size, ranging from 10 m2 to 1229 m2, with an average holding size of 207.5 m2. A total of 66 plant species belonging to 45 families were identified. Overall, a total of 1220 stem ha−1 contributed to an aboveground carbon stock of 64.35 ton ha−1 of which 50.4% is from fruit trees and the rest from timber trees. The results suggest that PRGIs can serve as reservoirs of non-native and native plant species, including five native tree species currently facing conservation concerns.

Terrestrial carbon sequestration under future climate, nutrient and land use change and management scenarios: a national-scale UK case study

Carbon sequestration (Cseq) in soils and plant biomass is viewed as an important means of mitigating climate change. Recent global assessments have estimated considerable potential for terrestrial Cseq, but generally lack sensitivity to climate warming, nutrient limitations and perspective on local land use. These are important factors since higher temperatures can accelerate the decomposition of soil organic matter, nutrient availability affects plant productivity, while land use pressures put broader constraints on terrestrial organic matter inputs and storage. Here, we explore the potential for Cseq under changing land use, climate and nutrient conditions in a UK-based national scale case study. We apply an integrated terrestrial C–N–P cycle model with representative ranges of high-resolution climate and land use scenarios to estimate Cseq potential across the UK. If realistic UK targets for grassland restoration and afforestation over the next 30 years are met, we estimate that an additional 120 TgC could be sequestered by 2100 (similar to current annual UK greenhouse gas emissions or roughly 7% of net emission cuts needed in meeting net zero), conditional on climate change of <2 °C. Conversely, we estimate that UK arable expansion would reduce terrestrial carbon storage by a similar magnitude. The most pessimistic climate trajectories are predicted to cause net losses in UK soil carbon storage under all land use scenarios. Warmer climates substantially reduce the potential total terrestrial carbon storage gains offered by afforestation and grassland restoration. We conclude that although concerted land use change could make an important moderate contribution to national level Cseq for countries like the UK, soil Cseq only provides a contribution if we are on a low emission pathway, and is therefore conditional on deep global cuts to emissions from fossil fuels, deforestation and soil degradation.

Predicting aboveground biomass carbon sequestration potential in hybrid poplar clones under afforestation plantation management in southern Ontario, Canada

Afforestation systems as a pathway for natural climate solutions contributing to terrestrial C sequestration are influenced by agroclimatic conditions, tree species and clones. This study validated a regression equation to predict aboveground biomass C (AGBC) sequestration potentials of hybrid poplar clones under afforestation plantation and compared these clones’ adaptability to three levels of land suitability in four afforestation sites in southern Ontario, Canada. Results validated the proven ability of the GenOnBio model to reasonably predict AGBC content in all tested clones. This research suggests that DN154 and FFC1 having C sequestration rates of 2.19 and 2.13 Mg C ha-1 y-1, respectively, are suitable for marginal lands having high land suitability condition. In contrast, DTAC29, and DTAC26 (0.56 and 0.88 Mg C ha-1 y-1, respectively) should not be selected for the above land suitability. On marginal lands with severe limitations, NM6 (1.53 Mg C ha-1 y-1) showed the highest adaptability for AGBC sequestration. Our findings confirm that poplar afforestation on marginal lands in southern Ontario, at least up to the age of 15 years, can significantly contribute to AGBC sequestration, which in turn can have significant positive influence on the current 2 billion tree planting program initiated by the federal government.

Biomass accumulation and carbon sequestration potential in varying tree species, ages and densities in Gunung Bromo Education Forest, Central Java, Indonesia

Abstract. Darmawan AA, Ariyanto DP, Basuki TM, Syamsiyah J, Dewi WS. 2022. Biomass accumulation and carbon sequestration potential in varying tree species, ages and densities in Gunung Bromo Education Forest, Central Java, Indonesia. Biodiversitas 23: 5093-5100. Forest biomass plays an important role in carbon storage to mitigate climate change. While many studies have investigated the carbon stock of various forests, adding knowledge in the context of education forest might enrich the importance of this forest as a carbon pool besides its role for education purposes. Gunung Bromo Education Forest in Karanganyar Regency, Central Java, Indonesia consists of several tree cover types with each type having a different ability to absorb carbon dioxide in the atmosphere. This research aimed to determine the accumulation of biomass in Gunung Bromo Education Forest and to investigate the potential for carbon sequestration across different tree species, age classes and densities. Three species of tree (i.e. pine, Indonesian rosewood and mahogany) with varying ages were measured and calculated the biomass (i.e. tree, litter and understorey) and total carbon sequestration potentials (i.e. tree, litter and understorey, and soil organic carbon). This study used purposive sampling method across 9 combinations of tree cover type and age classes, each with 3 replication, resulting in a total of 27 sampling points. The results showed pine stands planted in 1973 had the highest tree biomass of 461.08 t ha-1 and while the pine agroforest planted in 2016 and Indonesian rosewood agroforest planted in 2018 had the lowest tree biomass with 1.02 t ha-1 and 0.39 t ha-1, respectively. Similarly, the pine stands planted in 1973 had the highest total carbon sequestration of 372.68 t ha-1 and the lowest in the pine agroforest planted in 2016 and Indonesian rosewood agroforest planted in 2018 with 187.11 t ha-1 and 193.58 t ha-1 respectively. The results of this study strengthen the common agreement in previous carbon studies that tree age strongly affects biomass accumulation and carbon sequestration, in which the older the plant, the higher the carbon sequestration potential than that of younger plants.

Carbon stocks and changes in biomass of Mediterranean woody crops over a six-year period in NE Spain

Carbon sequestration and storage in biomass is one of the most important measures to mitigate climate change. Mediterranean woody crops can sequestrate carbon in the biomass of their permanent structures for decades; however, very few studies have focused on an assessment of biomass and carbon sequestration in these types of crops. This study is the first to estimate above- and belowground biomass carbon stock in Mediterranean woody crops through a bottom-up approach in the NE Iberian Peninsula in 2013. Moreover, this is the first time that an assessment of the annual changes in carbon stock in the study area over a six-year period is presented. For this purpose, eight crop- and site-specific equations relating biomass or biometric variables to crop age were calculated. Most of the data were our own measurements, but unpublished data supplied from other authors as well as data from literature were also considered. Census of Agriculture data was used to scale results from individual data up to the municipality level at the regional scale. Results show that in woody cropland in NE Spain the total biomass carbon stock in 2013 was 5.48 Tg C, with an average value of 16.44 ± 0.18 Mg C ha−1. Between 2013 and 2019, although there was a 2.8% mean annual decrease in the area covered by woody crops, the carbon stock in the biomass of these crops increased annually by 3.8% due to the growth of the remaining woody cropland. This new estimation of carbon stocks may contribute to better understand carbon balances and serve as a baseline to global inventories. It may also serve to assess and manage carbon storage as an ecosystem service provided by Mediterranean woody cropland for mitigating climate change and, in combination with adaptive strategies, for supporting a productive and resilient agro-food system.

Diversity and Carbon Storage in &lt;i&gt;Calligonum polygonoides&lt;/i&gt; Associated Shrub Ecosystem of Indian Desert

Calligonum polygonoides L., a shrub of Indian Desert, helps combat desertification. A 400 quadrates of 0.1 ha size were assessed in 12 arid districts of Rajasthan to monitor associations, diversity and status of C. polygonoides and its role in biomass production and carbon sequestration. With 9.23% frequency C. polygonoides was recorded in Barmer, Bikaner, Jaisalmer, Jodhpur and Sriganganagar districts with average height and collar-diameter of 1.83±0.71 m and 6.61±2.01 cm respectively. Recorded 6 trees and 12 shrubs species were dominated by Acacia tortilis (IVI=153.6) and C. polygonoides (IVI=120.0), respectively. Higher growth and carbon storage with reduced rainfall indicates strong adaptability of C. polygonoides , but climate severity adversely affected plant diversity. Shrub diversity, soil pH, EC, bulk density (BD) and organic and inorganic carbon storage varied ( p &lt;0.05) spatially. Vertical distribution of gravel and BD was significant. Contribution of C. polygonoides to total biomass carbon ranged between 24.83% in Jodhpur and 93.25% in Barmer district. Land use and climatic and edaphic factors had resulted in heterogeneity in shrub diversity influencing carbon stock in both vegetation and soils. Results obtained demonstrated the role of Calligonum in shrubby vegetation cover by which carbon storage could be promoted and land and environmental degradation can be minimized.

Optimized utilization of Salix—Perspectives for the genetic improvement toward sustainable biofuel value chains

AbstractBioenergy will be one of the most important renewable energy sources in the conversion from fossil fuels to bio‐based products. Short rotation coppice Salix could be a key player in this conversion since Salix has rapid growth, positive energy balance, easy to manage cultivation system with vegetative propagation of plant material and multiple harvests from the same plantation. The aim of the present paper is to provide an overview of the main challenges and key issues in willow genetic improvement toward sustainable biofuel value chains. Primarily based on results from the research project “Optimized Utilization of Salix” (OPTUS), the influence of Salix wood quality on the potential for biofuel use is discussed, followed by issues related to the conversion of Salix biomass into liquid and gaseous transportation fuels. Thereafter, the studies address genotypic influence on soil carbon sequestration in Salix plantations, as well as on soil carbon dynamics and climate change impacts. Finally, the opportunities for plant breeding are discussed using willow as a resource for sustainable biofuel production. Substantial phenotypic and genotypic variation was reported for different wood quality traits important in biological (i.e., enzymatic and anaerobic) and thermochemical conversion processes, which is a prerequisite for plant breeding. Furthermore, different Salix genotypes can affect soil carbon sequestration variably, and life cycle assessment illustrates that these differences can result in different climate mitigation potential depending on genotype. Thus, the potential of Salix plantations for sustainable biomass production and its conversion into biofuels is shown. Large genetic variation in various wood and biomass traits, important for different conversion processes and carbon sequestration, provides opportunities to enhance the sustainability of the production system via plant breeding. This includes new breeding targets in addition to traditional targets for high yield to improve biomass quality and carbon sequestration potential.

Biomass Production and Carbon Sequestration Potential of Different Agroforestry Systems in India: A Critical Review

Agroforestry systems (AFS) and practices followed in India are highly diverse due to varied climatic conditions ranging from temperate to humid tropics. The estimated area under AFS in India is 13.75 million ha with the highest concentration being in the states of Uttar Pradesh (1.86 million ha), followed by Maharashtra (1.61 million ha), Rajasthan (1.55 million ha) and Andhra Pradesh (1.17 million ha). There are many forms of agroforestry practice in India ranging from intensified simple systems of monoculture, such as block plantations and boundary planting, to far more diverse and complex systems, such as home gardens. As a result, the biomass production and carbon sequestration potential of AFS are highly variable across different agro-climatic zones of India. Studies pertaining to the assessment of biomass and carbon storage in different agroforestry systems in the Indian sub-continent are scanty and most of these studies have reported region and system specific carbon stocks. However, while biomass and carbon stock data from different AFS at national scale has been scanty hitherto, such information is essential for national accounting, reporting of C sinks and sources, as well as for realizing the benefits of carbon credit to farmers engaged in tree-based production activities. Therefore, the objective of this study was to collate and synthesize the existing information on biomass carbon and SOC stocks associated with agroforestry practices across agro-climatic zones of India. The results revealed considerable variation in biomass and carbon stocks among AFS, as well as between different agro-climatic zones. Higher total biomass (&gt;200 Mg ha−1) was observed in the humid tropics of India which are prevalent in southern and northeastern regions, while lower total biomass (&lt;50 Mg ha−1) was reported from Indo-Gangetic, western and central India. Total biomass carbon varied in the range of 1.84 to 131 Mg ha−1 in the agrihorticulture systems of western and central India and the coffee agroforests of southern peninsular India. Similarly, soil organic carbon (SOC) ranged between 12.26–170.43 Mg ha−1, with the highest SOC in the coffee agroforests of southern India and the lowest in the agrisilviculture systems of western India. The AFS which recorded relatively higher SOC included plantation crop-based practices of southern, eastern and northeastern India, followed by the agrihorticulture and agrisilviculture systems of the northern Himalayas. The meta-analysis indicated that the growth and nature of different agroforestry tree species is the key factor affecting the carbon storage capacity of an agroforestry system. The baseline data obtained across various regions could be useful for devising policies on carbon trading or financing for agroforestry.

Effect of species diversity levels and microbial consortium on biomass production, net economic gain, and fertility of marginal land

AbstractIncreasing the income of crop growers per unit area and restoring the fertility of marginal soils are major challenges of agricultural sustainability in the Indian agrarian economy. This study investigates the benefits of plant communities consisting of Indian licorice (Abrus precatorius L.), stevia (Stevia rebaudiana B.), chilli (Capsicum annum L.), and a microbial consortium of four plant growth‐promoting bacteria and fungi (Bacillus pseudomycoides, Bacillus firmus, Aspergillus luchuensis, and Aspergillus tamarii) on production of plant biomass, income of growers, and its ability to improve soil fertility over a 2 year period. The three crop species were planted in all possible groupings at one, two, and three species diversity levels with three replication and two treatments, that is, with plant growth‐promoting microbes (PGPM) and without PGPM. The maximum increases in biomass (6.8 mega gram ha−1) and aboveground carbon sequestration (3.2 mega gram ha−1) were found for the three species diversity level of LSC (Indian licorice–stevia–chilli) plus PGPM. The highest belowground carbon sequestration (35 mega gram ha−1) and maximum soil fertility benefits [for example, pH (1.16‐times), electrical conductivity (7.53‐times), bulk density (1.84‐times), soil total organic carbon (3.99‐times), available nitrogen (5.95‐times), dehydrogenase (6.16‐times), microbial biomass carbon (4.06‐times), and colony‐forming units (4.44‐times)] were recorded at the two species diversity level of LC (Indian licorice‐chilli) with and without PGPM, compared with the soil properties before cultivation of these plants/additives. The highest net income (9.9 Lac ha−1 yr−2) was estimated for the two species diversity level (LS) plus addition of PGPM.

​Biostimulants towards Soil Health Improvement: A Review

Biostimulants are organic products made up of peptides and amino acids which are readily available to plants. Changes in farming are being caused by agro-ecological practices that take into account biodiversity and the way soil works. In agriculture, biostimulants can be used to keep plant growth and productivity without use of chemicals. Biostimulants can be used to identify and enhance specific soil microorganisms and they can help them grow and thrive. Soil microbial activity and the activity of important plant growth hormones or enzymes are also considered to help crops grow and yield more. The words “soil health” and “soil tilth” aren’t new in the world of farming. Many factors, many of which are biological, affect the health of soil. With the application of biostimulants soil health gets improved by influencing soil health indicators. Chemical fertilizers affect soil environment, which ultimately affects the human and animal lives. Microbes in the soil called arbuscular mycorrhizal fungi (AMF) play an important role in maintaining long-term soil fertility by forming mutualistic relationships with the roots of food crops, which help them, grow and thrive. Plants thrive under biotic and abiotic stress, due to the activation of defense mechanisms through these substances. Biostimulants from seaweed extracts are very popular because they help plants to grow and be more resistant to stress. Repeated applications of biochar could make the soil more carbon-rich and productive, which could lead to more crop biomass and biological carbon sequestration over time. This review summarizes the description of biostimulants and their role in soil health.