Increase Carbon Sequestration Research Articles

Fast labile carbon and litter exhaustion under no-tillage after 5-year soil warming

No-tillage continuously contribute organic matter and increase carbon sequestration in the soil. However, global warming may stimulate microbial activity and accelerate soil organic matter (SOM) decomposition, also especially in the topsoil. Understanding the responses of microbial utilization of SOM accumulated under no-tillage to higher temperatures is necessary to develop management strategies to sustain soil fertility. Determine the response of microbial extracellular enzyme activities and SOM decomposition to long-term warming by incorporation of 14C-labelled maize litter to in situ warmed soil from no-tillage and till systems. We compared decomposability of litter and SOM in soils from a 5-year in situ experiment with two tillage systems (Till and No-till) and under two temperature levels: ambient temperature and continuous soil warming (+1.6 °C at 5 cm soil depth). We hypothesized that decomposition of crop litter (14C-labeled maize) at increasing temperature (15, 21, and 27 °C for 59 days) will be more intensive in warmed soil vs. ambient and the effects should be stronger under No-till vs. Till system. As expected, soil from field warming had always higher total CO2 efflux (from 5.5 to 12%) than the non-warmed counterpart in Till and No-till systems. Five-year warming increased temperature sensitivity (Q10) of CO2 efflux for 2-folds under No-tillage vs. Till. Litter decomposition (measured as 14CO2) in No-till with warming was 7.9% greater than in No-tillage without warming. Three extracellular enzymes (β-glucosidase, chitinase, and sulfatase) had higher activities under warming in No-till but not under Till system. Our results demonstrated that the 5-year in situ warming accelerated preferential microbial utilization of labile SOM fractions in No-till notably, and from stable SOM in Till system. Consequently, warming will accelerate SOM decomposition in future and this acceleration will be especially pronounced on the labile SOM under No-tillage systems.

Assessment of Greenhouse Gas Emissions and Carbon Reserves with Zero Processing of Chernozem in the Conditions of the Forest-Steppe Zone of the Middle Volga Region

The transition from conventional soil treatment technology to zero treatment technology contributes to an increase in carbon sequestration (Sorg) in the form of carbon dioxide (CO2) from the atmosphere into the soil and, as a result, a reduction in the adverse effects of the greenhouse effect on the ecological state of the environment. The effectiveness of the application of zero tillage is to a greater or lesser extent due to specific agro-climatic conditions, crop rotation systems, fertilizers and plant protection, soil quality and stability. The influence of zero tillage on the dynamics of sorghum reserves and greenhouse gas emissions (CO2, N2O, CH4) in the agro-climatic conditions of crop production (LLC “Orlovka AIC”, Samara region) was investigated. The study was conducted on agrochernozem heavy loam in September–November 2021 in conditions of an abnormally arid growing season and high summer temperatures. On plots with zero tillage, plant residues were received: 268–1720 kg С/ha, 3–66 kg N, 0.2–7.7 kg P and 12–44 kg K/ha. Based on the results obtained, recommendations are proposed for further improving the efficiency of zero tillage technology due, firstly, to reducing its adverse effect on the density of soil composition, and, secondly, taking into account the influence of underlying parent rocks and relief on water erosion of soil and redistribution of granulometric fractions of soil in the agricultural landscape, which will allow using this technology according to principles of adaptive landscape farming.

Is it more important to increase carbon sequestration, biodiversity, or jobs? A case study of citizens' preferences for forest policy in Finland

Forest management plays an important role in mitigating the most serious threats to the well-being of current and future generations: climate change and biodiversity loss. We examine citizens' preferences for alternative forest management policy goals, including the provision of carbon sinks, biodiversity, and forest sector jobs, using a discrete choice experiment in Finland. We explore preference heterogeneity using latent class multinomial logit models finding the highest willingness to pay for biodiversity-oriented forest policy. Comparing three forest policy scenarios, focusing on “Biodiversity,” “Climate,” or “Bioeconomy,” citizens preferred the overall environmental goals over economic ones. We observe considerable heterogeneity in respondents' preferences identifying five latent preference classes. The results provide valuable background information on citizens' values and preferences on tradeoffs built into future revisions of forest policy.

Non-negligible roles of archaea in coastal carbon biogeochemical cycling.

Coastal zones are among the world's most productive ecosystems. They store vast amounts of organic carbon, as 'blue carbon' reservoirs, and impact global climate change. Archaeal communities are integral components of coastal microbiomes but their ecological roles are often overlooked. However, archaeal diversity, metabolism, evolution, and interactions, revealed by recent studies using rapidly developing cutting-edge technologies, place archaea as important players in coastal carbon biogeochemical cycling. We here summarize the latest advances in the understanding of archaeal carbon cycling processes in coastal ecosystems, specifically, archaeal involvement in CO2 fixation, organic biopolymer transformation, and methane metabolism. We also showcase the potential to use of archaeal communities to increase carbon sequestration and reduce methane production, with implications for mitigating climate change.

Carbon Neutrality: A Review

Abstract The introduction of the idea of “carbon neutrality” gives the development of low carbon and decarbonization a defined path. Climate change is a significant worldwide concern. To offer a theoretical foundation for the implementation of carbon reduction, this research first analyzes the idea of carbon footprinting, accounting techniques, and supporting technologies. The next section examines carbon emission reduction technologies in terms of lowering emissions and raising carbon sequestration. Digital intelligence technologies like the Internet of Things, big data, and artificial intelligence will be crucial throughout the process of reducing carbon emissions. The implementation pathways for increasing carbon sequestration primarily include ecological and technological carbon sequestration. Nevertheless, proving carbon neutrality requires measuring and monitoring greenhouse gas emissions from several industries, which makes it a challenging undertaking. Intending to increase the effectiveness of carbon footprint measurement, this study created a web-based program for computing and analyzing the whole life cycle carbon footprint of items. The practical applications and difficulties of digital technologies, such as blockchain, the Internet of Things, and artificial intelligence in achieving a transition to carbon neutrality are also reviewed, and additional encouraging research ideas and recommendations are made to support the development of carbon neutrality.

Planting trees in livestock landscapes to protect soil and water also delivers carbon sequestration

Ecuador has committed to climate change mitigation by reducing greenhouse gas emissions from anthropogenic activities, including livestock production. This sector can also contribute to mitigation by increasing carbon sequestration and storage capacity through increasing tree coverage. Although feasible, tree cover expansion would require agricultural land, creating a conflict with food production, thus appropriate areas need to be selected, and the impacts on livestock production quantified. Following water protection legislation and soil protection guidelines, we use a combination of measurements on 100 farms with land cover datasets to identify suitable areas for increasing tree coverage in livestock landscapes. Land cover classification was performed in 2 km areas around 100 livestock farms in the coastal and Amazon regions in Ecuador. Riparian zones were identified following legislation and steepland pastures identified from a slope map. Pasture in riparian areas or steeplands (slope > 15%) were considered suitable for increasing tree coverage by restoration or silvopastoral systems (SPS). The impact of forest/silvopastoral on biomass production was quantified. Overall, 855 km of rivers were studied, between 1–18% of riparian areas were classified as pastures, whilst from the 85992 ha included in the land cover classification, 41668 ha were identified as steepland, 1–28% of steepland was covered by pastures. We estimate that steepland pasture conversion into forest could offset 1.8–10% of Ecuador’s annual GHG emissions from the agricultural sector, but its impacts could represent a decrease > 50% of pasture biomass production at landscape level. Transformation of riparian and steepland pastures into SPS, could deliver important carbon sequestration, with a reduction in pasture biomass production of less than 20%.

Recovery through proper grazing exclusion promotes the carbon cycle and increases carbon sequestration in semiarid steppe

Grazing exclusion changes soil physical-chemical characteristics, rapidly affects microbial community composition and function, and alters biogeochemical processes, e.g., carbon (C) cycle, over time. However, the temporal dynamics of CO2 emission and CH4 uptake during grassland restoration chronosequences remain poorly understood. We investigated soil CO2 emission and CH4 uptake, the genes related to CO2 and CH4 production and reduction (cbbL, cbbM, chiA, and pmoA), and associated microbial communities under different durations of grazing exclusion (0, 7, 16, 25, and 38 years) to reveal the mechanisms and potential of soil CO2 emission and CH4 uptake in a semi-arid steppe. The results showed that a proper exclusion period could significantly improve soil physical-chemical conditions, vegetation community, and soil C-cycling. The abundance of C-cycling functional genes (cbbL, cbbM, chiA and pmoA), CH4 uptake and CO2 emission rates showed a single-peak pattern with increasing duration of grazing exclusion, peaking at 16 years and then decreasing in the period between 25 and 38 years, indicating that the effect of exclusion weakened when the exclusion period was too long. The changes in C-cycling functional genes and microbial communities are primarily influenced by aboveground net primary productivity (ANPP), and are associated with CO2, CH4, soil water content (SWC), and soil organic carbon (SOC). Structural equation modeling showed that increases in SOC content and pmoA abundance caused by an increase in ANPP accelerated CO2 emission and CH4 uptake rates, respectively. Our results provide valuable insights into the critical role of grazing exclusion in promoting grassland restoration and carbon sequestration, and have potential implications for sustainable land management practices.

Persistent and enhanced carbon sequestration capacity of alpine grasslands on Earth’s Third Pole

The carbon sequestration capacity of alpine grasslands, composed of alpine meadows and steppes, in the Tibetan Plateau has an essential role in regulating the regional carbon cycle. However, inadequate understanding of its spatiotemporal dynamics and regulatory mechanisms restricts our ability to determine potential climate change impacts. We assessed the spatial and temporal patterns and mechanisms of the net ecosystem exchange (NEE) of carbon dioxide in the Tibetan Plateau. The carbon sequestration of the alpine grasslands ranged from 26.39 to 79.19 Tg C year-1 and had an increasing rate of 1.14 Tg C year-1 between 1982 and 2018. While alpine meadows were relatively strong carbon sinks, the semiarid and arid alpine steppes were nearly carbon neutral. Alpine meadow areas experienced strong increases in carbon sequestration mainly because of increasing temperatures, while alpine steppe areas had weak increases mainly due to increasing precipitation. Carbon sequestration capacity of alpine grasslands on the plateau has undergone persistent enhancement under a warmer and wetter climate.

Fuelwood Consumption: Its Effects on Carbon Sequestration in the Derived Savannah Region of Cross River North, Nigeria

Fuelwood harvesting accounts for about 40 percent of global removal of wood from forests and half of the World's population depend on it as their main source of energy. This study investigates the fuelwood consumption: Its effects on Carb on sequestration in the derived Savannah region of Cross River North, Nigeria. The study seeks to determine the type of fuelwood consumed and estimate carbon sequester. In order to achieve these objectives, primary data consisted of questionnaire, interviews, and field study while secondary data were obtained from Landsat, Nigeria Meteorological Agency (NIMET) Ogoja and the internet. Three hundred and ninety-one copies of questionnaires were returned out of three hundred and ninety-nine questionnaires administered. Regression, paired sample t test, percentages were used for analysis. Gmelina is the fuelwood tree used in the area with 54.7 percent due to its availability and accessibility. Fuelwood is an energy; income source; and it is affordable. Obanliku Local Government Area has the highest mean fuelwood consumption with 0.621795m3 and the least is 0.476925m3 in Yala Local Government Area. Carbon sequester in the study area is 20,394,418,025 tonnes. The regression model for the relationship between fuelwood consumption and carbon sequestration is expressed as: Fuelwood consumption = - 4855725.118 + 17270584.078carbon sequester. As fuelwood consumption decreases, carbon sequestration increases. Fuelwood consumption needs to be reduced to increase carbon sequestration and alternative energy sources should be made affordable, available and at little or no price by the recommendations.

Strategies for reducing inputs and emissions in turfgrass systems

AbstractTurfgrass systems (e.g., home lawns, commercial properties, golf courses, athletic fields, roadsides, sod farms, parks, and other green spaces) in the US employ 820,000 individuals, have a $60 billion economic impact, and cover nearly 2% (∼63,250 mi2; 163,800 km2) of the US. Turfgrass systems provide ecosystem services such as carbon sequestration, oxygen production, water and air purification, improved soil health, pollinator habitat, and evaporative cooling. Associated disservices with turfgrass systems include nutrient and pesticide leaching, greenhouse gas and particulate matter emissions, low plant diversity, and site‐specific, high water consumption. The goal of recent research efforts is to maximize the services and minimize the disservices by focusing on sustainability initiatives to develop best management practices such reducing management inputs (e.g., mowing, irrigation, fertilizer, and pesticides), incorporating pollinator‐friendly spaces, adopting new technologies, quantitatively assessing ecosystem services provided, minimizing energy inputs and greenhouse gas emissions, and increasing carbon sequestration. This part‐review, part‐management guide summarizes these efforts, identifies knowledge gaps, and outlines how turfgrass systems can adapt to and mitigate climate change.

Identifying Optimal Forest Management Maximizing Carbon Sequestration in Mountain Forests Impacted by Natural Disturbances: A Case Study in the Alps

The role of forests in mitigating climate change by acting as a carbon sink is becoming increasingly important. Forest management practices can either positively or negatively affect the ability of forests to mitigate climate change. The objectives of our study were to: (a) investigate the effects of natural disturbances on long-term carbon sequestration dynamics in forests and (b) identify opportunities to adapt current forest management practices to increase carbon sequestration in forests. The study focused on mixed mountain forests in the Slovenian Alps, dominated by Norway spruce, and used the SLOMATRIX model to simulate forest development. Three forest management scenarios were simulated: (1) no management, (2) business-as-usual and (3) an optimized scenario maximizing carbon sequestration in forests while achieving the required harvest. Our results indicate that both forest management practices and natural disturbances have an impact on carbon sequestration dynamics. Optimizing harvests resulted in changes in the diameter structure and species composition of the harvested trees. Although natural disturbances can hinder the mitigation of climate change impacts, they can also catalyze forest adaptation to climate change and reduce the time required to reach carbon equilibrium.

Carbon stock, aggregate stability and hydraulic properties of soils under tillage, crop rotation and mineral fertiliser application in sub-humid Zimbabwe

Appropriate tillage and crop diversifications can improve soil quality leading to yield sustainability. Our objective was to quantify tillage, crop rotation and mineral fertiliser application effects on carbon sequestration, aggregation and soil water movement after two cropping cycles in the smallholder sector of Zimbabwe. Two split-plot experiments were set up at four sites on sandy, loamy and clayey soils. At experiment 1, crop rotation (maize-soya bean; continuous maize) was the main plot and mineral fertiliser ((NPKS (180 N + 30P2O5+30K2O+6.5SO3 kg ha−1); control (no fertiliser added)) was the sub-plot. At experiment 2, tillage (reduced, conventional) was the main plot and mineral fertiliser (NPKS; control) was the sub-plot. Soil samples collected from 0 to 0.2 m and 0.2–0.4 m layers were analysed for soil organic matter (SOM) content, bulk density and proportion of water stable aggregates. Saturated hydraulic conductivities (Ks), steady state infiltration rates (is) and soil sorptivities (Sp) were estimated from fitting field infiltration data into the Phillip model. SOM stocks (mean = 3.483 Mg ha−1) were significantly increased by reduced tillage at the sandy site and higher (p < 0.05) in 0–0.20 m than in 0.20–0.40 m layers at clayey sites. Proportion of water stable aggregates increased (p < 0.05) under reduced tillage compared with conventional tillage and under rotation compared with continuous maize system. Bulk densities were 11% lower (p < 0.05) in the 0–0.20 m than in 0.20–0.40 m layers. The estimated Ks(1 × 10−4-8x10−4 cm s−1) and is (7.08–55 × 10−4 cm s−1) were at least 100% higher (p < 0.05) under rotation compared with continuous maize whilst sorptivities (0.050–0.143 cm s−05) did not vary across the treatments. NPKS fertiliser reduced (p < 0.05) is by up to 1.8 fold compared with the control. Short term adoption of reduced tillage and maize-soya bean rotation can mitigate soil structural degradation; increase water recharging and increase carbon sequestration quicker in sands than in the buffering clays making the practices more relevant in the smallholder sector.

Spatiotemporal distribution and attribution of carbon sequestration in karst rocky desertification land in southern China

&lt;p&gt;To mitigate the intensification of desertification and land degradation in karst areas of southern China, since the late 1990s, the Chinese government has implemented a series of ecological restoration projects. In the past couple of decades, the carbon sequestration potential of karst rocky desertification land increased significantly. However, few studies have explored the characteristics and driving mechanisms of carbon sequestration in karst areas. This study aimed to quantify the spatiotemporal patterns, trends, and drivers of carbon sequestration in the Huajiang River Basin, a typical karst basin, in southern China during 2000-2020 and its five geographic zones via the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) model. The five zones of the karst basin exhibited the following characteristics: (I) good natural background condition with positive feedback human intervention; (II) poor natural background condition with increased negative and decreased positive feedback human interventions; (III) poor natural background condition with increased positive and decreased negative feedback human interventions; (IV) non-karst land; and (V) poor natural background condition with no significant positive and negative feedback human interventions and with heavy reliance on natural ecosystem recovery. The results were four-fold. First, the Huajiang River Basin showed a significant increasing trend of carbon sequestration. The spatiotemporal variation of carbon sequestration significantly differed among the five zones (Ⅴ &amp;gt; Ⅲ &amp;gt; Ⅳ &amp;gt; Ⅱ &amp;gt; Ⅰ). The stability of carbon sequestration was lowest in zone III. Second, a 20-y&lt;span style="font-family: 'Times New Roman';"&gt;ear&lt;/span&gt; land-use/cover change directly affected the level of carbon sequestration. The conversion of cropland, grassland, and woodland to shrubland was the main reason for the increased carbon sequestration in zone I. Third, carbon sequestration was negatively correlated with the desertification level of karst rocky areas. The spatial distributions of moderate, serious, and extremely strong desertification levels in zone II showed an increasing trend. Zones I, III, and V exhibited no significant desertification. Finally, the integrated ecological management against desertification increased carbon sequestration. Negative feedback human interventions (e.g., quarrying) exerted a significant disturbing impact on carbon sequestration that needs to be addressed in the formulation of management practices.&lt;/p&gt;

Analyzing the spatiotemporal carbon change mechanism: a land-based carbon flow network (CFN) for cities

High carbon emissions played a significant role in global climate change, which made cities with rapid urbanization responsible for local carbon mitigation. In this study, a land-based CFN framework was established by taking 15 land use types as different network nodes. The framework was intended to be a dynamic structure containing the carbon emissions/sequestration tracking, land-based carbon network and utility analysis, and carbon change mechanism identification. By taking Guangzhou city as an empirical study, the carbon metabolism patterns were shown as increasing emission expansion and spatial differentiation. The high-level emission patches extended from the city center to the suburb with 1/2 to 1/3 the original size from 2000 to 2020, which featured as land use transition toward T in the north and to C2 in the south. All the changing carbon processes among land nodes were detected to conduct CFN utility analysis for mechanism investigation. Exploitation was found significantly contributed to the carbon emissions in 2000-2005 and fell over time. In the built-up area, the dominant carbon relationship has changed from exploitation to mutualism with enlarged carbon emissions in 2000-2005, 2005-2010, and 2010-2015, and the exploitation became dominant in 2015-2020 with increasing carbon sequestration. Under the increasing competitive relationship, carbon emissions of the related land nodes decreased more than 90% from 2000 to 2020 with favorable mutual restriction between pairwise nodes. It provided valuable insight for the carbon mitigation options at a city level through local urban planning.

Potential of biological invasion for carbon sequestration in a protected area: the case of the Limbe Botanic Garden (LBG) forest, Cameroon

The Limbe Botanical Garden (LBG) is a relict urban forest located in the heart of the city of Limbe. This forest has many ecological, economic, social and tourist functions and is the green lung of the city of Limbé. Unfortunately, this forest has always been threatened by various anthropic pressures and more recently by invasive exotic species. These threats make us fear the progressive disappearance of this massif, which would be a threat to the plant and animal populations, the riparian communities and the ecosystem services such as carbon regulation. The general objective of our study is to assess the validity of the hypothesis of increased carbon sequestration of invasive species compared to native species. For the floristic inventory, twenty 100 m2 (10 m x 10 m) plots were set up in this LBG urban forest. We recorded information such as the number of adult and juvenile individuals and the diameter of trees greater than or equal to 10 cm. The inventory recorded 349 plant species. The most frequent species is Cyathea camerooniana with 92.3% presence. Cedrela odorata has a frequency of occurrence of 76.9% in this urban forest and a frequency of 60% in the LBG. This taxon has a very high above-ground biomass (187.4 tC/ha) and therefore the highest carbon storage capacity (93.7 tC/ha). It is followed by Diospyros crassifolia and Dialium pachyphyllum, both native species. Cedrela odorata has a positive impact on carbon sequestration and therefore contributes to the well-being of the people. However, the conclusion needs to be qualified because invasive species can influence the functioning of forests in the long term.

Floral resources in Swedish grasslands remain relatively stable under an experimental drought and are enhanced by soil amendments if regularly mown

Abstract One of the main reasons why insect pollinators are declining is a lack of floral resources. In agricultural landscapes, remaining seminatural grasslands play a key role for providing such resources. However, droughts pose an increasing threat to the abundance and continuity of flowers. Soil amendments are a novel management tool for Swedish grasslands aiming to increase carbon sequestration and soil water holding capacity. In this study, we examined how drought is affecting floral resources (i.e. floral units, nectar quantity and nectar continuity) in grasslands with different mowing regimes, and if soil amendments could mitigate potential negative drought effects. In summer 2019, we set up an experiment combining rain‐out shelters (‘drought’), soil amendments (‘compost’) and different mowing regimes (‘mown’ vs. ‘abandoned’) in four extensively managed Swedish grasslands (48 plots, size 2 m2). Between May and August 2021, we counted the floral units nine times in each plot. We derived values for the nectar sugar production per floral unit from an existing database. We observed a decrease in floral units under drought in the mown, but not in the abandoned plots. Nectar quantity and continuity over the season were not significantly affected by drought across both mowing regimes—in the abandoned plots the nectar provision even extended slightly in duration (towards late summer). The compost treatment had positive effects on the floral units, nectar quantity and continuity (extending it towards early summer) in the mown, but not in the abandoned plots. The plant species in our study reacted differently to the treatments. Most of the nectar was provided by only few species (mainly Lathyrus pratensis, Vicia cracca and Anthriscus sylvestris). The results are species specific, thus other plant communities might respond differently. However, our experiment shows that nectar provision (based on database values) in grasslands with a native plant community and natural soil conditions remains relatively stable under drought. We also found that soil amendments increase floral resources in managed grasslands.

Natural climate solutions. The way forward

Climate change is a global challenge that threatens global ecological security and sustainable development. Finding ways to mitigate their impacts is paramount through engineering carbon storage, low-carbon energy transition, or natural climate solutions (NCS). NCS involve a set of measures (e.g., afforestation, land restoration, biochar reuse or sustainable land use practices). Implementing NCS increases carbon sequestration and mitigates climate change at the lowest costs and greenest ways. In addition, NCS practices can improve multiple ecosystem services (ES) such as air quality, flood and erosion regulation, pest control, water purification, wild food biomass, recreation or landscape aesthetics. However, unsustainable implementation of NCS, such as over-afforestation of dense mono-forest, can lead to tradeoffs with water supply, wildfire risk, and decreased grasslands and croplands. Therefore, to optimise the NCS implementation, reducing the tradeoffs associated and transforming the “expand ecosystem area” to “improve ecosystem management efficiency” is vital. Although NCS can contribute significantly to mitigating climate change, systematic climate actions must be accompanied by a transformation in the global society and investment in new technologies. This will be key to addressing global challenges such as the achievement of Sustainable Development Goals (SDGs), such as SDG 13 (Climate Action), SDG 15 (Life on Land), SDG 2 (Zero Hunger), SDG 3 (Good Health and Wellbeing), SDG 6 (Clean Water and Sanitation), and SDG 14 (Life Bellow Water).

Carbon dynamics in old-growth forests of the Central Hardwoods Region, USA

Managing old-growth forests and promoting old-growth complexity in aging forests for carbon emissions mitigation has become an important component of diversified land management strategies. In the midwestern US, the Central Hardwoods Region (CHR) is the largest continuous deciduous forested area and includes a diverse range of species compositions, forest structures, and topoedaphic environments. Understanding carbon storage potential in old-growth forests across the CHR is important for evaluating climate-adaptive management strategies to increase carbon sequestration in the region’s aging forests. We assessed forest carbon in two time periods (the early 1990s and the 2010s) in ten old-growth forests across a 770 km east-west productivity gradient from Indiana to Missouri. Further, we related anomalies in carbon pools between the two sampling periods to documented or observable disturbances. As expected, old-growth forests on more productive sites in the eastern portion of the study range stored more aboveground carbon (120–177 Mg C ha−1) than less productive sites to the west (93–117 Mg C ha−1). Over the twenty-year period, old-growth forests accumulated 9.2 ± 1.5 (mean ± SE) Mg C ha−1 or a 7 % increase in total aboveground carbon. Further, downed dead wood carbon increased 5 % (0.4 ± 0.7 Mg C ha−1), standing dead increased 7 % (0.3 ± 0.7 Mg C ha−1), live roots increased 4 % (1.0 ± 0.3), and dead roots increased by 68 % (0.3 ± 0.1 Mg C ha−1). However, stochastic disturbances can positively or negatively impact total carbon and carbon pools. Documenting carbon trends and disturbance effects in old-growth forests provides guidance to enhance the representation of structurally complex, late successional forests using active forest management. Old-growth forests are currently rare in the CHR landscape, but the abundance of aging forests in the region provides immense potential to store carbon, particularly when combined with strategies that optimize early- and late-successional habitats for carbon sequestration along with other ecological goods and services.

Are Portuguese Cowpea Genotypes Adapted to Drought? Phenological Development and Grain Quality Evaluation.

Along with population growth, global climate change represents a critical threat to agricultural production, compromising the goal of achieving food and nutrition security for all. It is urgent to create sustainable and resilient agri-food systems capable of feeding the world without debilitating the planet. The Food and Agriculture Organization of the United Nations (FAO) refers to pulses as a superfood, as one of the most nutritious crops with high health benefits. Considered to be low-cost, many can be produced in arid lands and have an extended shelf-life. Their cultivation helps reduce greenhouse gases and increases carbon sequestration, also improving soil fertility. Cowpea, Vigna unguiculata (L.) Walp. is particularly drought tolerant, with a wide diversity of landraces adapted to different environments. Considering the importance of knowing and valuing the genetic variability of this species in Portugal, this study assessed the impact of drought on four landraces of cowpea (L1 to L4) from different regions of the country and a national commercial variety (CV) as a reference. The development and evaluation of morphological characteristics were monitored in response to terminal drought (imposed during the reproductive phase), and its effects were evaluated on the yield and quality of the produced grain, namely the weight of 100 grains, color, protein content, and soluble sugars. Under drought conditions, the landraces L1 and L2 showed early maturation as a strategy to avoid water deficit. Morphological alteration of the aerial part of the plants was evident in all genotypes, with a rapid reduction in the number of leaves and a reduction in the number of flowers and pods by between 44 and 72%. The parameters of grain quality, the weight of 100 grains, color, protein, and soluble sugars did not vary significantly, except for sugars of the raffinose family that is associated with the adaptive mechanisms of plants to drought. The performance and maintenance of the evaluated characteristics reflect the adaptation acquired in the past by exposure to the Mediterranean climate, highlighting the potential agronomic and genetic value, still little exploited, that could contribute to production stability, preserved nutritional value, and food safety under water stress.

Soil carbon sequestration benefits of active versus natural restoration vary with initial carbon content and soil layer

Reducing terrestrial carbon emissions is a big challenge for human societies. Ecosystem restoration is predominant to reverse land degradation and carbon loss. Though active restoration of croplands is assumed to increase carbon sequestration more than natural regeneration, it still lacks the robust paired comparisons between them. Here we performed a large-scale paired comparison of active versus natural restoration effects on soil carbon sequestration across China. We found that two restoration strategies consistently enhanced soil carbon relative to croplands, however, the benefits of active restoration versus natural regeneration were highly context-dependent. Active restoration only sequestered more carbon in carbon-poor soils but less carbon in carbon-rich soils than natural regeneration. Moreover, active restoration fixed greater carbon in topsoil but less carbon in subsoil. Overall, these findings highlight landscape context-dependent application of active restoration and natural regeneration, further guiding the efficient management of limited resources to maximize the restoration benefits of carbon sequestration.