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Uncertainties in carbon storage estimates for disturbance-prone dryland ecosystems hinder accurate assessments of their contribution to the global carbon budget. This study examines the effects of land-use change on carbon storage in an African savanna landscape, focusing on two major land-use change pathways: agricultural intensification and wildlife conservation, both of which alter disturbance regimes. By adapting tree inventory and soil sampling methods for dryland conditions, we quantified aboveground and belowground carbon in woody vegetation (AGC and BGC) and soil organic carbon (SOC) across these pathways in two vegetation types (scrub savanna and woodland savanna). We used Generalized Additive Mixed Models to assess the effects of multiple environmental drivers on AGC and whole-ecosystem carbon storage (C-total). Our findings revealed a pronounced variation in the vulnerability of carbon reservoirs to disturbance, depending on land-use change pathway and vegetation type. In scrub savanna vegetation, shrub AGC emerged as the most vulnerable carbon reservoir, declining on average by 56% along the conservation pathway and 90% along the intensification pathway compared to low-disturbance sites. In woodland savanna, tree AGC was most affected, decreasing on average by 95% along the intensification pathway. Unexpectedly, SOC stocks were often higher at greater disturbance levels, particularly under agricultural intensification, likely due to the preferential conversion of naturally carbon-richer soils for agriculture and the redistribution of AGC to SOC through megaherbivore browsing. Strong unimodal relationships between disturbance agents, such as megaherbivore browsing and woodcutting, and both AGC and C-total suggest that intermediate disturbance levels can enhance ecosystem-level carbon storage in disturbance-prone dryland ecosystems. These findings underline the importance of locally tailored management strategies-such as in carbon certification schemes-that reconcile disturbance regimes in drylands with carbon sequestration goals. Moreover, potential trade-offs between land-use objectives and carbon storage goals must be considered.

期刊论文 2025-04-01 DOI: 10.1111/gcb.70163 ISSN: 1354-1013

Semi-natural grasslands and their diverse biota are threatened by changes in land-use like afforestation, abandonment of traditional practices, urban development or conversion into intensive agricultural land. Extensive loss and fragmentation of semi-natural grasslands consequently affects ecosystem functioning inherit to open landscapes and the sustainable provision of ecosystem services. Ecological restoration of grasslands has potential to halt further decline and hopefully reverse some of the damage done to the grasslands and vital ecosystem services they provide. By assessing grasslands before and after the restoration, we evaluated how restoring overgrown and forested semi-natural grasslands to open grasslands impacts nine ecosystem services: habitat maintenance, soil condition maintenance, soil carbon storage, pollination, pest regulation, provision of wild food and medicinal herbs, forage production, wood production and recreation. We also analyzed the relationship between ecosystem multifunctionality and species richness of multiple organism groups. We found that already few years after restoration, restored grasslands exhibited rapidly increasing biodiversity and ecosystem service provision. Similarly, the overall ecosystem multifunctionality increased significantly after restoration in previously overgrown and afforested grasslands. However, while a robust and strong positive relationship between multitrophic diversity and ecosystem multifunctionality existed before restoration, this relationship was somewhat weakened after restoration. We propose two potential explanations: first, the previously distinct condition classes became more similar, starting to resemble open grassland habitats in their species richness and composition. Second, the relationship may have been weakened by the temporarily disrupted and transitional nature of the ecosystem post-restoration, due to varying recovery rates among different species groups and ecosystem services. Notably, soil-related services (carbon storage and soil maintenance) take longer to respond to restoration, compared to other services. In addition, we detected significant negative impact of prolonged drought on pest regulation and forage production service in both restored and unrestored areas. Semi-natural grasslands are both biodiversity and ecosystem service hotspots in European landscapes and restoring these habitats significantly increases the provision potential of important ecosystem services. However, restoration planning must consider landscape history, regional characteristics and the importance of long-term monitoring for getting the most accurate results.

期刊论文 2024-10-15 DOI: 10.1016/j.agee.2024.109139 ISSN: 0167-8809

Due to underlying surface changes (USCs), the changes in the Taojiang River Basin's flood generation conditions could impact the flooding process in the basin. However, most studies have typically focused on either land-use changes (LUCs) or soil and water conservation measures (SWCMs) to assess the impact of the USCs on floods, which may not provide a more comprehensive understanding of the response of floods to the USCs. To investigate how the USCs have altered the floods in the Taojiang River Basin, located upstream of Poyang Lake, China, the HEC-HMS model, which incorporates the influence of the USCs into the parameter calibration, is established in this study to investigate the flood processes on an hourly scale. The flood peak and the maximum 72 h flood volume are selected as two indexes and are applied to analyze the changes in floods caused by the USCs. The 1981-2020 period is divided into three sub-periods (i.e., 1981-1992, 1993-2007, and 2008-2020) based on the conditions of the USCs. It is found that the two indexes have exhibited decreasing trends, mainly due to the USCs during 1981-2020. Benchmarked against the baseline period of 1981-1992, the two indexes decreased by 3.06% (the flood peak) and 4.00% (the maximum 72 h flood volume) during 1993-2007 and by 5.92% and 7.58% during 2008-2020. Moreover, the impacts of the LUCs and SWCMs are separated through parameter adjustments in the model, revealing that the SWCMs played a dominant role in the USCs in the Taojiang River Basin. The quantification and assessment of the impact of the USCs on floods of different magnitudes revealed that the influence decreases with increasing flood magnitude. The results of this study improve our understanding of how USCs affect the flooding process and therefore provide support for flood control management under changing environments.

期刊论文 2024-04-01 DOI: 10.3390/w16081120

Climate change will alter ecosystem metabolism and may lead to a redistribution of vegetation and changes in fire regimes in Northern Eurasia over the 21st century. Land management decisions will interact with these climate-driven changes to reshape the region's landscape. Here we present an assessment of the potential consequences of climate change on land use and associated land carbon sink activity for Northern Eurasia in the context of climate-induced vegetation shifts. Under a `business-as-usual' scenario, climate-induced vegetation shifts allow expansion of areas devoted to food crop production (15%) and pastures (39%) over the 21st century. Under a climate stabilization scenario, climate-induced vegetation shifts permit expansion of areas devoted to cellulosic biofuel production (25%) and pastures (21%), but reduce the expansion of areas devoted to food crop production by 10%. In both climate scenarios, vegetation shifts further reduce the areas devoted to timber production by 6-8% over this same time period. Fire associated with climate-induced vegetation shifts causes the region to become more of a carbon source than if no vegetation shifts occur. Consideration of the interactions between climate-induced vegetation shifts and human activities through a modeling framework has provided clues to how humans may be able to adapt to a changing world and identified the trade-offs, including unintended consequences, associated with proposed climate/energy policies.

期刊论文 2014-03-01 DOI: 10.1088/1748-9326/9/3/035004 ISSN: 1748-9326
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