[Temporal and Spatial Evolution and Prediction of Ecosystem Carbon Storage in Jiangxi Province Based on PLUS-InVEST Model].

Land-use changes are an important factor affecting the change in carbon storage in terrestrial ecosystems. Exploring the relationship between land-use changes and carbon storage provides reliable data support for optimizing regional land-use structure and maintaining regional carbon balance. Taking Jiangxi Province as an example, we first analyzed the land-use changes; then simulated the land-use pattern under three scenarios (i.e., natural development, ecological priority, and economic development scenarios) in 2030 based on the PLUS model; and finally estimated the carbon storage change in the past (i.e., 1990-2020) and future periods (i.e., three scenarios in 2030) using the InVEST model, analyzed the spatial-temporal characteristics, and proposed the corresponding suggestions. The results showed:① The carbon storage in Jiangxi Province showed a downward trend from 1990 to 2020, with a total reduction of 4.58×107 t. The increase in the water bodies and construction land and the decrease in cultivated land, woodland, grassland, and unused land was the major cause. ② The carbon storage under natural development, ecological priority, and economic development scenarios in Jiangxi Province in 2030 were 2.20×109, 2.24×109 and 2.19×109 t, respectively. ③ The carbon storage under the three scenarios showed similar spatial characteristics, wherein the high carbon storage was distributed in northern, northwest, and western regions, and the low carbon storage was distributed near the central region. These results can provide data support for future land spatial planning and improving the carbon storage of terrestrial ecosystems in Jiangxi Province.

Appling fluorescence spectroscopy with absolute principal component coefficient to explore dynamic migration of DOM fractions from an urbanized river during torrential rainfall.

This research delves into the dynamic interplay between urbanization and the characteristics of Dissolved Organic Matter (DOM) in the Anyang River, particularly under the stress of torrential rain. The motivation stems from a critical need to decipher how urban landscapes influence water quality, focusing on the intricate transformations and movements of DOM. Employing advanced fluorescence spectroscopy techniques like Excitation-Emission Matrices (EEM) and Parallel Factor Analysis (PARAFAC), the study meticulously differentiates DOM compositions in urban and agricultural settings. It unveils a pronounced distinction, with urban streams showing elevated proteinaceous DOM from wastewater, contrasting with the humic substances prevalent in agricultural runoff. The analysis also captures how intense rainfall events catalyze significant shifts in DOM profiles, thereby emphasizing the need for tailored water quality management strategies in urbanized catchments. This comprehensive approach not only bridges gaps in understanding the urban impact on riverine ecosystems but also sets a foundation for future research and policy development in the face of escalating environmental changes.

Will large-scale forestation lead to a soil water deficit crisis in China's drylands?

Trading water for carbon has cautioned large-scale afforestation in global drylands. However, model simulations suggested that the consumption of soil water could be partially offset by increasing precipitation due to vegetation feedback. A systematic meta-analysis of long-term and large-scale field observations is urgently required to address the abovementioned limitations, and the implementation of large-scale afforestation since 1978 in northern China provides an ideal example. This study collected data comprising 1226 observations from 98 sites in northern China to assess the variation in soil water content (SWC) with stand age after afforestation and discuss the effects of tree species, precipitation and conversions of land use types on SWC. We found that the SWC has been decreased by coniferous forest and broadleaf forest at rates of 0.6 and 3.2 mm decade-1, respectively, since 1978. There is a significant declining trend of SWC with the stand age of plantations, and the optimum growth stage for plantation forest is 0-20 a in northern China. However, we found increases in SWC for the conversion from grassland to forest and in the low-precipitation region, both are corresponding to the increased SWC in coniferous forest. Our study implies that afforestation might lead to a soil water deficit crisis in northern China in the long term at the regional scale but depends on prior land use types, tree taxa and the mean annual precipitation regime, which sheds light on decision-making regarding ecological restoration policies and water resource management in drylands.

The Effect of Habitat on Insect Movements: Experimental Evidence from Wild-Caught Butterflies.

There is broad evidence that the main driver of the ongoing biodiversity crisis is land-use change, which reduces and fragments habitats. The consequence of habitat fragmentation on behavioural responses of fitness-related traits in insects have been so far understudied. In herbivorous insects, oviposition-related behaviours determine access to larval food, and the fate of the next generation. We present a pilot study to assess differences in behaviours related to movement and oviposition in Limenitis camilla butterflies from Wallonia (Belgium), one of the most fragmented regions in Europe. We first quantified variation in functional habitat connectivity across Wallonia and found that fragmented habitats had more abundant, but less evenly distributed host plants of L. camilla. Secondly, we quantified the behaviours of field-caught L. camilla females originating from habitats with contrasted landscape connectivity in an outdoor experimental setting. We found differences in behaviours related to flight investment: butterflies from fragmented woodlands spent more time in departing flight, which we associated with dispersal, than butterflies from homogenous woodlands. Although results from this study should be interpreted with caution given the limited sample size, they provide valuable insights for the advancement of behavioural research that aims to assess the effects of global changes on insects.

A raw data on the physico-chemical water parameters and sedimentation rates of two different aquatic macrophytes in Tasik Berombak, Malaysia.

The excessive growth of aquatic macrophytes in a water system has a negative effect on the lake ecosystem. This article presents data on water parameters and sedimentation rates from sites that include different aquatic macrophytes at Tasik Berombak, a freshwater lake on Peninsular Malaysia's eastern coast. Areas with Hanguana malayana and Pandanus helicopus were selected for sampling, while an area without aquatic macrophytes served as the control. At the lake's surface and bottom, temperature, conductivity, total dissolved solids, dissolved oxygen (D.O.), and pH were measured in situ. The surface water was sampled for chemical analysis in the laboratory (chlorophyll-a, total suspended solids, total carbon, total organic carbon, inorganic carbon, total dissolved nitrogen, total dissolved phosphorus). Settling sediment was collected using cylinder traps deployed under the macrophytes at the bottom of the lake. The presented data includes the water parameters according to plant-base area, depth differentiation (top versus bottom), and variable correlation analysis. Understanding the impact of excessive aquatic plants on the lake ecosystem in a tropical environment requires information on water parameters and sedimentation rates from the aquatic plants. Therefore, these data can be used to monitor the impact of land use change on the aquatic plant community and, ultimately, the lake ecosystem.

Urbanization reduces soil microbial network complexity and stability in the megacity of Shanghai.

Urbanization is altering the co-occurrence networks of ecological communities that are critical to maintaining ecosystem functions and services. Soil microbial communities play key roles in various ecosystem processes, but how soil microbial co-occurrence networks respond to urbanization is unclear. Here we analyzed co-occurrence networks in soil archaeal, bacterial, and fungal communities from 258 soil sampling sites across the megacity of Shanghai along large urbanization gradients. We found that topological features of microbial co-occurrence networks were strongly altered by urbanization. In particular, microbial communities in more urbanized land-use and highly impervious land cover had less connected and more isolated network structures. These structural variations were accompanied by the dominance of connectors and module hubs affiliated with the Ascomycota in fungi and Chloroflexi in bacteria, and there were greater losses in efficiency and connectivity in urbanized than in remnant land-use in simulated disturbances. Furthermore, even though soil properties (especially soil pH and organic carbon) were major factors shaping topological features of the microbial networks, urbanization still uniquely explained a proportion of the variability, particularly those describing network connections. These results demonstrate that urbanization has clear direct and indirect effects on microbial networks and provide novel insights into how urbanization alters soil microbial communities.

Changes in Organic Carbon Stock in Soil and Whole Tree Biomass in Afforested Areas in Latvia.

This study investigates the soil organic carbon (SOC) and whole tree biomass carbon (C), soil bulk density (BD) as well as changes in these parameters in afforested areas in Latvia. The study covered 24 research sites in afforested areas-juvenile forest stands dominated by Scots pine, Norway spruce and Silver birch. The initial measurements were conducted in 2012 and repeated in 2021. The results show that afforestation mostly leads to a general decrease in soil BD and SOC stock in 0-40 cm soil layer and an increase in C stock in tree biomass across afforested areas with various tree species, soil types, and former land uses. The physical and chemical properties of the soil could explain the differences in changes in soil BD and SOC caused by afforestation, as well as the impact of past land use may have persisted. When comparing the changes in SOC stock with the increase in C stock in tree biomass due to afforestation, taking into account the decrease in soil BD and the resulting elevation of soil surface level, the afforested areas at juvenile development stage can be considered a net C sink.

Reforestation substantially changed the soil antibiotic resistome and its relationships with metal resistance genes, mobile genetic elements, and pathogens.

Revealing the effects of reforestation on soil antibiotic resistome is essential for assessing ecosystem health, yet related studies remain scarce. Here, to determine the responses of the soil antibiotic resistome to reforestation, 30 pairs of cropland and forest soil samples were collected from southwestern China, a region with high environmental heterogeneity. All the forests had been derived from croplands more than one decade ago. The diversity and abundance of soil antibiotic resistance genes (ARGs), metal resistance genes (MRGs), mobile genetic elements (MGEs), and pathogens were determined by metagenomic sequencing and real-time PCR. The results showed that reforestation significantly increased soil microbial abundance and the contents of Cu, total carbon, total nitrogen, total organic carbon, and ammonium nitrogen. Nevertheless, it decreased the contents of soil Zn, Ba, nitrate nitrogen, and available phosphorus. The main soil ARGs identified in this region were vancomycin, multidrug, and bacitracin resistance genes. Reforestation significantly increased the soil ARG abundance by 62.58%, while it decreased the ARG richness by 16.50%. Reforestation exerted no significant effects on the abundance of heavy metal resistance genes and pathogens, but it doubled the abundance of MGEs. Additionally, reforestation substantially decreased the co-occurrence frequencies of ARGs with MRGs and pathogens. In contrast, the correlation between ARGs and MGEs was greatly enhanced by reforestation. Similarly, the correlations between soil ARG abundance and environmental factors were also strengthened by reforestation. These findings suggest that reforestation can substantially affect the soil antibiotic resistome and exerts overall positive effects on soil health by decreasing ARG richness, providing critical information for assessing the effects of "grain for green" project on soil health.

Soil physicochemical properties change by age of the oil palm crop.

For decades there have been controversies related to the changes generated by oil palm plantations in the physicochemical properties of the soil, soil biota, and ecological interactions. Therefore, the present investigation evaluated root diameter and biomass at three ages of oil palm cultivation. Besides, we evaluated the effect of the ages on the physicochemical parameters of the soil in comparison with pasture plots. To know the diameter, fresh, and dry biomass of roots, soil sampling was carried out around the oil palm (3-, 5-, and 15-years-old) at distances of 1, 2, and 3 m from the trunk plant. Also, to know the changes in the properties of the soil, the sampling was carried out randomly in the same plots and the pasture plot (control). The results showed that both the diameter and the fresh and dry root biomass increased in 15-year-old plantations compared with 3- and 5-year-old. In addition, correlation analysis and principal component analysis indicated that the parameters evaluated are associated with the adult age of the oil palm. Also, the results of soil physicochemical showed that low soil fertility was associated with an increase in the age of the palm.

An integrated model chain for future flood risk prediction under land-use changes.

Flood is a very destructive natural disaster in the world that is strongly influenced by land-use change. Therefore, a comprehensive flood risk modeling considering the change in land-use is essential for understanding, predicting, and mitigating flood risk. However, most existing single modeling ignored the derivative effect of land-use change, which may reduce the reality of results. To further address the issue, this study presented an integrated model chain by coupling the Markov-FLUS model, the multiple linear regression and the improved TOPSIS model. By applying it in Guangdong Province, the future land-use simulation, spatialization of hazard-bearing bodies, and determination of flood risk were realized. The results show that the coupled model chain allows for good prediction of flood risk under different scenarios, which could be expressed by flood risk composite index (FRSI). In the natural growth scenario, the flood risk will show markedly increasing trend from 2020 to 2030 (FRSI = 2.06), with the high and highest risk zones will expand significantly. Spatially, these increased high flood risk zones mainly distributed on the periphery of existing built-up lands. On the contrary, the flood risk in ecological protection scenario tends to stabilize (FRSI = 1.98), which may be a reference for alternative development paths. These dynamic information identified by this model chain provides a deeper insight into the spatiotemporal characteristics of future high flood risk areas, which can facilitate reasonable flood mitigation measures to be developed at the most critical locations in the region. In further applications, more efficient spatialization models and climate factor are suggested to be introduced.

Human land-uses homogenize stream assemblages and reduce animal biomass production.

Human land-use change is a major threat to natural ecosystems worldwide. Nonetheless, the effects of human land-uses on the structure of plant and animal assemblages and their functional characteristics need to be better understood. Furthermore, the pathways by which human land uses affect ecosystem functions, such as biomass production, still need to be clarified. We compiled a unique dataset of fish, arthropod and macrophyte assemblages from 61 stream ecosystems in two Neotropical biomes: Amazonian rainforest and Uruguayan grasslands. We then tested how the cover of agriculture, pasture, urbanization and afforestation affected the taxonomic richness and functional diversity of those three species assemblages, and the consequences of these effects for animal biomass production. Single trait categories and functional diversity were evaluated, combining recruitment and life-history, resource and habitat-use, and body size. The effects of intensive human land-uses on taxonomic and functional diversities were as strong as other drivers known to affect biodiversity, such as local climate and environmental factors. In both biomes, the taxonomic richness and functional diversity of animal and macrophyte assemblages decreased with increasing cover of agriculture, pasture, and urbanization. Human land-uses were associated with functional homogenization of both animal and macrophyte assemblages. Human land-uses reduced animal biomass through direct and indirect pathways mediated by declines in taxonomic and functional diversities. Our findings indicate that converting natural ecosystems to supply human demands results in species loss and trait homogenization across multiple biotic assemblages, ultimately reducing animal biomass production in streams.

Organic farming offers promising mitigation potential in dairy systems without compromising economic performances.

There is a lack of clear empirical evidence towards the lower carbon footprint of organic food products, in particular in the dairy sector. Until now, small sample sizes, lack of properly defined counterfactual and the omission of land-use related emissions have hindered comparisons of organic and conventional products. Here we bridge these gaps by mobilizing a uniquely large dataset of 3074 French dairy farms. Using propensity score weighting, we find that the carbon footprint of organic milk is 19% (95%CI = [10%-28%]) lower than its conventional counterpart without indirect land-use change and 11% (95%CI = [5%-17%]) lower with indirect land use changes. In both production systems, farms' profitability is similar. We simulate the consequences of the Green deal target of 25% of agricultural land devoted to organic dairy farming and show that this policy would reduce the greenhouse gas emissions of the French dairy sector by 9.01-9.64%.

New indicator of habitat functionality reveals high risk of underestimating trade-offs among sustainable development goals: The case of wild reindeer and hydropower.

Although biodiversity is crucial for Sustainable Development Goals (SDGs), following the current trajectory, we risk failing SDG 15. Using a new indicator quantifying the loss of functional habitat (habitat that is simultaneously suitable and well-connected), we show that the real impact of renewable energy is far larger than previously assumed. Specifically, we estimate that the construction of hydropower reservoirs in south Norway caused a loss of ca. 222 km2 of functional habitat for wild reindeer (Rangifer tarandus)-which is far larger than assumed based on land inundation indices (110 km2). Fully mitigating these impacts is challenging: scenario analyses reveal that the measures proposed by societal actors would yield only a fraction of the habitat lost (2-12 km2) and could cause trade-off risks with other SDGs. Using indices of functional connectivity is crucial for environmental impact assessments, as entire ecological networks for several species can be affected far beyond the reservoirs.

Temperature Changes Induced by Biogeochemical and Biophysical Effects of Bioenergy Crop Cultivation.

The production of bioenergy with carbon capture and storage (BECCS) is a pivotal negative emission technology. The cultivation of dedicated crops for BECCS impacts the temperature through two processes: net CO2 removal (CDR) from the atmosphere (biogeochemical cooling) and changes in the local energy balance (biophysical warming or cooling). Here, we compare the magnitude of these two processes for key grass and tree species envisioned for large-scale bioenergy crop cultivation, following economically plausible scenarios using Earth System Models. By the end of this century, the cumulative CDR from the cultivation of eucalypt (72-112 Pg C) is larger than that of switchgrass (34-83 Pg C) because of contrasting contributions of land use change carbon emissions. The combined biogeochemical and biophysical effects are cooling (-0.26 to -0.04 °C) at the global scale, but 13-28% of land areas still have net warming signals, mainly due to the spatial heterogeneity of the biophysical effects. Our study shows that the deployment of bioenergy crop cultivation should not only be guided by the principles of maximizing yield and CDR but should also take an integrated perspective that includes all relevant Earth system feedbacks.

The future of suitable habitats of an endangered Neotropical grassland bird: A path to extinction?

Global changes increasingly worry researchers and policymakers and may have irreversible impacts on Earth's biodiversity. Similar to other phytophysiognomies, natural grasslands suffer from the effects of land use changes and rising temperatures, threatening animal and plant communities. Birds, being very sensitive to these changes, are widely studied and fundamental to understand the dynamics of ecosystems in relation to climate and land use changes. The Campo Miner Geositta poeciloptera is a grassland bird endemic to the Brazilian Cerrado and threatened with extinction that has been widely studied in recent years. We analyze the decrease in its extent of occurrence (EOO) and the effects of climate and land use change to understand the environmental suitability of the species in current and future scenarios. We used 5 common algorithms to produce ecological niche models. For future predictions, we use two general circulation models for two different greenhouse gas emission scenarios with different climate policies, an optimistic (ssp245) and a pessimistic (ssp585), plus two land use models focusing on increasing farmlands and reducing native grasslands. The current EOO represents ~45% of that presented by the IUCN EOO. The models generated for the present were satisfactory (TSS = 0.77 and ROC = 0.90) and showed high environmental suitability in areas where the species is currently found and low suitability where it is already extinct. All future scenarios have reduced suitable areas for the species, and the models of a greater increase in temperature and increase in farmlands and a greater decrease in grasslands were the worse. Our results reinforce the need to care about biome awareness disparity and the importance of actively preserving grassy-shrub areas. Apparently, the state of Minas Gerais will be the only stronghold of the species in the coming years; however, the lack of protected areas that guarantee its survival needs attention.

Integrating Habitat Availability, Permeability, and Configuration in a Model of Landscape Connectivity: The Contribution of Habitat's Site-to-Site.

The landscape configuration, the permeability of the matrix and the possibility of random dispersal movement of species are essential to robust modeling of the landscape connectivity. To represent this condition, we report a spatial model that integrates graph theory, circuit theory, metrics of habitat availability and includes a temporal aspect by looking into land use changes over time. We identify the possibilities of movement of species site-to-site over time in the landscape, taking into account not only the importance of sites of focal habitats, but also the potential relevance of the matrix for landscape connectivity. The modeling was applied to two rural landscapes, considering three functional groups of mammals with different resource-feeding and habitat requirements. The model indicated multiple and new dispersal non-linear potential routes to each group of mammals, considering its specific requirement to obtain resources and its movement pattern on the agricultural matrix.

Multi-spatiotemporal AOD trends and association with land use changes over the Guangdong-Hong Kong-Macao Greater Bay Area during 2001-2021.

Analyzing long-term variations of aerosol optical depth (AOD) is beneficial for determining high-pollutant-risk areas and formulating mitigation policies. In this study, multi-spatiotemporal trends and periodicity of AOD, as well as the persistence over the Guangdong-Hong Kong-Macao Greater Bay Area from 2001 to 2021, were investigated by the extreme-point symmetric mode decomposition (ESMD), Theil-Sen Median trend analysis and Hurst exponent. The results elucidate that AOD exhibits fluctuant variations during the 21-year period with the year 2012 as the turning point. There is a slight upward tendency (0.009 year-1) in the pre-2012 period but a pronounced downward trend (- 0.03 year-1) in the post-2012 period, suggesting an overall declining trend in the study area. The northern cities in the area present an increasing-stable-decreasing trend of monthly average AOD, whereas other cities have an increasing-fluctuating-decreasing trend over the study period. The decreasing rate in the western parts is higher than that in the eastern parts, like Zhaoqing, Jiangmen and Foshan city. A continuous decline of AOD is dominated over the study area, whereas an anti-persistence tendency is accumulated in the northeastern parts. Additionally, elevated AOD can be observed in unused land, water bodies and construction land, while grassland, cropland and woodland have lower AOD. The decreasing rate is larger when land-use types with high AOD are converted to those with low AOD; otherwise, the decreasing rate is smaller. The results have a great significance for improving the understanding of long-term variations of AOD, as well as providing a scientific basis to formulate environmental protection and mitigation practices.

Microbiome resilience of Amazonian forests: Agroforest divergence to bacteria and secondary forest succession convergence to fungi.

An alarming and increasing deforestation rate threatens Amazon tropical ecosystems and subsequent degradation due to frequent fires. Agroforestry systems (AFS) may offer a sustainable alternative, reportedly mimicking the plant-soil interactions of the natural mature forest (MF). However, the role of microbial community in tropical AFS remains largely unknown. This knowledge is crucial for evaluating the sustainability of AFS and practices given the key role of microbes in the aboveground-belowground interactions. The current study, by comparing different AFS and successions of secondary and MFs, showed that AFS fostered distinct groups of bacterial community, diverging from the MFs, likely a result of management practices while secondary forests converged to the same soil microbiome found in the MF, by favoring the same groups of fungi. Model simulations reveal that AFS would require profound changes in aboveground biomass and in soil factors to reach the same microbiome found in MFs. In summary, AFS practices did not result in ecosystems mimicking natural forest plant-soil interactions but rather reshaped the ecosystem to a completely different relation between aboveground biomass, soil abiotic properties, and the soil microbiome.

Land use drivers of riverine methane dynamics in a tropical river basin, India.

Rivers are globally significant natural sources of atmospheric methane (CH4). However, the effect of land use changes on riverine CH4 dynamics, particularly in tropical zones, remain ambiguous, yet important to predict and anticipate the present and future contribution of rivers to the global CH4 budget. The present study examines the magnitude and drivers of riverine CH4 concentration and emission in the tropical Krishna River (KR) basin, India. The large spatial variability of CH4 concentration (0.03 to 185.34 µmol L -1) and emissions (0.04 mmol m-2 d-1 to 1666.24 mmol m-2 d-1) in the KR basin was linked to the site-specific features of the catchments through which rivers are draining. Several fold higher CH4 concentration and emission was observed for the urban river sites (64.63 ± 53.17 µmol L-1 and 294.15 ± 371.52 mmol m2 d-1, respectively) than the agricultural (1.05 ± 2.22 µmol L-1 and 3.45 ± 9.72 mmol m2 d-1, respectively) and forested (0.49 ± 0.23 µmol L-1 and 1.26 ± 0.73 mmol m2 d-1, respectively) sites. The concentrations of dissolved oxygen, total phosphorus, and Chlorophyll-a were significant hydrochemical variables strongly coupled with the dissolved CH4 concentrations. On the other hand, percentage of built-up area emerged as the most important landscape-level driver indicating that urbanization has an overriding effect on riverine CH4 concentration in the agriculture dominated KR basin. Our study supports the growing notion that tropical urban rivers are hotspot of CH4 emission. Furthermore, we show that the pattern of increasing in riverine CH4 concentration with built-up area (%) is a general feature of Asian river basins. As the urban land cover and population following an exponential increase, Asian rivers might contribute substantially to the regional and global CH4 budget.

Pathways to sustainable land use and food systems in Canada.

Meeting global sustainability targets under the United Nations Sustainable Development Goals and the Paris Agreement requires paying attention to major land-use sectors such as forestry and agriculture. These sectors play a large role in national emissions, biodiversity conservation, and human well-being. There are numerous possible pathways to sustainability in these sectors and potential synergies and trade-offs along those pathways. This paper reports on the use of a model for Canada's land use to 2050 to assess three different pathways (one based on current trends and two with differing levels of ambition for meeting sustainability targets). This was done as part of a large international consortium, Food, Agriculture, Biodiversity, Land and Energy (FABLE), which allows for incorporating international trade in meeting both national and global sustainability targets. The results show not only the importance of increasingly stringent policies in meeting the targets, but also the role that population and consumption (e.g., diets) play in meeting the targets. Both the medium and high ambition sustainability pathways can drastically reduce greenhouse gas emissions while protecting forestland. Supplementary Information: The online version contains supplementary material available at 10.1007/s11625-022-01213-z.