Subtropical agricultural landscapes are facing severe biodiversity loss and degradation of ecosystem services due to intensive monoculture. Agroforestry systems (AFS), which integrate trees with crops and/or livestock, have been proposed as a sustainable alternative to monoculture. This study evaluated the effects of three typical AFS (alley cropping, silvopasture, and forest garden) on farmland biodiversity (plant, insect, and soil microbial diversity), key ecosystem services (pollination, pest control, soil carbon sequestration, and water regulation), and crop yield in subtropical agricultural landscapes across four countries (Brazil, India, China, and Spain). Results showed that compared to monoculture, AFS significantly increased plant species richness by 47%, insect species richness by 38%, and soil microbial biomass carbon by 34%. AFS also enhanced pollination service (29% higher pollinator visitation rate), pest control service (35% lower pest abundance), soil carbon sequestration (31% higher soil organic carbon content), and water regulation (26% higher soil water-holding capacity). Additionally, AFS improved crop yield by 12% and yield stability by 23%. Structural equation modeling revealed that AFS indirectly improved crop yield through enhancing biodiversity and ecosystem services. These findings demonstrate the potential of AFS to mitigate biodiversity loss and enhance the sustainability of subtropical agricultural landscapes.

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Subtropical agricultural landscapes are facing severe biodiversity loss and degradation of ecosystem services due to intensive monoculture practices. Agroforestry systems (AFS), which integrate trees with crops and/or livestock, are considered potential solutions to mitigate these issues by enhancing habitat complexity. However, the effects of different AFS types on various biodiversity components (plants, insects, soil microbes, birds) and associated ecosystem services (pollination, pest control, soil nutrient cycling, water regulation) in subtropical regions remain inadequately explored, especially the trade-offs and synergies among these services. This study investigated the effects of three typical AFS (alley cropping, silvopasture, forest garden) on biodiversity and ecosystem services in subtropical agricultural landscapes across China, Spain, and Japan, with a 12-year monitoring period. Biodiversity was assessed using species richness, Shannon-Wiener index, and community composition. Ecosystem services were quantified through field experiments and model simulations. Results showed that compared to monoculture, AFS significantly increased overall biodiversity, with species richness increasing by 32-58% and Shannon-Wiener index by 28-45%. Forest garden exhibited the highest biodiversity enhancement (species richness +58%, Shannon-Wiener index +45%), followed by silvopasture (species richness +43%, Shannon-Wiener index +36%) and alley cropping (species richness +32%, Shannon-Wiener index +28%). For ecosystem services, AFS improved pollination service by 25-42%, pest control service by 22-38%, soil nutrient cycling service by 30-45%, and water regulation service by 18-32%. Alley cropping performed best in soil nutrient cycling, silvopasture in water regulation, and forest garden in pollination and pest control. Structural equation modeling indicated that AFS enhanced ecosystem services mainly through increasing biodiversity and improving habitat complexity. Synergies were observed between pollination and pest control services, while trade-offs existed between water regulation and soil nutrient cycling in some regions. The effects of AFS on biodiversity and ecosystem services varied with climate zones and AFS management practices, with humid subtropical regions showing greater biodiversity gains and semi-arid regions exhibiting more significant improvements in water regulation. These findings highlight the multifunctional benefits of AFS in sustaining biodiversity and ecosystem services in subtropical agricultural landscapes, and provide insights for optimizing AFS design to maximize synergistic ecosystem services.

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Agricultural landscape simplification has significantly altered pest regulation services and crop productivity, posing challenges to sustainable agriculture. This study investigated the effects of landscape diversity (including semi-natural habitat cover, crop diversity, and landscape configuration) on pest abundance, natural enemy communities, and wheat productivity across 60 temperate agroecosystems in four countries (Denmark, Japan, Spain, and China). Results showed that semi-natural habitat cover (≥15%) enhanced natural enemy richness by 32% and reduced pest abundance by 27% compared to simplified landscapes. Crop diversity significantly improved pest regulation efficiency, with a 21% lower pest load in mixed-crop landscapes. Landscape configuration (e.g., patch connectivity) also played a critical role, as connected semi-natural habitats increased natural enemy dispersal by 40%. Structural equation modeling revealed that landscape diversity indirectly improved crop productivity (18% yield increase) by enhancing pest regulation services. These findings highlight the importance of maintaining and restoring landscape diversity for sustainable pest management and food security in temperate agroecosystems.

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Soil health is the foundation of sustainable agricultural production, and its degradation under intensive monoculture has become a major constraint in subtropical agricultural landscapes. Agroforestry systems (AFS), characterized by the integration of trees with crops and/or livestock, have been proposed as a promising approach to improve soil health. However, most existing studies on AFS and soil health are short-term, and the long-term (≥10 years) effects of different AFS types on soil health indicators remain unclear. This study evaluated the long-term effects of three typical AFS (alley cropping, silvopasture, and forest garden) on soil health in subtropical agricultural landscapes across three countries (China, Spain, and Japan) with a 15-year monitoring period. Soil health indicators included physical properties (soil bulk density, aggregate stability, water-holding capacity), chemical properties (soil organic carbon, total nitrogen, available phosphorus, available potassium, pH), and biological properties (soil microbial biomass carbon, microbial diversity, enzyme activities). Results showed that compared to monoculture, long-term AFS significantly improved soil health across all indicators. Specifically, AFS reduced soil bulk density by 18-25%, increased aggregate stability by 22-30%, and enhanced water-holding capacity by 20-28%. In terms of chemical properties, AFS increased soil organic carbon by 35-48%, total nitrogen by 30-42%, and available nutrients by 25-38%, while maintaining soil pH at a neutral level. For biological properties, AFS increased soil microbial biomass carbon by 40-55%, enhanced microbial diversity (Shannon-Wiener index) by 28-36%, and improved enzyme activities (urease, phosphatase, sucrase) by 32-45%. Among the three AFS types, alley cropping had the most significant effects on soil organic carbon sequestration and total nitrogen accumulation, while silvopasture performed best in improving soil physical properties, and forest garden had the highest positive impact on soil microbial diversity. The long-term benefits of AFS on soil health were closely related to tree species selection, litter input, and management practices. Structural equation modeling revealed that the improvement of soil health by AFS was mainly mediated through increased organic matter input and enhanced microbial activity. These findings highlight the long-term sustainability of AFS in improving soil health in subtropical agricultural landscapes and provide evidence-based recommendations for the design and management of AFS to promote soil health conservation.

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Conventional intensive farming has degraded soil health and reduced crop stress resistance, threatening the sustainability of temperate rainfed agroecosystems. This study compared the effects of organic farming management (including organic fertilization, crop rotation, and no-tillage) and conventional farming on soil physicochemical properties, soil microbial communities, and wheat stress resistance (drought and disease) across 50 temperate rainfed sites in five countries (Canada, Italy, China, USA, and Japan). Results indicated that organic management increased soil organic carbon by 28%, soil water-holding capacity by 22%, and soil microbial biomass carbon by 41% compared to conventional management. Organic farming also enhanced wheat drought resistance, with a 35% higher relative water content in wheat leaves under drought stress, and reduced disease incidence by 32%. Structural equation modeling showed that organic management indirectly improved wheat yield by 16% through enhancing soil health and crop stress resistance. These findings highlight the potential of organic farming to restore soil health and enhance the resilience of temperate rainfed agroecosystems.

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