Earth and Environmental Sciences

Shrimp farming boosts the economy and employment but poses ecological and social impacts. Our study develops a novel social-ecological systems (SES) model to explore the trade-offs and synergies among shrimp farming, mangrove forests, and agriculture associated in the context of enhancing the sustainability of shrimp production in coastal Bangladesh. The model simulates that a 30% increase in yield intensification per farm maximizes shrimp production with higher income, without affecting mangrove forest coverage and agricultural production. Limiting shrimp farming area expansion to ≤30% or prioritising mangrove restoration through interventions such as a 50% increase in forest coverage improves mangrove and agricultural production but entails trade-offs in the form of reduced shrimp production, income, and women’s participation. Sustainable shrimp farming, therefore, requires management of the interactions among climatic variables by adopting improved farming technologies and integrating shrimp-mangrove farming, monitoring market price fluctuations, and providing subsidies for shrimp inputs. This model guides the methodological discussion of quantifying trade-offs and synergies among shrimp farming, mangrove forests, and agriculture in the coastal SES globally.

The rise of IoT devices and smart technologies has transformed homes into complex interconnected environments, creating new challenges for energy management. Understanding how people actually use energy is now a key requirement for designing smarter, more efficient systems, and simulation provides a controlled way to test decisions before deploying them in real homes. However, traditional simulation tools rely on static occupancy profiles and deterministic models that overlook the variability of real household behavior. This paper introduces Home Agent-Based Individualized Time and Activity Simulator (HABITAS), a flexible agent-based framework capable of emulating diverse household scenarios and testing energy optimization strategies. HABITAS represents occupants as autonomous agents with unique routines, preferences, and needs, enabling realistic modeling of energy and resource use. The simulator integrates solar generation, battery storage, appliance use, water consumption, and environmental monitoring through a modular architecture that supports both real-time and fast-forward simulation. Through detailed simulations, HABITAS generated plausible residential load shapes and variability patterns consistent with behavioral expectations, illustrating its practical applicability. Its detailed, individualized outputs support research in demand response, energy policy, smart home design, and decentralized energy systems.

Water retention is a key ecosystem service in subtropical karst rocky desertification regions, where fragile geological conditions and intensive human activities exacerbate hydrological vulnerability and influence multiple ecosystem functions. Understanding how alternative land use policies may affect water retention is therefore important for sustainable land management and ecological restoration. The coupling between land use and water conservation in mining-impacted subtropical karst regions remains poorly quantified, and multi-scenario frameworks for post-mining restoration are particularly lacking. In this study, land use dynamics in Shaoguan City, south China, were examined based on multi-temporal data from 1994 to 2017. Future land use patterns for 2040 were simulated under four scenarios—Natural Development (NDS), Cropland Development (CDS), Conservation Priority (CPS), and Comprehensive Protection and Development (CPDS)—using the PLUS model, and water retention was estimated using the InVEST model as an ecosystem-service indicator of hydrological response. The results showed that historical land use change was dominated by the expansion of construction land and cropland, accompanied by a decline in forestland and other ecological land types, resulting in a decrease in water retention from 9.54 × 10 9 m 3 in 1994 to 9.31 × 10 9 m 3 in 2017. Multi-scenario simulations for 2040 indicated marked differences in both land use patterns and water retention outcomes. The CDS was characterized by extensive cropland expansion (+55.48%) and substantial forestland loss (−12.15%), and was associated with the lowest projected water retention (8.44 × 10 9 m 3 ). The NDS indicated continued urban and agricultural expansion, with moderate reductions in water retention (9.09 × 10 9 m 3 ). The CPDS achieved a relative balance between development and conservation, preserving moderate water retention (9.17 × 10 9 m 3 ) with limited forestland change. In the CPS scenario, expansion of construction land was more constrained, and forestland loss was alleviated, resulting in the highest projected water retention among the four scenarios (9.27 × 10 9 m 3 ), with the smallest decline relative to 2017. Among the simulated scenarios, the CPS scenario was projected to maintain the highest water retention. These findings suggest that land use configuration may influence water retention in karst rocky desertification regions. This study provides scenario-based insights that can inform land use planning and the enhancement of hydrological ecosystem services in subtropical karst landscapes.

Carbon storage is an effective ecological indicator for assessing ecosystem changes associated with land-use dynamics, particularly in carbon-sensitive alpine wetlands. This study evaluated land-use-associated carbon storage changes in the Dashanbao alpine wetland region of southwestern China from 2000 to 2024 by integrating multi-temporal land-use data, the InVEST carbon storage model, land-use transition analysis, wetland-related ecological subzones, and soil profile observations. The results showed that land-use change was dominated by transitions among grassland, cropland, and forestland. Grassland area decreased from 130.60 km 2 to 92.48 km 2 , whereas cropland and forestland increased by 22.44 km 2 and 15.20 km 2 , respectively. Total carbon storage increased from 3.203 Tg in 2000 to 3.477 Tg in 2015, but subsequently declined to 3.116 Tg in 2024, indicating an overall net loss during the study period. Grassland remained the dominant carbon pool, but its substantial contraction was the main driver of regional carbon-storage decline. Transition-pathway analysis identified grassland-to-cropland conversion as the primary carbon-loss pathway, contributing −0.271 Tg, whereas grassland-to-forestland and cropland-to-forestland transitions generated carbon gains of 0.085 Tg and 0.050 Tg, respectively. Soil profile observations revealed significant vertical differentiation of soil organic carbon, with mean values decreasing from 49.01 g kg −1 at 0.5 m to 10.48 g kg −1 at 3.0 m, confirming a significant negative relationship with soil depth. These findings demonstrate that carbon storage can effectively reflect land-use-associated ecosystem changes in alpine wetlands. This study highlights the value of coupling InVEST-based carbon assessment with transition-pathway analysis and soil-profile evidence, and suggests that conservation should prioritize high‑carbon grasslands, wet meadows, peatland-related zones, and strict control of grassland-to-cropland conversion.

Western China's endorheic basins are climate-sensitive, yet the non-linear coupling and scale-dependent drivers of their vegetation remain unclear. We applied the MS-XGSA (Multi-Scale XGBoost-SHAP Attribution framework), integrating machine learning and trend analysis, to examine NDVI dynamics across major basins and their riparian zones. Results reveal a hierarchical pattern where climate dominates at the basin scale, while topography and human activities act as localized modulators. As the spatial scale narrows to riparian buffers, the driving forces shift significantly toward hydrological dependence and concentrated anthropogenic interference. Vegetation exhibits pronounced non-linear responses to environmental stress, characterized by critical thermal and topographic thresholds that trigger abrupt browning, defined as a sudden and significant decline in vegetation greenness (NDVI), marking a rapid transition from stable growth to ecosystem degradation. Furthermore, the synergistic coupling of rising temperatures and declining precipitation creates compound risks that destabilize the ecosystem's water balance. A distinct threshold drift occurs between scales, with riparian zones displaying higher thermal tolerance. This quantifies their role as ecological refugia, where hydrological compensation and evaporative cooling mitigate macro-climatic pressure. This study characterizes the transition from climate-controlled regional processes to hydrologically-regulated local habitats, providing a scientific basis for identifying ecological tipping points and implementing scale-specific management to enhance arid ecosystem resilience.

Agricultural intensification is a major driver of biodiversity loss. Taxonomic indicators alone may not capture community responses to landscape simplification. We applied an integrated diagnostic approach combining univariate and multivariate taxonomic and functional analyses to study bird communities in Mediterranean agricultural landscapes. Ornithological censuses were conducted at 20 sites distributed across specialised agroecosystems ( n = 5), agroecological mosaics ( n = 7), and natural ecosystems ( n = 8), recording a total of 80 species. Taxonomic diversity was assessed using species richness (S) and the Shannon diversity index (H′). Functional diversity was assessed using functional richness (FRic), functional evenness (FEve), Rao's quadratic entropy (RaoQ), and trait-based multivariate analyses. Species richness and Shannon diversity index differed significantly across landscape contexts ( p < 0.001), with specialised agroecosystems showing lower diversity than the other two landscapes. Functional richness also varied significantly ( p = 0.0057), while FEve and RaoQ remained relatively stable, indicating that landscape simplification primarily reduced the breadth of ecological strategies, rather than completely restructuring trait distribution and functional redundancy. Community composition differed significantly across landscape contexts (PERMANOVA: p < 0.001). Trait-based analyses identified beak morphology and primary lifestyle as the traits most closely associated with landscape differentiation. Agroecological mosaics were shown to be key drivers of biodiversity within agricultural matrices, with taxonomic diversity comparable to that of natural ecosystems while remaining distinct from them in terms of composition and functional identity. By integrating complementary analytical approaches, this diagnostic approach provides a practical and transferable tool for biodiversity monitoring, conservation planning, and landscape assessment across diverse taxonomic and ecological contexts.

Site factors and spatial structure factors are key determinants influencing forest carbon storage. However, existing studies have mainly focused on the effects of site or stand structural factors on forest productivity, while comparatively less attention has been devoted to the integrated effects and causal pathways of site factors and specific spatial structural attributes (e.g., mixing degree, aggregation index, and competition index) on forest carbon storage. Additionally, traditional competition indices have not fully accounted for the dominant role of tree crowns in resource competition. This study, conducted in mixed forests in Longquan, Lishui City, Zhejiang Province, utilized data from 40 fixed 20 m × 20 m sample plots. A structural equation model (SEM) was constructed to systematically quantify the direct and indirect effects, as well as the pathways of site factors (elevation, slope, aspect, slope position, humus layer thickness) and spatial structure factors (mixing degree, aggregation index, competition index) on forest carbon storage, at both the stand and individual species scales. Furthermore, a modified crown-width-based Hegyi competition index (C_Hegyi)—was introduced and comparatively evaluated against the traditional diameter at breast height (DBH) distance-based competition index (V_Hegyi) across different tree species. Results indicate that: (1) For site factors, humus layer thickness and elevation have significant negative direct effects; slope and aspect primarily influence carbon storage through indirect pathways; (2) Among spatial structure factors, mixing degree and aggregation index significantly promote carbon accumulation, while competition index has a notable suppressive effect on carbon storage; (3) Different tree species exhibited significantly different response patterns to site and spatial structural factors, with carbon storage levels decreasing in the following order: Other Conifers (e.g., Pinus massoniana , Taxus chinensis , etc.) > Cunninghamia lanceolata ≈ Other Broadleaves (e.g., Ormosia hosiei , Liquidambar formosana , etc.) > Schima superba , revealing pronounced interspecific heterogeneity in carbon accumulation within mixed forests. (4) The comparison of competition indices indicates that C_Hegyi exhibits a 95.1% improvement in explanatory power among coniferous species, whereas V_Hegyi performs better in broadleaf species. This study provides a systematic understanding of the response mechanisms of site factors, stand spatial structure, and their interactions to carbon storage in mixed conifer–broadleaf forests in southwestern Zhejiang. The findings offer new theoretical support for optimizing forest structure, enhancing carbon sink functions, and implementing precise carbon sink management strategies.

Cropland quantity, quality, and ecological condition may improve in a composite assessment without becoming better aligned with zone-specific management targets. Conventional aggregation can offset deterioration in one dimension with gains in another, obscuring the resulting risk profile. We therefore propose a Target-Oriented Vector Coordination Model (TO-VCM) to evaluate whether county-level changes in cropland quantity (Q), quality (U), and ecology (E) align with policy-referenced management mandates. The model distinguishes structural alignment ( C stru ) from effective advancement ( L dev ) and integrates these indices with pathway classification and obstacle diagnosis. Applied to Qinghai Province, China, for 2020–2024, the framework showed that 22 of 35 counties improved in overall performance, while 9 of these counties also deviated further from zone-specific targets. Thus, higher composite scores did not necessarily indicate closer convergence with the intended management pathway. The TO-VCM provides a diagnostic basis for identifying such mismatches and informing differentiated cropland governance.

Promoting walking is a public health priority for enhancing health and well-being. However, the influence of people's health on environment-walking associations and its possible moderating role remains uncertain. Our aim was to 1) examine how selected health-related indicators, specifically body mass index (BMI) and self-perceived health, together with objective and perceived environmental features were associated with non-commute walking behaviour; and 2) investigate the potential moderating role of health on the environment-walking association; and 3) compare the relative explanatory roles of the health indicators, objective and perceived environmental characteristics. We used survey data from 366 adults aged 45–65 in Rotterdam and Maastricht, the Netherlands. Our outcome variable was self-reported walking frequency for non-commute trips. Data on neighbourhood environmental perceptions were also self-reported, while objective environmental characteristics were measured within 300 m, 600 m, and 1000 m of respondents' homes. Zero-inflated Poisson regression models showed that the BMI was negatively associated with non-commute walking frequency, accounting for socio-demographics and objective and perceived environmental features. Address density and perceived safety were positively associated with non-commute walking, whereas street connectivity and perceived neighbourhood aesthetics were inversely associated. Objective and perceived environmental features contributed to a similar extent to explaining non-commute walking behaviours. We found no evidence that BMI or self-perceived health moderated the association between the environment and non-commute walking. Our findings suggest that selected health-related indicators and objective and perceived environmental features independently influence non-commute walking behaviour. Objective and perceived environments seem equally important in explaining non-commute walking.

This study characterized urban infrastructure (UI) supporting physical activity (PA) in Greater Santiago (GS), Chile, and examined its spatial distribution. A conceptual model comprising four key dimensions — active transport, green areas, public transport, and safety — was used to guide selection of relevant indicators (23 total). Statistical and spatial analyses were conducted across 34 municipalities and 1623 neighborhoods using a summary index estimated as the unweighted mean of indicators within each dimension. We identified distinct spatial patterns across dimensions, with inequalities varying in magnitude and direction. UI indices were moderately correlated with area SES (highest: active and public transport r = 0.55/0.47; green areas and safety r = 0.46/0.44, for municipalities and neighborhoods). Associations with SES were more evident at the neighborhood level, particularly for green areas and active transport, while public transport was more evenly distributed and even favored low-SES municipalities. Cluster analyses (Local Moran's I) indicated that neighborhoods with higher PA-promoting infrastructure were predominantly concentrated in wealthier municipalities, while low-infrastructure clusters were more evenly spread. Green areas emerged as the scarcest and most unequally distributed dimension (Gini coefficient and p90/p10 ratio). Except for public transport, variability in indices was greater within municipalities than between them, underscoring the importance of targeting smaller geographical units for analysis and urban improvements. This study provides evidence on the spatial distribution of PA-promoting UI across municipalities and neighborhoods of GS and its implications for a territory with spatially and sectorially fragmented governance. These findings underscore the importance of addressing such disparities in urban planning and public policies aimed at fostering healthier and more equitable cities.