Biosphere, Volume 2, Issue 3 (September 2026) – 6 articles

The land surface temperature (LST) is a critical parameter in land–atmosphere exchange processes and urban climate regulation. This study quantifies the spatio-temporal relationship between the fractional vegetation cover (FVC) and Landsat-derived LST within the Santa Clara Valley, California, a region characterized by rapid late 20th-century urbanization. Utilizing a 5 km grid resolution, the research assesses thermal variations across diverse land cover categories over the 2001–2011 period. The analysis is conducted in two distinct phases: (1) a multi-temporal characterization of LST across heterogeneous urban land covers, and (2) a statistical correlation analysis between the FVC and LST. The results demonstrate a consistent, significant inverse relationship between the fractional vegetation cover and LST. These findings provide a foundational baseline for understanding the impact of urban canopy loss on regional heat islands and offer empirical evidence for cooling-based urban planning interventions in Mediterranean-climate metropolitan areas. Full article

The soil-biosphere nexus is a critical component embedded in the concepts of soil security and ecosystem services (ES) and is directly linked to several global challenges identified by the United Nations (UN). Although soil security has been proposed as a policy framework, a major problem is that there are no standard procedures to assess the five dimensions of soil security: capability, condition, capital, connectivity, and codification in relation to the soil-biosphere nexus. This study proposes a land cover change matrix, disaggregated by soil type (“biophysical soil security matrix”), as a tool to evaluate the biophysical soil security continuum and its temporary changes, integrated with ES valuation. The matrix was tested using the state of Minnesota (MN) as a case study. Although the dominant soil orders in MN possess high natural capability, widespread human-caused land degradation has dramatically lowered their actual biophysical condition and has fueled massive soil decarbonization. Historic land degradation in MN due to human activity totaled 98,516 km² through 2024, with nearly 480 km² of anthropogenically degraded land created between 2001 and 2024. Based on carbon emissions alone, we estimate that historic land degradation in MN has resulted in total social costs of nearly $50B (U.S. dollars, B = billion = 10⁹) through 2024, with about 10% of this total social cost being realized between 2001 and 2024. Trends like this threaten soil security by directly eroding the soil’s capacity to sustain ES. Based on the analyses and results, this study recommends conducting both soil-centric and human-centric analyses of soil security to ensure the sustainable use of soil. Full article

Agricultural drought is an important issue for food security, water availability and rural livelihoods, particularly in the semi-arid regions of the Indian state of Tamil Nadu, especially in Sivagangai District. This study combines multi-temporal remote sensing data and GIS techniques to evaluate the agricultural drought vulnerability during a 30-year time frame (1994–2024). Landsat satellite imagery and climate data were used to derive some key bio-physical indicators such as NDVI, NDWI, VCI, SMI, LST, LULC and SPI. An AHP was used to assign weights to each parameter and was created. The spatiotemporal analysis shows that there is a substantial reduction in vegetated and moist areas as well as a high growth of high and very high temperature areas and built-up land. The percentage of areas classified as ‘Very High’ drought vulnerability has increased significantly from 1.08% (1994) to 40.04% (2024), highlighting a growing threat from drought conditions. NDVI and NDWI were chosen as the most significant indices that affect drought. The findings reflect the deteriorating environmental condition and stress the need for specific mitigation measures, including afforestation, sustainable land-use planning and management of water resources. This study is both spatially explicit and scalable; it provides key information to local planners, policymakers and stakeholders to support agricultural resilience in drought-prone regions. Full article

Rapid urbanization in tropical Asia has fundamentally transformed land use–land cover while intensifying urban thermal stress, yet the relationship between land cover change and thermal conditions is frequently assumed to be spatially uniform. This study challenges that assumption by demonstrating that land cover–thermal relationships in Colombo District, Sri Lanka, are highly spatially and temporally heterogeneous, with statistically significant associations detected in only 17–47% of the study area in any given year, underscoring that context, not land cover type alone, governs thermal outcomes. Using multi-temporal Landsat satellite imagery, LULC maps were derived, and the urban heat island effect (UHIE) and urban thermal field variance index (UTFVI) were calculated for seven time periods (1989, 1996, 2002, 2009, 2014, 2019, 2024). Geographically weighted regression (GWR) was applied to model local relationships between LULC classes, namely wetland vegetation, water bodies, impervious surfaces, and other pervious surfaces, and thermal indices across a 500 m spatial grid, revealing a 74% loss in wetland vegetation and a 326% increase in impervious surfaces over the study period. Water bodies exhibited spatially variable cooling effects relative to wetland vegetation, most pronounced in eastern regions during earlier periods, while impervious surfaces showed consistent, spatially persistent warming effects concentrated in western and southern urban cores. By coupling GWR with a 35-year multi-sensor time series, this study provides a spatially explicit, longitudinal account of how land cover–thermal relationships evolve as tropical urbanization intensifies, offering an evidence base for spatially targeted rather than uniform climate adaptation planning in rapidly urbanizing tropical cities. Full article

Wildlife plays a vital role in maintaining ecological balance and biodiversity, relying on habitats that provide shelter, food, and essential resources. This study investigated wildlife distribution and diversity across the REDD+ program area in Cambodia’s Prey Lang Wildlife Sanctuary, a lowland evergreen forest ecosystem, and assessed the effects of forest habitats and anthropogenic pressure on their distribution. We used square transects for sampling and ArcGIS to calculate forest cover and distance to the nearest village as a proxy for human impact. Overall, we recorded seven mammals and two birds, with the great hornbill (Buceros bicornis) most frequently detected, followed by pileated gibbon (Hylobates pileatus), wild pig (Sus scrofa), long-tailed macaque (Macaca fascicularis), green peafowl (Pavo muticus), northern red muntjac (Muntiacus vaginalis), and Indochinese silvered langur (Trachypithecus germaini), while gaur (Bos gaurus) and sambar deer (Rusa unicolor) were least detected. Wildlife richness and abundance were higher in evergreen-dominated habitats than in mixed deciduous–evergreen forests. Certain K-selected species, including pileated gibbon, Indochinese silvered langur, and great hornbill, were highly specialized and preferred intact forests, whereas generalist species such as northern red muntjac, long-tailed macaque, and wild pig showed ecological flexibility in habitat use. These findings emphasize tailored conservation strategies: protecting intact evergreen forests via REDD+ supports specialized species, while adaptive management in mosaic landscapes benefits generalists, enhancing wildlife conservation and sustainable management of the Prey Lang Wildlife Sanctuary. Full article

Lokoja, the capital of Kogi State, Nigeria, situated at the confluence of the Niger and Benue Rivers, has experienced rapid urban expansion alongside heightened environmental risks, including flooding and ecosystem degradation. Using multi-temporal Landsat imagery (2000, 2010, 2020, 2024), Random Forest classification, and landscape metrics, this study analyses spatio-temporal patterns of urban growth and fragmentation in this underrepresented mid-sized African city. Urban land cover expanded from 6668 ha in 2000 to 15,985 ha in 2024 (net ~140% growth), following a non-linear trajectory of rapid expansion (2000–2010), partial consolidation (2010–2020), and renewed growth with intensified fragmentation (2020–2024). This growth caused severe ecological impacts: dense forest declined by 99.7% (from 373 ha to 1 ha), woodland by 73.9%, and core natural land cover by 23% to 13.8% of the landscape, below critical ecological thresholds. Edge density rose by 121%, exacerbating urban heat, runoff, and biodiversity loss, while apparent gains in grassland largely reflect secondary succession rather than recovery. This study recommends enforcing development restrictions below 10 m in elevation, with 100 m riparian buffers; restoring 500 ha of native corridors; mandating 20% urban tree canopy cover; and establishing community-based green space monitoring. The findings provide empirical insights into sustainability challenges facing mid-sized African cities and offer transferable strategies for ecologically sensitive urban planning. Full article