Quantifying potential forestation-induced variability in land surface temperature across India: a percentile-based and class-specific assessment

Abstract Forestations play a critical role in regulating temperature, with impacts evident at both global and regional scales. Although global-scale studies often highlight the cooling effects of forests through biogeochemical processes, relatively less emphasis has been placed on their biogeophysical influence on surface temperature at finer spatial scales. Given that climate warming is a global phenomenon, its impacts are often intensified locally. Assessing forestation-induced changes in daytime land surface temperature (LST) is crucial for understanding regional climate mitigation, particularly in human-dominated landscapes such as India. This study investigated forestation-induced changes in daytime LST across 14 major forest classes in India. We propose a percentile-based framework that links forest class fractions at the 75th, 85th, and 95th thresholds with variations in daytime LST to better quantify forestation-induced temperature changes, effectively capturing seasonal and class-specific variability at fine spatial resolution. Additionally, random forest regression was employed to identify the climatic drivers influencing forest greenness. The results demonstrate that the effect of forestation on daytime LST varies considerably across forest classes and percentile thresholds, with both cooling and warming effects. Cooling effects dominate in nine of the 14 classes, ranging from substantial cooling (−0.081 °C) in littoral and swamp forests (mangroves) to notable warming (+0.095 °C) in montane dry temperate forests of the Himalaya. A clear spatial and ecological pattern emerges, with low-elevation forest types generally exhibiting cooling, while high-altitude forest types show a tendency toward warming. Spatially, forestation is generally associated with cooling between 12–25° N latitude, while regions outside this band tend to experience warming. Variability in forest greenness is primarily explained by latent heat flux (LE), which accounts for over 70% of the variation in classes 4, 5, and 6, and by net photosynthesis, which accounts for up to 69.42% in class 14. The strong association between LE and forest greenness reflects the underlying coupling between evapotranspiration and photosynthetic activity in actively transpiring canopies. Additional influences of precipitation dynamics, drought conditions, and soil moisture availability further highlight the multifactorial regulation of leaf area index, an indicator of vegetation greenness. The study demonstrates that LST responses to forestation depend strongly on forest type and elevation. Low-elevation tropical and subtropical forests in central India cool the surface via enhanced evapotranspiration, while high-altitude temperate forests show localized warming, underscoring forest functional diversity in regional climate regulation.