Climate mitigation and adaptation potential of an endangered tree across land-use types under climate change

Abstract

This study assessed the distribution, growth, carbon stock, and soil effects of Podocarpus falcatus across different land-use types. Out of 408 plots along 64 transects, the species was found in 42 plots across 8 transects (with 100 m spacing and 200 m altitudinal intervals). Species distribution models projected potential range under current and future (2021–2100) climate scenarios using key environmental variables. Statistical analyses assessed its abundance, growth, and carbon stock. The results showed that the population structure of the species was characterized by a J-shaped curve, indicating poor regeneration potential. The occupancy rates were 10.3 % and 12.5 % at the plot and transect levels, respectively. Its abundance was significantly higher in church forests compared to forest and riverside areas (P = 0.025). The effect of P. falcatus on organic carbon, total nitrogen, available phosphorus, cation exchange capacity, and clay content was significantly higher in church forests compared to forest and riverside areas (P = 0.001). However, sand content was significantly higher in forest and riverside areas than in church forests (P = 0.001). The total biomass and carbon of P. falcatus across the land-use types were statistically non-significant (P = 0.729). Temperature annual range (31.4 %), percent silt (27 %), precipitation of the warmest quarter (9.3 %), and altitude (7.8 %) influenced species distribution. Its current potential distribution (30.8 %) could expand to 51.9–63.5 % under SSP2–4.5 and 44.9–59.6 % under SSP5–8.5. Podocarpus falcatus plays a vital role in carbon sequestration and soil enhancement, but its poor presence and regeneration threaten its sustainability. Thus, implementing climate-adaptive management strategies is essential for the long-term survival of the species.