Microclimate Niche separation in Myristica swamp and associated species

Abstract While extensive research exists on the taxonomy of Myristica swamp species, their microclimatic niches remain poorly understood. We assessed microclimatic niche differentiation among tree species in Myristica swamps, an endangered ecosystem in the Western Ghats, by quantifying soil moisture and temperature gradients across swamp, edge, and adjacent forest habitats. Our analysis revealed significant interspecific differences in environmental optima. We observed that soil moisture varied significantly across habitats (P < 0.001), whereas soil temperature exhibited subtler gradients. The general ‘swamp-specialist’ species occupied significantly wetter microsites than forest-generalist and edge species. Forest species demonstrated broad environmental tolerances, whereas swamp specialists exhibited narrower niche widths, particularly in response to temperature (MANOVA: Pillai’s trace = 0.427, approx. F₄,₈ 96 = 59.623, *p* < 2.2 × 10⁻¹⁶). These results bring to light the critical role of microclimate in structuring tree community composition across tropical wetland-terrestrial ecotones and highlight the vulnerability of specialized swamp endemics to environmental change.