Drivers of tropical rainforest composition and alpha diversity patterns over a 2,520 m altitudinal gradient

A study on the Talamanca Range-La Amistad Reserves reveals two distinct forest compositional zones—lowland (430–1,120 m asl) and montane (>2,150 m asl)—with a transitional zone (1,400–1,600 m asl) where lowland tropical and montane holarctic species coexist. Montane forests exhibit significantly lower alpha diversity, strongly influenced by altitude, soil, and spatial factors. Researchers analyzed 32 undisturbed rainforest plots using NMS ordination and linear regressions to assess the relationship between forest composition, alpha diversity metrics, and environmental variables. The findings suggest that vegetation and soil respond to altitude as an integrated system, challenging niche assembly models.

Veintimilla, D., Ngo Bieng, M. A., Delgado, D., Vilchez‐Mendoza, S., Zamora, N., & Finegan, B. (2019). Drivers of tropical rainforest composition and alpha diversity patterns over a 2,520 m altitudinal gradient. Ecology and Evolution, 9(10), 5720–5730. Portico. https://doi.org/10.1002/ece3.5155