Co-limitation towards lower latitudes shapes global forest diversity gradients

Giants of the Amazon: How does environmental variation drive the diversity patterns of large trees?

“…Areas that are low or humid have trees with smaller crowns (Barbier et al, 2010) but with high species heterogeneity, mainly because they are ecotones or forest transition areas (Amaral et al, 2021;Marques et al, 2011;Silveira et al, 2016). These wetlands are also hotspots for endemic flora and fauna (Berde et al, 2020;Morrone, 2014) and contribute significantly to regional and global biodiversity (Junk et al, 2006;Liang et al, 2022). Similar results have been found…”

“…More generally, it has long been known that the diversity of tree species follows latitudinal variations, consistent with the metabolic theory of biodiversity (Liang et al, 2022), or is affected by graindependent effects of both environment and biogeographic regions (Keil & Chase, 2019). In the Amazon basin tree diversity at the onehectare scale are driven by gradients of precipitation and soil (Esquivel Muelbert et al, 2016;Ter Steege et al, 2003).…”

“…Multiple, recent initiatives that combine forest inventories have allowed further analysis of ecological and spatial variation over large scale (e.g., Bastin et al, 2018;Crowther et al, 2015;ForestPlots.net et al, 2021;Slik et al, 2015). These studies have confirmed that parts of South America and particularly western Amazonia, as well as the Andean foothills, are global epicenters for plant diversity and trees in particular (Cazzolla Gatti et al, 2022;Liang et al, 2022;Sabatini et al, 2022;Ter Steege et al, 2013).…”

The effect of habitat transformation on a twig epiphytic orchid: Evidence from population dynamics

“…The tropical Andes represent a hotspot of biodiversity (Myers et al, 2000;Liang et al, 2022) and endemism (Gentry, 1982;Olson and Dinerstein, 1998) and at the same time is one of the geographical areas with the highest rate of anthropogenic habitat transformation (Etter and van Wyngaarden, 2000;Etter et al, 2006). These anthropogenic changes can influence demographic dynamics (Rodríguez-Echeverry and Leiton, 2021), survivorship or persistence of populations (Philpott et al, 2008).…”

Latitude influences stability via stabilizing mechanisms in naturally-assembled forest ecosystems at different spatial grains

“…A positive relationship may emerge given the potentially destabilizing effects of warmer climates, resulting in stability increasing with latitude 28,29,38 . A negative relationship may emerge if the stabilizing role of biodiversity is stronger than the destabilizing effects of climate, mirroring the latitudinal diversity gradient 39 , and resulting in stability decreasing with latitude; or there might not be a directional change in stability with latitude, as biodiversity and stability may be decoupled in naturally-assembled ecosystems 36,40 . We anticipate that species asynchrony and species stability will decrease and increase with latitude, respectively, and that their stabilizing effects will be stronger at the smaller spatial grain, with weak or neutral effects at the large grain (Fig.…”