TY - JOUR
T1 - Water and energy availability mediate biodiversity patterns along an elevational gradient in the tropical Andes
AU - Tolmos, Maria Laura
AU - Kreft, Holger
AU - Ramirez, Jorge
AU - Ospina, Román
AU - Craven, Dylan
N1 - Publisher Copyright:
© 2022 The Authors. Journal of Biogeography published by John Wiley & Sons Ltd.
PY - 2022
Y1 - 2022
N2 - Aim: How tree taxonomic and phylogenetic diversity vary with elevation at multiple spatial scales may provide new insights into the ecological and evolutionary processes influencing biogeographical patterns. The effect of water- and energy-related climatic variables on forests diversity across elevations, as well as how clades have evolved on and established across mountain regions lack consensus. Here, we tested whether changes in biodiversity with elevation are consistent with one of, or multiple, competing hypotheses: the water–energy dynamics (WED), species–energy relationship (SER), Tropical Niche Conservatism (TNC) and Out of The Tropics hypothesis (OTT). Location: Patia watershed, Colombia. Taxon: Seed plants (trees). Methods: We used a large dataset of 490 0.1 ha forest plots in nine elevational belts (545–3410 m a.s.l) that correspond to three different life zones, and quantified alpha and gamma scales using taxonomic and phylogenetic diversity indices. We fitted linear mixed-effects models to evaluate how taxonomic and phylogenetic alpha diversity changed with elevation, precipitation and aboveground biomass. We assessed taxonomic and phylogenetic beta diversity using the Sørensen index and its spatial turnover and nestedness components. Results: Taxonomic and phylogenetic alpha diversity decrease with elevation. Yet, at the gamma scale, taxonomic and phylogenetic diversity predominantly increased with elevation. Taxonomic and phylogenetic beta diversity were strongly influenced by species turnover, and followed a hump-shaped pattern with elevation. Main conclusions: Overall, diversity shows a decreasing trend at the local scale, while coarse-scale gamma diversity followed a pattern of nonlinear increases for both taxonomic and phylogenetic diversity. Evidence supports the influence of SER and WED on diversity patterns across elevations, yet neither evolutionary hypotheses had sufficient empirical support to be conclusive.
AB - Aim: How tree taxonomic and phylogenetic diversity vary with elevation at multiple spatial scales may provide new insights into the ecological and evolutionary processes influencing biogeographical patterns. The effect of water- and energy-related climatic variables on forests diversity across elevations, as well as how clades have evolved on and established across mountain regions lack consensus. Here, we tested whether changes in biodiversity with elevation are consistent with one of, or multiple, competing hypotheses: the water–energy dynamics (WED), species–energy relationship (SER), Tropical Niche Conservatism (TNC) and Out of The Tropics hypothesis (OTT). Location: Patia watershed, Colombia. Taxon: Seed plants (trees). Methods: We used a large dataset of 490 0.1 ha forest plots in nine elevational belts (545–3410 m a.s.l) that correspond to three different life zones, and quantified alpha and gamma scales using taxonomic and phylogenetic diversity indices. We fitted linear mixed-effects models to evaluate how taxonomic and phylogenetic alpha diversity changed with elevation, precipitation and aboveground biomass. We assessed taxonomic and phylogenetic beta diversity using the Sørensen index and its spatial turnover and nestedness components. Results: Taxonomic and phylogenetic alpha diversity decrease with elevation. Yet, at the gamma scale, taxonomic and phylogenetic diversity predominantly increased with elevation. Taxonomic and phylogenetic beta diversity were strongly influenced by species turnover, and followed a hump-shaped pattern with elevation. Main conclusions: Overall, diversity shows a decreasing trend at the local scale, while coarse-scale gamma diversity followed a pattern of nonlinear increases for both taxonomic and phylogenetic diversity. Evidence supports the influence of SER and WED on diversity patterns across elevations, yet neither evolutionary hypotheses had sufficient empirical support to be conclusive.
KW - elevational gradient
KW - environmental filtering
KW - evolutionary processes
KW - phylogenetic diversity
KW - spatial scales
KW - taxonomic diversity
KW - tree diversity
KW - tropical Andes
KW - water–energy dynamics
UR - http://www.scopus.com/inward/record.url?scp=85126435035&partnerID=8YFLogxK
U2 - 10.1111/jbi.14332
DO - 10.1111/jbi.14332
M3 - Artículo
AN - SCOPUS:85126435035
JO - Journal of Biogeography
JF - Journal of Biogeography
SN - 0305-0270
ER -