Facilitative plant interactions and climate simultaneously drive alpine plant diversity.
Interactions among species determine local-scale diversity, but local interactions are thought to have minor effects at larger scales. However, quantitative comparisons of the importance of biotic interactions relative to other drivers are rarely made at larger scales. Using a data set spanning 78 sites and five continents, we assessed the relative importance of biotic interactions and climate in determining plant diversity in alpine ecosystems dominated by nurse-plant cushion species. Climate variables related with water balance showed the highest correlation with richness at the global scale. Strikingly, although the effect of cushion species on diversity was lower than that of climate, its contribution was still substantial. In particular, cushion species enhanced species richness more in systems with inherently impoverished local diversity. Nurse species appear to act as a 'safety net' sustaining diversity under harsh conditions, demonstrating that climate and species interactions should be integrated when predicting future biodiversity effects of climate change.
Departamento de Botánica, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Casilla 160-C, Concepción, Chile; Instituto de Ecología y Biodiversidad, Casilla 653, Santiago, Chile.
Lohengrin A
LA
Cavieres
Rob W
RW
Brooker
Bradley J
BJ
Butterfield
Bradley J
BJ
Cook
Zaal
Z
Kikvidze
Christopher J
CJ
Lortie
Richard
R
Michalet
Francisco I
FI
Pugnaire
Christian
C
Schöb
Sa
S
Xiao
Fabien
F
Anthelme
Robert G
RG
Björk
Katharine J M
KJ
Dickinson
Brittany H
BH
Cranston
Rosario
R
Gavilán
Alba
A
Gutiérrez-Girón
Robert
R
Kanka
Jean-Paul
JP
Maalouf
Alan F
AF
Mark
Jalil
J
Noroozi
Rabindra
R
Parajuli
Gareth K
GK
Phoenix
Anya M
AM
Reid
Wendy M
WM
Ridenour
Christian
C
Rixen
Sonja
S
Wipf
Liang
L
Zhao
Adrián
A
Escudero
Benjamin F
BF
Zaitchik
Emanuele
E
Lingua
Erik T
ET
Aschehoug
Ragan M
RM
Callaway
D000064:Acclimatization; D000531:Altitude; D001208:Asia; D044822:Biodiversity; D002980:Climate; D005060:Europe; D016014:Linear Models; D008954:Models, Biological; D009520:New Zealand; D009656:North America; D010944:Plants; D013020:South America
Alpine; cushion species; foundation species; nurse plants; positive interactions; species richness