TY - JOUR
T1 - Habitat-islands in the coastal Atacama Desert: loss of functional redundancy, but not of functional diversity, with decreased precipitation
AU - Stotz, Gisela C.
AU - Salgado-Luarte, Cristian
AU - Vigil, Alonso T.
AU - De La Cruz, Henry J.
AU - Pastén-Marambio, Víctor
AU - Gianoli, Ernesto
N1 - Publisher Copyright:
© The Author(s) 2021. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For permissions, please e-mail: [email protected].
PY - 2021/4/17
Y1 - 2021/4/17
N2 - BACKGROUND AND AIMS: Aridity is increasing in many regions of the world, but microclimatic conditions may buffer plant communities from the direct effects of decreased precipitation, creating habitat islands. However, reduced precipitation can also impact these communities indirectly by decreasing the suitability of the surrounding habitat, thus limiting incoming propagules and increasing the chances of population decline and species loss. We test whether decreased precipitation results in loss of species and functional diversity within habitat islands, evaluating in particular whether declines in species diversity and abundance are less likely to result in loss of functional diversity if species/individual loss is stochastic (i.e. independent of species/individual traits) and communities/populations are functionally redundant. METHODS: Lomas communities are discrete plant communities embedded in the Atacama Desert, maintained by the microclimatic conditions created by fog. We recorded species and functional diversity in six Lomas communities along a 500 km long precipitation gradient in northern Chile. Functional traits were measured in 20 individuals per species, in those species that accounted for approx. 75 % of the abundance at each site. We calculated functional diversity and functional redundancy of the community, and intraspecific functional variation. KEY RESULTS: Decreased precipitation was associated with lower species diversity and lower species abundances. However, no traits or functional strategies increased or decreased consistently with precipitation, suggesting stochastic species/individual loss. Species with stress-tolerant strategies were predominant in all sites. Although species diversity decreased with decreasing precipitation, functional diversity remained unchanged. Lower functional redundancy in the drier sites suggests that mainly functionally redundant species were lost. Likewise, intraspecific functional variation was similar among communities, despite the lower species abundance in drier sites. CONCLUSIONS: Decreased precipitation can impact habitat island communities indirectly by decreasing the suitability of the surrounding habitat. Our results support the idea that a stochastic loss of species/individuals from functionally redundant communities and populations does not result in loss of functional diversity.
AB - BACKGROUND AND AIMS: Aridity is increasing in many regions of the world, but microclimatic conditions may buffer plant communities from the direct effects of decreased precipitation, creating habitat islands. However, reduced precipitation can also impact these communities indirectly by decreasing the suitability of the surrounding habitat, thus limiting incoming propagules and increasing the chances of population decline and species loss. We test whether decreased precipitation results in loss of species and functional diversity within habitat islands, evaluating in particular whether declines in species diversity and abundance are less likely to result in loss of functional diversity if species/individual loss is stochastic (i.e. independent of species/individual traits) and communities/populations are functionally redundant. METHODS: Lomas communities are discrete plant communities embedded in the Atacama Desert, maintained by the microclimatic conditions created by fog. We recorded species and functional diversity in six Lomas communities along a 500 km long precipitation gradient in northern Chile. Functional traits were measured in 20 individuals per species, in those species that accounted for approx. 75 % of the abundance at each site. We calculated functional diversity and functional redundancy of the community, and intraspecific functional variation. KEY RESULTS: Decreased precipitation was associated with lower species diversity and lower species abundances. However, no traits or functional strategies increased or decreased consistently with precipitation, suggesting stochastic species/individual loss. Species with stress-tolerant strategies were predominant in all sites. Although species diversity decreased with decreasing precipitation, functional diversity remained unchanged. Lower functional redundancy in the drier sites suggests that mainly functionally redundant species were lost. Likewise, intraspecific functional variation was similar among communities, despite the lower species abundance in drier sites. CONCLUSIONS: Decreased precipitation can impact habitat island communities indirectly by decreasing the suitability of the surrounding habitat. Our results support the idea that a stochastic loss of species/individuals from functionally redundant communities and populations does not result in loss of functional diversity.
KW - climate change
KW - fog
KW - fragmentation
KW - functional diversity
KW - Functional redundancy
KW - functional strategies
KW - habitat islands
KW - intraspecific functional variation
KW - isolation
KW - Lomas communities
KW - precipitation
KW - species diversity
UR - http://www.scopus.com/inward/record.url?scp=85105688777&partnerID=8YFLogxK
U2 - 10.1093/aob/mcaa206
DO - 10.1093/aob/mcaa206
M3 - Article
C2 - 33515007
AN - SCOPUS:85105688777
SN - 0305-7364
VL - 127
SP - 669
EP - 680
JO - Annals of Botany
JF - Annals of Botany
IS - 5
ER -