info:eu-repo/semantics/lecture
Plant intraspecific trait variation correlates positively with species? niche breadth
Autor
Fajardo-Yáñez, Leichson Alex
Siefert, Andrew
Institución
Resumen
It is assumed that widespread, generalist species have high phenotypic
variation, but we know little about how intraspecific trait variation (ITV)
relates to species abundance and niche breadth. In the temperate
rainforest of southern Chile, we hypothesized that species with wide
niche breadth would exhibit 1) high among-plot ITV, 2) a strong
relationship between trait values and the environment, and 3) a close fit
between traits and local environment trait optima. We measured leaf
functional traits (leaf area, LMA, leaf N and P concentrations) of saplings
in woody species, and compared the relative abundance of each species
with its niche breadth, measured as the range of light, soil N and P
availability. We used the slope of the linear regression of species’ traitenvironment
relationships to assess the strength and direction of these
relationships, and measured the degree to which species’ trait values
track the environmental optimum across plots. In some cases, species
having wide niche breadth had high ITV in leaf N and also matched traits
(LMA and leaf P) to local optima along the light gradient; they also had
high ITV in general and matched leaf P to local optima along the soil P
gradient. The relationship between species with wide niche breadth and
the strength of intraspecific trait-environment relationships was
generally weak and varied depending on the niche dimension and trait in
question. Species varied considerably in the strength of traitenvironment
relationships and total magnitude of ITV, and this variation
was not generally strongly related to species abundances or niche
breadth patterns. In conclusion, trait variation at the community level is
not driven by a few abundant, widely distributed species, but depends on
the aggregate trait responses of both abundant and rare species. This
makes it difficult to scale individual species trait responses up to the
community level. FONDECYT FONDECYT