Habitat fragmentation is a pervasive and ongoing global phenomenon.
Habitat fragmentation can cause a cascade of abiotic and biotic changes
in the habitat that remains. Implications for populations that survive
the initial disturbance are numerous and complex.
It has been shown that habitat fragmentation negatively affects
plants growing in remnant forests, but the specific underlying
demographic mechanisms are less known. I have most recently begun
searching for these mechanisms using a decade-long dataset of an
understory plant (Heliconia acuminata Rich.) from fragmented Amazonian
forests. It is well established that fragmentation reduces survivorship
and reproduction in plants living in forest remnants. My efforts have
demonstrated that forest fragmentation also changes long-term growth
rates in the focal plants; these smaller, slower growing plants in
fragments in turn have lower rates of survival and reproduction (Gagnon
et al. 2011).
I am now exploring a series of additional demography-related
questions for plants in forest understories using stochastic matrix
models. Examples include: to what extent does species demography vary
among sites in tropical forest habitat; how does habitat fragmentation
alter the influence of different vital rates on population growth rates;
and how does habitat fragmentation alter projected growth of
populations in stochastic environments?