Demography of the understory herb Heliconia acuminata (Heliconiaceae) in an experimentally fragmented tropical landscape

Habitat fragmentation remains a major focus of research by ecologists
decades after being put forward as a threat to the integrity of
ecosystems. While studies have documented myriad biotic changes in
fragmented landscapes, including the local extinction of species from
fragments, the demographic mechanisms underlying these extinctions are
rarely known. However, many of them – especially in lowland tropical
forests – are thought to be driven by one of two mechanisms: (1) reduced
recruitment in fragments resulting from changes in the diversity or
abundance of pollinators and seed dispersers or (2) increased rates of
individual mortality in fragments due to dramatically altered abiotic
conditions, especially near fragment edges. Unfortunately, there have been
few tests of these potential mechanisms due to the paucity of long-term
and comprehensive demographic data collected in both forest fragments and
continuous forest sites. Here we report 11 years (1998-2009) of
demographic data from populations of the Amazonian understory herb
Heliconia acuminata (LC Rich.) found at Brazil’s Biological Dynamics of
Forest Fragments Project (BDFFP). The resulting data set comprises
>66000 plant×year records of 8586 plants, including 3464 seedlings
that became established after the initial census. Seven populations were
in experimentally isolated fragments (one in each of four 1-ha fragments
and one in each of three 10-ha fragments), with the remaining six
populations in continuous forest. Each population was in a 50×100m
permanent plot, with the distance between plots ranging from 500 m-60 km.
The plants in each plot were censused annually, at which time we recorded,
identified, marked, and measured new seedlings, identified any previously
marked plants that died, and recorded the size of surviving individuals.
Each plot was also surveyed 4-5 times during the flowering season to
identify reproductive plants and record the number of inflorescences each
produced. These data have been used to investigate topics ranging from the
way fragmentation-related reductions in germination influence population
dynamics to statistical methods for analyzing reproductive rates. This
breadth of prior use reflects the value of these data to future
researchers. In addition to analyses of plant responses to habitat
fragmentation, these data can be used to address fundamental questions in
plant demography, the evolutionary ecology of tropical plants, and for
developing and testing demographic models and tools. Though we welcome
opportunities to collaborate with interested users, there are no
restrictions on the use this data set. However, we do request that those
using the data for teaching or research inform us of how they are doing so
and cite this paper and the data archive when appropriate. Any publication
using the data must also include a BDFFP Technical Series Number in the
Acknowledgments. Authors can request this series number upon the
acceptance of their article by contacting the BDFFP’s Scientific
Coordinator or E. M. Bruna.