Data from: A degradation debt? large-scale shifts in community composition and loss of biomass in a tropical forest fragment after 40 years of isolation
Zahawi, Rakan A., Organization for Tropical Studies
Oviedo-Brenes, Federico, Organization for Tropical Studies
Peterson, Chris J., University of Georgia
Published Aug 02, 2018 on Dryad.
Cite this dataset
Zahawi, Rakan A.; Oviedo-Brenes, Federico; Peterson, Chris J. (2018). Data from: A degradation debt? large-scale shifts in community composition and loss of biomass in a tropical forest fragment after 40 years of isolation [Dataset]. Dryad. https://doi.org/10.5061/dryad.s5r8q
Habitat loss and fragmentation are among the biggest threats to tropical biodiversity and associated ecosystem services. We examined forest dynamics in a mid-elevation 365-ha fragment in southern Costa Rica. The fragment was isolated in the mid-1970s and belongs to the Las Cruces Biological Station. A 2.25-ha permanent plot was established in the center of the old-growth forest (>400 m to nearest edge boundary) and all plants >5 cm DBH were censused, mapped, and identified to species in two surveys taken ~5–6 years apart (>3,000 stems/survey). Although the reserve maintains high species richness (>200 spp.), with many rare species represented by only one individual, we document a strong shift in composition with a two-fold increase in the number of soft-wooded pioneer individuals. The dominant late-successional understory tree species, Chrysochlamys glauca (Clusiaceae), and most species in the Lauraceae, declined dramatically. Turnover was high: 22.9% of stems in the first survey were lost, and 27.8% of stems in the second survey represented new recruits. Mean tree diameter decreased significantly and there was a 10% decrease in overall biomass. Such alteration has been documented previously but only in smaller fragments or within ~100 m of an edge boundary. Further penetration into this fragment was perhaps driven by a progressive invasion of disturbance-adapted species into the fragment’s core over time; the loss of once-dominant late successional species could be a contributing factor. The pattern found is of particular concern given that such fragments represent a substantial portion of today’s remaining tropical habitat; further studies in similar-sized fragments that have been isolated for similar prolonged periods are called for.
FDP inventory for Dryad
Woody plant inventories from first and second survey of the Las Cruces Biological Station forest dynamics plot.
FDP grid topography for Dryad
X, Y coordinates and elevation relative to an arbitrary starting point, for all corners of the 10 m x 10 m grid demarking the LCBS forest dynamics plot. In addition, change in elevation and steepness (degrees) between adjacent grid points.