1. The long-term fate of populations experiencing disequilibrium conditions with their environment will ultimately depend on how local colonization and extinction dynamics respond to abiotic conditions (e.g. temperature and rainfall), dispersal limitation and biotic interactions (e.g. competition, facilitation, or interactions with natural enemies). Understanding how these factors influence distributional dynamics under climate change is a major knowledge gap, particularly for small ranged and dispersal-limited plant species, which are at higher risk of extinction. Epiphytes are hypothesized to be particularly vulnerable to climate change and we know little about what drives their distribution and how they will respond to climate change. To address this issue, we leveraged a 10-year data set on the occupancy dynamics of the endemic orchid Lepanthes rupestris to identify the drivers of local colonization and extinction dynamics and assess the long-term fate of this population under multiple climate change scenarios. 2. We compared 290 dynamic occupancy models in their ability to predict the colonization and extinction dynamics of a L. rupestris metapopulation. The model set predicted colonization-extinction dynamics as a function of asymmetric patch connectivity, moss area, elevation, temperature (minimum, maximum and variability), and/or rainfall. 3. The best model predicted that local colonization increases with increasing asymmetric patch connectivity but decreases as minimum temperature and maximum temperature variability increase. The best model also predicted that local extinction increases with increasing variability in maximum temperature. Negative effects were more severe in smaller patches. 4. Synthesis: Overall, our results demonstrate the role of asymmetric connectivity, climate and interactions with moss area as drivers of colonization and extinction dynamics. Moreover, our results suggest that asymmetrically dispersed epiphytes may struggle to persist under climate change because their limited connectivity may not be enough to counterbalance the negative effects of increasing mean or variability in temperature.

We used presence/absence data on a permanent plot (18°18′N, 65°47′W) of 975 mapped occupied and non-occupied patches (either rock or tree phorophytes).  Many times these patches were surveyed multiple times a year from 1999–2008.  The total moss area was estimated in each patch using a 150 cm² grid.  See Tremblay et al. 2006 for details on plot establishment and design.

1. Dataset info: lepa_all.csv

2. Researchers:
Miguel A. Acevedo, Wildlife Ecology and Conservation, University of Florida
Lydia Beaudrot, Department of Biosciences, Program in Ecology and Evolutionary Biology, Rice University
Elvia J. Meléndez-Ackerman, Department of Environmental Sciences, University of Puerto Rico, Río Piedras
Raymond L. Tremblay, Department of Biology, University of Puerto Rico, Humacao

3. Contact:
Original data sheets stored by
Raymond L. Tremblay
raymond.tremblay@upr.edu

4.  Dates: 1999-2008

5. Geographic location: Luquillo Experimental Forest, Puerto Rico

6. Column definition:
UID: unique id for phorophyte
x.coord.: X-coordinate
y.coord.: Y-coordinate
z.coordinate: Z-coordinate
Phorophyte: Phorophyte type either rock or tree
X70199: Sampling in 1999
X20100: First sampling of 2000
X80100: Second sampling of 2000
X10101: First sampling of 2001
X60101: Second sampling of 2001
X10102: First sampling of 2002
X60102: Second sampling of 2002
X120202: Third sampling of 2002 (late in the year)
X61003: First sampling of 2003
X12404: First sampling of 2004
X7104: Second sampling of 2004
X12205: First sampling of 2005
X91705: Second sampling of 2005
X72406: First sampling of 2006
X20307: First sampling of 2007
X61507: Second sampling of 2007
X10208: First sampling of 2008
Total_Moss_area: Total are covered by moss in the phorophyte

Environmental data available in: https://luq.lter.network/datacatalog

Methods are described in Acevedo et al. 2020 Local extinction risk under climate change in a neotropical asymmetrically dispersed epiphyte. Journal of Ecology