title: Demographic response by a small epiphytic orchid.
abstract: OBJECTIVE
  Biotic changes are an inevitable consequence of climate change. Epiphytes may be more susceptible to changes in climate variation, but data regarding responses to climate variability under field conditions are limited. We evaluated whether the abundance of demographic stages in the epiphytic orchid Lepanthes rupestris at the Luquillo Experimental Forest in Puerto Rico was associated with short-term changes in climate variation over an 8-yr period.
  
  
  METHODS
  We used cross-correlation analyses to evaluate associations between the abundance of seedlings, juveniles, adults, and fruits per subpopulation, population growth, colonization and extinction rates in L. rupestris with variables related to precipitation and temperature, with and without lag- responses.
  
  
  RESULTS
  We detected significant negative correlations between the average number of seedlings and the number of dry days, between the average number of fruits and minimum average temperature with a 6-mo response lag, and between the average number of adults and the maximum temperature with a 1-yr response lag. Neither population growth rate nor probability of colonization and extinction were directly related to climatic variation between 2000 and 2007.
  
  
  CONCLUSIONS
  Associations between climatic variables and demographic stages could have negative implications for this orchid within the context of expected drying trends in the Caribbean. Results argue for the establishment of long-term monitoring studies of orchid populations, because only long-term studies would provide the appropriate temporal scale to detect and predict climate change effects and adaptive management of orchid populations.
authors: Institute for Tropical Ecosystem Studies, College of Natural Sciences, University of Puerto Rico-Rio Piedras, San Juan, 00936-8377, USA. polaya16@yahoo.com
authors: Paola
authors: P
authors: Olaya-Arenas
authors: Elvia J
authors: EJ
authors: Meléndez-Ackerman
authors: Maria Eglee
authors: ME
authors: Pérez
authors: Raymond
authors: R
authors: Tremblay
mesh_terms: D002980:Climate; D029595:Orchidaceae / Q000254:growth & development*; D011156:Population Density; D011157:Population Dynamics; D011647:Puerto Rico; D013559:Symbiosis