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Population Viability Analysis of the Epiphytic Ghost Orchid ( D endrophylax lindenii ) in C uba
Author(s) -
Raventós José,
González Elaine,
Mújica Ernesto,
Doak Dan F.
Publication year - 2015
Publication title -
biotropica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.813
H-Index - 96
eISSN - 1744-7429
pISSN - 0006-3606
DOI - 10.1111/btp.12202
Subject(s) - epiphyte , extinction (optical mineralogy) , population , ecology , biology , disturbance (geology) , population growth , population size , population decline , habitat , demography , paleontology , sociology
To design feasible conservation and management policies for wild species, it is critical to understand the effects of periodic disturbances, be they natural or anthropogenic. The C aribbean B asin is characterized by high cyclonic activity that has a strong impact on the demography and population dynamics of many taxa, including epiphytic orchids. We conducted a 5‐yr study of rare ghost orchid demography, D endrophylax lindenii , to assess the stability of a protected population of this species in C uba. Using both stochastic and deterministic integral projection models, we found that mean annual population growth rates are negative (λ = 0.975). However, we found both population growth rate and extinction risk are highly sensitive to survival rates and reproduction, a difficult to quantify rate for many orchids including our study species. While this species is fairly long‐lived, its relatively slow increase in annual survival with increasing size may reflect the lack of a protected ( i.e ., subterranean) storage organ—a life‐history trait that may typify other epiphytic species and increase susceptibility to disturbance events. Hurricanes, which are predicted to increase in frequency as a result of climate change, dramatically increase adult mortality. Simulations of these effects indicate that hurricanes and similar disturbances could result in near certain extinction in short time horizons (25 yr) if their annual probability of occurrence exceeds 14 percent. These results suggest a need to better quantify recruitment rates, as well as the sensitivity of population dynamics of this and other orchid species to hurricanes and other periodic disturbances.