z-logo
Premium
Persistencia Poblacional de Torreya taxifolia : Comparaciones del Declive de un Arbol Conífero Basadas en Proyecciones de Modelos
Author(s) -
Schwartz Mark W.,
Hermann Sharon M.,
Van Mantgem Phillip J.
Publication year - 2000
Publication title -
conservation biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.2
H-Index - 222
eISSN - 1523-1739
pISSN - 0888-8892
DOI - 10.1046/j.1523-1739.2000.98393.x
Subject(s) - extinction (optical mineralogy) , endangered species , persistence (discontinuity) , geography , population , local extinction , leslie matrix , extinction probability , ecology , population size , biology , forestry , demography , biological dispersal , habitat , paleontology , geotechnical engineering , sociology , engineering
The Florida torreya (   Torreya taxifolia ) is a coniferous tree endemic to a 35‐km stretch of bluffs and ravines along the east side of the Apalachicola River in northern Florida and southern Georgia. This formerly locally abundant tree has declined as a result of disease during the 1950s and is on the U.S. endangered species list. With no seed production in the wild, this species is headed toward extinction. We conducted a survey on roughly 200 trees from 1988 to 1996 and used these data to estimate the likelihood of population persistence during the next several decades. We compared a stage‐class transition matrix model ( RAMAS) and an individual‐based stochastic model ( TORSIM) of growth and mortality to project future populations. Given the current lack of seed production in the wild, all models predict extinction. The question of concern is the imminence of this predicted extinction. Differing predicted times to extinction would suggest different immediate management recommendations. Both models predicted an over 90% likelihood of persistence during the next 50 years. Predictions differed in that the transition matrix model was less optimistic than the individual‐based model regarding persistence. Model sensitivity analysis showed that the results were robust to significant decreases in growth and sprouting probabilities. Submodels identified different persistence likelihoods in different populations. Nonetheless, unless management of the population can facilitate maturation and seed production, extinction of this species in the wild is inevitable.

This content is not available in your region!

Continue researching here.

Having issues? You can contact us here