title: Low tortoise abundances in pine forest plantations in forest-shrubland transition areas.
abstract: In the transition between Mediterranean forest and the arid subtropical shrublands of the southeastern Iberian Peninsula, humans have transformed habitat since ancient times. Understanding the role of the original mosaic landscapes in wildlife species and the effects of the current changes as pine forest plantations, performed even outside the forest ecological boundaries, are important conservation issues. We studied variation in the density of the endangered spur-thighed tortoise (Testudo graeca) in three areas that include the four most common land types within the species' range (pine forests, natural shrubs, dryland crop fields, and abandoned crop fields). Tortoise densities were estimated using a two-stage modeling approach with line transect distance sampling. Densities in dryland crop fields, abandoned crop fields and natural shrubs were higher (>6 individuals/ha) than in pine forests (1.25 individuals/ha). We also found large variation in density in the pine forests. Recent pine plantations showed higher densities than mature pine forests where shrub and herbaceous cover was taller and thicker. We hypothesize that mature pine forest might constrain tortoise activity by acting as partial barriers to movements. This issue is relevant for management purposes given that large areas in the tortoise's range have recently been converted to pine plantations.
authors.affiliation: Área de Ecología, Departamento de Biología Aplicada, Universidad Miguel Hernández, Av/ Universidad, Elche, Spain.
authors.forename: Roberto C
authors.initials: RC
authors.lastname: Rodríguez-Caro
authors.affiliation: Centre for Research into Ecological and Environmental Modeling, University of St Andrews, The Observatory, Buchanan Gardens, St. Andrews, United Kingdom.
authors.forename: Cornelia S
authors.initials: CS
authors.lastname: Oedekoven
authors.affiliation: Área de Ecología, Departamento de Biología Aplicada, Universidad Miguel Hernández, Av/ Universidad, Elche, Spain.
authors.forename: Eva
authors.initials: E
authors.lastname: Graciá
authors.affiliation: Department of Biology, Queens College, City University of New York, New York, New York, United States of America.
authors.forename: José D
authors.initials: JD
authors.lastname: Anadón
authors.affiliation: Centre for Research into Ecological and Environmental Modeling, University of St Andrews, The Observatory, Buchanan Gardens, St. Andrews, United Kingdom.
authors.forename: Stephen T
authors.initials: ST
authors.lastname: Buckland
authors.affiliation: Departamento de Ecología e Hidrología, Área de Ecología, Universidad de Murcia, Murcia, Spain.
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Esteve-Selma
authors.affiliation: Fundación Nueva Cultura del Agua, Zaragoza, Spain.
authors.forename: Julia
authors.initials: J
authors.lastname: Martinez
authors.affiliation: Área de Ecología, Departamento de Biología Aplicada, Universidad Miguel Hernández, Av/ Universidad, Elche, Spain.
authors.forename: Andrés
authors.initials: A
authors.lastname: Giménez
mesh_terms: D003247:Conservation of Natural Resources; D017753:Ecosystem; D065928:Forests; D005843:Geography; D028223:Pinus; D011156:Population Density; D013030:Spain