Management of Protected Areas and Its Effect on Ecosystem Function: Removal of Prosopis flexuosa Seeds by Mammals in Argentinian Drylands

CLAUDIA M. CAMPOS, V.E. CAMPOS, F. MIGUEL, M.I. CONA

PLOS ONE

PUBLIC LIBRARY SCIENCE

Lugar: San Francisco; Año: 2016

1932-6203

The ecological function of animal seed dispersal depends on species interactions and canbe affected by drivers such as the management interventions applied to protected areas.This study was conducted in two protected areas in the Monte Desert: a fenced reserve withgrazing exclusion and absence of large native mammals (the Man and Biosphere ÑacuñánReserve; FR) and an unfenced reserve with low densities of large native and domestic ani-mals (Ischigualasto Park; UFR). The study focuses on Prosopis flexuosa seed removal bydifferent functional mammal groups: ?seed predators?, ?scatter-hoarders?, and ?opportunis-tic frugivores?. Under both interventions, the relative contribution to seed removal by differ-ent functional mammal groups was assessed, as well as how these groups respond tohabitat heterogeneity (i.e. vegetation structure) at different spatial scales. Camera trapswere used to identify mammal species removing P. flexuosa seeds and to quantify seedremoval; remote sensing data helped analyze habitat heterogeneity. In the FR, the majorfruit removers were a seed predator (Graomys griseoflavus) and a scatter-hoarder (Micro-cavia asutralis). In the UFR, the main seed removers were the opportunistic frugivores(Lycalopex griseus and Dolichotis patagonum), who removed more seeds than the seedpredator in the FR. The FR shows higher habitat homogeneity than the UFR, and functionalgroups respond differently to habitat heterogeneity at different spatial scales. In the FR,because large herbivores are locally extinct (e.g. Lama guanicoe) and domestic herbivoresare excluded, important functions of large herbivores are missing, such as the maintenanceof habitat heterogeneity, which provides habitats for medium-sized opportunistic frugivoreswith consequent improvement of quality and quantity of seed dispersal services. In theUFR, with low densities of large herbivores, probably one important ecosystem function thisgroup performs is to increase habitat heterogeneity, allowing for the activity of medium-sized mammals who, behaving as opportunistic frugivores, did the most significant seedremoval