Does a giant tortoise taxon substitute enhance seed germination of exotic fleshy-fruited plants?  

作　　者：Annika Waibel Christine J.Griffiths Nicolas Zuel Bernhard Schmid Matthias Albrecht 

机构地区：[1]Institute of Evolutionary Biology and Environmental Studies,University of Zurich,Winterthurerstrasse 190,8057 Zurich,Switzerland [2]Mauritian Wildlife Foundation,Grannum Road,Vacoas,Mauritius [3]School of Biological Sciences,University of Bristol,Woodland Road,Bristol BS81UG,UK [4]Present address:Mediterranean Institute for Advanced Studies Department of Biodiversity and Conservation,(‘Consejo Superior de Investigaciones Cientı´ficas-Universitat de les Illes Balears’),Miquel Marques 21,07190 Esporles,Mallorca,Balearic Islands,Spain

出　　处：《Journal of Plant Ecology》2013年第1期57-63,共7页植物生态学报（英文版）

摘　　要：Aims The use of exotic species as taxon substitutes to restore lost ecological interactions is currently hotly debated.Aldabrachelys gigantea giant tortoises have recently been introduced to three islands in the Mascarene archipelago(Ile aux Aigrettes,Round Island and Rodrigues)to resurrect herbivory and seed dispersal functions once performed by extinct giant tortoises.However,potential unintended impacts by frugivore substitutes on native ecosystems,e.g.whether they will facilitate the germination of exotic plant species,are largely unknown.We investigated whether A.gigantea introduced to Rodrigues in 2006 could enhance the germination percentage of four widespread fleshy-fruited exotic species on the island.Using germination trials to forecast unintended impacts that could arise from the introduction of a frugivorous taxon substitute enables conservation managers to limit potential adverse negative interactions before they occur.Methods In germination trials that ran over 4 months,we investigated the effects of ingestion(gut passage and deposition in faeces)by subadult and adult A.gigantea on the germination percentage of four exotic fleshy-fruited plant species introduced to Rodrigues.We fed fruits of these plant species to sub-adult and adult A.gigantea to test how variation in age and size of the frugivore would affect seed germination.Feeding of distinctly coloured plastic pellets together with the fruits allowed us to test for individual tortoise effects on seed germination.Important Findings Ingestion by A.gigantea increased the percentage of seeds germinating of Mimusops coriacea and Lantana camara,but not percentage of germination of Veitchia merrillii or Wikstroemia indica.Seeds were more likely to germinate following ingestion by sub-adult rather than adult tortoises,which may be a consequence of the shorter gut passage time observed for sub-adults.Our results demonstrate that introduced frugivorous taxon substitutes could facilitate germination of exotic and invasive plants and highlight the need fo

关 键 词：ecological analogues exotic species invasion gut passage plant–frugivore interactions seed germination 

分 类 号：Q94[生物学—植物学]