title: Evaluating realized seed dispersal across fragmented tropical landscapes: a two-fold approach using parentage analysis and the neighbourhood model.
abstract: Despite the importance of seed dispersal for survival of plant species in fragmented landscapes, data on seed dispersal at landscape scales remain sparse. Effective seed dispersal among fragments determines recolonization and plant species persistence in such landscapes. We present the first large-scale (216-km2) direct estimates of realized seed dispersal of a high-value timber tree (Dysoxylum malabaricum) across an agro-forest landscape in the Western Ghats, India. Based upon an exhaustive inventory of adult trees and a sample of 488 seedlings all genotyped at 10 microsatellite loci, we estimated realized seed dispersal using parentage analysis and the neighbourhood model. Our estimates found that most realized seed dispersal was within 200 m, which is insufficient to effectively bridge the distances between forest patches. We conclude that using mobility of putative animal dispersers can be misleading when estimating tropical tree species vulnerability to habitat fragmentation. This raises serious concerns about the potential of many tropical trees to recolonize isolated forest patches where high-value tree species have already been removed.
authors.affiliation: ETH Zürich, Institute of Terrestrial Ecosystems, Ecosystem Management, Zürich, CH-8092, Switzerland.
authors.forename: Sascha A
authors.identifier: http://orcid.org/0000-0003-2883-0666
authors.initials: SA
authors.lastname: Ismail
authors.affiliation: ETH Zürich, Institute of Terrestrial Ecosystems, Ecosystem Management, Zürich, CH-8092, Switzerland.
authors.forename: Jaboury
authors.initials: J
authors.lastname: Ghazoul
authors.affiliation: Ashoka Trust for Research in Ecology and the Environment, Royal Enclave, Srirampura, Jakkur Post, Bangalore, 560064, India.
authors.forename: Gudasalamani
authors.initials: G
authors.lastname: Ravikanth
authors.affiliation: College of Forestry, University of Agricultural and Horticultural Sciences (Shimoga), Ponnampet, Karnataka, 571216, India.
authors.forename: Cheppudira G
authors.initials: CG
authors.lastname: Kushalappa
authors.affiliation: Ashoka Trust for Research in Ecology and the Environment, Royal Enclave, Srirampura, Jakkur Post, Bangalore, 560064, India.|Department of Crop Physiology, University of Agricultural Sciences, GKVK Campus, Bangalore, 560065, India.
authors.forename: Ramanan
authors.initials: R
authors.lastname: Uma Shaanker
authors.affiliation: ETH Zürich, Institute of Terrestrial Ecosystems, Ecosystem Management, Zürich, CH-8092, Switzerland.
authors.forename: Chris J
authors.initials: CJ
authors.lastname: Kettle
mesh_terms: D003247:Conservation of Natural Resources; D005843:Geography; D007194:India; D008962:Models, Theoretical; D010802:Phylogeny; D011058:Pollen / Q000502:physiology; D058614:Seed Dispersal / Q000502:physiology*; D036226:Seedlings / Q000502:physiology; D014329:Tropical Climate
keywords: 
  Dysoxylum malabaricum
  ; Ocyceros griseus (Malabar grey hornbill); Western Ghats; fragmentation; realized seed dispersal; recolonization; recruitment; spatial isolation