Spatial and temporal effects on recruitment of an Afromontane forest tree in a threatened fragmented ecosystem Vale ´rie Lehouck a,b, * , Toon Spanhove a,b , Alemu Gonsamo c , Norbert Cordeiro d,e , Luc Lens a a Terrestrial Ecology Unit, Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium b Ornithology Section, Zoology Department, National Museums of Kenya, P.O. Box 40658, 00100 Nairobi, Kenya c Department of Geography, University of Helsinki, P.O. Box 64, 00014, Finland d Departments of Botany and Zoology, The Field Museum, 1400 S. Lake Shore Drive, Chicago, IL 60605-2496, USA e Department of Biological, Chemical, and Physical Sciences, Roosevelt University, 430 S. Michigan Avenue, Chicago, IL 60605, USA ARTICLE INFO Article history: Received 23 June 2008 Received in revised form 9 November 2008 Accepted 17 November 2008 Available online 27 December 2008 Keywords: Eastern Arc Germination Seedling survival Regeneration Xymalos monospora Plantation ABSTRACT Tropical forest fragmentation affects animal and plant populations in different ways. For plants, early stages (seed to seedling) are more sensitive to habitat alteration than adults, and can shape their future spatial patterns. Therefore, studying how seed germination and seedling growth and survival vary at different spatiotemporal scales enhances our under- standing about plant recruitment in fragmented ecosystems. In this study we examine if, and to what extent, recruitment at early life-stages of Xymalos monospora (Monomiaceae), a bird-dispersed Afrotropical tree, differs between and within forest fragments that vary in size, surrounding matrix and microhabitats. Three years of field experiments (2004– 2006) in south-east Kenya, revealed that patterns of seed germination and seedling survival and growth were largely inconsistent, both in space and time. Recruitment was not consis- tently higher in larger or less disturbed fragments. At smaller spatial scales within forest fragments, recruitment was subject to high between-year variation too, with decreased ger- mination in gaps only in the dry year of 2004. However, performance of seeds and seedlings was consistently better away from than under conspecific fruiting trees. Our results imply that fragmented tree populations of X. monospora may become age-structured, or ultimately go extinct, if recruitment fails in subsequent years. This may especially affect populations in small, disturbed forest fragments, where seed dispersal and buffering against stochastic processes are generally reduced. Exotic plantations bordering indigenous forest fragments may provide suitable conditions for native tree recruitment; hence, forest expansion through enrichment planting should be considered in future conservation plans. Ó 2008 Elsevier Ltd. All rights reserved. 1. Introduction Biodiversity is currently being lost at unprecedented rates due to a huge variety of human activities, with the most pervasive threat being habitat destruction and degradation (Bailly et al., 2004). Tropical forests are increasingly being threatened by large-scale deforestation (e.g. Laurance et al., 2004), most of- ten in areas densely populated by humans and/or 0006-3207/$ - see front matter Ó 2008 Elsevier Ltd. All rights reserved. doi:10.1016/j.biocon.2008.11.007 * Corresponding author: Address: Terrestrial Ecology Unit, Ghent University, K.L. Ledeganckstraat35, 9000 Ghent, Belgium. Tel.: +32 (0)9/ 264 50 39; fax: +32 (0)9/264 87 94. E-mail addresses: ValerieLehouck@gmail.com (V. Lehouck), ToonSpanhove@hotmail.com (T. Spanhove), Alemu.Gonsamo@helsinki.fi (A. Gonsamo), NCordeiro@roosevelt.edu (N. Cordeiro), Luc.Lens@ugent.be (L. Lens). BIOLOGICAL CONSERVATION 142 (2009) 518 – 528 available at www.sciencedirect.com journal homepage: www.elsevier.com/locate/biocon