Indian Ocean coastal thicket is of high conservation value for preserving taxonomic and functional diversity of forest-dependent bird communities in a landscape of restricted forest availability David A. Ehlers Smith, Yvette C. Ehlers Smith, Colleen T. Downs ⇑ University of KwaZulu-Natal, School of Life Sciences, Private Bag X01, Scottsville, Pietermaritzburg 3209, South Africa article info Article history: Received 24 November 2016 Received in revised form 28 January 2017 Accepted 29 January 2017 Keywords: Ecosystem services Forest fragmentation Forest regeneration Habitat structure RLQ analysis Trait space abstract The Indian Ocean Coastal Belt Forest is extremely biodiverse but is threatened by anthropogenic land-use change. In South Africa, remnant forest patches are divided into highly restricted but protected indige- nous forest (IF) and abundant but unprotected coastal thicket/dense bush (DB), which likely represents secondary/regenerating IF. We tested the hypothesis that DB had value for conserving forest- dependent avian taxonomic and functional diversity, as (a) DB is situated with in the forest- anthropogenic land-use mosaic and (b) birds maintain diverse ecosystem functions and are sensitive to environmental change given their varied biological traits. We conducted 149 and 112 fixed-radius point-count surveys of avian communities in 99, and 24, patches of DB and IF, respectively, at each loca- tion recording microhabitat vegetation structure. We compared vegetation characteristics and taxonomic species richness between vegetation classes, and tested the breadth of functional trait-space and for sig- nificant associations with vegetation structures at each survey location, using RLQ analysis. Vegetation classes differed significantly, but floral species overlap and vegetation structures in DB closely resembled regenerating IF habitat. Specialist ground-nesting and insect-gleaning species corresponded to taller, more diverse IF structures. Other biological traits and total species richness overlapped broadly across both classes, but IF had significantly higher mean species richness. Given the relatively high taxonomic and functional diversity of the avian community in the abundant DB, the scarcity of IF, and the proximity of DB to the anthropogenic land-use mosaic, we recommend allocating suitable DB patches to the Protected Area Network, which may simultaneously help preserve avian taxonomic and functional diver- sity, facilitate colonisation throughout the fragmented landscape and provide ecosystem services to anthropogenic land uses. Ó 2017 Elsevier B.V. All rights reserved. 1. Introduction Global rates of habitat loss and biodiversity decline continue to increase annually (FAO, 2011; WWF, 2012), with forest biomes being at the forefront of land clearance and destruction (Secretariat of the Convention on Biological Diversity, 2010). Mitigation mea- sures, including the allocation and maintenance of Protected Area Networks (PANs) face increasing challenges from encroachment and degradation (e.g. DeFries et al., 2005; Nellemann et al., 2007). Therefore, identifying biodiversity-rich ecosystems to incor- porate into PANs is of high priority. Typically, PANs seek to maximise the biological diversity contained within their borders, and are primarily concerned with conserving regions of high species diversity, particularly if those species are rare or threat- ened (e.g. Pimm et al., 2001; Dudley, 2008). Identifying the underlying causes of species’ distributions and predicting responses to changes in environmental conditions, such as climate, vegetation structure, and anthropogenic disturbance is central to conservation planning. Within fragmented landscapes, where habitat exists as patches either in isolation or within a matrix of other land-use types, species distributions and commu- nity assemblages are simultaneously influenced by macrohabitat, or landscape-scale conditions such as habitat-patch size and the context of the surrounding environment, and microhabitat, or local-scale factors such as vegetation structure and resource avail- ability (e.g. Fahrig, 2003; Pardini et al., 2005; Ehlers Smith et al., 2015; Zellweger et al., 2016). Two theories are often broadly http://dx.doi.org/10.1016/j.foreco.2017.01.034 0378-1127/Ó 2017 Elsevier B.V. All rights reserved. Abbreviations: IF, indigenous forest; DB, coastal thicket/dense bush; PAN, Protected Area Network. ⇑ Corresponding author. E-mail address: downs@ukzn.ac.za (C.T. Downs). Forest Ecology and Management 390 (2017) 157–165 Contents lists available at ScienceDirect Forest Ecology and Management journal homepage: www.elsevier.com/locate/foreco