Effects of past and present land use on vegetation cover and regeneration in a tropical dryland forest Felipe Pereira Marinho a , Guilherme Gerhardt Mazzochini a, * , Adriana Pellegrini Manh ~ aes a , Wolfgang W. Weisser b , Gislene Ganade a a Department of Ecology, Centro de Bioci^ encias, Universidade Federal do Rio Grande do Norte, Lagoa Nova, Natal, RN 59072970, Brazil b Terrestrial Ecology Research Group, Department of Ecology and Ecosystem Management, School of Life Sciences Weihenstephan, Technische Universit€ at München, Hans-Carl-von-Carlowitz-Platz 2, 85350 Freising, Germany article info Article history: Received 6 July 2015 Received in revised form 26 December 2015 Accepted 27 April 2016 Keywords: Grazing Clear-cut history Vegetation cover Land management Desertification abstract Brazilian Caatinga is one of the most diverse dryland ecosystem of the world and is threatened by strong land use pressure and poor protection. In this study, we investigate the effects of past and present land use on plant community richness and structure. We used satellite information to identify 55 Caatinga forest plots with and without past vegetation clearing. We also quantified current land use, i.e. grazing by domestic animals, and selective logging. Caatinga vegetation structure, measured as vegetation cover, vegetation height, basal area and woody plant density, as well as recruitment, measured as woody plant seedling density and species richness, were negatively affected by both past and current land use. Past clear-cut not only had strong effects on most vegetation measures, but also increased current grazing which further negatively affected vegetation structure. Selective logging had little measurable effects but increased recruitment in plots previously clear-cut. Increasing time since the last clear-cut increased negative effects on vegetation, presumably because of a prolonged negative effect of grazing. Our results suggest that grazing needs to be prevented in areas degraded by clear-cut to allow vegetation restoration through natural succession and avoid further degradation and desertification. © 2016 Elsevier Ltd. All rights reserved. 1. Introduction Land use change is the main cause of land degradation world- wide, but the degree of degradation will depend on land use type and on the resilience of the impacted ecosystem (Gunderson, 2000; Htun et al., 2011). The use of native forests for livestock grazing or logging not only directly impacts the vegetation but also modifies environmental conditions such as the light reaching the soil, soil compaction and wind exposure (Coffin et al., 1996; Conant et al., 2001; Zaady et al., 2013). A common consequence of such land uses in many forests is an impoverished vegetation with a lower average tree height, tree basal area, plant density and species number. This might occur either due to direct effects of land use and through indirect effects of enhancement of stressful conditions (Dorrough and Scroggie, 2008). In dryland ecosystems, maintenance of vegetation cover criti- cally depends on plant recruitment within existing vegetation patches, as seedlings can rarely establish on bare ground (Vieira et al., 2013). Even chronic low-intensity disturbances such as se- lective logging or grazing can have pervasive effects on plant di- versity and composition of vegetation patches (Ribeiro et al., 2015). For example, selective logging for charcoal production may alter woody species composition because species with high wood den- sity are preferred (Ramos et al., 2008). On the other hand, small gaps formation from selective logging can promote seedling den- sity and diversity if the understorey is light limited (Costa and Magnusson, 2002). Grazers can modify the native vegetation by favoring unpalatable species or by causing overall mortality of seedlings due to trampling (Aschero and García, 2012; Cipriotti and Aguiar, 2005; Pereira et al., 2003). However, positive effects of grazing on native species seed dispersal and consequently seedling establishment have also been reported in dry ecosystems (Aschero and García, 2012). The intensive and chronic land-use leads to formation of iso- lated vegetation patches surrounded by bare ground in several drylans around the world (K efi et al., 2007; Maestre and Escudero, 2009). After land abandonment, secondary forest dynamics will * Corresponding author. E-mail address: gmazzochini@gmail.com (G.G. Mazzochini). Contents lists available at ScienceDirect Journal of Arid Environments journal homepage: www.elsevier.com/locate/jaridenv http://dx.doi.org/10.1016/j.jaridenv.2016.04.006 0140-1963/© 2016 Elsevier Ltd. All rights reserved. Journal of Arid Environments 132 (2016) 26e33