Contents lists available at ScienceDirect Agriculture, Ecosystems and Environment journal homepage: www.elsevier.com/locate/agee The role of natural vegetation strips in sugarcane monocultures: Ant and bird functional diversity responses Leonardo Fabio Rivera-Pedroza a , Federico Escobar b , Stacy M. Philpott c , Inge Armbrecht a, ⁎ a Biology Department, Universidad del Valle- Meléndez, Calle 13 No 100-00. Cali, Ed. 320, Of. 3027, Colombia b Instituto de Ecología, A.C., Carretera antigua a Coapetec 351, El Haya, Xalapa, C.P. 91070, Veracruz, Mexico c Environmental Studies Department, University of California, 1156 High Street, Santa Cruz, California, 95064, USA ARTICLE INFO Keywords: Associated biodiversity Conservation biological control Functional groups Landscape homogenization Tropical dry forest ABSTRACT Simplification of landscapes due to the increase of monocultures negatively impacts biodiversity and its func- tions. In tropical landscapes that are dominated by sugarcane monocultures, some small natural vegetation patches still exist, yet little is known about their capacity to harbor functional biodiversity that may complement agroecological management of the crop. We compared ant and bird diversity in natural vegetation strips to diversity within sugarcane monocultures at increasing distances from the vegetation strips. We also compared functional groups of ants and birds in order to evaluate the role of vegetation strips in regulating pests of economic importance. During two seasons between 2015 and 2016, we studied 12 sites in the Cauca Valley, Colombia, with both natural vegetation strips and sugarcane monoculture and then sampled ants and birds in natural vegetation strips and at four distances towards the interior of the sugarcane matrix (up to 150 m and 350 m respectively). Species richness of ants and birds differed in vegetation strips and sugarcane matrix with decreases in richness as the distance from vegetation strips increased. Furthermore, predatory functional groups of ants and birds were less abundant in the sugarcane matrix, with important implications for key predation services on key sugarcane pests (e.g., Diatraea spp. – Lepidoptera: crambidae). Our results provide evidence that even in highly modified landscapes dominated by monocultures, the conservation of small patches of natural vegetation favors functional biodiversity. Therefore, maintaining and promoting and natural vegetation strips is especially important in highly industrialized monoculture landscapes in order to promote beneficial biodiversity for ecosystem services without sacrificing production area. 1. Introduction Agricultural expansion and intensification are considered the main causes of ecosystem homogenization and global biodiversity loss (Millennium Assessment, 2007). This is worrisome, among other rea- sons, because biodiversity maintains the life support systems necessary for human existence on Earth (Chapin et al., 2000; Foley et al., 2005). Nonetheless, the increase of arable land for food and the energy de- mand for plant-based biofuels is augmenting the need for agricultural land worldwide (Christofoletti et al., 2017). In the tropics, some crop areas will be expanded to meet energy demand as well as demands for other supplies (i.e., sugarcane, African palm and soy); most of these crops already occupy large tracts of fertile land, and are intensively managed in monocultures that require use of heavy machinery and high agrochemical application. At the landscape scale, agricultural expansion generates patches of natural habitat immersed in a matrix dominated by one or few crops (Inclán et al., 2016). The resulting natural vegetation remnant patches become reservoirs for biodiversity (Fahrig et al., 2011) and are funda- mental for the maintenance of key ecosystem services such as pest control, microclimate regulation, and water and soil protection within agricultural landscapes (Millennium Assessment, 2007). In addition, loss of remnant vegetation generates greater homogeneity in the land- scape and, in turn, can directly influence the top-down effects of pre- dators, affecting trophic networks (Philpott et al., 2008, 2009). In contrast, maintenance of natural vegetation in agricultural landscapes contributes to increased productivity, sustainability, and resilience (Pacheco et al., 2013). In the future, appropriately designed landscapes promise to be an economically sustainable and viable alternative, and will reduce the use of pesticides in crops (Letourneau et al., 2011; https://doi.org/10.1016/j.agee.2019.106603 Received 31 December 2018; Received in revised form 6 May 2019; Accepted 12 July 2019 ⁎ Corresponding author. E-mail addresses: leonardo.fabio.rivera@correounivalle.edu.co (L.F. Rivera-Pedroza), federico.escobar@inecol.mx (F. Escobar), sphilpot@ucsc.edu (S.M. Philpott), inge.armbrecht@correounivalle.edu.co (I. Armbrecht). Agriculture, Ecosystems and Environment 284 (2019) 106603 Available online 05 August 2019 0167-8809/ © 2019 Elsevier B.V. All rights reserved. T