1 Reptiles in restored agricultural landscapes: The value of 2 linear strips, patches and habitat condition 3 4 This is the submitted version of the manuscript. The final version is published in 5 Animal Conservation: http://dx.doi.org/10.1111/acv.12121 6 7 Authors: Sacha Jellinek a, Kirsten M. Parris b, Michael A. McCarthy c, Brendan A. Wintle d & Don 8 A. Driscoll e 9 a Centre of Excellence for Environmental Decisions, School of Botany, University of Melbourne, 10 Parkville, Melbourne, Vic 3072, Australia. Email: [email protected] (Corresponding 11 Author) Ph: +61 (0)410 917 123 12 b Centre of Excellence for Environmental Decisions, School of Botany, University of Melbourne, 13 Parkville, Melbourne, Vic 3072, Australia. Email: [email protected] 14 c Centre of Excellence for Environmental Decisions, School of Botany, University of Melbourne, 15 Parkville, Melbourne, Vic 3072, Australia. Email: 16 [email protected] 17 d Centre of Excellence for Environmental Decisions, School of Botany, University of Melbourne, 18 Parkville, Melbourne, Vic 3072, Australia. Email: [email protected] 19 e The Fenner School of Environment and Society, Hancock Building (43), Biology Place, 20 Australian National University, Canberra, ACT 0200, Australia. Email: [email protected] 21 22 Keywords: Agricultural landscapes, distance, ground layers, linear strip, patch, reptile, 23 revegetation, restoration, vegetation condition 24 1 1 Abstract 2 Habitat restoration, including revegetation of linear strips and enlargement of 3 remnant patches, may benefit native fauna in highly fragmented landscapes. 4 Such restoration has occurred around the world, even though the relative 5 importance of strips and patches of vegetation remains controversial. Using 6 reptile communities from south-eastern Australia, we assessed the conservation 7 value of revegetation in strips and alongside remnant patches compared with 8 remnant vegetation and cleared roadsides. We also examined the distance that 9 reptiles occurred from remnant patches into linear vegetation. We found that 10 reptile species richness and counts did not substantially differ between 11 revegetated, remnant and cleared habitats, or between linear strip and patch 12 treatments. This may indicate that species sensitive to land clearing have 13 already been lost from the landscape. These results imply that if specialist 14 species have already been lost, we may be unable to measure the effects of 15 agriculture on biodiversity. Furthermore, revegetation with the expectation that 16 fauna will recolonize may be unrealistic and translocations may be necessary. 17 Unexpectedly, we recorded higher species richness and counts of rare reptile 18 species in remnant linear strips as distance from remnant patches increased. 19 Ground layer attributes were important for increasing reptile species richness 20 and counts and in structuring reptile communities, explaining approximately 21 three times as much variation as remnant shape or vegetation type (remnant, 22 revegetated, cleared). Management agencies should protect and effectively 23 manage remnant linear strips if rarer reptiles are to be retained, paying 24 particular attention to ground layer attributes. The decision to include ground 2 1 layers in future revegetation activities will be more important than the shape of 2 restored areas. 3 4 Introduction 5 Habitat loss and fragmentation as a result of intensive agriculture is a major 6 threat to biodiversity conservation around the world (Harrison and Bruna, 1999, 7 Lindenmayer, 2009). Broad-scale habitat restoration through revegetation is 8 now necessary to maintain or increase biodiversity in these landscapes (Huxel 9 and Hastings, 1999, Ruiz-Jaen and Aide, 2005, Ryan, 2000). However, there is 10 debate about the effectiveness of revegetating for maintaining faunal species, 11 because revegetated areas generally do not contain the same faunal 12 communities as remnant habitats (Munro, Fischer, Barrett et al., 2011, Munro, 13 Fischer, Wood et al., 2009). There is also debate about whether it is better to 14 revegetate linear strips or to enlarge existing remnant patches (Bailey, 2007, 15 Simberloff and Cox, 1987, Tewksbury, Levey, Haddad et al., 2002). 16 17 There are benefits and drawbacks to enlarging patches of habitat and to 18 focusing on restoration of linear strips to link remnant areas together. Enlarged 19 patches would provide a larger habitat area and have greater interior habitat yet 20 would remain isolated from similar habitats, limiting species movement and 21 dispersal (Bennett, Crooks and Sanjayan, 2006, Hodgson, Thomas, Wintle et 22 al., 2009). Restored linear strips could allow the movement and dispersal of 23 native plants and animals, but have a greater edge-to-area ratio than patches 3 1 and may act as conduits of disease and invasive species, decreasing their 2 value for native species (Brown, Phillips, Webb et al., 2006, Simberloff, Farr, 3 Cox et al., 1992). Further, the distance that fauna can move along linear strips 4 is not well established (Haddad, Bowne, Cunningham et al., 2003). 5 Understanding the movement of a species is important because species with 6 limited dispersal abilities such as reptiles and amphibians would be less able to 7 move along linear strips or escape degraded habitats (Carthew, Horner and 8 Jones, 2009). 9 10 The response of faunal groups such as birds and mammals to habitat 11 fragmentation and habitat restoration are reasonably well studied, while groups 12 such as reptiles have received little attention in the ecological literature 13 (Bateman, Chung-MacCoubrey and Snell, 2008, Cunningham, Lindenmayer, 14 Crane et al., 2007, Kanowski, Reis, Catterall et al., 2006, Munro, Lindenmayer 15 and Fischer, 2007). While researchers report that some reptile communities 16 have persisted in fragmented landscapes (Cabrera-Guzman and Hugo 17 Reynoso, 2012, Kitchener, Chapman, Dell et al., 1980, Smith, Arnold, Sarre et 18 al., 1996), other studies report that some reptile species and communities have 19 declined (Dixo and Metzger, 2009, Driscoll, 2004, Mac Nally and Brown, 2001). 20 Reptiles are strongly influenced by vegetation type and structure, and this may 21 have a stronger effect than remnant shape or size in highly modified landscapes 22 (Jellinek, Driscoll and Kirkpatrick, 2004, Michael, Cunningham and 23 Lindenmayer, 2010, Schutz and Driscoll, 2008). 24 4 1 In order to maintain reptiles that are sensitive to loss of native vegetation, it is 2 essential to determine how effective revegetation is for conserving or recovering 3 reptile communities in enlarged and connected habitats. In two agricultural 4 landscapes in south-eastern Australia we asked if reptile species richness and 5 counts, and counts of individual species was influenced by: (i) the shape of the 6 sampled area (linear strip or patch), the type of the sampled area (remnant, 7 revegetated or cleared) and the interactions of shape and type; (ii) increasing 8 distance from patches along remnant, revegetated and cleared linear strips; (iii) 9 environmental variables and how these account for variation in reptile 10 community composition compared with shape and site-type. This information 11 could assist management agencies and community groups to plan restoration 12 activities that will best maintain reptile species in modified agricultural 13 landscapes. 14 15 Materials and Methods 16 Study region 17 This study took place in two regions of Victoria, south-eastern Australia: Benalla 18 (Fig. 1 a) and Wimmera (Fig. 1 b). These two regions have been cleared for 19 intensive agriculture for over 150 years, and have less than 10% of their native 20 vegetation remaining (Duncan, Moxham and Read, 2007, Radford, Bennett and 21 Cheers, 2005). Cropping and livestock production are the dominant agricultural 22 industries in these regions (Jellinek, Parris and Driscoll, 2013a). 23 5 1 Within each of the two regions (Benalla and Wimmera), we surveyed two 2 treatment shapes: (1) linear strips and (2) enlarged patches of remnant native 3 vegetation (Fig. 2 a, b, c). Linear strips were defined as areas of habitat along 4 roadsides or fence lines that were approximately 20 - 40m wide and at least 5 500m long. Linear strips always originated from a remnant patch that was a 6 similar size and shape to remnant patches in the patch treatment. Patches were 7 approximately square or oval-shaped and at least 4 hectares in size. Within 8 linear strips there were four site-types, and within enlarged patches there were 9 two site-types (Fig. 2 a). The site-types in our linear strip treatment were (i) a 10 revegetated linear strip, which had been cleared but was revegetated using 11 native trees and shrubs 8 - 14 years ago; (ii) a cleared linear strip, which had 12 been cleared of trees and shrubs and contained a grassy ground layer; (iii) a 13 remnant linear strip, containing remnant native vegetation that had not been 14 cleared; and (iv) a patch of remnant native vegetation, from which the linear 15 strips originated (Fig. 2 b). In some cases it was not possible to have a single 16 remnant patch from which the three linear strips originated and situations arose 17 where two of the three linear strips originated from one remnant patch while the 18 third originated from a nearby remnant patch (<1 km away). In replicates where 19 only one remnant patch was used, the patch was surveyed using two lots of five 20 pitfall lines to ensure consistent trapping effort. 21 22 Within the patch treatments, there were two site-types: (v) a remnant patch, 23 containing remnant native vegetation that had not been cleared; and (vi) an 24 adjacent revegetated patch, containing native trees and shrubs 8 - 14 years old 6 1 that had been cleared prior to being revegetated (Fig. 2 c). Each treatment set 2 was replicated in five locations (Fig. 2 a) within each of the two regions. We use 3 the term "site" to refer to a site-type within a location and region.