دانلود رایگان مقاله عملکرد دالان حیات وحش با اطلاعات ژنتیکی از گوزن های کوچک

Abstract

Traffic infrastructure such as fenced motorways may reduce functional connectivity by impeding the movement of wildlife and thus reduce gene flow across landscapes. This may result in increased genetic differentiation, eventually leading to decreasing genetic diversity in wildlife populations owing to genetic drift. Landscape managers and conservation agencies apply a range of measures to mitigate such adverse effects in intensively managed landscapes. Efficient measures to facilitate landscape permeability for wildlife include expert-assessed wildlife corridors. However, whether wildlife corridors are used as such and whether they fulfill their purpose remains largely unknown. Here, we evaluated whether the expert-based categorization of wildlife corridors into functional, impaired and interrupted held true in the Swiss Plateau by testing the landscape’s permeability using genetic assessments. We identified the spatial genetic structure of roe deer (Capreolus capreolus) and tested, whether the estimated gene flow supported the expert categorization of wildlife corridors. Among the four study regions (ca. 300–2600 km2), pairwise genetic differentiation was rather low (FST ranging between 0.008 and 0.0264). However, wildlife corridors identified as intact on the basis of expert evaluation showed higher gene flow between populations of roe deer (mean FST = 0.008) than corridors classified as impaired or interrupted (mean FST = 0.022). Thus, expert judgement on the functionality of wildlife corridors could be generally confirmed by our genetic assessment on the permeability of landscapes for roe deer. This shows that genetic methods may constitute a useful set of tools to identify the state of management measures and to prioritize action plans for maintaining functional wildlife corridors across landscapes.

Discussion

Wildlife corridors connect wildlife populations on the landscape, but need to be tested for their effectiveness. We evaluated such corridors, as identified by experts of hunting administrations, game keepers and wildlife biologists, regarding their functionality by relying on the genetic data of 1102 roe deer individuals in the four study regions of the Swiss Plateau. Results show that corridors identified as intact were confirmed by a higher degree of gene flow than corridors classified as impaired or interrupted which exhibited higher genetic differentiation (Table 2). Out of the five wildlife corridors classified as interrupted, four showed statistically significant FST values between groups at each corridor end (Table 2). Two corridors categorized asimpaired (2) or interrupted (8) did not exhibit statistically signifi- cant genetic differentiation between groups. Corridor 2 was located between Winterthur ZH and Rickenbach ZH, crossing motorways A1 (Fig. 2A); corridor 8 was located in the vicinity of Zofingen (AG), crossing motorway A2 (Fig. 2D). Potential reasons for this outcome may be found in the local landscape context. Both corridors were located within quite densely populated areas with likely more options to cross the motorway if a regular road with limited traffic may be viewed as likely underpass or bridge. Such a landscape context may make the presumed barriers more permeable to gene flow in roe deer. This demonstrated the importance of landscapescale assessments to understand the local permeability of a landscape for a particular organism instead ofsolely focusing on the assumed obstacle (e.g., motorway).