Corridor quality affects net movement, size of dispersers, and population growth in experimental microcosms

Dongbo Li,Jane Memmott,Isobel L G Shan,Christopher F Clements

doi:10.1007/s00442-020-04834-2

Abstract

Corridors are expected to increase species dispersal in fragmented habitats. However, it remains unclear how the quality of corridors influences the dispersal process, and how it interacts with corridor length and width. Here we investigate these factors using a small-scale laboratory system where we track the dispersal of the model organism Collembola Folsomia candida. Using this system, we study the effects of corridor length, width, and quality on the probability of dispersal, net movement, body size of dispersers, and the rate of change in population size after colonization. We show that corridor quality positively affected dispersal probability, net movement, and the rate of change in population size in colonised patches. Moreover, corridor quality significantly affected the size of dispersers, with only larger individuals dispersing through poor quality corridors. The length and width of corridors affected both the rate at which populations increased in colonised patches and the net number of individuals which dispersed, suggesting that these physical properties may be important in maintaining the flow of individuals in space. Our results thus suggest that corridor quality can have an important role in determining not only the probability of dispersal occurs but also the phenotypes of the individuals which disperse, with concomitant effects on the net movement of individuals and the rate of change in population size in the colonised patches.

Highlights

Corridors in fragmented landscapes have been regarded as one of the key approaches for mitigating the negative effects of habitat fragmentation
Corridor length had a negative effect on the probability of dispersal, whilst the width did not influence the probability of dispersal (Table 1)
Corridor length and width had no effect on the body size of first dispersers (Table 2), there was a significant interaction between corridor width and quality (Table 2), as the body size of first dispersers in narrow and poor corridor treatments were significantly larger than those in narrow and good corridors

Summary

Introduction

Corridors in fragmented landscapes have been regarded as one of the key approaches for mitigating the negative effects of habitat fragmentation. It has been shown that wildlife corridors promote the dispersal of plants and animals (Gilbert-Norton et al 2010), rescue populations from extinction (Rantalainen et al 2006), and maintain species richness at both small (Gilbert et al 1998) and large scales (Damschen et al 2006).

Methods

Results

Conclusion