Impacts of herbivory by ecological replacements on an island ecosystem

作者：Rosemary J. Moorhouse‐Gann, Ian P. Vaughan, Nik C. Cole, Martine Goder, Vikash Tatayah, Carl G. Jones, Daevid Mike, Richard P. Young, Michael W. Bruford, Malin Rivers, Helen Hipperson, Isa‐Rita M. Russo, David W. G. Stanton, William O. C. Symondson · 发表于：Journal of Applied Ecology · 年份：2021 · DOI：10.1111/1365-2664.14096 · 被引用次数：23 · 研究领域：Wildlife Ecology and Conservation、Turtle Biology and Conservation、Amphibian and Reptile Biology

Abstract The use of ecological replacements (analogue species to replace extinct taxa) to restore ecosystem functioning is a promising conservation tool. However, this approach is controversial, in part due to a paucity of data on interactions between analogue species and established taxa in the ecosystem. We conducted ecological surveys, comprehensively DNA barcoded an ecosystem's flora and inferred the diet of the introduced Aldabra giant tortoise, acting as an ecological replacement, to understand how it might have modified island plant communities on a Mauritian islet. Through further dietary analyses, we investigated consequential effects on the threatened endemic Telfair's skink. Dietary overlap between tortoises and skinks was greater than expected by chance. However, there was a negative correlation between tortoise and skink preferences in herbivory and minimal overlap in the plants most frequently consumed by the reptiles. Changes in the plant community associated with 7 years of tortoise grazing were characterised by a decrease in the percentage cover of native herbs and creepers, and an increase in the cover of an invasive herb when compared to areas without tortoises. However, tortoise dietary preferences themselves did not directly drive changes in the plant community. Tortoises successfully dispersed the seeds of an endemic palm, which in time may increase the extent of unique palm‐rich habitat. We found no evidence that tortoises have increased the extent of p...