Past Human Disturbance Effects upon Biodiversity are Greatest in the Canopy; A Case Study on Rainforest Butterflies

PLoS One. 2016 Mar 7;11(3):e0150520. doi: 10.1371/journal.pone.0150520. eCollection 2016.

Abstract

A key part of tropical forest spatial complexity is the vertical stratification of biodiversity, with widely differing communities found in higher rainforest strata compared to terrestrial levels. Despite this, our understanding of how human disturbance may differentially affect biodiversity across vertical strata of tropical forests has been slow to develop. For the first time, how the patterns of current biodiversity vary between three vertical strata within a single forest, subject to three different types of historic anthropogenic disturbance, was directly assessed. In total, 229 species of butterfly were detected, with a total of 5219 individual records. Butterfly species richness, species diversity, abundance and community evenness differed markedly between vertical strata. We show for the first time, for any group of rainforest biodiversity, that different vertical strata within the same rainforest, responded differently in areas with different historic human disturbance. Differences were most notable within the canopy. Regenerating forest following complete clearance had 47% lower canopy species richness than regenerating forest that was once selectively logged, while the reduction in the mid-storey was 33% and at ground level, 30%. These results also show for the first time that even long term regeneration (over the course of 30 years) may be insufficient to erase differences in biodiversity linked to different types of human disturbance. We argue, along with other studies, that ignoring the potential for more pronounced effects of disturbance on canopy fauna, could lead to the underestimation of the effects of habitat disturbance on biodiversity, and thus the overestimation of the conservation value of regenerating forests more generally.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biodiversity*
  • Butterflies*
  • Conservation of Natural Resources
  • Human Activities*
  • Humans
  • Rainforest*

Grants and funding

The Crees Foundation (www.crees-manu.org) and its director Quinn Meyer have supported this research as part of their conservation and biodiversity monitoring programme and the University of Glasgow have supported field work conducted at the Manu Learning Centre. The TJMF Foundation provided crucial support for this work through their Amazon Research Programme grant to the University of Glasgow. The Darwin Initiative provided financial support of the Sustainable Manu project, a collaborative initiative between the Crees Foundation and The University of Glasgow that supported this research. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.