Impacts of climate warming on range shifts with emphasis on tropical mountains

Climate warming induced range shifts are evident globally for a wide range of taxonomic groups. However, whether such responses have taken place in tropical insect species is unclear. I provided the first such evidence that tropical insects have moved uphill over four decades of climate warming. I repeated a historical moth transect on Mount Kinabalu in Borneo in 2007, 42-years after the original survey in 1965. I duplicated the 1965 sampling strategy in 2007, and excluded sites where habitat changes were evident. I estimated that the average elevation of 102 montane moth species, in the family Geometridae, increased by a mean of 67 m. A sub-group of species retreated their upper boundaries, which may be associated with cloud cover changes and the presence of geological / vegetation transitions. Without these constraints, most species expanded their upper boundaries upwards (by an average of 152 m) more than they retreated at their lower boundaries (77 m), indicating that different ecological mechanisms may predominate in leading and trailing edge populations. Declines of local endemic species, ecological barriers constraining uphill movements, disappearing climate types and a decreasing area of land at higher elevations are the major concerns for conservation. Research of biodiversity risk under warming is urgently required in Southeast Asia. I conducted a meta-analysis of range shifts representing ~1700 species worldwide. The average rate of elevational range shift was 12.2 m/decade uphill, and latitudinal shifts averaged 17.6 km/decade poleward. These rates are faster than previously reported. Latitudinal range shifts responded to the rates of regional warming, but these were not the cases for elevational range shifts. Poikilotherms shifted their distributions faster than homeotherms. The original data and meta-analysis presented in this thesis indicate that climate change is having a pervasive impact on the distributions of species, including in the tropics.

Name dc:type.qualificationname

Ph.D

Level dc:type.qualificationlevel

doctoral

Grantor dc:publisher.institution

University of York

Year dc:date.issued

2011

Author dc:creator

• Chen, I Ching

Advisor dc:contributor.advisor

• Thomas, Chris

Identifier

uk.bl.ethos.533495

OAI identifier oai:identifier

oai:etheses.whiterose.ac.uk:1256