, the #1 open access web portal for PhD theses...

Why PhD theses...

PhD thesis is the result of years of hard work.

keyword researchMeasured by download count PhD theses are one of the most popular items world wide on open access repositories. But unless a thesis is published, it is very difficult for other researchers to find out about it and get access to it. Theses are often under-used by other researchers. attempts to address this issue by making it easy to identify and locate copies of many theses in various disciplines.

Insect diversity patterns along environmental gradients in the temperate forests of northern China

Insect diversity patterns along environmental gradients in the temperate forests of northern China
Yi Zou


Department of Geography, University College London, London, UNITED KINGDOM.


Insects, which represent the most species-rich taxa, are extremely important ecosystem components. The diversity patterns of insects have, however, been widely ignored in biodiversity research. In my thesis, I aim to establish a basic understanding of the diversity patterns of insect assemblages in the temperate forest and forest plantation ecosystems of Northern China, and to investigate how these patterns correlate with vegetation and environmental conditions. The study aims to give further insights into the insect diversity status and measures to conserve or even enhance their diversity in the large secondary and plantation forests which have been and are currently established throughout northern China.

The study focuses on two distinct insect taxa: ground beetles (Coleoptera: Carabidae) and geometrid moths (Lepidoptera: Geometridae). In the main study area located within the Changbaishan Natural Reserve (CNR) in Jilin Province, 4844 individuals (47 species) of ground beetle and 9285 individuals (155 species) of geometrid moth were sampled. In addition, 1488 ground beetles (24 species) and 2047 geometrid moths (165 species) were sampled in the secondary and plantation forest area at Dongling Mountain (DLM) in Beijing.

A first important result of this work is that the α-diversity of both ground beetle and geometrid moth assemblages decreased significantly with increasing elevation at CNR. My results also show that the relationships between phyto-diversity and the diversity of insects are weak and furthermore likely to be driven by underlying environmental factors. The significant changes which have recently occurred in the plant species composition at CNR chiefly related to changes in the climatic conditions suggest that insect species are also under high pressure in this area. Finally, this study suggests that in the temperate religions of Northern China, secondary and plantation forests can potentially harbour high levels of insect α-diversity compared with mature, more pristine forests.