The effects of litter quantity and quality on soil nutrients and litter invertebrates in two contrasting forests of southwestern China

• Main Author: Lu, Jessica Ming Chieh
• Language: English
• Published: University of British Columbia 2013
• Online Access: http://hdl.handle.net/2429/44926

Yunnan Province in southwestern China is a highly biodiverse region in the world, yet a large part of the forests are cut down every year to accommodate plantations of rubber, tea and eucalyptus. Within the small areas of protected habitats, recent observations indicate that there is a lack of regeneration of seedlings. One possible explanation for this lack of regeneration could be due to litter dynamics. We designed and carried out a short term litter decomposition experiment to test the direct effects of litter manipulations on soil nutrients and litter invertebrates in a lowland and a montane tropical forest. Our experimental design involved testing both litter quantity and litter quality. To test for the effects of litter quantity, we manipulated different depths of mixed litter, with and without periodic topping up. To test for the effects of litter quality, we compared single species of litter versus mixed litter control plots. The response of soil nutrients to these manipulations were monitored using ion exchange membranes. We show a clear difference in the available soil nutrients between the two sites, and while the litter quantity experiment had an effect on soil nutrients at the lowland site, it had no effect at the montane site. The litter quality treatments produced no overall difference in responses at either site. The response of litter invertebrates to litter manipulations was estimated using pitfall traps. We show that, litter invertebrate composition between the two forests is different. Invertebrate abundance does increase with increasing biomass at the montane site, although there seems to be a threshold of litter volume beyond which there is an effect. In the lowland site, invertebrate abundance is highest in the litter removal plots, although a general increase with litter biomass was detected. Litter species does not have an effect on either invertebrate abundance or richness at either site. === Science, Faculty of === Botany, Department of === Graduate