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The Study Progress on the Impact of Atmospheric Nitrogen Deposition on Soil Properties and Herb-layer Diversity inRemnant Forests Along an Urban-rural Gradient in Guangzhou, Southern China

Date: Jul 06, 2012

Atmospheric nitrogen (N) deposition in subtropical metropolitan regions has increased greatly because of rapid urbanization, and such increase could lead to N-related changes in soil properties and plant diversity in remnant forests of urban ecosystems.

PhD candidate HUANG Liujing and her supervisor Dr. REN Hai at South China Botanical Garden, CAS, the pattern of atmospheric N deposition along an urban–rural gradient in metropolitan Guangzhou, southern China, and assessed the potential influence of N deposition on soil properties and understory plant diversity in remnant forests. They found that a steep urban-to-rural N deposition gradient exists in the metropolitan region of Guangzhou in southern China. They suggested that rapid urbanization and the associated high atmospheric N pollution may lead to the reduced herb-layer diversity; (2) the decline in herb-layer diversity appeared to result from N-related changes in soil properties (i.e., decreases in pH and loss of extractable Ca and K) rather than from the competition-based mechanisms typical of forests with more N-efficient dominant species. Increased N deposition results in soil acidification and nutrients leaching that reduce the growth and survival of N-sensitive plants;(3) plant diversity responses to N deposition reflected changes in herb-layer species with particular functional traits, i.e., forbs and ferns are more N-sensitive than tree seedlings and grasses to elevated N deposition. These findings have important implications for the management of remnant forests. A regional policy linking atmospheric pollution and land protection is needed to protect the most N-sensitive herb species (e.g., forbs and ferns) in these remnant forests.

This work has been published in Plant Ecology (Liujing Huang, Weixing Zhu, Hai Ren*, Hongfeng Chen, Jun Wang. Impact of atmospheric nitrogen deposition on soil properties and herb-layer diversity in remnant forests along an urban-rural gradient in Guangzhou, southern China. Plant Ecology. DOI 10.1007s11258-012-0080-y). This study was funded by the ‘Eleventh Five-Year’ National Key Technology Program (2008 BAJ10B03-5) and the Kadoorie Farm and Botanic Garden Corporation, and National Natural Science Foundation of China (40871249, 31100469).


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