%0 Journal Article %A Zhen-Xin LI %A Zhi-Yun OUYANG %A Hua ZHENG %A Xing-Liang LIU %A Yi-Ming SU %T COMPARISON OF RAINFALL REDISTRIBUTION IN TWO ECOSYSTEMS IN MINJIANG UPPER CATCHMENTS, CHINA %D 2006 %R 10.17521/cjpe.2006.0094 %J Chinese Journal of Plant Ecology %P 723-731 %V 30 %N 5 %X

Background and Aims Ecosystems in western Sichuan Province are diverse, and their hydrological functions are important to the ecological stability of the upper drainages of the Yangtse River. It is important to study rainfall redistribution by vegetation in this area to understand the hydrological functions of ecosystems. We studied Abies faxoniana conifer forest and Quercus aquifolioides shrubland in the Dengsheng subalpine dark coniferous forests positioning research station in the upper catchments of Minjiang River, Sichuan. Our objectives were to: 1) determine the magnitude of canopy layer interception, stem flow and water holding capability of ground litter and soil and 2) analyze factors that influence rainfall interception.

Methods We studied rainfall redistribution in the ecosystems from July to September, 2001 and June to August, 2002. We measured total rainfall with one standard and two automatic rain gages, throughfall with eight randomly placed barrel gages (30 cm diameter and 40 cm height) in the forest ecosystem and four in the shrub ecosystem, stem flow of trees in the forest ecosystem but not in the shrub ecosystem, and microclimate in both ecosystems and on open ground outside of the forest. Pearson correlation and partial correlation methods were used to analyze five factors influencing rainfall interception: rainfall volume, rainfall intensity, duration of single rainfall events, time interval between consecutive rainfall events and average air temperature during individual rainfall events.

Key Results In the forest ecosystem, canopy rainfall interception accounted for 33.33% of the total rainfall, stem flow 0.07% and throughfall 66.60%. For the shrubland ecosystem, rainfall interception accounted for 24.95% and throughfall 75.05%. Water holding capability was larger for conifer forest ground litter including lichens (1.746 mm) than for shrubland ground litter (0.941 mm). Bulk moisture content was larger for conifer forest (39.66%) than shrubland (38.19%). The relationship between throughfall percentage and rainfall could be modeled with a logistic equation.

Conclusions Interception in the conifer forest was mainly affected by rainfall volume, duration of rainfall and time interval time between consecutive rainfall events. For the shrubland, interception was mainly affected by rainfall volume, duration of rainfall and temperature. Differences between rainfall redistribution and factors affecting rainfall interception are analyzed and discussed in relation to local rainfall characteristics and microclimate differences between the two ecosystems.

%U https://www.plant-ecology.com/EN/10.17521/cjpe.2006.0094