Effects of forest plantations on rainfall redistribution and erosion in the red soil region of Southern China

摘要

To evaluate the effects of different forest plantations on rainfall redistribution, we measured throughfall, stemflow, interception loss, surface runoff and soil loss from July 2004 to September 2005 in the three types of forest plantations Eucommia ulmoides, Vernicia fordii and Pinus massoniana. The results showed that differences in throughfall and stemflow between the three forest plantations were significant (p < 0p"05). Throughfall was highest in the V.fordii plantation and stemflow was highest in the E.ulmoides plantation. Throughfall plus stemflow below the E.ulmoides canopy was greater than that underneath the other forest types. Moreover, significant spatial variation in throughfall was observed. Throughfall in P.massoniana was 28p"0-39p"7% higher at a stem distance < 60 cm or 11p"5% lower at a stem distance > 120 cm than in the other forests, but the difference was not significant between E.ulmoides and V.fordii. Moreover, the difference in throughfall at stem distances 60-120 cm was not significant between the different forest plantations. For E.ulmoides, throughfall under the peripheral crown part was 16p"1% higher than that close to the stem. In contrast to E.ulmoides, P.massoniana had 26p"8% lower throughfall under the peripheral crown part than close to the stem. No significant difference was found in throughfall for the various stem distances underneath V.fordii. Stemflow in E.ulmoides was 2-3 times higher than in the other forests (p < 0p"01). Interception loss accounted for 19p"9% of gross rainfall for E.ulmoides, 20p"8% for V.fordii and 27p"2% for P.massoniana. Surface runoff and soil loss differed considerably among the three types of forest plantations. Annual runoff and total soil loss were lowest in the P.massoniana forest and highest in the V.fordii forest. This study indicated that P.massoniana, as a reforestation tree species, had the most positive effect on soil and water conservation among the three forest plantations. Copyright pb 2008 John Wiley & Sons, Ltd.