广东白盆珠水库水源林土壤水源涵养能力研究

Study on the soil water conservation capacities of water conservation forest in baipenzhu reservoir of Guangdong Province

通过对广东省白盆珠水库水源林土壤类型调查及土壤水分物理性质的测定,结果表明:库区水源林水平地带性土壤属赤红壤,山地土壤垂直带谱明显,分布有赤红壤、山地红壤、山地黄壤和山顶灌丛草甸土4个类型。土壤容重约为1.338g·cm-3,随海拔升高土壤砂粒含量增加。土壤总孔隙度在45%～50%,非毛管孔隙度在5%～9%之间,毛管孔隙度35%～50%。不同森林类型土壤的最大持水量在30%～50%,即50～60mm,变化不大;蓄水容量有较大区别,范围在500～850t·hm-2,灌丛草甸土最大,针阔混交林次之,沟谷阔叶林最小;排水能力约在130～180t·hm-2,并以灌丛草甸土为最大,次生阔叶林为最小。该库区水源林土壤的排水和蓄水容量分别为62.69万t、316.29万t,消洪补枯能力明显。但水源林土壤非毛管孔隙度较小,蓄水量小于广东各种有林地森林类型平均蓄水量,所以该库区的水源林还需加强保育,以提升土壤的水源涵养能力。

The main soil types and soil water physical properties of water conservation forest were studied in the paper, in Baipenzhu Reservoir of Guangdong Province.Results showed that the soil types of horizontal zonality were lateritic red soil. there are 4 soil types including lateritic red soil mountainous red soil, mountainous yellow soil and mountainous shrub meadow soil in vertical zonality. The vertical sequence of mountain soil types is very distinctness.The bulk weight was about 1.338 g.cm^-3. Contents of sand particles increased with altitude. Total porosities, non-capillary porosity and capillary porosity of the soil were 45%-50%,5% -9% and 35%-50% respectively. And non-capillary porosity was lower than capillary porosity. Under the different vegetation types, maximum water holding capability of soil were 30% -50%（be equivalent to 50-60 mm precipitation）. Storage water capacity were 500-850 t.hm^-2（be equivalent to 50-85 mm precipitation）, that of shrub meadow soil was the highest and mixed needleleaf broadleaf forest was second and gully broad leaved forest was the smallest. Drainage capacity was about 130- 180 t.hm^-2 with that of shrub meadow soil was the highest and secondary broadleaved forest was the smallest. In Baipenzhu Reservoir of Guangdong Province, Drainage and Storage water capacities of the total forest areas were 62.69 and 316.29 ten thousand tons respectively. The effects and capabilities of dispel flood and compensate scanty of forest were very remarkable. Nevertheless, compared with the same forest types, the non-capillary porosity of water conservation forest in Baipenzhu Reservoir was relatively small than that of tropical and subtropical forests. The storage water capacities was smaller than that of the averages of forest types in Guangdong Province. Therefore, it is necessary to strengthen the conservation of water conservation forest and improvement the water conservation capacities of soil in Baipenzhu Reservoir.