Water Holding Characteristics of Litters from Five Typesof Public Welfare Forest in Lushui County

The water holding capacity, water holding ratio and water absorption rate of the litters sampled from five types of public welfare forests in Lushui County, Nujiang Prefecture, Yunnan Province were studied through water immersing method to study the water conservation property of the forest types. The results showed that the litter amount accumulated, water holding capacity, water holding ratio and water absorption rate of the litters were different in five types of public welfare forests. Both of the water holding capacity and water holding ratio increased hastily with prolonging the immersing time within 0.5-8.0 h. These two index values increased slowly when the litters were immersed within 8-12 h, and they did not change significantly after 12 h immersion for the water holding capacity of the litters all reached saturated. On the contrary, the water absorption rate of the litters from five types of public welfare forests decreased quickly with prolonging the immersing time duration within 0.5-8.0 h, and then decreased slowly after 8 h of immersion. The relationship between water holding capacity (WH) of the litters from the five types of public welfare forests and the immersion time (t) could be expressed by logarithmic equation. The relationship between water holding ratio (WR) and the immersion time (t) could be modeled by logarithmic equation. The relationship between the water absorption rate (WA) and the immersion time (t) could be expressed by power equation.