Comparing the Water-holding Characteristics of Broadleaved, Coniferous, and Mixed Forest Litter Layers in a Karst Region

摘要

Karst forests are often located in mountainous regions, and because of various geological factors both soil and water loss are major conservation concerns. We investigated the water-holding characteristics of 3 typical karst forest types through field sampling and laboratory experiments. The results showed that (1) the total litter mass of the coniferous forest was significantly higher than that of either the mixed forest or the broadleaved forest; (2) the mass of semidecomposed litter was significantly higher than that of undecomposed litter; (3) the litter layers of the mixed and coniferous forests had similar maximum water-holding capacity, whereas the maximum water-holding capacity of the broadleaved forest was significantly lower; (4) the maximum water-retention capacity of both the mixed and coniferous forests was significantly higher than that of the broadleaved forest; and (5) water-absorption rate and maximum water-holding capacity varied significantly across forest and litter types, with the mixed forest and undecomposed litter layers tending both to hold more water and to absorb water more quickly than the other forest types or the semidecomposed litter layer. Because of the elevated water-holding capacity and absorption rate of the mixed forest in karst regions, special emphasis on the conservation of this complex forest ecosystem is critical from both hydrological and ecological perspectives.