Effect of two patterns of forest rehabilitation on soil enzyme activity and its relationship with soil fertility

Abstract

Soil enzyme activity and their seasonal variation-vertical distribution, the relationship between soil enzyme activity and soil fertility were measured on the two different patterns of forest rehabilitation with the methods of fixed sample plots, mechanical sampling and conventional enzyme activity- physicochemical characters determination. The results showed that the ranked order of urease and cellulose activity were Pleioblastus amarus plantation>Betula luminifera plantation>cropland, catalase activity was P. amarus plantation> cropland> B. luminifera plantation. The change of enzyme activity in B. luminifera plantation and P. amarusplantation was more acute than cropland, which showed that different utilization types had a close connection with soil enzyme activity. In the aspect of total amount in different soil layers, invertase, urease, cellulose and catalase activities were P. amarus plantation> B. luminifera plantation>cropland, which showed enzyme activity of slope farmland was improved in two patterns of forest rehabilitation. Rhizosphere effect showed the ratio of rhizospheric soil enzyme activity vs. non-rhizospheric soil enzyme activity (R/S value) of those four soil enzyme activities in B. luminifera plantation and P. amarus plantation were more than 1, which showed the two forests had high rhizosphere effect, and had a certain contribution to increase the soil enzyme activity. The enzyme activity is closely related with the soil fertility for forest rehabilitation and this indicated that enzyme activity could be used to characterize soil fertility, which had positive significance to improve the soil and biological fertility.   Key words: Forest rehabilitation, soil enzyme, rhizosphere effect, soil fertility.