Effects of three silvicultural measures on understory vegetation in Pinus sylvestris var. mongolica plantation

An experiment was conducted to study effects of three silvicultural measures, i.e. enclosure, sanitation cutting and pruning on the basic characteristics, community composition, herb biomass and plant species diversity of understory vegetation in Pinussylves tris var. mongolica plantation.The results indicated that the plant community in understory was highly fragmented; with the increasing of enclosure time, the coverage and biomass of herb community was increased, but the herb species diversity was decreased; transformation of 40-year-old plantation into scattered trees and grasses by sanitation cutting increased the understory coverage, the heights of main species and the herb biomass while significantly decreased the herb species diversity index; pruning showed little impact on herb species diversity.