陕西榆林地区不同人工林下沙蒿种群特征OA

Artemisia desertorum,a native sand-fixing plant of the Mu Us Sandy Land,has become an in-creasing cause of pollen allergy in the Yulin region.This study investigates the potential of plantations to control the spread of allergenic A.desertorum populations.A field inventory was conducted in Mengjiawan and the Sandy Land Forest Park in Yuyang District,Yulin City,Shaanxi Province.60-year Salix psam-mophila plantations,3-year and 20-year Pinus sylvestris var.mongolica plantations,and native A.deserto-rum vegetation were selected to assess the population characteristics of A.desertorum,and to evaluate the effects of plantations on its density,coverage,and individual crown.The results revealed that:(1)S.psam-mophila plantations significantly suppressed A.desertorum,reducing population density and coverage by 59.6%and 56.1%,respectively,compared to native vegetation.(2)The suppressive effect of P.sylvestris plantations varied with stand age.In 3-year stands with low canopy closure(28.0%),the coverage of A.desertorum increased by 58.3%compared with that of the pure A.desertorum population.In contrast,in 2 0-year P.sylvestris stands with 50.1%canopy closure,the crown and coverage of A.desertorum de-creased by 47.8%and 53.6%,respectively.Both plantations can effectively suppress A.desertorum.We recommend maintaining the stability of S.psammophila plantations and implementing canopy closure-and density-based management for P.sylvestris plantations.These findings provide a scientific basis for regula-ting allergenic A.desertorum populations.