Human disturbance influences occupancy of Altai wapiti in Mongolia

Abstract

We studied the eff ects of thinning on the tree growth and stand characteristics of pine plantations (Pinus sylvestris) in northern Mongolia. The study sites are located in the Tujiin Nars area, where 18-and 20-year-old plantations were thinned in 2016 and 2017, respectively. In each site, three plots in thinned and an unthinned (control) plot were established to examine changes in growth and stand characteristics. Thinning induced an increase of the tree diameter increment, and it was strongly correlated with annual precipitation and year of planting at all sites. The eff ects of thinning on the tree height growth were insignifi cant. Crown morphology diff ered signifi cantly between thinned and unthinned stands; thinning increased crown diameter and crown projection area, but mean crown length and crown form index were higher in unthinned stands.