Dominant Species Composition, Environmental Characteristics and Dynamics of Forests with Picea jezoensis Trees in Northeast China

To describe the characteristics and dynamics of the Picea jezoensis (PJ) community, a survey of 48 forest plots containing PJ trees was conducted in Northeast China. Methods of community grouping, analysis of variance, and linear regression, and indicators of relative basal area (RBA, reflecting the dominance degree of species in the community) and temporary stability (TS, reflecting the stability of forest plant community), were employed. The objectives were to describe the dominant species composition and environment of the PJ community and to quantify the changes in PJ’s dominance status. Communities with PJ trees were divided into four groups: PJ as the first dominant species; PJ as the second dominant species; PJ being co-dominant but ranked third or lower; and PJ as a non-dominant species. Among them, the PJ community (i.e., where PJ is the first dominant species) occupied sites at the highest elevation with a mean value of 1408 m, on gentle slopes ≤ 10°, where the tree species occurring with PJ mainly included Betula costata and Abies nephrolepis. A linear relationship was found between the TS and RBA. The threshold for PJ shifting between being the first and second dominant species in the community was RBA = 0.387. This study provides a scientific basis for judging the attributes and status of PJ community and the protection and restoration of PJ forests. These findings also provide comparable information for ecological research and conservation of PJ forests in other areas.