Species composition characteristics of forest community in the paleo-stone stream of the eastern Liaoning mountainous region

Abstract

To study species composition and structure of a forest community, the type of community member was determined based on community survey data in 26 sampling areas. Then an analysis on species composition and floral elements of the forest community, which grew in the paleo-stone stream of eastern the Liaoning mountainous region, was made. Also, the main characteristics of tree species in three forest types (deciduous broadleaf forest, mixed broadleaf-conifer forest, and dark coniferous forest) were researched. Results showed that (1) vascular plant species of 60 families, 107 genera, and 143 species in the forest community of the paleo-stone stream including 10 families, 12 genera, and 15 species of fern; and 50 families, 95 genera, and 128 species of spermatophyte. Only Rosaceae, Ranunculaceae, and Liliaceae had more than ten species of spermatophyte. The forest community had vascular plants in the tree layer (32 species), in the shrub layer (45 species), and in the herb layer (83 species) with four species in the outer layer. (2) For the main characteristics of tree layer species in a deciduous broadleaf forest, the importance value of Tilia amurensis was 26.31%, Quercus mongolica was 15.71%, Acer mono was 11.27%, Acer pseudo-sieboldianum was 9.37%, Fraxinus mandshurica was 9.08%, and Carpinus cordata was 8.65% with the rest of the tree species' importance values ranging from 0.11% to 2.94%. In the mixed broadleaf-conifer forest, the importance value of Tilia amurensis was 19.71% and Abies nephrolepis was 14.87% with the rest of the tree species' importance values ranging from 0.28% to 7.25%. In the dark coniferous forest, the importance value of Abies nephrolepis was 56.18% with the rest of the tree species' importance values ranging from 0.17% to 8.91%. There was a high number of cosmopolitan species and north temperate species of the paleo-stone stream, and the families of monotypic genera in tree layer, shrub layer, and herb layer were obvious. The constructive species and co-edificato species in the three forest types were also obvious.