Variations in Species and Functional Plant Diversity among Forest Types on the Ridge of the Baekdudaegan Mountains, South Korea

This study was conducted to compare species and functional diversity of terrestrial plants among forest types by analyzing the variations in species and functional trait compositions in a large-scale natural forest ecosystem. Plant data were collected at 1,100 plots and a total of 802 plant species from 97 families and 342 genera were found along the ridge of the Baekdudaegan Mountains in South Korea. Forest types were divided into four categories including Quercus mongolica, Pinus densiflora, other deciduous and other coniferous forest types. To analyze the variations in plant diversity among forest types, we used two species diversity indices such as species richness and the Shannon-Weaver index as well as a newly introduced functional diversity such as Rao’s index. In functional trait composition, megaphanerophyte, geophyte and hemicryptophyte were the dominant traits, whereas the relative proportion of helophyte and hydrophyte and epiphyte indicated less than 1%. In diversity patterns among forest types, species richness and diversity for total plants showed the lowest value in P. densiflora forest type, while other deciduous and Q. mongolica forest types had the highest values of species richness and diversity for woody and herbaceous plants, respectively. However, functional diversity did not depict a clear distinction among four forest types for plant groups. This study suggests that although taxonomical richness and diversity may be different among forest types, there may be no differences in functional diversity. Moreover, these indistinct patterns in functional diversity may be a result of disturbance and successional gradients compounded in a forest type in addition to the type of functional traits used for comparison and contrast among forest types. Therefore, a further study with various functional traits and different environmental gradients should be consistently evaluated to achieve a better understanding of the diversity patterns of plant communities in mountain ecosystems.