Effects of Topography on Tree Community Structure in a Deciduous Broad-Leaved Forest in North-Central China
Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden of the Chinese Academy of Sciences, Wuhan 430074, China
The University of Chinese Academy of Sciences, Beijing 100049, China
Research Center for Ecology and Environment of Qinghai-Tibetan Plateau, Tibet University, Lhasa 850000, China
College of Science, Tibet University, Lhasa 850000, China
Shaanxi Meteorological Service Center, Xi’an 710014, China
Foping National Nature Reserve, Foping 723400, China
Author to whom correspondence should be addressed.
Forests 2019, 10(1), 53; https://doi.org/10.3390/f10010053
Received: 30 November 2018 / Revised: 2 January 2019 / Accepted: 8 January 2019 / Published: 11 January 2019
(This article belongs to the Special Issue Impacts of Complex Forest Structures on Tree Regeneration)
Topography strongly influences the compositional structure of tree communities and plays a fundamental role in classifying habitats. Here, data of topography and 16 dominant tree species abundance were collected in a fully mapped 25-ha forest plot in the Qinling Mountains of north-central China. Multivariate regression trees (MRT) were used to categorize the habitats, and habitat associations were examined using the torus-translation test. The relative contributions of topographic and spatial variables to the total community structure were also examined by variation partitioning. The results showed the inconsistency in association of species with habitats across life stages with a few exceptions. Topographic variables [a + b] explained 11% and 19% of total variance at adult and juvenile stage, respectively. In contrast, spatial factors alone [c] explained more variation than topographic factors, revealing strong seed dispersal limitation in species composition in the 25-ha forest plot. Thus, the inconsistent associations of species and habitats coupled with high portion of variation of species composition explained by topographic and spatial factors might suggest that niche process and dispersal limitation had potential influences on species assemblage in the deciduous broad-leaved forest in north-central China.