Balancing Effect of Larch Plantations (Larix Kaempferi) on Understory Plant Diversity in a Sub-Tropical Forest Ecosystem, China

Abstract

Abstract. We evaluated effects of larch plantations on understory plant diversity by conducting large-area investigations on three types of tree stands, including pure larch plantations (Larix kaempferi, an exotic coniferous deciduous tree species), pure liriodendron plantations (Liriodendron chinense, a native broad-leaved deciduous tree species) and mixed stands (L. kaempferi and L. chinense) in a subtropical forest. A total of 19 plantation areas, 684 quardrats, and 10 environmental factors [elevation, slope, ratio of light availability (RLA), soil pH, soil water content (SWC), soil organic matter (SOM), soil total nitrogen (STN), soil total phosphorus (STP), soil total potassium (STK)] were surveyed. Species richness and Shannon's diversity were statistically similar in the three types of tree stands but Shannon's diversity was somewhat higher in mixed plantations. Environmental conditions were similar in the three types of tree stands (P﹥0.05). Species richness and Shannon's diversity increased with increasing elevation and understory light availability (P<0.05). Canonical Correspondence Analysis (CCA) showed that distribution of shrubs was determined by elevation, while herb distribution was related primarily to soil fertility followed by elevation. Based on the unchanged environmental conditions after establishment of larch plantations, we conclude that larch plantations had balancing effect on understory plant diversity.

Estimating the distribution characters of Larix kaempferi in response to climate change

“…The final prediction results were then imported into ArcGIS ® v. 10.2 software to prepare maps using the "Reclass" tool, and the surface area of the different suitable regions was calculated using the "Raster Reclassify" tool. We employed the contribution rate of environmental variables, the displacement value, and the Jackknife method to assess the importance of environmental variables in delineating the geographic patterns of potential distribution areas for L. kaempferi (Li et al 2016). The contribution rate increased the gain value by gradually correcting the coefficient of a single essential factor, and the gain value was assigned to the environment variable that determined this essential factor.…”

“…The successful introduction and cultivation of plant species depends on the availability of environmental conditions suitable for its growth (Huang et al 1996). In recent years, studies on L. kaempferi forests have been conducted on the physical and chemical properties of soil (Kotani et al 2019), the growth processes and structural fea-tures of stands in different areas (Yoshida et al 2005, Fukatsu & Nakada 2018, the characteristics of the understory plant diversity (Li et al 2016), and the productivity and ecological adaptability (Chen et al 2015). However, the effects of climate change on the distribution of L. kaempferi have not been documented.…”