Variation of the biotic neighbourhood and topographic effects on tree survival in an old‐growth temperate forest

Abstract

Aims Tree mortality can determine forest dynamics and succession, alter nutrient cycling and contribute to tree species co‐existence. Understanding the mechanisms that maintain species diversity is a central goal of community ecology. In this study, we incorporated survival data from a 10‐yr interval census to determine whether there is significant interspecies variation in the effects of biotic neighbourhood variables and whether there is significant spatial variation in the effects of topographic variables on tree survival in a broadleaved‐Korean pine temperate forest. Location Temperate forest, northeast China. Methods We used GLMM and geographically weighted GLM as well as their corresponding test approaches to determine whether there is significant interspecies variation in the effects of biotic neighbourhood variables over variable neighbourhood radii and whether there is significant spatial variation in the effects of topographic variables on tree survival across multiple spatial scales in an old‐growth temperate forest dynamics plot in northeast China. Results Our results showed that the effects of neighbourhood variables on tree survival varied among species and effects of topography varied over space. However, the results depended on the neighbourhood radius and spatial scale. The neighbourhood radius affected detection of variation in neighbourhood effects among species, and the spatial scale similarly affected detection of spatial variation in the effects of topography. The effect of conspecific neighbour density on survival varied more widely among species than that of the average phylogenetic dissimilarity of heterospecific neighbours, regardless of the neighbourhood radius. Moreover, the effect of elevation varied more widely over space than those of convexity and hill shade at any quadrat scale. Conclusions Our findings highlight that future studies should account for variations in the neighbourhood radius among species and/or circumstances as well as the spatial scale when assessing factors that contribute to species co‐existence in long‐lived organisms. Species leaf phenology, shade and drought tolerance and environmental filtering may explain these variations in the effects of neighbourhood and topographic variables on tree survival. Overall, our results indicate that both density dependence and resource niche partitioning are important mechanisms for maintaining biodiversity in this broad‐leaved Korean pine temperate forest.

Habitat Filtering Covers the Strength of Density Dependence and Functional Density Dependence on Seedling Survival in Cangshan Mountain, Southwest China

“…In our study, seedling height was positively associated with individual survival in plot C, which was consistent with previous findings [6,28,29]. Larger individuals are less sensitive to biological stress, as their greater height can allow them to gain more light resources and protect against damage by pathogens and herbivorous insects [12,53]. However, seedling height had insignificant positive effects in plots A and B. Oshima et al [54] reported different responses to seedling height among species of Dipterocarpus and Shorea.…”

The scale dependency of trait‐based tree neighborhood models

“…Thus, it is likely that the link between heterospecific neighborhood density and tree growth might not be sensitive to the variation in neighborhood radius in the Luquillo forest. Furthermore, we were not able to capture the effects of conspecific density on tree survival and growth at 5m, as previously reported (Zhu et al 2017), and the strength of the effect did not change for larger neighborhood radii. This could be because the 5m radius neighborhood was so narrow that the probability of encountering a conspecific neighbor was very small, especially for neighbor trees > 10 cm DBH.…”

Individual‐level leaf trait variation and correlation across biological and spatial scales

“…The climate is temperate continental monsoon with most rainfall in summer. The mean annual temperature is −0.3°C, and the mean annual precipitation is 676 mm (Piao et al., 2013; Zhu et al., 2017). The mixed broad‐leaved Korean pine ( Pinus koraiensis ) forest is the most common vegetation type in Northeast China, and the Liangshui Reserve has a large area of these primary and undisturbed forests.…”