Factors promoting the natural regeneration of Larix principis-rupprechtii plantation in the Lvliang Mountains of central China.

Wenjun Liang,Xi Wei

doi:10.7717/peerj.9339

Abstract

Given their complexity, targeted care and management of different areas and tree species are necessary for enhancing the natural regeneration of forests. Thus, an understanding of changes in the overstory and understory is essential for ensuring successful regeneration. Promoting the natural regeneration of Larix principis-rupprechtii plantations is considered challenging; indeed, regional sustainable development through natural regeneration of many stands has often been considered unattainable. Here, we studied several plots with varying extents of regeneration to identify the most important factors that affect regeneration. The plots were divided into three forest types based on the number of regenerating plants. For each type of plot, we measured various factors that might potentially affect regeneration. Representational difference analysis was used to identify the most important factors >9% contribution). Based on these factors, multiple corrections were made to construct a structural equation model of topography, stand structure, soil properties and litter to identify the most important factors driving variation in regeneration. Positive correlations were detected between regeneration with diameter at breast height (0.21) and litter thickness (0.57). Regeneration was negatively correlated with soil (−0.54) and slope (−0.48). Additionally, the number of regenerating plants and the height of regenerating plants were strongly positively correlated. However, there was no significant relationship between regeneration and litter accumulation, stand density, altitude, average tree height, total P and total N. Overall, our study showed that key factors for promoting natural regeneration include appropriate litter thickness, strong parent trees, a gentle slope and sufficient quantities of soil nutrients. Moreover, our findings provide a reference for the design of effective management and restoration plans.

Highlights

Forest regeneration provides the generation of overstory trees, which occupy an important position in forest ecosystems (Abe et al, 2008), and is considered one of the most vital processes in the replacement of old trees with young ones
redundancy analysis (RDA) can be used to distinguish the relative contribution of each soil nutrient, stand structure, litter and topographical variable on regeneration, and to assess the correlations between variables and multivariable data, by determining the best predictor of vegetation regeneration based on statistical theory
A comprehensive understanding of how environmental factors affect tree seedlings is necessary for ensuring the success of the natural regeneration of plantations

Summary

Introduction

Forest regeneration provides the generation of overstory trees, which occupy an important position in forest ecosystems (Abe et al, 2008), and is considered one of the most vital processes in the replacement of old trees with young ones How to cite this article Liang W, Wei X. Factors promoting the natural regeneration of Larix principis-rupprechtii plantation in the Lvliang Mountains of central China. Natural regeneration ensures the spatial and temporal continuity of forest cover and the stability of the ecological and social benefits provided by forest ecosystems (Puhlick, Laughlin & Moore, 2012; Chen & Cao, 2014). Natural regeneration provides many advantages relative to artificial regeneration: namely lower costs, superior adaptation to microhabitats, and higher seedling densities (Kolo, Ankerst & Knoke, 2017)

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Conclusion