Regeneration of Betula albosinensis in Strip Clearcut and Uncut Forests of the Qinling Mountains in China

Yaoxin Guo,Gaihe Yang,Di Kang,Gang Li,Dexiang Wang,Youning Hu,Ben Bond-Lamberty

doi:10.1371/journal.pone.0059375

Abstract

To contribute to a better understanding of the regeneration strategy of Betula albosinensis forests and the likely reasons behind either the successful recovery or failure after strip clearcutting, we compared the population structures and spatial patterns of B. albosinensis in eight B. albosinensis stands in Qinling Mountains, China. Four cut and four uncut stands were selected, and each sampled using a single large plot (0.25 ha). Results indicated that, on the one hand, B. albosinensis recruitment was scarce (average of 48 stems ha−1) in the uncut stands, relative to the mature population (average of 259 stems ha−1), suggesting a failure of recruitment. On the other hand, the subsequent regeneration approximately 50 years after the strip clearcutting showed that the density of the target species seedlings and saplings has increased significantly, and the current average density of seedlings and saplings was 156 stems ha−1. The clumped spatial pattern of B. albosinensis suggested that their regeneration was highly dependent on canopy disturbance. However, recruitment remained poor in the uncut stands because most gaps were small in scale. The successful regeneration of sunlight-loving B. albosinensis after strip clearcutting was attributed to the exposed land and availability of more sunlight. Bamboo density did not influence B. albosinensis recruitment in the uncut stands. However, stand regeneration was impeded after strip clearcutting; thus, removing bamboo is essential in improving the competitive status of B. albosinensis at the later stage of forest regeneration after clearcutting. The moderate severity of disturbance resulting from strip clearcutting reversed the degeneration trend of primary B. albosinensis stands. This outcome can help strike a balance between forest conservation and the demand for wood products by releasing space and exposing the forested land for recruitment. Life history traits and spatiotemporal disturbance magnitude are important factors to consider in implementing effective B. albosinensis regeneration strategies.

Highlights

IntroductionA deciduous hardwood, is a tree species endemic to China, distributed in the mid-high mountains of warm temperate regions
Betula albosinensis, a deciduous hardwood, is a tree species endemic to China, distributed in the mid-high mountains of warm temperate regions
Densities ranged from 244 stems ha21 to 276 stems ha21 in the uncut stands, whereas B. albosinensis were more abundant and had an approximate twofold increase in the cut stands

Summary

Introduction

A deciduous hardwood, is a tree species endemic to China, distributed in the mid-high mountains of warm temperate regions. As one of the most important species in the Qinling Mountains, B. albosinensis thrives over a wide elevation range of 1950 m to 2750 m [1,2]. No direct study has reported on the regeneration of B. albosinensis trees in forests where they dominate after natural disturbance or artificial management treatments. This type of ecological knowledge is essential in implementing conservation strategies and ensuring the sustainable utilization of forests [8,9]. Disturbances play an important role in the regeneration dynamics of many mature hardwood forests [8–

Methods

Results

Conclusion