Effects of logging on landscape-level tree diversity across an elevational gradient in Bornean tropical forests
Effects of logging on landscape-level tree diversity across an elevational gradient in Bornean tropical forests
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婆罗洲热带森林中伐木对海拔梯度上景观树木多样性的影响
DOI：
10.1016/j.gecco.2021.e01739
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发表时间：
2021
影响因子：
4
通讯作者：
Kanehiro Kitayama
中科院分区：
文献类型：
--
作者：
Sakiko Yano;Ryota Aoyagi;Shogoro Fujiki; John B. Sugau;Joan T. Pereira;Kanehiro Kitayama
伐木造成了生物多样性和相关生态系统服务的大量损失。因此，研究伐木如何在景观尺度上影响生物多样性，以规划负责任的热带森林管理是很重要的。尽管许多基于图的研究已经表明了伐木对当地树种丰富度（α多样性）的影响，但对沿环境梯度的物种更替（β多样性）的影响在很大程度上仍然未知。在这项研究中，我们评估了测井干扰如何影响婆罗洲Trus Madi山东坡沿海拔梯度的α和β多样性。我们进一步研究了先锋树种和晚演替树种在栖息地范围内的差异，以阐明β多样性格局的机制。我们选择了90个样地，每个样地的半径为20 m，在海拔较低（海拔285-600 m）和较高（海拔600-1105 m）的地区，干扰强度（从高度退化森林到原始森林的5个等级）范围内。剩余地上生物量是过去干扰强度的一个指标，在不同样地之间差异很大（低海拔地区为5.4-570.6 Mg ha−1，高海拔地区为3.1-771.6 Mg ha−1）。胸径大于10 cm的树木均记录胸径和种名。我们计算了每个样地每20棵树的物种数量来表示alpha多样性。β多样性沿海拔梯度计算为标准化成分不相似度（β偏差）与海拔差之间关系的斜率。随着砍伐强度的增加，α多样性在高海拔地区（17.3 ~ 12.3种/ 20棵树）和低海拔地区（16.8 ~ 11.3种/ 20棵树）呈下降趋势。在高度受干扰地区，β多样性沿海拔梯度也下降到几乎为零。先锋树种比晚演替树种海拔范围更广。这些结果表明，优势树种在采伐后从晚演替树种向先锋树种的转变是导致β多样性沿海拔梯度下降的主要原因。我们得出结论，保护和恢复β多样性对维持热带生产林至关重要。
Logging has caused a substantial loss of biodiversity and associated ecosystem services. Therefore, it is important to examine how logging affects biodiversity on a landscape scale to plan responsible management of a tropical forest. Although a number of plot-based studies have shown the effect of logging on local tree species richness (alpha diversity), the effect on species turnover along environmental gradients (beta diversity) remains largely unknown. In this study, we evaluated how logging disturbance affects alpha and beta diversity along an elevational gradient on the eastern slope of Mount Trus Madi in Borneo. We further investigated how pioneer and late-successional tree species differed in the habitat range to clarify the mechanism underlying the beta diversity pattern. We selected 90 plots, each with a radius of 20 m, with a range of disturbance intensity (five classes from highly degraded forests to pristine forests) in lower (285–600 m asl) and higher elevation areas (600–1105 m asl). The remaining above-ground biomass, which is an indicator of past disturbance intensity, strongly varied across the plots (5.4–570.6 and 3.1–771.6 Mg ha−1in lower and higher elevation areas, respectively). Diameter at breast height (DBH) and species name were recorded for all trees with a DBH larger than 10 cm. We calculated the species number per 20 individual trees for each plot to represent alpha diversity. Beta diversity along the elevational gradient was calculated as the slope of the relationship between standardized compositional dissimilarity (beta deviation) and the elevational difference. Alpha diversity decreased in higher (17.3–12.3 species per 20 trees) and lower areas (16.8–11.3 species per 20 trees) with increasing logging intensity. Beta diversity along the elevational gradient also decreased to almost zero in highly disturbed areas. Pioneer tree species had a wider elevational range than late-successional species. These results suggest that the shift in dominant tree species after logging (from late-successional to pioneer species) was the main driver of the decline in beta diversity along the elevational gradient. We conclude that preserving and restoring beta diversity are important to sustain tropical production forests.