Three decades of post-logging tree community recovery in naturally regenerating and actively restored dipterocarp forest in Borneo
Three decades of post-logging tree community recovery in naturally regenerating and actively restored dipterocarp forest in Borneo
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DOI：
10.1016/j.foreco.2021.119036
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发表时间：
2021-02-26
影响因子：
3.7
通讯作者：
Dent, Daisy H.
中科院分区：
文献类型：
--
作者：
Hayward, Robin M.;Banin, Lindsay F.;Dent, Daisy H.
选择性采伐影响了大面积的热带森林，人们对如何管理选择性采伐的森林以加强恢复日益感兴趣。然而，与生物量恢复的轨迹相比，伐木和主动恢复（解放采伐和富集种植）对树木群落组成的影响知之甚少。在此，我们评估了选择性采伐和主动恢复生物量恢复对树种多样性、群落组成和森林结构的长期影响。我们在Danum Valley保护区（DVCA， 12块地，总计0.6公顷）的46块未砍伐的原始森林中，以及在普查前23-35年，位于马来西亚婆罗洲沙巴与DVCA相邻的Ulu Segama森林保护区（34块地，总计1.7公顷）的地点，对胸高（DBH）直径bb0 = 2厘米的所有茎干进行了普查。在人口普查前12-24年，在17个被砍伐的森林地块上实施了积极的恢复处理，包括富集种植和攀援砍伐。采伐后的样地基底面积和茎杆密度（5 ~ 10 cm DBH）均低于未采伐后的样地，但幼树（2 ~ 5 cm DBH）和成树（10 cm DBH）的茎密度差异不显著。自采伐以来，在任何大小等级，基片面积和样地水平的茎密度都没有随时间变化，尽管主动恢复的小树和杆状茎密度低于自然更新的采伐林。采伐后树苗物种多样性低于未采伐后树苗物种丰富度和多样性指标均未见明显变化。然而，在所有茎粗等级（PER-MANOVA）中，被采伐森林和未采伐森林的树种组成存在差异，这反映在23个仅存在于未采伐森林的重要指示物种上。PER-MANOVA检验显示，没有证据表明，在任何大小类别中，自采伐或积极恢复处理以来，总体物种组成随时间变化。然而，当比较自然更新林和主动恢复林时，自然更新林鉴定出2种指示物种，主动恢复林鉴定出3种指示物种。总之，我们的研究结果表明，无论采取何种积极的恢复措施，选择性采伐对树木群落组成都有持久的影响，即使在物种丰富度和多样性稳定的情况下，物种组成在采伐后20多年内仍与未采伐的森林不同。积极的恢复工作应该有针对性，监测和改进，以确保森林恢复的多个指标取得积极成果。
Selective logging has affected large areas of tropical forests and there is increasing interest in how to manage selectively logged forests to enhance recovery. However, the impacts of logging and active restoration, by liberation cutting and enrichment planting, on tree community composition are poorly understood compared to trajectories of biomass recovery. Here, we assess the long-term impacts of selective logging and active restoration for biomass recovery on tree species diversity, community composition, and forest structure. We censused all stems >= 2 cm diameter at breast height (DBH) on 46 permanent plots in unlogged, primary forest in the Danum Valley Conservation Area (DVCA; 12 plots, totalling 0.6 ha) and in sites logged 23-35 years prior to the census in the Ulu Segama Forest Reserve adjacent to DVCA (34 plots, totalling 1.7 ha) in Sabah, Malaysian Borneo. Active restoration treatments, including enrichment planting and climber cutting, were implemented on 17 of the logged forest plots 12-24 years prior to the census. Total plot-level basal area and pole (5-10 cm DBH) stem density were lower in logged than unlogged forests, however no difference was found in stem density amongst saplings (2-5 cm DBH) or established trees (>= 10 cm DBH). Neither basal area, nor plot-level stem density varied with time since logging at any size class, although sapling and pole stem densities were lower in actively restored than naturally regenerating logged forest. Sapling species diversity was lower in logged than unlogged forest, however there were no other significant effects of logging on tree species richness or diversity indices. Tree species composition, however, differed between logged and unlogged forests across all stem size classes (PER-MANOVA), reflected by 23 significant indicator species that were only present in unlogged forest. PER-MANOVA tests revealed no evidence that overall species composition changed with time since logging or with active restoration treatments at any size class. However, when naturally regenerating and actively restored communities were compared, two indicator species were identified in naturally regenerating forest and three in actively restored forests. Together our results suggest that selective logging has a lasting effect on tree community composition regardless of active restoration treatments and, even when species richness and diversity are stable, species composition remains distinct from unlogged forest for more than two decades post-harvest. Active restoration efforts should be targeted, monitored, and refined to try to ensure positive outcomes for multiple metrics of forest recovery.