The impact of liana proliferation on recovery of biomass in secondary tropical forests

藤本植物增殖对热带次生林生物量恢复的影响

• 批准号: 2115559
• 金额: --
• 依托单位: University of Stirling
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2018
• 资助国家: 英国
• 起止时间: 2018 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2115559
• 关键词: impact; liana; proliferation; recovery; biomass

The world's tropical forests are essential carbon sinks and home to the majority of terrestrial biodiversity. Over half of the world's remaining forests are categorised as degraded or secondary forests and deforestation continues; between 1990 and 2015 there was a net loss of 129 million ha of forest, with the largest forest losses occurring in the tropics [1]. The rate of deforestation and timber extraction in Southeast Asia exceeds that of most other tropical regions [2,3]. Timber exports from Borneo alone surpass those from all of tropical Africa and Latin America combined [4]. The majority of the remaining undisturbed forest in Southeast Asia is classified as production forest [5] and therefore is open to selective logging.In dipterocarp forests of Southeast Asia virtually all large trees have high timber value with direct implications for the impacts of selective logging. On the first logging rotation typically all marketable stems are removed, leaving only small stems and less desirable timber species. After the first logging rotation, the forest may be logged again, frequently less than 20 years later [6]. This process leaves behind a highly degraded forest with altered structure and composition; logged forests tend to have low, open canopies, high liana densities and reduced abundance of late-successional tree species [7].It is widely accepted that selectively logged forests have greater conservation value than other degraded forest habitats [7]. A recent review indicated that selectively logged forests typically retain most of their biodiversity and associated ecosystem functions [8].However, most studies have investigated the diversity and composition of animal species not trees, which may be more severely impacted by direct extraction and physical damage than the animal species that depend on them. In addition, selective logging may have, as yet unseen, impacts on tree regeneration that limits the sustainability of these forests in the long term. First, removal of high value timber trees reduces potential seed sources limiting seedling recruitment of high-wood density species and potentially shifting future composition of adult trees in the long term [9]. Second, physical damage to the residual forest stand and changes in forest structure post-logging can result in the proliferation of lianas. Recent studies have shown that liana abundance can significantly impact forest dynamics and aboveground biomass [AGB; 10,11]. However no studies have investigated how selective logging may impact future forest composition, and the role that lianas play in shaping the forest communities that regenerate after selective logging.This project aims to investigate1. The mechanisms that determine recruitment into the tree community in selectively logged compared to undisturbed forests2. The role of lianas in shaping community dynamics 3. The long-term sustainability of logged forests in Southeast Asia.

世界热带森林是重要的碳汇，是大多数陆地生物多样性的家园。世界上一半以上的剩余森林被归类为退化或次生林，森林砍伐仍在继续; 1990年至2015年期间，森林净损失1.29亿公顷，热带地区的森林损失最大。东南亚的森林砍伐和木材开采速度超过了大多数其他热带地区[2，3]。仅婆罗洲的木材出口就超过了热带非洲和拉丁美洲的总和[4]。东南亚大部分未受干扰的森林被归类为生产林[5]，因此可以选择性采伐。在东南亚的龙脑香林中，几乎所有的大树都具有很高的木材价值，这直接影响了选择性采伐的影响。在第一轮采伐时，通常所有可销售的树干都被清除，只留下小树干和不太理想的木材品种。在第一轮采伐后，森林可能会再次采伐，通常不到20年后[6]。这一过程留下了结构和组成发生变化的高度退化的森林;采伐的森林往往具有低而开放的树冠，高藤本植物密度和后期演替树种的丰度减少[7]。人们普遍认为，选择性采伐的森林比其他退化的森林栖息地具有更大的保护价值[7]。最近的一项审查表明，选择性采伐的森林通常保留了大部分生物多样性和相关的生态系统功能[8]。然而，大多数研究都调查了动物物种的多样性和组成，而不是树木，树木可能比依赖它们的动物物种受到更严重的直接提取和物理损害的影响。此外，选择性采伐可能对树木再生产生尚未看到的影响，从而限制这些森林的长期可持续性。首先，高价值用材树的移除减少了潜在的种子来源，限制了高木材密度物种的幼苗补充，并可能长期改变成年树木的未来组成[9]。其次，采伐后对残留林分的物理破坏和森林结构的变化可导致藤本植物的增殖。最近的研究表明，藤本植物的丰富程度可以显着影响森林动态和地上生物量[AGB; 10，11]。然而，还没有研究调查选择性采伐如何影响未来的森林组成，以及藤本植物在塑造选择性采伐后再生的森林群落中所起的作用。机制，确定招聘到树木社区选择性采伐相比，不受干扰的forests 2。藤本植物在塑造群落动态中的作用3。东南亚被砍伐森林的长期可持续性。