Including Tree Diversity In Predictions Of Tropical Forest Drought Responses

将树木多样性纳入热带森林干旱响应的预测中

基本信息

批准号：
NE/N014022/1
负责人：
Lucy Rowland
金额：
$ 65.6万
依托单位：
UNIVERSITY OF EXETER
依托单位国家：
英国
项目类别：
Fellowship
财政年份：
2016
资助国家：
英国
起止时间：
2016 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=NE%2FN014022%2F1
关键词：
Including Tree Diversity Predictions Tropical

项目摘要

Tropical forests are one of the world's most important ecosystems; they are a biodiversity hot spot, store vast quantities of carbon, mitigate climate change, and influence global weather patterns. Predicting how these tropical forests will respond to climate change is a priority for making global policy decisions. Prolonged reductions in soil moisture and acute drought events are predicted to be a key threat to tropical forest in the coming century. The fate of tropical forests if exposed to drought in the future will depend on which types of trees die and which can survive from seedling to adult. Understanding this requires knowledge of which properties trees possess that alter their risk of dying or their survivorship during drought, as well as how these properties change between trees of different types, ages or heights. Currently most vegetation models used to predict the responses of tropical forest responses to future climate change only consider there to be one or two fixed types of tropical tree. They only account for very limited differences in how trees of different canopy heights and positions respond to drought. Therefore these models are currently unlikely to capture the variations in drought responses from real-world diversity in tree properties and which will ultimately determine the resilience of tropical forests to drought stress. Representing the dependency of tropical forest drought responses on the diversity of tree properties in vegetation models is complex. It requires new data on how trees of different functional types and developmental stages respond to prolonged exposure to drought stress. My aim is to collect the data necessary to understand how drought survivorship of tropical trees is related to tree properties and their variation throughout a trees development in drought conditions. I will use this data to develop vegetation models and provide a step change in how they represent tropical forest drought responses. I have the exciting opportunity to use the longest running tropical forest drought experiment in the world, a site where 50% of incoming rainfall has been excluded for the last 15 years. Here I will test if tropical trees at different developmental stages and with different properties respond differently to long-term drought stress and how this influences mortality risk. I will make detailed physiological measurements of properties associated with a trees ability to survive in drought, on important tree taxa of different size classes; these taxa will include species found to be highly sensitive and resistant to drought stress. To accompany this study, seedlings from the focal taxa will be grown in a seedling drought experiment which will be used to test if drought resistance in seedlings increases following prior exposure to drought. Finally seedlings from mother trees which have been exposed to 15 years of experimental drought and seedlings from those which have not been exposed to drought will be grown in lab conditions and subjected to various soil drought conditions. This will test if prior exposure to drought in mother trees induces production of seedling which are more drought-resistant.My research will create the only data-set which is able to test how functional properties, developmental stage and drought exposure control the risk of drought-induced mortality and which types of tree are most likely to survive from seedling to adult to sustain tropical forests under future drought conditions. This will provide a unique opportunity for my model development work, using a hierarchy of models from the scale of a single tree model to a dynamic global vegetation model. My ultimate goal is to represent the important differences in drought responses, based on a trees canopy position and the properties it possesses, to enable more accurate predictions of how tropical forests will respond to future climate change.

热带森林是世界上最重要的生态系统之一；它们是生物多样性热点，储存大量碳，减缓气候变化，并影响全球天气模式。预测这些热带森林将如何应对气候变化是制定全球政策决策的首要任务。预计土壤湿度的长期减少和严重干旱事件将成为下个世纪热带森林的主要威胁。如果未来遭受干旱，热带森林的命运将取决于哪些类型的树木死亡以及哪些类型的树木能够从幼苗到成年存活下来。了解这一点需要了解树木拥有哪些特性会改变它们在干旱期间死亡或存活的风险，以及这些特性在不同类型、年龄或高度的树木之间如何变化。目前，大多数用于预测热带森林对未来气候变化反应的植被模型只考虑存在一两种固定类型的热带树木。它们仅解释了不同树冠高度和位置的树木如何应对干旱的非常有限的差异。因此，这些模型目前不太可能捕捉现实世界树木特性多样性对干旱反应的变化，而这最终将决定热带森林对干旱胁迫的恢复能力。在植被模型中表示热带森林干旱响应对树木特性多样性的依赖性是复杂的。它需要关于不同功能类型和发育阶段的树木如何应对长期干旱胁迫的新数据。我的目的是收集必要的数据，以了解热带树木的干旱生存能力与树木特性及其在干旱条件下树木发育过程中的变化之间的关系。我将使用这些数据来开发植被模型，并在它们代表热带森林干旱反应的方式上提供一步改变。我有一个激动人心的机会使用世界上运行时间最长的热带森林干旱实验，该实验地点在过去 15 年里已经排除了 50% 的降雨量。在这里，我将测试不同发育阶段和具有不同特性的热带树木对长期干旱胁迫的反应是否不同，以及这如何影响死亡风险。我将对不同大小级别的重要树类群，对与树木在干旱中生存的能力相关的特性进行详细的生理测量；这些类群将包括对干旱胁迫高度敏感和抵抗力的物种。为了配合这项研究，来自焦点类群的幼苗将在幼苗干旱实验中生长，该实验将用于测试幼苗的抗旱性在之前经历干旱后是否会增强。最后，来自经历过15年实验性干旱的母树的幼苗和来自未经历过干旱的母树的幼苗将在实验室条件下生长，并经受各种土壤干旱条件。这将测试母树先前暴露于干旱是否会诱导产生更抗旱的幼苗。我的研究将创建唯一的数据集，能够测试功能特性、发育阶段和干旱暴露如何控制干旱风险-引起的死亡率以及哪些类型的树木最有可能从幼苗存活到成年，以在未来的干旱条件下维持热带森林。这将为我的模型开发工作提供一个独特的机会，使用从单树模型规模到动态全球植被模型的模型层次结构。我的最终目标是根据树冠位置及其所拥有的特性来表示干旱反应的重要差异，以便更准确地预测热带森林将如何应对未来的气候变化。

项目成果

期刊论文数量（9）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

New insights into large tropical tree mass and structure from direct harvest and terrestrial lidar.

DOI：
10.1098/rsos.201458
发表时间：
2021-02-10
期刊：
Royal Society open science
影响因子：
3.5
作者：
Burt A;Boni Vicari M;da Costa ACL;Coughlin I;Meir P;Rowland L;Disney M
通讯作者：
Disney M

Differential nutrient limitation and tree height control leaf physiology, supporting niche partitioning in tropical dipterocarp forests

DOI：
10.1111/1365-2435.14094
发表时间：
2022-06-29
期刊：
FUNCTIONAL ECOLOGY
影响因子：
5.2
作者：
Bartholomew, David C.;Banin, Lindsay F.;Rowland, Lucy
通讯作者：
Rowland, Lucy

Appendix from Modelling tropical forest responses to drought and El Niño with a stomatal optimization model based on xylem hydraulics.

附录来自使用基于木质部水力学的气孔优化模型模拟热带森林对干旱和厄尔尼诺现象的反应。

DOI：
10.6084/m9.figshare.7058105
发表时间：
2018
期刊：
影响因子：
0
作者：
Cleiton B. Eller
通讯作者：
Cleiton B. Eller

Divergence of hydraulic traits among tropical forest trees across topographic and vertical environment gradients in Borneo.

DOI：
10.1111/nph.18280
发表时间：
2022-09
期刊：
NEW PHYTOLOGIST
影响因子：
9.4
作者：
Bittencourt, Paulo Roberto de Lima;Bartholomew, David C.;Banin, Lindsay F.;Bin Suis, Mohamed Aminur Faiz;Nilus, Reuben;Burslem, David F. R. P.;Rowland, Lucy
通讯作者：
Rowland, Lucy

Modelling tropical forest responses to drought and El Niño with a stomatal optimization model based on xylem hydraulics.

DOI：
10.1098/rstb.2017.0315
发表时间：
2018-10-08
期刊：
Philosophical transactions of the Royal Society of London. Series B, Biological sciences
影响因子：
0
作者：
Eller CB;Rowland L;Oliveira RS;Bittencourt PRL;Barros FV;da Costa ACL;Meir P;Friend AD;Mencuccini M;Sitch S;Cox P
通讯作者：
Cox P