Natural enemies, climate, and the maintenance of tropical tree diversity

天敌、气候和热带树木多样性的维持

• 批准号: NE/J011169/1
• 负责人: Owen Lewis
• 金额: $ 41.43万
• 依托单位: University of Oxford
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2012
• 资助国家: 英国
• 起止时间: 2012 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FJ011169%2F1
• 关键词: Natural; enemies; climate; maintenance; tropical

At least 50% of earth's plant and animal species is found in tropical rainforests, but this rich biodiversity is under threat from deforestation and climate change. Ecologists are interested in understanding why these habitats are so diverse, and how their diversity will change in the future. One leading explanation for high plant biodiversity in tropical forests is the Janzen-Connell Effect. This theory suggests that pests such as plant-feeding insects and fungal diseases can help maintain tropical biodiversity if (1) they specialise on particular plant species, and (2) they cause 'density-dependent' mortality (i.e., they kill more seeds and seedlings where these are locally abundant). This pest pressure acts as a negative feedback mechanism, putting locally rare plant species at an advantage and preventing any one species from reaching high abundance. Recent research shows that this form of density-dependence from both insects and fungi plays a key role in the maintenance of plant diversity in the tropics. We now want to discover how this process changes under different climatic regimes. Wetter tropical forests have more plant species than drier forest, and we will test the theory that more intense density-dependent pest pressure in these places is a factor behind these differences. We will also investigate whether future changes to the climate (higher or lower rainfall) are likely to alter the strength of the Janzen-Connell Effect, and consequently plant diversity. Our work will take place in Panama, where we will take advantage of a steep gradient in rainfall and soil humidity from the dry (Pacific) coast to the humid (Atlantic) coast to test our hypotheses. We will carry our experiments in the field and in controlled nursery conditions that manipulate the density of seeds and seedlings and the presence of fungal pathogens and plant-feeding insects, and we will analyse long-term data and build mathematical models to explore whether and to what extent climate change will alter tropical plant diversity.

在热带雨林中，至少有50％的地球动植物物种是在热带雨林中发现的，但是这种丰富的生物多样性受到森林砍伐和气候变化的威胁。生态学家有兴趣了解为什么这些栖息地如此多样化，以及它们将来的多样性将如何变化。热带森林中高植物生物多样性的一种主要解释是Janzen-Connell效应。该理论表明，诸如植物喂养昆虫和真菌疾病之类的害虫可以帮助维持热带生物多样性，如果（1）它们专门从事特定的植物物种，并且（2）它们会导致“密度依赖性”死亡率（即，它们在局部丰富的地方杀死更多的种子和种子）。这种害虫压力是一种负反馈机制，使局部稀有的植物物种有优势，并防止任何一种物种达到高丰度。最近的研究表明，这种昆虫和真菌的密度依赖性形式在维持热带地区的植物多样性中起着关键作用。现在，我们想发现在不同气候制度下这一过程如何变化。湿的热带森林比干燥的森林具有更多的植物物种，我们将测试以下理论：这些地方更强烈的密度依赖性害虫压力是这些差异的一个因素。我们还将调查未来对气候的变化（降雨量较高）是否可能会改变Janzen-Connell效应的强度，从而改变种植多样性。我们的工作将在巴拿马举行，我们将利用从干燥（太平洋）海岸到潮湿（大西洋）海岸的降雨和土壤湿度的陡峭梯度，以检验我们的假设。我们将在田间和受控的苗圃条件下进行实验，这些实验操纵种子和幼苗的密度以及真菌病原体和植物喂养昆虫的存在，我们将分析长期数据并构建数学模型，以探索以及在何种程度上以及在何种程度上会改变热带植物的多样性。

项目成果

Plant-soil feedbacks from 30-year family-specific soil cultures: phylogeny, soil chemistry and plant life stage.

• DOI: 10.1002/ece3.1487
• 发表时间: 2015-06
• 期刊: ECOLOGY AND EVOLUTION
• 影响因子: 2.6
• 作者: Mehrabi, Zia;Bell, Thomas;Lewis, Owen T.
• 通讯作者: Lewis, Owen T.

Seed predation by insects across a tropical forest precipitation gradient

• DOI: 10.1111/een.12672
• 发表时间: 2018-09
• 期刊: Ecological Entomology
• 影响因子: 2.2
• 作者: C. Jeffs;P. Kennedy;P. Griffith;Sofia Gripenberg;Lars Markesteijn;O. Lewis

Soil carbon stocks across tropical forests of Panama regulated by base cation effects on fine roots

• DOI: 10.1007/s10533-017-0416-8
• 发表时间: 2018-01-01
• 期刊: BIOGEOCHEMISTRY
• 影响因子: 4
• 作者: Cusack, Daniela F.;Markesteijn, Lars;Turner, Benjamin L.
• 通讯作者: Turner, Benjamin L.

Increased mortality of tropical tree seedlings during the extreme 2015–16 El Niño

2015-16 年极端厄尔尼诺现象期间热带树苗死亡率增加

• DOI: 10.1111/gcb.15809
• 发表时间: 2021
• 期刊: Global Change Biology
• 影响因子: 11.6
• 作者: Browne, Luke;Markesteijn, Lars;Engelbrecht, Bettina M. J.;Jones, F. Andrew;Lewis, Owen T.;Manzané‐Pinzón, Eric;Wright, S. Joseph;Comita, Liza S.
• 通讯作者: Comita, Liza S.

Assessing the potential for indirect interactions between tropical tree species via shared insect seed predators

评估热带树种之间通过共享昆虫种子捕食者间接相互作用的潜力

• DOI: 10.1111/btp.12759
• 发表时间: 2020
• 期刊: Biotropica
• 影响因子: 2.1
• 作者: Downey H