Field theoretic techniques for macroecology and community assembly

宏观生态学和群落组装的场论技术

• 批准号: EP/G051402/1
• 负责人: James ODwyer
• 金额: $ 27.84万
• 依托单位: University of Leeds
• 依托单位国家: 英国
• 项目类别: Fellowship
• 财政年份: 2010
• 资助国家: 英国
• 起止时间: 2010 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FG051402%2F1
• 关键词: Field; theoretic; techniques; macroecology; community

Our world is undergoing rapid changes due to human activity. My research has the overarching goals of understanding how these changes will impact ecological communities, and how we may mitigate their effects. To achieve these goals, I will further develop our theoretical understanding of how ecological communities work, and the primary outcome of this project will be to derive and test new predictions for the way biodiversity is structured across different spatial scales. Given the tremendous complexity of a typical ecological community, it is impossible to include every single detail in any tractable analysis. One therefore has to come up with a strategy for keeping only the most pertinent information, so that we may throw away the details that don't matter but still make accurate predictions. Stephen Hubbell's Neutral Theory is the canonical example of this kind of parsimonious strategy, and it makes surprisingly successful ecological predictions while having very few adjustable parameters. One key output is known as the species abundance distribution, which tells us on average how many species we should expect to find with any given population size in an ecological community. However, there are three important spatial patterns for which it is not yet possible to make analytical predictions in Neutral Theory. The first is how this species abundance distribution changes with sample area---for example, we would expect to find more and more rare species as sample area is reduced. But what is the exact predicted form of this relationship? We don't yet know. The second pattern is known as the species-area relationship, which describes precisely how the number of species found should increase with sample area. And the third pattern is known as distance decay, which tells us how many species we should expect two communities to have in common, as a function of their geographical separation. The first theme of my proposed research will use field theoretical techniques drawn from my doctoral background in theoretical physics, in concert with methods developed during my postdoctoral work in ecology. Using this combination of approaches I will generate new, analytical predictions for these three patterns in Neutral Theory, going beyond the computer simulations available thus far. The application of these tools is quite novel in the context of community ecology, and will open up the opportunity for interaction across the life science interface.The second theme of my research will begin to add more complexity to this picture, by considering a phenomenon known as density dependence. The effect of density dependence is that when population size increases in a local region, leading to overcrowding, individuals find it harder to survive in that region and the population size drops back down. I will continue to use tools from field theory, with a particular focus on interacting field theories to analyze this complex problem, and to determine what difference density dependence makes to the three spatial patterns above.Finally, I will test my new predictions against a broad range of ecological datasets, stretching across life's domains, from trees down to microbes. While macroscopic organisms have a long history in ecology, microbial ecology in particular is a much younger field---and yet we know that microbes are essential to many processes in nature. Modern molecular techniques allow us to explore microbial ecology with unprecedented resolution, and with the collaboration of a large network of colleagues I will test my predictions against this data. Confronting my novel analytical methods with new kinds of ecological data will allow me to make draw important conclusions about the rules by which ecological communities play.

由于人类活动，我们的世界正在经历迅速的变化。我的研究的总体目标是了解这些变化将如何影响生态社区，以及我们如何减轻其影响。为了实现这些目标，我将进一步发展我们对生态群落如何工作的理论理解，这个项目的主要成果将是推导和测试生物多样性在不同空间尺度上的结构方式的新预测。鉴于一个典型的生态群落的巨大复杂性，不可能在任何易于处理的分析中包括每一个细节。因此，我们必须想出一个策略，只保留最相关的信息，这样我们就可以扔掉那些无关紧要的细节，但仍然可以做出准确的预测。斯蒂芬·哈贝尔（Stephen Hubbell）的中性理论是这种简约策略的典型例子，它在几乎没有可调整参数的情况下做出了令人惊讶的成功生态预测。一个关键的输出被称为物种丰度分布，它告诉我们在一个生态群落中，在任何给定的种群规模下，我们平均应该找到多少物种。然而，有三个重要的空间模式，它还不可能在中性理论作出分析预测。第一个是物种多度分布如何随样本面积而变化---例如，随着样本面积的减少，我们预计会发现越来越多的稀有物种。但这种关系的确切预测形式是什么？我们还不知道。第二种模式被称为物种-面积关系，它精确地描述了发现的物种数量如何随着样本面积的增加而增加。第三种模式被称为距离衰减，它告诉我们两个群落应该有多少物种是共同的，作为它们地理距离的函数。我提出的研究的第一个主题将使用从我的理论物理学博士背景得出的场论技术，与我在生态学博士后工作期间开发的方法相一致。使用这种方法的组合，我将为中性理论中的这三种模式产生新的分析预测，超越迄今为止可用的计算机模拟。这些工具的应用在社区生态学的背景下是相当新颖的，并将打开跨生命科学界面的互动机会。我的研究的第二个主题将开始通过考虑一种被称为密度依赖的现象来给这幅图增加更多的复杂性。密度依赖的影响是，当人口规模在局部地区增加，导致过度拥挤，个体发现更难在该地区生存，人口规模回落。我将继续使用场论的工具，特别关注相互作用场论来分析这个复杂的问题，并确定密度依赖对上述三种空间模式的影响。最后，我将用广泛的生态数据集来测试我的新预测，这些数据集横跨生命的领域，从树木到微生物。虽然宏观生物在生态学中有着悠久的历史，但微生物生态学是一个非常年轻的领域-然而我们知道微生物对自然界中的许多过程都是必不可少的。现代分子技术使我们能够以前所未有的分辨率探索微生物生态学，在一个庞大的同事网络的合作下，我将根据这些数据测试我的预测。用新的生态数据来面对我的新分析方法，将使我能够得出关于生态群落发挥作用的规则的重要结论。

项目成果

PhylOTU: a high-throughput procedure quantifies microbial community diversity and resolves novel taxa from metagenomic data.

• DOI: 10.1371/journal.pcbi.1001061
• 发表时间: 2011-01-20
• 期刊: PLoS computational biology
• 影响因子: 4.3
• 作者: Sharpton TJ;Riesenfeld SJ;Kembel SW;Ladau J;O'Dwyer JP;Green JL;Eisen JA;Pollard KS
• 通讯作者: Pollard KS