Goyal Akshit, Rocks Jason W, Mehta Pankaj
Department of Physics, Massachusetts Insitute of Technology, Cambridge, MA 02139.
International Centre for Theoretical Sciences, Tata Institute of Fundamental Research, Bengaluru 560089.
ArXiv. 2024 Nov 22:arXiv:2403.01276v2.
How ecosystems respond to environmental perturbations is a fundamental question in ecology, made especially challenging due to the strong coupling between species and their environment. Here, we introduce a theoretical framework for calculating the steady-state response of ecosystems to environmental perturbations in generalized consumer-resource. Our construction is applicable to a wide class of systems, including models with non-reciprocal interactions, cross-feeding, and non-linear growth/consumption rates. Within our framework, all ecological variables are embedded into four distinct vector spaces and ecological interactions are represented by geometric transformations between these spaces. We show that near a steady state, such geometric transformations directly map environmental perturbations - in resource availability and mortality rates - to shifts in niche structure. We illustrate these ideas in a variety of settings including a minimal model for pH-induced toxicity in bacterial denitrification. We end by discussing the biological implications of our framework. In particular, we show that it is extremely difficult to distinguish cooperative and competitive interactions by measuring species' responses to external perturbations.
生态系统如何应对环境扰动是生态学中的一个基本问题，由于物种与其环境之间的强耦合，这一问题极具挑战性。在此，我们引入一个理论框架，用于计算广义消费者-资源模型中生态系统对环境扰动的稳态响应。我们构建的框架适用于广泛的系统类型，包括具有非互惠相互作用、交叉取食以及非线性生长/消费率的模型。在我们的框架内，所有生态变量都被嵌入到四个不同的向量空间中，生态相互作用由这些空间之间的几何变换来表示。我们表明，在稳态附近，这种几何变换直接将资源可用性和死亡率方面的环境扰动映射到生态位结构的变化上。我们在多种情形下阐释了这些观点，包括细菌反硝化中pH诱导毒性的一个极简模型。最后，我们讨论了我们框架的生物学意义。特别地，我们表明通过测量物种对外部扰动的响应来区分合作和竞争相互作用极其困难。
