Gupta Aryaman, Gascoigne Samuel J L, Barabás György, Blonder Benjamin Wong, Qi Man, Fenollosa Erola, Thornley Rachael, Hernandez Christina, Hector Andy, Salguero-Gómez Roberto
Department of Biology, University of Oxford, Oxford, UK.
Mathematical Institute, University of Oxford, Oxford, UK.
Ecol Lett. 2025 Aug;28(8):e70182. doi: 10.1111/ele.70182.
Climate change is increasing the magnitude and frequency of precipitation extremes. Consequently, grassland community dynamics are destabilising and becoming harder to predict since models typically simulate long-term (asymptotic) behaviour, potentially neglecting short-term (transient) behaviour. Here, we use cover data from an experiment performed over 8 years to model short- and long-term responses of three functional groups (grasses, legumes, and non-leguminous forbs) to precipitation extremes. We use Integral Projection Models (IPMs) and pseudospectral theory to track transient grassland community dynamics driven by response lags and interannual shifts. We show that the cover-class structure and inter-cover-class interactions of functional groups make them transiently unstable but asymptotically stable, that is, disturbances are initially amplified before eventually dissipating. We also show that grasses dominate under irrigation, while legumes and forbs dominate under drought. We demonstrate that the pseudospectra of IPMs enable computationally and data-wise inexpensive assessment of whether transient dynamics drive community responses to disturbances.
气候变化正在增加极端降水的强度和频率。因此，草原群落动态变得不稳定且更难预测，因为模型通常模拟长期（渐近）行为，可能忽略了短期（瞬态）行为。在此，我们使用一项为期8年的实验中的覆盖数据，来模拟三个功能组（禾本科植物、豆科植物和非豆科杂类草）对极端降水的短期和长期响应。我们使用积分投影模型（IPM）和伪谱理论来追踪由响应滞后和年际变化驱动的瞬态草原群落动态。我们表明，功能组的覆盖类结构和类间相互作用使它们瞬态不稳定但渐近稳定，也就是说，干扰最初会被放大，最终才会消散。我们还表明，在灌溉条件下禾本科植物占主导，而在干旱条件下豆科植物和杂类草占主导。我们证明，IPM的伪谱能够以计算和数据成本较低的方式评估瞬态动态是否驱动群落对干扰的响应。
