Grassland ecosystems support a wide range of species and provide key services including food production, carbon storage, biodiversity support, and flood mitigation. However, yield stability in these grassland systems is not yet well understood, with recent evidence suggesting water stress throughout summer and warmer temperatures in late summer reduce yield stability. In this study we investigate how grassland yield stability of the Park Grass Experiment, UK, has changed over time by developing a Bayesian time-varying Autoregressive and time-varying Generalised Autoregressive Conditional Heterogeneity model using the variance-parameterised Gamma likelihood function.

翻译：摘要：草地生态系统支撑着广泛的物种多样性，并提供包括粮食生产、碳储存、生物多样性维护和洪水缓解在内的关键生态服务。然而，这些草地系统的产量稳定性尚未得到充分理解——近期证据表明，夏季的水分胁迫与夏末的升温会降低产量稳定性。本研究通过采用方差参数化伽马似然函数，构建了贝叶斯时变自回归及时变广义自回归条件异方差模型，旨在探究英国帕克草地试验中产量稳定性随时间的变化规律。