Towers Isaac R, O'Reilly-Nugent Andrew, Sabot Manon E B, Vesk Peter A, Falster Daniel S
Evolution & Ecology Research Centre, The University of New South Wales, Sydney, New South Wales, Australia.
Climate Friendly, Sydney, New South Wales, Australia.
Plant Cell Environ. 2024 Dec;47(12):4849-4869. doi: 10.1111/pce.15042. Epub 2024 Aug 5.
Future changes in climate, together with rising atmospheric , may reorganise the functional composition of ecosystems. Without long-term historical data, predicting how traits will respond to environmental conditions-in particular, water availability-remains a challenge. While eco-evolutionary optimality theory (EEO) can provide insight into how plants adapt to their environment, EEO approaches to date have been formulated on the assumption that plants maximise carbon gain, which omits the important role of tissue construction and size in determining growth rates and fitness. Here, we show how an expanded optimisation framework, focussed on individual growth rate, enables us to explain shifts in four key traits: leaf mass per area, sapwood area to leaf area ratio (Huber value), wood density and sapwood-specific conductivity in response to soil moisture, atmospheric aridity, and light availability. In particular, we predict that as conditions become increasingly dry, height-growth optimising traits shift from resource-acquisitive strategies to resource-conservative strategies, consistent with empirical responses across current environmental gradients of rainfall. These findings can explain both the shift in traits and turnover of species along existing environmental gradients and changing future conditions and highlight the importance of both carbon assimilation and tissue construction in shaping the functional composition of vegetation across climates.
未来的气候变化，加上大气[此处原文缺失具体内容]上升，可能会重新组织生态系统的功能组成。由于缺乏长期历史数据，预测性状将如何响应环境条件，特别是水分可利用性，仍然是一项挑战。虽然生态进化最优性理论（EEO）可以为植物如何适应环境提供见解，但迄今为止，EEO方法的制定是基于植物将碳增益最大化的假设，这忽略了组织构建和大小在决定生长速率和适合度方面的重要作用。在这里，我们展示了一个以个体生长速率为重点的扩展优化框架如何使我们能够解释四个关键性状的变化：单位面积叶质量、边材面积与叶面积比（胡伯值）、木材密度和边材比导率，以响应土壤湿度、大气干旱[此处原文缺失具体内容]和光照可利用性。特别是，我们预测，随着条件变得越来越干燥，高度生长优化性状将从资源获取策略转变为资源保守策略，这与当前降雨环境梯度下的实证响应一致。这些发现可以解释沿现有环境梯度的性状变化和物种更替以及未来不断变化的条件，并突出了碳同化和组织构建在塑造跨气候植被功能组成方面的重要性。
