1. To facilitate conservation planning, there is a need for improved confidence in forecasts of climate change impacts on species distributions. Towards that end, there have been calls for the development of process‐based models to test hypotheses concerning the mechanisms by which temperature shapes distribution and to corroborate forecasts of correlative models.
2. Models of temperature‐dependent growth (TDG) were developed for two Australian riverine blackfishes with disjunct longitudinal distributions: Gadopsis marmoratus (occupies lower, warmer elevations) and Gadopsis bispinosus (occupies higher, cooler elevations). The models were used to (a) predict blackfish monthly and annual growth dynamics under current and future climate scenarios within different elevation bands of their current distribution, and (b) test the hypothesis that, under the current climate, the distributions of each species would be positively correlated with predicted TDG.
3. Increases in mean annual growth were forecast for both species under all warming scenarios, across all elevation bands. Both species currently occupy annual habitat temperatures below those optimal for growth. Under certain warming scenarios, the predicted increases in annual growth belie forecasts of within‐year dynamics that may interact with the phenology of blackfish to impair recruitment.
4. There was not a significant positive linear relationship between predicted TDG and observed abundance among river segments for either species. Both species were strongly under‐represented where annual growth rates were forecast to be optimal and over‐represented where growth rates were forecast to be intermediate.
5. Confidence in forecasts of climate change impacts based on correlative models will increase when those forecasts are consistent with a mechanistic understanding of how specific drivers (e.g. water temperature) affect processes (e.g. growth). This process‐based study revealed surprises concerning how future climates may affect fish growth dynamics, showing that although the blackfish distributions are correlated with temperature the temperature‐dependent mechanisms underpinning that correlation require further investigation.

中文翻译：

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当前和未来的气候对两条河鱼类生长动态和分布的影响

1. 为了促进保护规划，需要提高对气候变化对物种分布影响的预测的信心。为此，人们呼吁开发基于过程的模型，以测试有关温度形状分布机制的假设，并证实相关模型的预测。
2. 针对两种纵向分布不连续的澳大利亚河滨黑鱼，开发了温度依赖性生长（TDG）模型：Gadopsis marmoratus（海拔较低，海拔较高）和Gadopsis bispinosus（海拔较高，海拔较低）。这些模型用于（a）预测在当前和未来气候情景下其当前分布的不同海拔范围内的黑鱼每月和每年的生长动态，以及（b）检验在当前气候下每个物种的分布将与预测的TDG正相关。
3. 在所有变暖情况下，所有海拔范围内，这两种物种的年均增长均被预测。目前，这两个物种的年栖息地温度均低于其最适生长温度。在某些变暖的情况下，预测的年增长率将掩盖对年内动态的预测，而这些动态可能与黑鱼的物候相互作用，从而影响募集。
4. 两种物种的预测TDG与河段之间观测到的丰度之间没有显着的正线性关系。在预测年增长率最佳的情况下，这两种物种的代表性都大大不足，而在预测增长率为中度的情况下，两种物种的代表性都很高。
5. 当这些预测与对特定驱动因素（例如水温）如何影响过程（例如增长）的机械理解一致时，对基于相关模型的气候变化影响的预测的信心将会增加。这项基于过程的研究揭示了有关未来气候如何影响鱼类生长动态的惊奇，表明尽管黑鱼的分布与温度有关，但依赖于温度的机制仍需要进一步研究。