Context

Metapopulation theory makes useful predictions for conservation in fragmented landscapes. For randomly distributed habitat patches, it predicts that the ability of a metapopulation to recover from low occupancy level (the “metapopulation capacity”) linearly increases with habitat amount. This prediction derives from describing the dispersal between two patches as a function of their features and the distance separating them only, without interaction with the rest of the landscape. However, if individuals can stop dispersal when hitting a patch (“habitat detection and settling” ability), the rest of habitat may modulate the dispersal between two patches by intercepting dispersers (which constitutes a “shadow” effect).

Objectives

We aim at evaluating how habitat detection and settling ability, and the subsequent shadow effect, can modulate the relationship between the metapopulation capacity and the habitat amount in the metapopulation.

Methods

Considering two simple metapopulation models with contrasted animal movement types, we used analytical predictions and simulations to study the relationship between habitat amount and metapopulation capacity under various levels of dispersers’ habitat detection and settling ability.

Results

Increasing habitat detection and settling ability led to: (i) larger metapopulation capacity values than expected from classic metapopulation theory and (ii) concave habitat amount–metapopulation capacity relationship.

Conclusions

Overlooking dispersers’ habitat detection and settling ability may lead to underestimating the metapopulation capacity and misevaluating the conservation benefit of increasing habitat amount. Therefore, a further integration of our mechanistic understanding of animals’ displacement into metapopulation theory is urgently needed.

中文翻译：

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分散器的栖息地检测和沉降能力可调节栖息地数量对种群种群适应力的影响

语境

迁移种群理论为支离破碎的景观的保护做出了有用的预测。对于随机分布的栖息地斑块，它预测从低居住水平恢复的种群的能力（“种群能力”）随栖息地数量线性增加。该预测来自于描述两个斑块之间的散布，这些散布是它们的特征的函数以及仅将它们分开的距离的函数，而与其他景观无关。但是，如果个人在碰到一块补丁时可以停止扩散（“栖息地检测和沉降”能力），则其余的栖息地可能会通过拦截分散器来调节两个补丁之间的扩散（这构成“阴影”效应）。

目标

我们旨在评估栖息地的检测和沉降能力以及随后的阴影效应如何调节种群中种群的迁移能力与栖息地数量之间的关系。

方法

考虑到两个具有不同动物运动类型的简单种群模型，我们使用分析预测和模拟研究了在不同水平的分散器栖息地检测和沉降能力下栖息地数量与种群分布之间的关系。

结果

栖息地检测和沉降能力的提高导致：（i）种群容量值比经典种群理论所预期的要大；（ii）凹形栖息地数量与种群容量关系。

结论

忽视分散器的栖息地检测和沉降能力可能会导致低估了种群的扩散能力，并错误地评估了增加栖息地数量的保护效益。因此，迫切需要将我们对动物迁徙的机械理解进一步整合到后代种群理论中。