Linking ecological connectivity to population resilience in a marine system

由于气候变暖、栖息地退化和非本地物种入侵等人类活动带来的多重共同压力，我们这个星球的生态系统正在以前所未有的速度发生变化。从理论上讲，分布在斑块中的物种在不断变化的条件下坚持下来并表现出对压力的韧性的能力，可能部分取决于斑块之间的个体移动，这使得当地种群得以补充。这一理论已发展并主要应用于陆地系统；在海洋环境中很大程度上缺乏支持经验的证据。在海洋中，与陆地不同，阻碍个体运动的物理边界通常是不存在的，这可能会限制当前理论在海洋系统中的适用性。我们建议以海带床为模型系统，研究个体扩散(称为连通性)影响海洋种群持久性和恢复力的条件。海带床是生产力很高的沿海海洋生态系统，为各种无脊椎动物和鱼类提供栖息地。个体海带的扩散距离小于海带斑块之间的距离，而栖息的无脊椎动物的扩散距离要大得多。因此，栖息地工程师(海带)和它所支持的物种之间的迁徙调节种群持久性的条件预计会有所不同。我们将评估种群所占斑块的大小以及个体需要穿越的斑块之间的距离对海带和附着并生长在海带上的入侵无脊椎动物的持久性和弹性的重要性。为了实现这一点，我们将使用过去30年收集的历史数据来参数化人口模型和现场的实验操作。了解连通性在生态时间尺度上的作用，对于预测变化范围和种群灭绝至关重要。使用海带床作为一个易于处理的模型系统，我们的研究将促进我们对一个非常有价值的沿海生态系统和服务提供者的弹性的理解，目前该系统正受到海洋变暖和入侵物种的压力。建立海洋保护区网络是最常见的海洋养护行动，其中连通性被认为是一个关键的设计要素。我们的发现将有助于正在进行的本地和全球讨论，提供关于将连通性纳入设计过程的条件(物种特征、栖息地类型)的具体建议。

The ecosystems of our planet are changing at an unprecedented rate due to multiple, co-occurring pressures from human activities, such as climate warming, habitat degradation, and invasions by non-native species. In theory, the ability of species distributed in patches to persist through changing conditions and to exhibit resilience to pressures may depend in part on the movement of individuals between patches, which enables replenishment of local populations. This theory has been developed and applied mainly to terrestrial systems; supporting empirical evidence is largely lacking in the marine environment. In the ocean, unlike on land, physical boundaries impeding individual movement generally are absent, and this may limit the applicability of current theory in marine systems. We propose to examine the conditions under which dispersal of individuals (referred to as connectivity) affects the persistence and resilience of marine populations, using kelp beds as a model system. Kelp beds are highly productive coastal marine ecosystems that provide habitat for a wide range of invertebrates and fishes. Dispersal distance of individual kelps is less than the distance between kelp patches, while dispersal distances of resident invertebrates are much greater. Thus, conditions under which movement regulates population persistence are expected to vary between the habitat engineer (kelp) and species it supports. We will evaluate the importance of the size of a patch that a population occupies, and the distance between patches that individuals need to traverse, in the persistence and resilience of kelps and an invasive invertebrate that attaches and grows on the kelps. To achieve this, we will use historical data collected in the last 30 years to parameterize population models and experimental manipulations in the field. Understanding the role of connectivity on ecological timescales is essential for predicting shifting ranges and population extinctions. Using kelp beds as a tractable model system, our research will advance our understanding of resilience of a highly valuable coastal ecosystem and service provisioner, currently under pressure by ocean warming and invasive species. Establishing networks of Marine Protected Areas is the most common marine conservation action, in which connectivity is considered a key design element. Our findings will contribute to ongoing local and global discussions by providing specific recommendations on the conditions (species traits, habitat types) under which to incorporate connectivity in the design process.