While freshwater dwellers are highly sensitive to physical changes in their habitat, it is possible that climate warming may affect them less than terrestrial species (see figure). For example, freshwater ecosystems could benefit from the fact that water warms more slowly than land because of its high heat capacity. Water also dampens short-term heat waves, especially in deep lakes, while heat can take full effect on land. Thus, water could act as a buffer against rising temperatures and provide some protection for freshwater inhabitants, especially in deep waters.
In contrast, terrestrial species may be more exposed to climate warming and increasingly, they also lack shady, cool refuges such as forests due to land conversion. The integrative approach of the researchers therefore suggests that terrestrial species may be under greater pressure to adapt rapidly to higher temperatures. In extreme cases, this selection pressure could lead to the extinction of species.
A way forwards
The researchers hope that by implementing the proposed integrative approach conservation practitioners and policymakers will have new tools for biodiversity conservation. “To preserve biodiversity, it is important to know which processes are most influential at any given time, because only then can measures be targeted,” says Agnieszka Sendek, co-lead author of the study. For example, if ecosystems are strongly influenced by ecological drift, i.e., populations are declining rapidly, the primary goal could be to protect population sizes and conserve large-scale habitats. However, if human activities primarily limit dispersal, measures should be taken to better connect remaining habitats. If warming is the overriding problem, the goal may be to create shaded, cool habitats to provide refuges for animals and plants.