The concept of ecosystem engineering was first formalised in the mid-1990s (Jones et al, 1994). Ecosystem engineers can be defined as “organisms whose presence or activity alters their physical surroundings or changes the flow of resources, thereby creating or modifying habitats”. One of the challenges facing us as we attempt to reverse the loss of natural capital and rebuild is how to “scale-up” from individual restoration sites to large-scale ecologically-sustainable landscapes. Last week I read about how beavers are being reintroduced in California to slow and conserve water helping to restore underground aquifers. The article suggests that rather than spend billions to redirect streams and build a few big dams, the [US] government could build tens of thousands of smaller dams for far less money and get beavers to maintain them for free. Similar ideas have been proposed and have just started in the United Kingdom. One can imagine other examples, from ants and earthworms as soil engineers, to mangroves as natural sea walls. I would be very interested to hear from anyone who has practical experience with using [other] ecosystem engineers, either plant or animal, for ecosystem-based adaptation.