Our discussion of homegrown national parks continues. This time we look at another core element of Dr. Tallamy’s work - keystone species. It turns out that not all native plants have an equal impact on restoring biodiversity. There are certain general of plants that support many more ecological functions in a community.

It’s a bit like that one person in your neighborhood who serves on the local PTA, turns up for all the town meetings, is always there to look after an ailing neighbor, and finds your cat when he goes missing. These plants support many more species of insects that produce those all important caterpillars which the birds depend upon to raise their young.

So this week Coralie Palmer introduces us to the five top genera of trees that Dr Tallamy considers to be keystone species.