Important article from Nature on the importance of looking at non-native, hybrid, “impure” ecosystems: Ragamuffin Earth (July 2009).

Excerpted:

Most ecologists and conservationists would describe this forest in scientific jargon as ‘degraded’, ‘heavily invaded’ or perhaps ‘anthropogenic’. Less formally, they might term it a ‘trash ecosystem’. After all, what is it but a bunch of weeds, dominated by aggressive invaders, and almost all introduced by humans? It might as well be a city dump.

A few ecologists, however, are taking a second look at such places, trying to see them without the common assumption that pristine ecosystems are ‘good’ and anything else is ‘bad’. The non-judgemental term is ‘novel ecosystem’. A novel ecosystem is one that has been heavily influenced by humans but is not under human management. A working tree plantation doesn’t qualify; one abandoned decades ago would. A forest dominated by non-native species counts… even if humans never cut it down, burned it or even visited it.

No one is sure how much of Earth is covered by novel ecosystems.