In Chapters 6 & 7 of her novel, Marris focuses on “invasive” or “exotic” species and the idea of emerging “novel ecosystems”, which, according to an ecologist she spoke to named Erle Ellis, now take up around 35% of the world’s ice-free land (pg 120). Species that have been introduced to ecosystems where they have not been found before are referred to as exotic species, or nonnative. However, it is when those species begin to cause problems in the ecosystems they have inhabited – by preying on native species, taking all the native species’ food supply, etc. – that they become “invasive”, and largely viewed by ecologists as a problem that needs to be eradicated.
Marris gives a number of examples of such “invasive” species that have wreaked havoc on the ecosystems they have been introduced to. She mentions the case of the Stephen Island’s flightless wren, which was driven to extinction by a population of feral cats that were accidently let loose on the island (page 98), as well as zebra mussles of the Great Lakes, flammable cheatgrass, and the Asian tiger mosquito, each of which have caused significant damage to the areas where they have been introduced.
However, Marris then goes on to suggest that perhaps we are overreacting about the issues these invasive species cause, and that we should re-examine our attitudes towards them, instead of spending countless money, manpower and resources trying to get rid of them. She points to various examples of introduced, exotic species that have not been harmful to their habitats, and in some cases have even helped save some of the native species from extinction, as the case with the Turkey Oaks which helped keep Britain’s blue tits from going extinct (page 106). She also mentions how we have spent so many resources making sure these exotic species don’t flourish, for fear of “genetic pollution, as the case with the ruddy duck and the white-headed duck in the UK (page 109), when there is really no need for these efforts and all that the cross-breeding of these ducks was doing was creating a new species, as part of the “novel ecosystems” Marris advocates for.
Marris expands on the idea of novel ecosystems in Chapter 7, where she mentions ecologists Lugo and Mascaro, who are proponents of such ecosystems, where introduced and native species can live together and flourish in diverse mixes, something which many traditional ecologists are still weary about. She mentions the example of the “mango forest”, a novel ecosystem where mangos that were planted a while ago have flourished and created a forest of many exotic species otherwise not found in the area. Marris says that these novel ecosystems represent the future of our planet, and whether this is so I’m not sure, but something tells me there may be more to this than mentioned in these chapters, since these invasive species must be hated by so many ecologists and conservationists for a reason, and Marris seemed to have brushed off that hatred rather quickly.
