heise: the cost is comparative.o, it's $50 million that we will invest in mountain lion habitat that we won't invest in something else. so, i think there needs to be democratic decision making and extensive consultation about whether we want to do this and who will raise the money for this, who will pay for this. what do we owe mountain lions, what do we owe to other species of plants and animals? pauly: man-made structures act as barriers for lots of species in urban areas. but some aspects of our infrastructure actually allow non-native species to thrive. the big moment for thinking about water in los angeles is 1913. once you have permanent water on the landscape, lots of non-native species, if they get introduced, can now make it. so, what's happened is that non-native species that get introduced to southern california, that are maybe from a more tropical place, now can make it here because there's much more water. and one of the ways that a lot of these species are coming in is actually via the nursery plant tr