Great post! I missed Eric's comment, but it seems like "life or death" of Mad Men refers to its value: is it still a good show or not? Thus, this ecosystem describes a circulation of critique and judgment that is very much pegged to the story itself, first and foremost. It may be a broadly unscientific "sense" of a critical "climate" (more nature metaphors!), but that doesn't mean it can't be studied. I think the value of "ecosystem", in this situation, is that it describes a constant give and take between the story (one kind of objectively verifiable phenomenon) and critical reception (another kind). This give and take is not stable, and is thus, for all intents and purposes, subjective. Our reading of a story and our sense of critical reception are more granular and thus relatively more stable—given the various scales of temporality through which we interact with the ecosystem: i.e. the speed at which culture interacts with a work and the speed with which individuals do—and can be engaged with more objectively (and thus seem more scientific).
I'm intrigued by your idea of multiple life forms in the ecosystem, but I lost the thread of your last tangent a little bit. Are you suggesting that we might think of the mediascape as the world and various life forms as "entities" constituted by that world--they are thus OF this world, if no longer really in it? I take "mediascape" to be something very public, and these life forms to be something more personal, more subject to individual hermeneutics. Close?