Re: biofuel crops as habitat?

Just ran across this article in a new pub, Global Change Biology (GBC) Bioenergy which looked at how perennial feedstocks impact animal biodiversity. Perennial biomass feedstocks enhance avian diversity by Robertson et al. 2010 (DOI: 10.1111/j.1757-1707.2010.01080.x). [Note: sorry I will try to find "open" articles, but this is tough!! Please let me know if you want me to send pdf]

The authors looked at bird (and bird food=bugs) diversity and abundance in 3 kinds of habitat:
1) corn monoculture
2) switchgrass plot
3) mixed-grass prairie

This included surveying 20 sites of each type above, but just in the upper mid-west (Michigan).

The clear expectation is that corn (annual plant) would support the lowest bird diversity (this has already been shown). We also already know that mixed-grass prairie, which is largely what the midwest once was before modern agriculture, supports very high bird diversity and abundance. The big question is, what would the perennial switchgrass plot (switchgrass is native to N. America and is one of the mixed prairie grasses) be like in terms of supporting bird diversity and habitat?

It turns out that there was a greater diversity of birds with a larger patch (plot) size for both switchgrass & prairie, but not for corn. Also, the perennials (not corn) supported more arthropods (mainly insects), a key component in many birds' diets. Even though there was greater bird diversity overall in the mixed prairie habitat, the switchgrass plot was also pretty good.

Overall, this suggests that at least for some locations and for one species of cellulosic feedstock (switchgrass)--growing perennial energy crops can be managed to maintain habitat for native grassland birds.