Have you ever blushed when telling someone you want to spend X dollars (where X is some large number) to control an invasive plant because of what it does to salamanders? I mean who ever even sees salamanders anyway. Well, the New Scientist recently had this news flash.
Currently wheat crops in East Africa and the Middle East are being hit hard by a new, virulent strain of an old pathogen, black stem rust (Puccinia graminis), known as Ug99. Given the limited genetic diversity of modern wheat strains, this fungus has the potential to greatly affect food production and result economic and humanitarian suffering. Turns out that the alternate host for Puccinia graminis, the one where the fungus undergoes its sexual reproductive stage, is our old invasive friend barberry (Berberis sp.). It’s not clear, at least not to me, what role naturalized barberry would really play in distributing and magnifying a Ug99 infection in the United States, but it can’t hurt. At any rate the broad distribution of barberry in the U.S. (see the USDA’s PLANTS website for a more or less complete barberry range map) will ensure that reproducing Ug99 organisms are crossed with the widest possible range of other rusts and get maximum opportunity to breed new and even more exotic versions of themselves.
Interestingly, though not surprisingly, it turns out that the highly pathogenic soybean rust (Phakopsora pachyrhizi H. Sydow & Sydow) winters on kudzu, which is one of original poster children of the invasive plant world. Actually, there are almost a hundred known hosts of Phakopsora pachyrhizi, including beans, peas, and clover, nonetheless, apparently few are themselves as resistant to the effects of the disease while allowing such profuse sporulation as kudzu.
So…there are a couple of good reasons to spend time, energy, and money preventing and controlling invasive species, reasons that involve more than “just” environmental damage. Because we (humans) are so vigorously stirring a globe-sized stew of species and genes, invasives can effect real human suffering and economic hardship, even if they’re growing off in the woods somewhere where no one but the salamanders can see them.