Vilsack Pro-Forest, Probably Doesn't Matter

In his Senate confirmation hearing today for the post of Secretary of Agriculture, former Iowa Governor Tom Vilsack demonstrated laudable ecological awareness when describing the role of the nation's forests in providing clean water to 60 million Americans. He further said that forests would be important to dealing with global warming, apparently in recognition of their function as a carbon sink.

He was responding to questions by Sen. Amy Klobuchar (D-MN), who was concerned that the the departmental budget he'll oversee has recently been shifted from a 20 percent allocation towards firefighting towards a 50 percent allocation towards firefighting. Vilsack said that he'd do his best to ensure that forest management and fire prevention got their due.

This would seem like good news for agriculture, because it's a plan to keep more water in the soil, in streams and rivers, and trickling down to our fast-depleting aquifers.

But the problem may be largely beyond his control. The Western bark beetle infestation is likely to "kill virtually every mature lodgepole pine in Colorado", and has left patches of dead forest "from New Mexico to Canada." This means that the West is also covered in large stands of rickety, dry, dead trees. Past fire suppression has prevented natural thinning, and ensures that any eventual fire, when it comes, will be very hot and destructive - as well as very expensive to rein in. Global warming has played a part as well, with winter temperatures not getting cold enough to halt the beetles' advance.

In other words, there's a gap between what he says he'd like to do and what he'll probably be able to do.

The situation of the US' Western forests should be taken as a warning to agriculture. In addition to obvious weather threats to the plant communities we maintain for food and fiber, the potential for warmer weather to allow the spread of insect pest populations that we can't deal with effectively. This is already happening in other parts of the world with insects that spread illnesses to humans. Malaria has resurfaced in the United Kingdom, for example.

Why would that happen just from warmer weather?

Insects, and plants, don't just manage their life cycles through the passage of chronological time. Their body clocks operate on degree days, where a given amount of growth takes a certain amount of heat. This means that insects grow faster and reproduce on shorter time scales when it's warmer out than when it's cooler than their preferred temperature range. The expansion of altitudes and latitudes at which given warmer weather insects can live means they can move into areas that were previously too cold for them, and where they have no normal competition.

The same forces that have expanded the reach of mosquitos infected with West Nile pose a changing threat scenario for keeping crops from being lost to insects, and may even bring new insect-borne threats to livestock communities. Our incoming Secretary of Agriculture is going to have to deal with this predictable problem whether or not there are any Senators to question him about it.

(Photo credit: tomsaint11 on Flickr.)