Wednesday, May 27, 2009

The Growing Season

As we approach the growing season here in central New York we thought it might be interesting to write about Agriculture and the effects of climate change on this industry.

Agriculture is one of the central pillars of New York State’s economy – and as our climate changes, our whole agricultural system will change in response. One’s first thought might be, “Well, warmer temperatures mean a longer growing season and think of all the cool things we can plant now!” This is true up to a point, but with warmer temperatures come new problems, new pests, and losses of crops that can’t adapt to heat.

Don’t all of us, here in New York, occasionally wish for a longer summer? It certainly felt like we got it last year…The first hard frost here in Ithaca was 2 to 3 weeks late. So what’s the problem with this? Increased growing season and increased carbon dioxide in the atmosphere (remember plants use CO2 for photosynthesis) could indeed boost harvests. Unfortunately the flip side is that summer will not only be longer, but also hotter and drier. Weather patterns would change, water would evaporate more quickly in the hotter climate and extreme weather events like floods, damaging thunderstorms, tornados, and hurricanes would be more common. Drought would also become a more frequent event. Crops would be more stressed, farmer costs would rise as they needed new ways to irrigate, and our precious water resources would be increasingly taxed.

With milder winters and hotter summers, we would also see an increase in pests that can infest and damage crops. Upstate New York already has it’s share of damaging pests, but cold winters often control population numbers and keep pests from the more southern regions from moving north. For example, the corn earworm, which is common in the south, spreads only as far north as Ohio, Virginia, and southern New Jersey. Cold winters keep it from permanently infesting more northern regions. With milder winters, however, it will easily be able to enlarge its range. An additional issue with agricultural pests is that as summers become longer and warmer, these organisms have additional time for breeding. This means that more generations will be produced over the growing season, and thus more pests for longer periods of time.

So what does all of this mean? Though growing crops may be more challenging, we should continue to see agriculture as a major part of upstate New York’s economy. There will be major changes though – Can you imagine New York without maple syrup or apples? Our warming climate could impact our most traditional crops!

Maple trees, and the associated syrup industry, thrive in New England and in upstate New York. Unfortunately, an earlier, warmer spring could lessen the amount of maple syrup extracted during sugaring season. Maple syrup is harvested during a transitional time in early spring, when the weather goes through a freeze-thaw cycling, very cold nights with days above freezing. This cycle encourages movement of sap through the tree, and with an earlier and quicker spring, we expect fewer days and a diminished harvest.

Apples too could be impacted negatively. Though a longer growing season seems positive, many apple trees need a certain number of days below freezing in order to set large amounts of fruit. With warmer winters, many traditional varieties of apples will no longer produce large amounts of big fruit, and with warmer and earlier springs, apples will bloom earlier. Spring temperatures, as we well know, are incredibly changeable, and if bloom comes early, followed by frost, the flowers and fruit could be damaged.

Climate change is intertwined with every natural process that happens on earth. With climate change comes new weather patterns, new water systems, and new ecosystems for plants and animals. With each change, a new set of conditions is established with new interactions happening between all processes and organisms. Each week we pass on tips for you to consider implementing in order to live “lightly” on the world. Some might wonder where the connection between these tips and the reality of New York’s agricultural economy is, but as we are all learning, using sustainable agricultural methods and buying locally grown food will not add to existing problems, and may eventually help solve them.

-Elizabeth Humbert

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