By Alison Laurio -- firstname.lastname@example.org
WINCHESTER -- While vineyards are adapting to warmer temperatures, some parts of the Northern Shenandoah Valley are eyeing potential water shortages.
Frederick County expects a water deficit between 2020 and 2030, based on the current supply. Middletown also must find sources of water as its needs will exceed the amount it buys from Winchester.
Last year, area officials worked on plans for future water supplies and how to respond to drought as required by the state.
Agriculture depends on weather. When it comes to climate, it's complicated, but all connected.
Joshua A. Kincaid, chairman of the Environmental Studies Department at Shenandoah University, said students are taught about climate change and global warming, but it's more complex than just temperatures.
The earth is a system of subsystems -- a collection of interdependent parts: hydrosphere, biosphere, lithosphere and atmosphere, he said.
"I tend to think of the earth as an automobile, at least when explaining the system in class," Kincaid said. "You have this system of interacting parts -- engine, transmission, drive shaft, radiator, etc., and a problem in one subsystem could affect one or more other subsystems -- and ultimately the whole system."
The many interactions, synergies and feedbacks -- both positive and negative -- make it difficult to be certain in many cases, he said.
"You are working with a complicated system and not an isolated piece of it," Kincaid said. "We all know a forest has trees, but a forest is much more than the trees themselves."
Some places in the Southeast are actually cooling, he said.
"Virginia seems to be getting a little warmer and drier," Kincaid said. "In terms of gardening and agriculture in general, it's complicated."
That, in part, is because the warmer it gets, the faster plants can possibly grow -- up to a certain point. And warmer conditions are associated with an increase in carbon dioxide, which is also a fertilizer. But plants internally "fix" the carbon dioxide differently (during photosynthesis) and have different designations depending on how they do it -- wheat is a C3 plant, and corn is C4, Kincaid said.
"In a CO2-rich world, C3 plants take advantage of that, so you're going to get a competitive advantage over C4 plants," he said. "Many weed species are C3. You could get a weed species advantage to outgrow many of our native plants."
Besides native versus non-native, other possible changes include:
• Nutrition in crops. "Anything when planted that grows quickly, tends to be less nutritious," Kincaid said.
That could affect wild animals, which would "have to forage more to get the same amount of nutrients," he said.
• Water supplies. "Our aquifers are being depleted," Kincaid said. "Higher temperatures do not necessarily mean greater rainfall."
• Some insect populations "could get out of control." The South American native fire ants are found throughout the southeastern U.S. -- including some parts of Virginia.
"This species could spread northward if a warming trend persists," he said. "Possible damages include destruction of crops (especially seedlings), destruction of agricultural fields via mound building and even the death of young or injured animals."
"These things are not going to happen everywhere," Kincaid said. "Some places will get warmer and drier, some places will get warmer and wetter, some places will get cooler and drier and some places will get cooler and wetter."