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How will global warming affect plants?

In areas of the world where temperatures are documented to be growing warmer, plants are showing the effects. Some of these effects are good – increased microbial action in the soil making plants more productive. Some are bad – plants moving to cooler locations.

And other effects tend to be neutral (or maybe it's who's doing the perceiving).

Gardeners, for instance, often long for plants that grow only in climates that have typically had winter weather warmer than their own. But now they're finding that many plants are making themselves at home where they wouldn't grow before. ( discusses it in more detail.)

The downside of that is, potentially: Plants that are currently a big part of a particular climate -- , for instance -- will be sorely missed if they migrate northward.

Warmer temperatures – say, 3 degrees C warmer – and stronger winds (which are considered part of global warming) actually quicken the spread of seeds, pollen, and plants, earlier this month. This could help plants survive and be useful in repopulating forests that have been leveled by fire.

The plants best suited to move easily into a new climate zone tend to be those that live on the edge of their current zone, published in the journal New Phytologist.

Less snow cover – which keeps soil temperatures steady – would lead to more thawing and refreezing of soil, which adversely affects roots of many plants. However, , this heaving action "increases microbial action and breaks up the soil, make plants more productive."

We've written previously about possible changes to various weeds due to climate change. noted that if higher temperatures cause invasive plants to move to areas with warmer temperatures (and some invasive plants could become less competitive than they are now, researchers found), this will provide space for welcome restoration of their current acreage.

On the food front: A couple of days ago, in an article titled , Reuters noted research findings that tested several food crops such as cassava and sorghum – which are staples in Africa, Asia, and Latin America – to see how they reacted to elevated CO2 levels.

One result: At double the current rates of Co2, the plants produced much higher levels of chemicals that break down in cyanide gas if chewed or crushed and much lower levels of protein. (The protein is necessary for people and cattle to break down the cyanide so it has no effect on them.)

Some other reports you might be interested in:

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All in all, the answer to our question is: It's a mixed bag. Stay tuned for more research – and real-life experience.