Part 1: How climate affects trees and shrubs

In many parts of North America, including the more temperate parts of Ontario, Quebec, and British Columbia, Nature has caused havoc among many plant species. In my own backyard, lilacs, maples, and white birch are already budding. When, in late December, I saw plump lilac buds grow in size, I worried that I wouldn’t see the bush bring forth aromatic flowers in spring. That led me to do a little research.

There is a science to watching how and when things happen in nature, and how those things mesh with other events. It’s called phenology. The definition of that word is really “the study of periodic plant and animal life cycle events.” (Data from: Wikipedia; Text under: CC-BY-SA) It’s the study of when things like flowers, fruits, and leaves; bees and wasps; mosquitoes and ticks appear. In this 3-part series, I’ll talk about how climate affects the health of trees in general, and their ability to survive and adapt to new weather patterns; the damage that climate can have on trees and shrubs and how that can affect production of seeds for future generations; and the effects of insect life-cycles and the meshing of their cycles with those of plants.

Part 1: How climate affects trees and shrubs in North America

Early budding can be devastating to many species of trees, shrubs, and bushes. You see, some plants can survive the variations in temperature, especially when their flowers and fruits are buried inside other structures, like inside leaf buds. Almost all tree species in North America flower and fruit first, and leaf out later. That’s because it takes so much energy for the tree to produce the necessary reproductive parts. Once that has been accomplished, the leaves can sprout and photosynthesize to provide nourishment throughout the season for new rings to form and new branches to grow.

Even with phenology, many plants simply have not been studied through unusual climatic factors, especially if they are dependent upon pollinators like bees. As our world gets warmer, plants can actually migrate north – in other words, live healthier in its northern edges – successfully. No, we don’t have Ents in North America, and trees can’t really walk or fly, but their seeds can travel and take hold in similar habitats. But if warmer temperatures move too quickly, the southern borders can get so hot that plants dry out, burn, or get too much sunshine, and they die. If seeds can’t be gathered and brought north, or if they get damaged or lost by more violent weather, whole populations and hybrids can be wiped out.

We know that trees living at the borders of their comfort zone, sometimes known as their horticultural zone or gardening zone, sometimes struggle against competition with plants and enemies that aren’t found in their more natural areas. Have you ever dug up a sapling on a camping trip to plant it in your yard, just to find that it dies of a disease or pest? Even if you find the right soil and the climate is the same, the tree has been uprooted and must try to adapt to this new space. It’s just like moving from Milwaukee to Ogden, Utah. The weather may be similar, but you would feel very out-of-place and your health may suffer. If you go on vacation to South America, you may pick up a “bug” that causes intestinal pain and discomfort by drinking the water. Why don’t residents have the same problem? Because they have adapted to the water. It’s really the same thing with plants. They are also living beings.

You might be asking, “I’m already recycling, reducing what I buy and discard, and reusing as much as I can. But none of that helps the migration of plants. So, what can I do about it?”

I’m glad you asked! You can become familiar with trees that may be scarce in your area. Your local natural resources or forestry department may have a list of plants that are becoming extirpated or are marked rare. Horticulture societies may also have an interest in tracking these species. Educate yourself about identifying these plants in all seasons. Mark them, map them, and advise the department. Some of these departments even have classes that you can take to help collect seeds. And once in awhile, you can even be paid for collections!

This is an activity that you can do in all seasons. Identify the plant, make the map, and look around for seedlings and saplings. The more information you can collect, the better. Remember to mind your safety in the woods! Follow, tweet and twitter, and sign up for our newsletter.