Sunday, October 26, 2014

Trees that Heal the Land

Well, that seems like an ambitious title, doesn’t it? The development boom is going again and tracts of land are rapidly turning into subdivisions. Some tracts are wooded and some are pasture. No matter how they start out, the “homesites” often end up being cleared to the dirt from one end to the other because it is cheaper that way.

The developer pops the house up and carpets the area with sod and pine straw and a sprinkling of shrubs around the foundation of the house. The end result is so far from what might have been there naturally that it looks like plastic. Given that the sod and the landscaped shrubs are 95% non-native, this is literally an engineered wasteland … from the perspective of the native insects and birds around it.

Oak leaves in spring
This is where healing the land comes in.  What would bring life back to this place? Native plants would do the job. Recent talks by entomologist Doug Tallamy present an approach that encourages us to flip landscaping norms 180 degrees. 


Rather than putting lawn everywhere and then adding a few decorative plants, the approach advocated by Dr. Tallamy spins that idea around: put lawn only where you need to walk or play and fill the rest of the space with non-lawn plants like perennials, shrubs and trees. These are the plants that support insects and birds, and locally native perennials, shrubs and trees support them more than any other.

How can one transition to that approach?

Not everyone has room for a lot of plants or a budget to make large changes. Small changes can still be meaningful and that’s where the idea of TREES healing the land comes in. Tree selection can make a big impact. Research shows that indigenous trees can support a lot of wildlife.

The best approach is first to see what is native in your area. If you live in Georgia, chances are there are oaks and maples, perhaps a hickory, a willow and a hawthorn. These are all excellent candidates to be your tree (or two). “Let It Be An Oak” is one of Tallamy’s recent talks for a very good reason. His research shows that over 500 insects use the oak genus (Quercus) as a host plant in the mid-Atlantic region.

Baby oakworms on oak leaf
Can you imagine choosing one plant and instantly having that kind of impact? Now don't be alarmed - they are not all-devouring insects, let me assure you. Sometimes you hardly notice them.

Sure, sometimes they can get a little crazy – one little sapling had dozens of caterpillars this year. The trees always survive and they often send out new leaves. Nature knows how to take care of itself.

Not every caterpillar makes it to adulthood. Plenty of them are picked off by birds to feed their chicks or for their own meal. Migratory warblers are insect eaters and wouldn't you like to have them stop by for lunch? Other caterpillars are taken by predatory bugs. A healthy environment balances itself out even without our intervention.

This guy would love a baby oakworm

So if you’re in a position to restore some life to your landscape big or small, consider the healing power of trees to make a difference to wildlife.

To get you started here is a list of the top 12 trees when it comes to being a host plant. Of course these also offer other benefits like nuts, seeds and berries and some of them provide nectar and pollen for pollinators.

Common Name

Plant Genus

# Butterfly/moth species supported
Oak

Quercus

534
Black cherry

Prunus

456
Willow

Salix

455
Birch

Betula

413
Poplar

Populus

368
Crabapple

Malus

311
Blueberry

Vaccinium

288
Maple

Acer

285
Elm

Ulmus

213
Pine

Pinus

203
Hickory

Carya

200
Hawthorn

Crataegus

159

2 comments:

  1. Great article. I was a bit surprised to see morning glory (Ipomoea) and honeysuckle (Lonicera) on the lists at your link.

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