Garden as if life depends on it

Friday, December 14, 2012

Have you ever thought about what happens when a native wooded area is cleared for a building site?  It is obvious that the trees and undergrowth has been removed, but what about all the creatures that were living in or would visit this area?  The insects that were feeding on plants growing in the woods are gone; the birds no longer have a reason to visit this location to look for food such as caterpillars and other insects because their food plants are gone.  When a local habitat is removed local extinction takes place.  All the creatures, large and small, are gone from this area. This kind of destruction takes place every day.  The plants and the animals who were visiting the habitat have disappeared.

 Through a process called photosynthesis, plants create oxygen.  Plants moderate weather patterns and plants deliver almost all the ecosystems services that keep us around.  Without plants, animals that depend on them disappear.  Plants make food and provide shelter for animals.  The once pristine world has been converted into cities, suburbs and agriculture for human needs.  Breeding birds have suffered great losses of populations.

 Natural preserves set aside do not provide enough habitats for healthy ecosystems.  We need corridors of native plants to keep sustaining all the animals that depend on them.  Often, our yards support very little biodiversity.  Our challenge is to raise the carrying capacity of our yards and neighborhoods so that they can be healthy, functioning ecosystems.  The carrying capacity depends on plants, the basis of the food web. 

 All plants do not support wildlife equally.  Exotic plants, such as those from China, Asia, etc. do not support local diversity.  Non native plants support fewer insects and thus support fewer birds which feed on the insects.  Nearly all birds depend on insects, especially caterpillars, to feed to their young and must nest in an area where such insects are found.

 Plants produce distasteful chemicals in their leaves for defense against insects.  Some insects have adapted and specialize in order to eat specific plants.  This adaptation takes a long evolutionary exposure to develop this ability to ingest poisonous or distasteful leaves without suffering consequences.  Most insects can develop and reproduce only on the plant species with which they share an evolutionary history. The downside of this specialization is that they must have specific plants in order to survive and reproduce.  An example of this specialization is Monarch butterflies and milkweed.

 So, why should we be concerned about insects?  Many mammals depend on insects as a source of food.  Nearly all nesting birds feed insects to their babies.  Some take as many as 300 caterpillars a day when feeding their young.  Predator birds, such as hawks, feed on the smaller birds.  Other mammals such as squirrels, possums, frogs also feed on insects.  Plants are at the base of the food web….insects feed on them, mammals feed on the insects.  Other mammals feed on the insect feeders.  We cannot remove insects in the local food web without the food web collapsing.

 We need to think about our properties in a different way.  We need to consider, when designing and planting our landscapes, how we can add to the ecosystem services to insure the survival of the food web.  Plants should not be viewed as just ‘decorations’.  Is the solution to just plant native species?  Not necessarily because not all native plants support equal amounts of wildlife.  Oaks (Quercus) and Prunus species are two of the top plant genera that support butterflies and moths.  For further information about plants and the numbers of Lepidoptera (moths and butterflies) they support please see:

 To share our neighborhoods with wildlife we need to:

Create corridors of appropriate plants connecting natural areas

Reduce the area now in lawn – an essentially worthless ecosystem

Begin the transition from non-native, exotic ornamental plants to native ornamentals.

 It is a design challenge of our time, especially in south Florida.  Canopy trees, sub-canopy, a shrub layer and ground covers using native plant material will help to have a healthy food web in our yards and neighborhoods.  Planting natives is a ‘grass roots’ approach to conservation in our own yards.  This is something we can all do.  The way we garden, the way we landscape, is going to determine what life looks like in the future.  Garden as if life depends on it…..

This article was written based upon a lecture by University of Delaware professor Dr. Doug Tallamy, author of ‘Bringing Nature Home’.





Monarch caterpillar feeding on milkweed leaves
blog comments powered by Disqus