Elroy Limmer was in a pretty good position to help people see the forest as well as the trees. As Peoria’s City Arborist, he dealt with numerous questions and concerns regarding proper tree care. For example, a home owner once complained that his sizable catalpa tree had so many caterpillars feeding on it, he was afraid they could kill his tree. What should he spray? This I had to see, so I tagged along with Elroy to check it out.
The tree was a veritable cornucopia of caterpillars. Hundreds had been devouring foliage, but as we looked closer, it appeared each caterpillar had upon its back, several pupae of parasitic wasps. Most of these caterpillars had been so depleted by the growing parasites, they were no longer feeding, or even moving, despite the abundance of their favorite food. In other words, thanks to the wasps, the tree was already adequately protected. This was a great example of how natural systems can resist pest outbreaks. Insecticide would have poisoned the wasps. The problem with pesticides and weed killers, like any poisons, is that they don’t know when to stop.
Where there are abundant species of flora and fauna, the very presence of diversity is protective. Something will hopefully take advantage of a pest population and keep it under control, thereby protecting the entire system. Writer/ scientist, Rachel Carson, compared this to nature’s immune system.
Unfortunately on a global scale, diversity (the immune system) is diminishing as extinctions grow. This is an ominous problem and potential disaster. Some downplay this trend, pointing out that “extinction is natural.” While this is a true statement, it’s been estimated from the fossil record that approximately one extinction generally occurs per million species per year. This would result in maybe ten extinctions per year. The problem is that today there are around 27 thousand extinctions annually… just in the tropics!
The biggest contributors to this monumental loss of species can be remembered by using the acronym H.I.P.P.O.: Habitat Loss, Invasive Species, Pollution, Population (human), and Over-harvesting. Loss of habitat is commonly a result of deforestation, urbanization, and agriculture. Invasive species are a major and ongoing problem crowding out natives. Pollution from industrial effluent and petroleum spills is bad enough, but then there are vast releases of greenhouse gasses, resulting in global warming, acidification of the oceans, ice melt, flooding, loss of permafrost, and extensive droughts. As human populations continue to grow, more habitats disappear, and excessive hunting and fishing take a direct toll. As Pogo would say, “we have met the enemy, and he is us.”
We are at a unique place in human history. It’s true, we, as a species, have never been in a position to cause more extinctions than we are today. But conversely, we’ve also never been in a position to prevent more extinctions. Most of us would like to insure a healthy environment for posterity. A diverse environment is fundamental to long-term stability. Look at biodiversity as ecological wealth. Harvard Ecologist, Dr. E.O. Wilson emphasizes how much wealth… “[Destroying rain forest for economic gain] is like burning a Renaissance painting to cook a meal.”
Forests are so much more than just trees. Forests represent a treasure trove of genetic wealth. They provide air, water, diversity, education, recreation, climate buffering, research, beauty. In the words of Aldo Leopold, “We abuse land because we regard it as a commodity belonging to us. When we see land as a community to which we belong, we may begin to use it with love and respect.”
Dr. Wilson has put forth some practical suggestions for protecting and restoring life on Earth. “We should preserve every scrap of biodiversity as priceless while we learn to use it and come to understand what it means to humanity.” He suggests this is cost effective and doable. We need to identify and focus efforts on the most critical habitats. “Twenty-five of the hottest spots, or more precisely the intact biologically rich habitats within them, cover a mere 2.3 percent of Earth’s land surface, yet they are the exclusive homes of 42 percent of the planet’s vertebrate species (mammals, birds, reptiles, and amphibians) and 50 percent of its flowering plants.” Wilson insists the price represents a mere pittance compared to what humanity stands to gain. We can give no greater gift to our grandchildren. It’s literally the gift of life.
Environmental health begins right in our own yards. In order to restore habitat at our new house, we’ve spent the past three years planting trees, shrubs, and perennials… this gets rid of turf grass, which has almost no habitat value, and replaces it with plants that provide food, cover, and places to nest. For water, we simply added a bird bath. In a place visible from the dining room table, we established a bird feeding station, and finally, we’ve added bird houses around the yard and even a “toad abode.” Already we are seeing a lot more life in our yard.
We use no pesticides or herbicides. Not only does this make our yard healthier for wildlife, it’s also a huge benefit for us … not to mention friends and relatives (and especially children) who visit. The typical weed killers, whether personally or professionally applied to urban yards, are known endocrine disruptors and are capable of causing cancers, such as lymphoma and leukemia, and can accumulate (from shoes) on your floors and carpeting.
“As we search for a less extractive and polluting economic order, so that we may fit agriculture into the economy of a sustainable culture, community becomes the locus and metaphor for both agriculture and culture.” Wes Jackson
“The care of the Earth is our most ancient and most worthy, and after all our most pleasing responsibility. To cherish what remains of it and to foster its renewal is our only hope.” Wendell Berry.”
Sites to surf for more information: wildones.org, nrdc.org, nature.org, nwf.org, audubon.org, populationconnection.org