Biodiversity refers to the variety of life forms found in a specific habitat or ecosystem. Your yard is its own ecosystem, with distinct weather patterns, soil structure, rainfall (or irrigation), and insect, invertebrate, microorganism, plant and critter populations. To better understand what happens in a limited gene pool, check out Eddie Izzard’s hysterical video about Royals.
Limiting genetic diversity, such as the monoculture of commercial agriculture, makes it easy to decide when to plant, how to plant, and what treatments to apply. It also makes a crop (or species) profoundly vulnerable to pests and disease. The more diversity found in a habitat, the more likely that that habitat will be healthy.
Urban and suburban areas are considered concrete deserts by birds, bats, and beneficial insects. Creating a diverse environment, suited to your microclimate, in your yard, garden, or even on a balcony, provides many benefits. These include natural pest control, increased pollination, water and energy conservation, and emotional well being. Read on!
Natural pest control
In a diverse ecosystem, everything is relatively balanced. Natural predators and processes limit the population of pests and disease. For example, rodents are considered pests in the garden and in our homes. Gophers can be poisoned or trapped, but barn owls will eat 1 or 2 rodents every night. Would you rather catch an occasional glimpse of an owl, soaring across an evening sky, or dispose of a squished or poisoned gopher? The choice is yours. Family Food Garden has a nice comparison of good bugs and bad bugs.
Rather than automatically spraying for pests, such as aphids, you can leave the earliest pest populations to their own devices. Lady beetles, soldier beetles, and lacewings will be attracted to this easy food source and you get to eat chemical-free produce. In a bird-friendly environment, caterpillars and other larval pests are gobbled up each spring, before they can destroy tender new plants.
Pollination processes work in tandem with healthy environments and population diversity. Spraying pesticides and herbicides can interrupt this balance. Honeybees are not the only pollinators in a garden. Beetles, hummingbirds, bumblebees, ants, moths and butterflies, and bats help to pollinate garden produce. Whenever the life cycle of one member of a community is interrupted, it affects all members of that habitat.
Water & energy conservation
Encouraging biodiversity can also protect waster and energy resources, especially when that biodiversity is geared toward indigenous plants and animals. These living things have evolved to thrive in specific microclimates, which reduces the need for water, feeding, and weeding. For example, most varieties of lawn seed originated in areas with significantly more rain than we get in the Bay Area. Current estimates for water consumption in this area see an increase of 40% in the next 25 years! Since most of our water is already imported from other areas, we need to do what we can to conserve.
The Children and Nature Network research, in conjunction with their No Child Left Inside program, has shown that children behave and learn better in more natural environments. The same must be true for adults. Also, one type of soil microorganism has been shown to improve mood!
Basics of backyard biodiversity
So, what are specific things you can provide to improve biodiversity in your habitat?
Food (natural sources):
* Native Plants
Plants are near the bottom of the food chain. They have evolved to create a fixed set of protections and processes that depend upon other native flora and fauna. Native plants have evolved in tandem with local climate, soil, flora and fauna populations, and seasonal changes, without human assistance. These plants require the least amount of water, weeding, pruning, and other resources. They reduce pollution because they do not require pesticides, herbicides or fertilizers. There is no runoff pollution from a native plant garden. These plants commonly emit chemicals that minimize weeds in their immediate area. Native plants are far more resilient, which means less work for you!
Plants and animals have co-evolved over thousands of years. Local birds, insects and animals are looking for plants that have certain characteristics. Those characteristics are found in native plants. [Did you know that some plants have indicators that let nectar eaters know how much nectar is available?]
Native bunch grasses, which were replaced by the eastern grasses that cover local foothills, were able to stay green all summer. The golden hills we see are the result of an invasive plant that has interfered with many native life cycles. Another example: Sudden Oak Death. Our live oaks have evolved to deal with drought each summer. As the live oaks are watered, the fungus that causes Sudden Oak Death is able to overcome and kill these massive beauties.
You can learn more about native plants from the CA Native Plant Society.
You can grow a surprising amount of food in your own yard. Ask me how!