An Introduction to Habitat Design
Habitat loss has pushed our planet past the brink of ecological crisis - and there is little doubt that humans are the culprits. With our population growth and over-consumption have come huge ecosystem modifications, climate change, and the beginning of the earth's sixth great extinction event. This study published in Conservation Biology concludes that “current extinction rates are 1,000 times higher than natural background rates of extinction and future rates are likely to be 10,000 times higher.”
In the face of this crisis we are presented with both a challenge and an opportunity to promote habitat conservation and restoration. By taking into consideration the following concepts, humans can create ecologically sound habitats that will sustain key species, provide ecological and aesthetic benefits, and will begin to rebuild what has been lost.
CHOOSE NATIVE PLANTS
What is the difference between a oak tree and a boxwood? To the human eye, there are some apparent differences in size, shape, and color of leaves. But to certain wildlife, an oak tree is a shelter, a food source, or a place to build a nest and lay eggs. In fact, according to the Resource Conservation District of the Santa Monica Mountains, in their region “over 5,000 species of insects, 58 species of reptiles and amphibians, 105 species of mammals and over 150 species of birds rely on oaks for some of their life cycle.” To these same wildlife species, a boxwood provides no support to their needs and lifecycles.
Native oaks are what is known as a keystone species. Without the existence of the oak, the life cycles of many other organisms would be disrupted, in turn disrupting an entire ecosystem. If the non-native boxwood ceased to exist, there would be little to no impact on wildlife and the surrounding ecosystem in that region.
This is just one example of the key role a native plant can play in the lives of the species in its habitat. When we choose to integrate appropriate native plants in our landscapes, we are supporting a ecosystem integrity and encouraging the prosperity of native pollinators, birds, mammals, and other wildlife.
THE IMPORTANCE OF BIODIVERSITY
By restoring native habitat, we can encourage biodiversity and create resilient and sustainable landscapes. Biodiversity is the variety of life existing in a habitat. We can look at the biodiversity of the organisms living on one leaf, or the biodiversity of organisms living in an entire forest.
Why is biodiversity so important? The bottom line is that (usually) the more complex and biodiverse an ecosystem is, the more resilient and productive it will be. The question of the importance of biodiversity can be answered through the lens of economics, aesthetics, politics, science, or ethics. Any way we choose to explore this question, it is clear that maintaining biodiversity is key to the success of the human population as well as to the health of our planet. (Check out this video about why biodiversity is important to humans.)
ADAPTATION EQUALS SURVIVAL
Cary Fowler wrote “To many people, 'biodiversity' is almost synonymous with the word 'nature,' and 'nature' brings to mind steamy forests and the big creatures that dwell there. Fair enough. But biodiversity is much more than that, for it encompasses not only the diversity of species, but also the diversity within species.” There are differences, both in appearance and genetics, that occur within the same species. This in an incredibly important concept because it is within these differences that adaptation occurs. Adaptation is the key to species survival.
When selecting native plants for a landscape, consider that a local cultivar is already adapted to it’s local climate and habitat. Additionally, the wildlife within that community has adapted and grown alongside this local cultivar. Each species depends on others, so by planting locally adapted vegetation we are encouraging a stronger local wildlife community.
INCREASE HABITAT SIZE
There is a direct link between the size of a habitat and the biodiversity in that habitat. By creating landscape corridors, which are strips of habitat that connect what would otherwise be isolated patches of habitat, many smaller spaces can be joined together to create a larger habitat capable of supporting more diverse species. In this example, a wildlife corridor was created through a golf course to support the ecologically important wolf community. This successfully increased the area of high quality habitat available to wolves and increased their access to prey.
PLANT FOR THE NATIVE HABITAT
A common tendency when trying to increase biodiversity is to plant as many different species of native vegetation as possible in a landscape. But does it make sense to plant a native forest tree, a native beach shrub, and a native wetland grass in the same area? Perhaps a better approach is to first examine the conditions of the natural habitat in the surrounding area. Identify what plant species are thriving or have historically been present, observe the soil type, and note the climatic conditions. By selecting the appropriate plants for the habitat type, a balanced habitat filled with native plant and wildlife species will flourish.
Once an appropriate native habitat is identified, we can choose specific varieties of vegetation to attract particular wildlife species for that habitat. For example, planting native milkweed to attract endangered monarch butterflies in a field, or planting native “trumpet” shaped flowers to attract hummingbirds. Read more about attracting wildlife with native plants.
DON’T FORGET SOIL
One of most biodiverse ecosystems that is often overlooked exists right under our feet. Healthy, organic soil can contains billions of microbes in just one teaspoon. This complex ecosystem provides innumerable services to landscapes, including improved air and water quality, nutrients for vegetation, stability for structures, carbon storage and flood control. Maintain and build healthy soils by using appropriate organic amendments and compost, avoiding synthetic pesticides and herbicides, and managing stormwater to reduce erosion.