I was a princess in a castle. Not a ‘come save me, I’m so frail’ princess, but a princess that hunted with falcons, rode griffins and tamed dragons. I had a castle, a fortress, surrounded by an impenetrable forest. My castle was guarded by ancient giants and magic.
I was a small, muddy girl in overalls. I made a fortress in my Great Grandmothers’ lilac bush, flanked on either side by old knobby oaks. The sparrows visited the branches and the neighbor dog could come sniff me through the fence. I had built an entire world within a shrub; I lived through adventures and decorated my throne with leaves and acorns. The garden became a vehicle for my imagination.
Too often the landscapes or gardens with which we surround our homes are thought of only for their aesthetic purpose. Or they are ignored entirely. Yes, gardens and well maintained landscapes are pretty but is that their only function?
As we justify the time and resources spent on managing our home landscapes, we often forget to mention the intrinsic benefits we receive from our landscapes. These benefits can be classified into a few distinct categories; environmental functions, human health benefits, societal and economic benefits. Throughout the next few posts, I would like to explore each of these categories in more depth discussing first the myriad of environmental benefits associated with the urban landscape.
The Urban Environment
The urban environment is an ecosystem, a vastly different ecosystem from that which came before human development, but still an ecosystem. Many of the environmental functions of our urban ecosystems have been altered due to our involvement. In an area where leaves would have once been left to decompose and return their nutrients to the soil, now there is a manicured lawn whose trimmings are bagged up and hauled to the curb. This does not mean that all value is lost, the presence of plants in our urban landscapes provide the backbone for a multitude of services; erosion control, reduction of urban heat island, wildlife habitat, water filtration, noise reduction, air filtration, nutrient cycling and carbon sequestration.
Plants have been used for erosion control for many years, to stabilize banks and to prevent loss of soil around stormwater ponds. It would seem unlikely that anyone would dispute the ability of plants to hold onto the soil, however some plants do this better than others. In a comparison of native prairie grasses and turfgrass the root depth of native grasses is much deeper and more widespread than that of turfgrass. To highlight a native species that many in Florida can recognize; sea oats are wonderful at holding onto soil. They live in a harsh environment of shifting sands and yet are able to stabilize and grow the dunes that are so important to our coastal habitats. They have vast net-like roots that grab the sand and hold on through tides, storms and wind. It has become common to see canals and ditches being fortified with seedlings to prevent sediment intrusion into the already impaired urban runoff.
Not only do plants hold soil, they also decrease the impacts of urban heat island effect. Trees and other plants provide shade, but also through their unique photosynthetic processes create micro-climates. These micro-climates are created when water vapor is released by plants as a byproduct of photosynthesis. This water vapor in the atmosphere helps to buffer the temperature, minimizing extremes; cooler during the day and warmer at night. The green space that is incorporated into urban landscapes lowers the overall urban heat island effect. In an environment where concrete is king; grass, trees and shrubs provide much needed cooling.
Have you ever walked through a park with a deep green canopy? There is a calmness around trees, sounds are softer, the air is more gentle and the light is easier on our eyes. Trees and other plants have the benefit of creating sound barriers. In environments where traffic noise is common, humans and wildlife are affected. Some studies show that stress and heart disease drastically increase as homes get closer to major highways. This has been related to the presence of constant background noise. The presence of plants around our homes lowers this constant noise and creates a much needed stillness.
Despite these and more wonderful side effects of urban plants, perhaps the most important is the presence of wildlife habitat. The patterns of urban and suburban development that have been in place since the early 1950’s have had a distinct effect on the fragmentation of valuable habitat. How many neighborhoods are named for the species they have displaced? Panther Crossing, Bobcat Trail, Osprey Roost, Oak Village, Cypress Grove: all names might represent a species that once was prevalent and now may be absent. This is not to say that there is no value in a single oak, or a single cypress grove, on the contrary, one oak tree can support over 250 distinct species of life.
Several species have been able to adapt to our urban environments; raccoons, possums, foxes, coyotes, squirrels etc. Unfortunately, we often refer to these animals most suited to our built environments as “pests”. Rather than cheer for those species that have been able to survive our encroachment we label them as a nuisance and try to remove them. We see benefits for wildlife in the parks and green spaces that are encouraged and as we learn more about our impact; urban species will continue to adapt and multiply.
Habitat value exists in our urban environments, we just need to provide a few basic elements to encourage a diversity of species; water, space, plant diversity, cover and food. Encourage pollinators to your property with flowering and nectar rich plants like: native milkweed, coral honeysuckle, native sunflowers, blanket flower, goldenrod etc. Encourage birds and bats by planting trees and providing nesting materials. Plants with fruit such as; firebush, holly, native plums, paw paw and wild coffee will entice mammals and larger birds of prey that eat mammals. Small steps can be taken in the landscape to create valuable habitat for wildlife.
One of the greatest challenges to protecting our larger fauna comes from the lack of continuous green corridors. Encourage your local community to create wildlife overpasses/underpasses for highways, create wildlife corridors along existing bike paths and abandoned rail lines.
Our urban ecosystems are not dead, we have only to breathe a little life, and maybe a little imagination into them.
Follow these links for research on Urban Ecosystems:
Air pollution reduction and Temperature Reduction by Gainesville’s Urban Forest:
Restoring the Urban Forest Ecosystem:
City of Tampa Urban Ecological Analysis: http://edis.ifas.ufl.edu/pdffiles/FR/FR26500.pdf
Landscaping for Backyard Wildlife Habitats: