As the population density in Southern Oregon increases and spreads outward, open space, wildlife habitat and natural resources diminish.

As the population density in Southern Oregon increases and spreads outward, open space, wildlife habitat and natural resources diminish.

As author Doug Tallamy explained at this year's Oregon Urban and Community Forestry Conference in Portland, when we shrink a habitat, we lose niche space.

In addition, when nonnative flora outcompete native plants, which many creepy-crawlies simply can't eat, it's hard on our bird populations.

Today, says Tallamy, chair of the Entomology Department at the University of Delaware, our yards tend to support very little biodiversity.

What can we do to raise the carrying capacity of our neighborhoods so they can be healthy, functioning ecosystems? One way is to get your garden "wildlife habitat-certified" by the National Wildlife Federation. This program is designed to enlist homeowners in the effort to make their yards kinder to the fauna in their midst.

By providing food, water, cover and places for wildlife to raise their young, more than 150,000 people across the country have had their yards certified, according to the group's website,

Planting native species is the easiest way to provide the foliage, nectar, pollen, berries, seeds and nuts that many birds and types of wildlife need to survive and thrive. An added bonus is that native plants require less watering, saving time and money.

To get your garden "wildlife habitat-certified," you'll need to provide at least three food sources. One plant species worth considering is manzanita (Arcostaphylos), including kinnikinnick, a charming ground cover featuring small, white or pink flowers in the spring, followed by red berries that attract birds in the fall.

Oregon grape (Berberis aquifolium) is another good choice, as is Oregon boxwood (Paxistime myrsinites). It can survive our hot summers with little or no water; just be sure to give it enough water during its first one to two years of establishment.

Other Oregon natives include oceanspray, with its foamy-white flower clusters, red flowering currant (a hummingbird "magnet"), bitter cherry, thimbleberry, yarrow, showy milkweed (food source of the monarch butterfly), meadow checkermallow, goldenrod (a late-summer bloomer) and tall Oregon grape, an early-blooming sun lover. Some of these are most easily obtained at nurseries specializing in native plants.

If a yard or garden has room for a new tree to grow to maturity — both above and below ground — here are a few ideas.

For yards with lots of room, consider Willamette Valley ponderosa pine or bigleaf maple. Wild cherry or Pacific madrone are possible native-tree choices for a medium-sized yard, and on small, partly shaded sites, the lovely dogwood attracts birds.

Oregon white oaks provide favorable habitat for a number of important wildlife types, including dark-eyed juncos, nuthatches, pileated woodpeckers and Western grey squirrels. Provide full sun, good drainage and plenty of room for these eventual giants of the landscape.

Provide a source of water, as it can be difficult for wildlife to find it at certain times of the year. Ponds, small streams, rain gardens or birdbaths are helpful water sources for insects, amphibians and our feathered friends.

Wildlife also need shelter from the weather and places to hide from predators. Two sources of shelter are required for certification. Wooded areas, ground cover, a log pile, shrubs and roosting boxes all are examples of shelter homeowners can provide.

Birds and bugs also need protected places to mate, bear and raise young. Mature trees, dead trees, dense shrubs, water gardens, nesting boxes and host plants for caterpillars all qualify. Two are needed for certification.

Other than concrete paving, a lawn is the least productive thing for the ecosystem that we can have in our yards. Reducing or eliminating the amount of lawn in one's yard or garden is a positive step toward enhancing the ecosystem services a landscape provides. Also, try to leave some areas on your property "wild," where grass and native, noninvasive weeds can grow undisturbed.

Cynthia Orlando has a degree in forest management and is a certified arborist with Oregon Department of Forestry.