Prairie Landscape

Demonstrating our belief in sustainable landscaping and the need to improve and diversify our urban landscape wherever possible, Friends of Trees has added a small prairie in front of our office. With the addition of the prairie landscape, we hope to increase habitat for native insects and animals, diversify urban landscapes with more native habitat, educate and demonstrate sustainable landscaping choices, and conserve and redirect rainwater.

We don't know for certain what the landscape and vegetation communities in the Willamette River Valley were prior to human influence, but the soils indicate that a prairie ecosystem was predominant. Native Americans undoubtedly had an impact on the vegetation by using fire for hunting and by increasing edible plants, but the valley was still dominated by grassland vegetation prior to European settlement in the early 19th century.

Diversifying our urban landscape with pocket habitats of grassland/prairie plant cover increases and diversifies habitat for most flora and fauna. An increase in prairie/grassland plants can translate into increases in insect pollinators. Benefits of pollinators include "enhancing fruit set and size, seed production and viability, seedling vigor, and the genetic diversity of plant populations." (Cane and Tepedino, 2001) Populations of insect pollinators such as butterflies and bees have declined in recent years. Some suspected causes of the decline are habitat loss, invasive species, climate change, and the use of insecticides. A decline in insect pollinators can affect species of plants not directly pollinated by the insects and ultimately cause the overall decline of beneficial plant communities. By increasing prairie land cover, we provide pocket habitat for these important pollinators.

In the front of our office, we have planted a mostly native prairie landscape with a bioswale. The bioswale collects the excess water coming off the conventional part of our roof in the downspouts. We have planted a variety of native grasses, sedges, and rushes in the swale in order to absorb that water rather than allowing it to run off into the storm drains. In the larger landscape we have some fairly common plants like kinnikinnick and wild strawberry. These plants were planted because of their drought tolerance, which is a necessity for prairie plants. For this reason, some of the species in the prairie landscape have also been planted on Friends of Trees' new ecoroof. One such example is wild strawberry (Fragaria virginiana var. platypetala).

As homeowners and community members, we can have a positive impact on our urban environment. Restoring some urban settings to their pre-settlement vegetation communities enhances both plant and wildlife diversity in our urban forest. Benefits include improved air quality, cooler air in summer, reduced urban heat island effect, filtered and cooled stormwater runoff, reduced energy consumption from shade in summer and windbreaks in winter, increased habitat for pollinating insects, and generally improved neighborhood aesthetics. Please join us in this effort to diversity urban landscapes and improve the benefits of our urban forest community.

Native Plant List

*Non-native
� Planted in Swale

Diversity: Secrets Behind the Buzzword

The term diversity is thrown around in environmental speak. Chestnut blight and Dutch elm disease are two very important reasons why diversity is stressed for ecological habitats and landscapes. Globalization has increased the importing of pests from one ecosystem to another. These "pests" often exploit their new environment and take over niches that once belonged to native species. Since these pests originated elsewhere, their native predators cannot keep populations in check. Once a "pest" takes hold, it can be very difficult to eradicate.

In the case of Chestnut blight, we are still seeing the results of this devastating fungus in the absence of these beautiful trees in our eastern forests. What once was a very important tree in Native American culture and in the development of our nation has been replaced by other tree species that do not provide the benefits that Chestnuts once did.

Click here to learn more about invasive plants in the Portland-Vancouver area and what you can do to reduce their impact on our region's ecosystems.