What is a green roof?

Green roof systems are described as an extension of the existing roof which involves a high quality water proofing and root repellant system, a drainage system, filter cloth, a lightweight growing medium and plants.¹While there is some debate as to the effectiveness of green roof structures at addressing some of the larger issues associated with urban environmental degradations and climate change, green roofs have been found be beneficial. For example, these systems have been found to lower rooftop and building temperatures, thereby reducing the urban heat island effect found in so many of today’s cities, as well as improving the quality of stormwater runoff while decreasing the amount of runoff during storm events. Green roofs also slow precipitation that rooftops capture so that when it drains to the public sewer system, or some other receiving body, it happens over a period of hours and sometimes days rather than minutes or seconds.  This reduction in rainwater release dampens the pulse, or volume of water, that must be transported off-site and treated in wastewater plants. In cities or areas with combined rainwater and sewer systems, such as Seattle and Portland, this pulse sometimes overwhelms the wastewater treatment plant, resulting in released sewage and rainwater. In our region, preventing combined sewer overflows is an important action for improving the ecological health of Puget Sound and other large bodies of water. Continue reading →

INTRODUCTION

Native plant propagation, restoration, and conservation are complex activities that require many steps and decisions, and face many challenges. On one hand, there is broad agreement, at least among restorationists, over the importance of native plants and the benefits of habitat restoration. But on the other, there is widespread uncertainty and dissent about how to achieve these restoration goals. What should be planted and where? How should plant-materials for restoration be obtained? Where should they come from? What is the overall goal? The objective of this paper is to identify areas of agreement and disagreement to help frame debates in native plant restoration, and thus improve our ability to discuss and conduct this work from a position of mutual understanding and productive dialogue. Continue reading →

This spring I spend my days at Mima mounds natural area preserve and glacial heritage prairie in Thurston County, Washington.  I monitor camas distributions on mounds and their inter-mound swales, along north-south gradients.  I record camas phenological stages and the relative abundance of other ethnobotanical species important to the Native peoples of this land. Each day, when the prairie warms up it becomes a-buzz with busy bees, pollinating future camas crops.  Butterflies dance on the breeze, a pair of Northern harriers soar over mounded terrain, and meadowlarks sing happily as I count “Bud – Bud – Flower – Fruit – Fruit – Flower – Flower – Fruit . . .” My volunteer companion, Dale Pressler, records this monotonous drone.  Riffle club shell-fire and a remote-control toy airplane periodically shatter the serenity of our routine. But the prairie’s beauty, the secrets lying dormant in these earth mounds, and my desire to complete my PhD keep me coming back, day after day, week after week. Continue reading →

Adapting to the challenges we face in the future includes bringing native plants closer to our everyday lives. Looking at native plants and how we used them in a historical context is important because we need to preserve and recover traditional uses of plants and invent new ways to use them in order to promote their preservation.

Use of Native Plants in the Pacific Northwest

This pertains to the northwestern corner of the United States and adjacent islands of the San Juan Archipelago. Prior to 1859, this area was sparsely inhabited with people of European heritage. Through the 1870s, movement around the area was only possible by canoe or pack train and it was not until the 1890s that wagon roads for freight and stage were in place. Continue reading →

I.    INTRODUCTION

Surface erosion and mass soil losses from landslides are of great concern to land managers. Accelerated erosion and slope instability can be caused or exacerbated by human activities. Increased erosion can cause adverse cumulative watershed problems by increasing sedimentation, degrading water supplies, reducing forest productivity, destroying anadromous fish habitat, and degrading other critical environmental functions. Structurally mature and floristically complex plant communities significantly reduce surface erosion and contribute greatly to maintaining slope stability. Management of forested, coastal, urban, agricultural, and riparian areas should conserve plant cover.  The relative effectiveness of vegetation in any specific locale will be a function of site-specific conditions. Continue reading →