Every year, Michigan taxpayers spend tens of billions of dollars on capital infrastructure projects such as roads, sewers and waterlines. As a state, we recognize the role maintaining and expanding these investments can play in our economic development. Few communities, however, make a similar investment in their "green" infrastructure-the network of forests, greenways, parks, waterways and other undeveloped spaces that form the natural life support system for our nation.

As urban sprawl degrades recreational opportunities for Michigan citizens and threatens the viability of several of the state's key industries (tourism and agriculture among the most important), preservation of Michigan's green infrastructure is taking on new significance. Many community leaders and activists, however, lack the vocabulary to actively pursue a green infrastructure plan. Sensing this, the Sprawlwatch Clearinghouse has issued an important new monograph that serves as a primer for those looking to incorporate natural space planning into their overall community development plans. Green Infrastructure: Smart Conservation for the 21st Century can be ordered from www.sprawlwatch.org.

Authors Mark Benedict, director of the Conservation Leadership Network at the Conservation Fund, and Edward McMahon, vice president and director of Land Programs at the Conservation Fund and former president of Scenic America, give readers a concise survey of green infrastructure planning practices that is highlighted with case studies from around the country. The monograph includes background on the green infrastructure movement as well as principles and strategies that can be used in every Michigan community.

The key to successful natural space planning is not the preservation of isolated bits of open space or sensitive features, but the development of networks and corridors that allow ecosystems to thrive. This is not a new concept. Frederick Law Olmsted, one of the country's foremost landscape architects, wrote, "No single park, no matter how large and how well designed, would provide the citizens with the beneficial influences of nature.... A connected system of parks and parkways is manifestly far more complete and useful than a series of isolated parks."

Activist organizations and MEC members have recognized this for decades. The Rails-to-Trails Conservancy is responsible for more linear trails and natural space corridors than any other nongovernmental organization in the country. The Southeast Michigan Greenways Initiative is developing a cutting-edge plan to use natural spaces for community connectivity and buffering between sprawling developments. These organizations, however, are only just now coming into their strength, and they need support from activists and government leaders alike.

From Olmsted and Benton MacKaye, founder of the Georgia-to-Maine Appalachian Trail, to former President Clinton and Maryland Governor Parris Glendenning, a continuum of support has developed for green infrastructure planning. With the help of the Sprawlwatch monograph, community leaders can gain the basic tools to join in this important struggle.