You don't need to actually set foot on our region's steep wooded hillsides to appreciate their value. Think of your favorite local panoramic view. It's a geographic certainty the vista is at least partially framed by an enduring wooded slope.

		Patrick McShea works for the Division of Education at Carnegie Museum of Natural History and is on the Board of Directors for Allegheny Land Trust (McSheaP@CarnegieMNH.Org)

As living components of southwestern Pennsylvania's landscape fabric, such hillsides are far undervalued in their undeveloped state precisely because they lie in such plain sight. According to the findings of a recent multidiscipline study, a partial list of benefits provided by undeveloped hillsides includes the stabilization of slide-prone soils, the reduction of storm water runoff, the mitigation of temperature build-up during summer heat waves and even the enhancement of adjacent property values.

Moreover, in the language of the report's urban design segment, the ribbons of rugged terrain that define the boundaries of neighborhoods and direct the routes of major transportation corridors are "form givers." These ubiquitous slopes -- which were long ago carved from once level terrain by the down-cutting action of our rivers and their tributary streams -- are in topographic fact the framework responsible for the mosaic pattern of development that today makes Pittsburgh different from other cities.

The year-long study, titled "An Ecological and Physical Investigation of Pittsburgh's Hillsides," was initiated in 2004 to help the Pittsburgh Department of City Planning and its Hillsides Committee reconcile preservation and development efforts involving the approximately 11 percent of city area with a slope greater than 25 degrees.

Supported by the Heinz Endowments, a team of professionals from Carnegie Mellon University, the University of Pittsburgh and the architectural firm Perkins Eastman researched zoning approaches used by other cities and charted existing soil conditions, plant cover and, where applicable, building patterns on the city's most tilted acreage. The team's synthesis of expertise in geology, ecology, urban design, zoning law and economic development has already produced both recognition and results. In October the hillside study earned an urban design award from the American Institute of Architects. In December, Pittsburgh City Council adopted a Steep Slope Overlay ordinance based upon the work's recommendations.

Last month's unanimous City Council decision to incorporate a 16-acre tract of Mount Washington's "Saddle" into the patchwork of properties that will make up Grandview Scenic Byway Park can be viewed as further evidence of the study's ongoing impact.

From a long-term perspective, however, the "city limits" reach of the hillside study might paradoxically be exceeded by its grasp. Due to the report's accessibility -- and more importantly, because of the great potential for more widespread application of its far-sighted recommendations -- the study might eventually also influence land use patterns throughout Pittsburgh's collar of slope-rich suburbs.

The report is on the Web site of the Allegheny Land Trust, the nonprofit organization charged with managing finances for the hillside study (www.AlleghenyLandTrust.org). Here, a developer working in Shaler, a council member from Baldwin Borough or a concerned citizen in Penn Hills can read clear explanations, review statistical documentation and even view photographic evidence for the value of preserving many of the steep overgrown places we regularly view but never visit.

The Allegheny Land Trust knows a lot about hillside preservation. During its 13 years of existence, this organization has used strategic purchases, donations of property and conservation easements to protect nearly 1,300 acres of property in Allegheny and Washington counties. Much of that property consists of steep slopes, and on some of those tracts the overriding natural value is a commodity that defies easy quantification: a complex inter-related community of diverse wild plants and animals.

Visitors to the Land Trust's 230-acre Barking Slopes Biological Diversity Area in Plum get a hint of those interactions every spring when they walk the gravel road along the base of the tract's towering Allegheny River bluffs to view blooming trillium and other early wildflowers.

A botanist on the hillside study team noted that Pittsburgh's steepest wooded tracts appear to act as refuges for native plant species. That phenomenon is eminently observable here, seven miles upriver from the city's eastern limits.

You don't need to appreciate the mix of trees, shrubs and wildflowers on these cliffs and terraces to value this protected forest. Just ask the people who live across the water in Cheswick and Springdale. For many of them the annual April appearance of blossoms and pale green leaves on this steep slope signals a welcome end to winter. It's not necessary to actually visit the messenger to get that message.