Major addition to the ChesLen Preserve

Natural Lands Trust recently acquired a 197-acre property that expands what was already one of the largest private nature preserves in southeastern Pennsylvania.

The property, situated along Cannery Road in Newlin Township, Chester County, adjoins the ChesLen Preserve which was established in 2007 when Natural Lands Trust received donations of land from philanthropist H.F. “Gerry” Lenfest and Chester County. With the addition, the preserve has grown to 1,263 acres.

The recently-purchased property features oak woodlands bordering a rare landscape known as a serpentine barren.

“The ChesLen Preserve was already one of the region’s gems” said Molly Morrison, president of Natural Lands Trust. “With this addition, it becomes not just larger but home to one of the most unusual and important natural communities on the East Coast.”

Serpentine barrens are a unique ecosystem - a grassy savanna dotted with small trees and plants that are found only in this particular landscape. Just seven barrens sites remain of the eighteen that were once scattered throughout Chester, Delaware and New Castle Counties. The stretch of barrens within and around the ChesLen Preserve is commonly referred to as the “Unionville Barrens” and is one of the most biologically diverse serpentine sites in Pennsylvania.

The barrens derive their name from serpentinite, the rock present just beneath the soil. Serpentinite is a geologic oddity, a metamorphic rock typically found on the seabed deep below the ocean. Shifts in the earth’s crust placed serpentinite on the continent in scattered locations along the East Coast, where it was slowly revealed by erosion.

The soil that forms from this rock is unlike any other in the world. Thanks to its unique mineral and chemical composition, few plant species can grow in serpentine soil. However, a number of rare plants — including colorful wildflowers — thrive in the generally inhospitable barrens and some threatened and endangered animal species feed exclusively on these plants. Without the barrens, those native plants and animals could be lost.

In a study detailing the biological and historical value of the area, Dr. Roger Latham, a conservation biologist, stresses the need to protect the Unionville Barrens. “Of all ecosystem types, temperate grassland, the category that includes the prairie and savanna at the Unionville Barrens, is in the direst straits.”

Ironically, it was mining that helped to keep the Unionville Barrens from disappearing entirely. Portions of Chester County serpentine barrens were mined from the late 1800s through the early 1900s. They were a source for minerals and semi-precious stones as well as serpentine building stone, the light-green stone recognizable to area residents in old public buildings and houses. Mining provided the repeated disturbances that are needed to deter invasion by non-barrens vegetation. Following the retreat of the mining industry, the grasslands at the Unionville Barrens dwindled to just nine acres from the fifty-eight acres present during the 1930’s. These losses heighten the sense of urgency to protect and restore the barrens.

The ChesLen Preserve stretches more than two miles across Newlin Township, touching the borders of West Bradford and East Marlborough Townships. It is a classic landscape of rolling countryside, dense woodlands, numerous streams, and two miles of the West Branch of the Brandywine Creek. ChesLen also features historic sites such as Stargazer’s Stone, a monument Charles Mason and Jeremiah Dixon utilized during their historic survey expedition to set the border between Maryland and Pennsylvania.

The purchase of the 197-acre addition was made possible by support from H.F. “Gerry” Lenfest, the Chester County Preservation Partnership Program, and the Pennsylvania Department of Conservation and Natural Resources.

“Once again, we have seen Mr. Lenfest’s generosity yield extraordinary results,” Morrison noted. “With his leadership and the support of the County and the Commonwealth, the ChesLen Preserve is now an even greater gift to the region’s current and future residents.”

“It had long been my hope that the woodlands and barrens there would be preserved,” Mr. Lenfest said. “I am gratified to again work with Natural Lands Trust to further the conservation of this important landscape.”

Chairman of the Chester County Commissioners, Terrence Farrell, expressed the County’s excitement about the addition. “My fellow Commissioners - Carol Aichele and Kathi Cozzone - and I are thrilled to see this beautiful and ecologically-sensitive property protected, forever,” Farrell stated. “It makes the ChesLen Preserve an even more spectacular resource for the citizens of the County.”