EAST BRANDYWINE The Brandywine Conservancy plans to plant its 25,000th tree Saturday as part of its five-year tree reforestation campaign in Chester County.

Volunteers will plant 650 trees, including maples, oaks and magnolias, along the East Branch of the Brandywine Creek in East Brandywine Township. More trees in the county mean better air and water quality and less storm water runoff.

Forests covered more than 90 percent of the Brandywine watershed hundreds of years ago, according to the conservancy. That number is now down to about 28 percent.

"We can keep our natural systems in much better balance even as we grow and develop," said Wesley Horner, the conservancy's senior advisor for water resources. "And that's what we're trying to do."

The conservancy is preparing to plant 1,800 more trees in East Nottingham Township and Pennsbury Township by early May. It has set a new goal of planting 50,000 trees by its 50th anniversary in 2017.

- Michaelle Bond