Since its founding in 1975, Shipley Nature Center in Central Park has seen major changes. At first, oak, sycamore, alder, willow, redwood and pine trees were planted at the former county dumpsite. Shrubs grew, flowers bloomed and wildlife flourished. Then, due to neglect during the 1990s, the center went into decline. The entire east side became a jungle of nonnative castor bean, passion vine, giant reed and Brazilian pepper trees. Tamarisk and myoporum crowded out native plantings on the north side, and the pine forest on the west side was dying. Poison hemlock had spread everywhere.
Restoration of the nature center began in 1999 with removal of tamarisk and myoporum, funded by the Robert Mayer Corp. The following year, the city hired crews to fell and remove dozens of dead and diseased Monterey pines. They also began an assault on the passion vine that was smothering and killing native trees. In 2001, the city hired the Orange County Conservation Corps to begin removal of the forest of giant reed that had overtaken the eastern side.