In September 2009, more than 500 volunteers gathered at Phil Hardberger Park to begin the process of recreating the once thriving savanna in a pilot project of three acres. The volunteers planted 50,000 native grass and wildflower plants in one day. By summer 2010, the restored grasslands are expected to once again be thriving.
Prairies are grasslands that are almost or entirely lacking trees or other woody plants. Savannas are grasslands that are dotted with trees, clumps of trees or small woodlands. Prairies and savannas were once a dominant feature of the Texas landscape, as well as landscapes from Canada to Mexico through the center of North America. It is estimated that less than 3 percent of the original landscape remains. Much of Phil Hardberger Park was originally a savanna.
Park staff members also spread seeds of an additional 60 species of native prairie plants. Prairies and savannas are rich in species diversity. This wide range of plant species will support a wide range of insects, reptiles, mammals and birds that are dependent upon the diverse grass and wildflower species.
These efforts are the first steps in implementing a core mission of the Master Plan, which is to restore the native landscape. Phil Hardberger Park presents an opportunity to renew native plant communities and wildlife habitats that are decreasing rapidly in the region, recapturing the significant landscape identity of South Texas. To have the unique prospect of restoring a native savanna in the midst of an urban community is but one of the many values of the park.
Other steps outlined in the Master Plan include:
Liberate the Oaks
Heritage live oak trees will be liberated from encroaching shrubs and planted with a ground plane of native grasses and wildflowers. The intent is to showcase some of the most exceptional specimens believed to be several centuries old.
Preserve Heritage Trees
Protecting and preserving the historic woodlands ensures habitat integrity and biodiversity across the site while maintaining culturally important trees. While some wildlife prefers an open savanna habitat, others require the closed and more protected woodland habitat. And many species require both. The junction of two habitat types is called an ecotone and is almost always richer in species diversity than either of the two joining habitats alone.
Restore the Grasslands
Restoration of the grasslands reintroduces a native ecosystem at the site, providing ecologically rich edge conditions and recapturing the unique landscape identity of South Texas.
Increasing the growth of native flora promotes overall biodiversity and demonstrates the unique qualities of Phil Hardberger Park as a cultivated wild in the City of San Antonio.
A rangeland health indicator survey revealed 6 major soil types including the blackland prairie Austin series. Findings show a complete reversal of cover classes from once open oak savanna of 15% - 30% tree cover to 66% - 98% tree cover now. Soil compaction, loss of soils, sparse ground cover and patches of increasers show the effects of overgrazing which increases run-off and erosion. Persimmon, juniper and whitebrush are aggressive colonizing species requiring control. Due to fire suppression, woody plants now dominate many areas altering the hydrologic function of soil and decreasing rain water infiltration. Although ground cover is not good, the tree canopy has prevented major erosion of the area. Lewisville and Austin series would benefit from grassland restoration and all soil types by removal of some juniper, persimmon, whitebrush and other woody plants, improving hydrologic function and biotic potential of the soil.
The landscape of Phil Hardberger Park is segmented into areas known as landscape patches. Below is a detailed description of each landscape patch.
Live Oak Woodlands
These areas are dominated by live oaks averaging 40 feet tall with an average diameter-at-breast height (DBH) of 20 inches. Understory is sparse. Other species found within these areas consist mainly of cedar elm, occasional Ashe juniper, hackberry, Texas persimmon, condalia; whitebrush, prickly pear, tasajillo, frost weed, Indian mallow, zexmenia, agarita, greenbrier, and croton. There is a great deal of oak seedling recruitment as well as snags throughout these areas. Deadfall and snags (dead standing trees) are vital components of a healthy woodland and provide food and habitat to many organisms.
Live Oak/Ashe Juniper Woodlands
Vegetation within this area mainly consists of more scattered live oak, Ashe juniper, mesquite, Texas persimmon, soapberry, hackberry, condalia, elbowbush, agarita, cow-itch, frost weed, zexmenia, and streambed bristlegrass . There is obvious live oak seedling recruitment in this area. Live oaks average approximately 40 feet tall with an average DBH of 20 inches. There are a number of large persimmons and mesquites within this area and a thicker understory than the live oak woodlands.
Live Oak/Mixed Deciduous Woodlands
Vegetation within this area is concentrated into islands with grass breaks between. These islands have a closed canopy and mainly consist of live oak, cedar elm, Texas persimmon, hackberry, and scattered Ashe juniper. The understory mainly consists of frostweed, elbow bush, agarita, Arkansas yucca, prickly pear, straggler daisy, greenbrier, sedge, and velvet leaf mallow.
Live Oak/Cedar Elm Woodland
This area is located in a bottomland area with very little understory. Trees mainly consist of scattered live oaks and cedar elms. Within the understory are frost weed, agarita, greenbrier, prickly pear, and velvet leaf mallow.
Vegetation within this area mainly consists of hackberry, mesquite, Texas persimmon, condalia, whitebrush, and frost weed. Straggler daisy provides a dense ground covering within this area. There is also a very open canopy with a thicker shrub layer mainly consisting of whitebrush.
A pasture located near the house mainly consists of shrubby mesquite, croton, nightshade, Bermuda grass, pigweed , fanpetals, and panicgrass.