Xeriscape in the City Highlights At-risk Habitats

Eastern prickly pear

By Devin Floyd

April 29th, 2020

At this high-traffic urban corner we are engaging the public with an educational exhibit highlighting some rare, local ecosystems. This work has become part of our brand – the creation of outdoor interactive exhibits of local natural history (plants, animals, fungi, geology, etc).

With southern exposure and ideal site conditions, we’ve introduced most of the vegetative and ground cover facets of 2 remarkable local natural communities: Basic Ash-Hickory Woodland and Piedmont Mafic Barren. We mimicked the pavement bedrock that is typical of the community by using locally sourced metabasalt (Luck Stone, Shadwell). This is the natural bedrock type at the project site. Bedrock, its residual soils, and the impacts on recruitment and sustainability of native plants, is such an important part of native plant landscaping and restoration. It is most often overlooked, or overly simplified (most people think pH is important, and it is actually very secondary). At this site, the bedrock’s cation-rich chemistry creates the chemically unique clayey soil substrate (elevated calcium, iron, manganese, and magnesium) that supports these rare natural communities. The soil is clayey, rocky, yet productive. It is calcium-rich, yet moderately acidic.

We are about 50% finished with the restoration. Diversity is slowly climbing as we introduce the species that are naturally part of the community. In the images taken today on site you will see some indicator species for the community types, including fragrant sumac (Rhus aromatica), slim-leaf panicgrass (Dichanthelium linearifolium), wild pink (Silene caroliniana), hairy lipfern (Cheilanthes lanosa), woodland sunflower (Helianthus divaricatus), and eastern prickly pear (Opuntia humifusa). Several prominent parts of the community, like Appalachian phacelia (Phacelia dubia), have not been introduced yet. It would create a carpet of thousands of flowers through the project area this time of year (as seen in the final image taken in a wild example of the community). We are waiting for a reduction in non-native species and an increase in soil stability before introducing that and many other species.