San Antonio Chapter

Stressed Out: A Look at Tree Health in San Antonio and How to Strengthen Our Urban Landscape

Tree Health

January 2025 Presentation by Michael Nentwich. Stressed Out: A Look at Tree Health in San Antonio and How to Strengthen Our Urban Landscape.

Join us for a discussion about the stresses on our urban forest in San Antonio with Bexar Branches Alliance President Michael Nentwich. Is it the extreme heat during the summer, the extended heat waves, the severe cold events, the extended drought, or all of it? Once we can identify and name the stresses, let’s consider what we can do to maintain tree health and diversity in Bexar County.

Michael has more than 15 years of experience in community forestry management and program development. Currently the President and founder of Bexar Branches Alliance, Michael previously was San Antonio’s first City Forester and later served as City Forester with the City of Norfolk, Virginia. He has a BA in Environmental Science and MS in Forestry from Stephen F. Austin University.

With increasing extreme weather patterns that have stressed, particularly, our urban trees in Bexar County.  As a follow-up to the January Chapter Meeting Presentation by Michael Nentwich (recording below), we would like to hear from you as to species of trees (some perhaps not currently considered a native species to our ecoregions) that you would like to see become available through the nursery trade.  Many of these are not being commercially grown at this time, but have proven to be resilient in our landscapes and in the wild.   Please click here to see a list of trees and shrubs that experienced  professionals have imagined would be good candidates.  If you have additions or want to comment, please email info@bexarbranches.org

View Recording of Lecture

About the Region

2026 Fall Symposium Logo

This low-elevations region of Texas extends inland from the barrier islands, about 60 or so miles, and stretches from Brownsville to Louisiana. In total, it covers about 9.5 million acres, with a high point of 150 feet in elevation. More than 1000 species of plants can be found in this region. On the southern end, species more common in Mexico (such as Sabal mexicana) and Central America occur.

The barrier islands provide us with dune systems, and clay flats to the inland side, which have species found in these areas alone. Many plants here, such as Ipomoea pes-caprae (beach morning glory), can be found throughout tropical regions of the globe. I’ve encountered the same species on the beaches of Guam.

Once inland, vast marshes and wet prairies occur. Occasionally, oak (Quercus fusiformis) groves can be found. Common grasses include species of Bothriochloa, Paspalum, and Sporobolus; eastern gamagrass (Tripsacum dactyloides); and switchgrass (Panicum species). Many rivers and creeks cut through the Gulf Prairies, and along these riparian areas various species of trees, Sabal minor, and other plants adapted to clay soils can be found. Due to overgrazing, farming, and fire suppression, woody species such as mesquite (Prosopis glandulosa) and huisache (Acacia farnesiana), and invasive species such as chinaberry (Melia azedarach), Brazilian pepper (Schinus terebinthifolius), and Chinese tallow (Sapium sebiferum) have increased and displaced our native flora.

Source: Wildflowers of Texas by Michael Eason