Can volunteers at the Southwest Nature Preserve restore the former glory of a Cross Timbers prairie in Arlington? A hardy crew launched the initiative in March during a reconnaissance field trip. They marked invasive species for later removal. The aim was to learn more about removal techniques and survey the grassland to develop long-term land management policies to revive this habitat.
The preserve is in the Eastern Cross Timbers, known for its ecotones – the intersection between upland post oak forests and prairie habitat. Invasive species – both natives and non-natives – are encroaching on the prairie after a century of fire suppression and the end of ranching on the site decades ago. Of particular concern are such invasive species as Chinaberry, Chickasaw plum, honey locust, sumac and mesquite, which can outcompete desirable native species that make up the prairie ecosystem.
This prairie is home to two treasured species the preserve wants to protect. One is the preserve’s healthy collection of Glen Rose yucca. They are unique to only four counties in the country, all in Texas, according to the National Conservation Resource Service Plant Database.
Also of concern is preserving the health of some very old post oaks – once the kings of the post oak savanna here. These include the Caddo Oak, a 200-year-old post oak, given historic status in 2019 by the Texas Historic Tree Coalition. These oaks are threatened by nearby woody species, which compete for water during stressful droughts. In addition, the leaf litter from Chinaberries, which crowd around several of these oaks, changes the soil chemistry.
This is a long-term effort, led by volunteers with the Friends of Southwest Nature Preserve, in partnership with the City of Arlington Parks & Recreation.
Jim Domke and Lynn Healy remove a large vine to help protect on a large oak in the Eastern Cross Timbers.
Kim Courtney marks an invasive Chinaberry for removal near one of the old oaks in the prairie ecotone of the Southwest Nature Preserve.