While Texas is feeling some reprieve from the heat this week, slightly cooler temperatures and minimal rainfall will do little to help trees being affected by drought and extreme heat conditions.
According to the Texas A&M Forest Service Forest Drought application, 85% of the state is experiencing some level of drought, including 57.6 million acres of the state’s 60 million acres of forestland – the effects becoming apparent.
Trees in the Rio Grande Valley, Davis Mountains, Southern Plains, Cross Timbers and Hill Country are showing the most effect from the conditions, that is the most change in greenness. Whether that change is from stress or mortality can only be determined with time.
Leaves turning brown and dropping early is the most commonly seen symptom but others include oak trees lacking acorns, scorching leaves, tip burn and hypoxylon canker.
Texas A&M Forest Service uses a combination of remote sensing satellite imagery and on-the-ground observations to monitor the health and productivity of forests.
The agency uses High Resolution Forest Monitoring System (HiForm), a USDA Forest Service product, that uses satellites to produce Normalized Difference Vegetation Index (NDVI) change products to monitor changes in forests that result from severe weather, wildland fire, logging, insects and disease.
NDVI shows how green plants are. A change or deviation in NDVI means that trees are changing their chlorophyll signature, and showing either stress or mortality, even if it’s not yet evident for some regions.
As forecasters predict the drought to continue through November, landowners should remain diligent in caring for the health of their trees and forests. Continued monitoring is also critical to fully assess the overall impact and to determine the next steps, since trees may be going dormant and leaf out again in the spring.
Managed landscapes are generally far more resilient to extreme weather conditions, so practices that include planting locally adapted trees, managing invasive and providing supplemental water to high-value trees are important actions landowners can take.
Texas A&M Forest Service experts are available to provide tips on how to keep trees healthy during extreme drought conditions.
For additional information on drought and trees, visit https://tfsweb.tamu.edu/afterthestorm/drought/