PS 4-40 - Understanding landscape use pattern of multispecies livestock grazing in patch burning management

Background/Question/Methods

Production of cattle, sheep and goat are major agricultural enterprises on Texas rangelands, especially in the Edwards Plateau region. Historically, fire was not used as a management tool in this region. More recently, prescribed fire has been used, and studies have evaluated how cattle use the landscape after fire. However, studies of livestock species grazing together on patch burned areas are lacking. This study’s objective was to examine landscape use of cattle, sheep, and goats grazing where patch burning treatments were implemented within a Mesquite-Oak-Savanna ecosystem in Texas, USA. Patch burns were installed on a ~29% of the study area (480 of 1655 ha) in February 2019 and September 2020. After burns, animals from the resident herd were randomly selected and GPS collars placed on 34 goats, 33 sheep, and 8 cows. Collars were set to collect movement data every 10 minutes during a 20-month period. GPS data were evaluated to determine locations where animals grazed and their preferences for different areas of the landscape. High resolution multispectral images were used to delineate vegetation into grass and woody vegetation types and location data were intersected with the vegetation type and burned area maps to assess landscape use.

Results/Conclusions

The vegetation type classification using multispectral imagery delineated around 30% of the total landscape area as woody and 70% as herbaceous vegetation types. Cattle and sheep had preference for herbaceous vegetation types during morning (6 to 9 am) and afternoon (5 to 8 pm) grazing periods. Cattle and goats grazed recently burned patches more often than sheep. During the growing season (April to October), the standardized preference index indicated cattle preferred to visit areas classified as herbaceous vegetation types in the recent burned patches. During the dormant season (November to March), goats preferred to visit areas classified as herbaceous and woody vegetation types in both previous and recent burned patches. On a daily basis, Goats traveled longer distances on herbaceous vegetation areas compared to the other two species, with an average of 225 meters/day in burned and 385 meters/day in unburned patches. This study provides an opportunity to evaluate how multiple livestock species use the landscape after patch burning and can provide information to land managers on how multi-species livestock grazing and patch burning would influence their management of grazing lands. Future work will focus on paired comparisons of GPS locations with camera trap observations of livestock and wildlife species.