Soil Modification as a Restoration Tool to Reduce Old World Bluestems in Texas Coastal Prairies

Scientific Disciplines
Biological Sciences - Terrestrial
Keywords
Ecology
Montana State University
Grassland
Welder wildlife foundation refuge
Native vegetation
South texas
soil
vegetation
soil modification
Old World bluestemBothriochloas, DichanthiumBothriochloas, Dichanthium
Authors
Years
Volumes
Volume 18, No. 1-4

Soil modification as a restoration tool to reduce 
Old world bluestems in texas coastal prairies
Adam Mitchell*, Department of Ecology, Montana State University, Bozeman, MT 59717
Andrea R. Litt, Department of Ecology, Montana State University, Bozeman, MT 59717
Anthony D. Falk, South Texas Natives, Caesar Kleberg Wildlife Research Institute, Kingsville, TX 
78363
Forrest S. Smith, South Texas Natives, Caesar Kleberg Wildlife Research Institute, Kingsville, TX 
78363
Nonnative Old World bluestem (OWB) grasses (e.g., Bothriochloas, Dichanthium spp.) 
have become dominant throughout the southern and central Great Plains, altering native plant 
communities and habitat quality for wildlife. Although conventional management strategies 
have not resulted in elimination or reduction of these grasses, modifying soil conditions to 
favor native plants may be an alternative restoration tool. We examined efficacy of 10 soil 
modification treatments (soil disturbance alone, pH increase, pH reduction, carbon addition, 
addition of soil mycorrhizae, and each combined with seeding of native vegetation) on 
60 research plots at the Welder Wildlife Foundation Refuge in southern Texas in summer 
2011. We sampled soil chemistry, vegetation density, cover, and height, and abundance of 
soil, terrestrial, and flying arthropods four and eight weeks after initial treatments. Severe 
drought prevented plant growth on treated plots and may have decreased the efficacy of 
soil treatments, especially pH reduction. As such, we compared vegetation and arthropod 
communities only between undisturbed plots dominated by native vegetation and dominated 
by OWBs. Species richness of vegetation was higher on plots dominated by native vegetation 
(4.4 species/m2, SE = 0.6) compared to plots dominated by OWBs (2 species/m2, SE = 0.5). 
Arthropods were more abundant in native vegetation (175 individuals/m2, SE = 4.1) relative 
to OWB-dominated plant communities (41, 1.3). Isopods and ants were the most abundant 
groups overall, although some of these taxa are nonnative. We will continue to collect data 
over the next two years to explore further soil modification as a restoration tool in grasslands 
impacted by OWBs.