My research focuses on grassland restoration and management. To do this, we test ecological theory and look for new ways to apply this understanding to land management. Current work focuses on the role of grazers on grassland communities and the their impact on habitat conditions for wildlife. We are also examining the role of spatial structure from seed arrival and soil heterogeneity on grassland restoration. Below are some on-going projects and interesting past results.
Current Projects
Cattle Grazing on Conservation Reserve Program (CRP)
Replanted native prairie in the CRP program covers nearly 1 million acres in Kansas alone, but many of these prairies exhibit low plant diversity and limited habitat for wildlife. Native prairies were historically grazed by bison that reduced the abundance of dominant grass species—increasing opportunities for more plant species to succeed—and creating higher habitat heterogeneity important wildlife. We are testing whether utilizing periodic cattle grazing can improve habitat for for plant and animals on these restored grasslands.
Soil & Seeding Heterogeneity Experiment (2017-present)
Some ecological theory suggests that few plant species should be able to co-exist, yet we find some prairies that can have over 20 species in 1 square meter! One possible explanation is that both plants and soils exhibit heterogeneous spatial structure. Unlike most animals, neither plants or soils can move and this creates small “neighborhoods” that vary based on how seeds arrive at a location and how soils form and interact with the plants that establish in individual patches. This spatial structure may reduce competitive exclusion for long time periods. We are testing this idea by creating plots with heterogeneous and homogeneous soil and also altering the patchiness of seed arrival (uniform vs aggregated).
Kjaer EL, Houseman GR, Luu KN, Foster BL, Laanisto L, and Golubski AJ (2024) Spatial pattern of seed arrival has a greater effect on plant diversity than does soil heterogeneity in a grassland ecosystem. Plant and Soil 502:557-572. DOI: 10.1007/s11104-024-06565-2. PDF
Herbivore Diversity Experiment (2010-present)
Interesting result: Limiting insects reduced plant richness after 5 years
Reducing insect herbivores (↓) lowered plant species richness in a 12-year experiment in restored tallgrass prairie. This effect developed slowly, first appearing in year 5 and persisting after year 8. The magnitude of the richness-suppressing effect of insect reduction exceeded that of soil fertilization. Reducing small mammals (↓) and larger mammals (↓rabbits and ↓deer) minimally affected plant species richness.
Russell FL, Houseman GR, and Conard JM (2026) Insect herbivores increase plant species richness in a long-term grassland experiment. Journal of Ecology 114. DOI: 10.1111/1365-2745.70280
Past Research
Spatial Seeding Experiment
Interesting result: The spatial structure of seed arrival altered legume establishment
Sowing seeds in three aggregated patches strongly increased leadplant (Amorpha canescens) in comparison to sowing the same amount of seed over the entire plot.
Houseman GR (2026) Restoring grassland legumes using overseeding can depend on seed spatial structure. Restoration Ecology 34:e70275. https://doi.org/10.1111/rec.70275
Restored Grasslands Across A Precipitation Gradient
Interesting result: Short-term cattle grazing did not negatively effect plant communities
Watson DF, Houseman GR, Jameson ML, Jensen WE, Reichenborn M, Morphew A, and Kjaer EL (2024) Short-Term Cattle Grazing Effects on Restored Conservation Reserve Program Grasslands Across a Steep Precipitation Gradient. Rangeland Ecology and Management 94:38-47. DOI:10.1016/j.rama.2024.02.002.