Population Dynamics of Green Rabbitbrush in Disturbed Big Sagebrush Communities

Abstract

We investigated the dynamics of green rabbitbrush populations in relation to burning, livestock grazing, and chemical shrub-control as a range-improvement practice in big sagebrush communities. Green rabbitbrush plants sprout from roots, and density increases by seedling establishment after a fire. Achene production and seedling establishment are paramount to dominance by rabbitbrush after burning of big sagebrush communities. Rabbitbrush continues to dominate and periodically reestablished itself for at least 15 years. Reduced populations of rabbitbrush persist in communities where dominant big sagebrush plants are 40 to 50 years old. Partial reduction in big sagebrush or rabbitbrush populations by applications of 2,4-D results in a large increase in seedling establishment of both species. When these communities are not disturbed or when all shrubs are removed, no shrub seedlings are established.