Natural Resources, School of


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A DISSERTATION Presented to the Faculty of The Graduate College at the University of Nebraska In Partial Fulfillment of Requirements For the Degree of Doctor of Philosophy, Major: Natural Resources Science, Under the Supervision of Professors Felipe Chavez-Ramirez and James Stubbendieck. Lincoln, Nebraska: August, 2011

Copyright 2011 Luis Enrique Ramírez Yáñez


Land management strategies can directly and indirectly affect plant assemblages and their behavior. Little research has been performed in south central Nebraska to quantify the effect of fire and grazing interactions on species composition, vegetation structure, forage quality, and potential cost associated with land management.

I evaluate the effect of season-long continuous, patch-burning, and rotational grazing approaches on vegetation and ranching costs to determine their value as conservation tools. This study includes data collected between 2007 and 2009 from grasslands in south central Nebraska. I found that land management influence plant assemblages by shifting communities when grazing and/or fire are present, but other environmental factors such as water availability can play important roles sustaining specific plant communities.

Vegetation structure has been widely accepted as a predictor of wildlife use, but few practical tools are available to measure structure in grassland vegetation. This study explored the adaptation of several diversity indices for use as vegetation structure descriptors. Differences between time after prescribed burning and management approach were detected proving the need to explore the potential use these indices in conjunction of wildlife habitat use data in order to better understand wildlife-habitat relationships.

Continuous grazing resulted in different plant communities. However, abnormally wet years during the study resulted in no observed advantages in terms of forage quality and management cost from the alternative patch-burning and rotational grazing systems.

Advisers: Felipe Chavez-Ramirez and James Stubbendieck