Submitted to: Mexican Society for Range Management
Publication Type: Abstract Only
Publication Acceptance Date: 7/1/1996
Publication Date: N/A
Citation: Interpretive Summary:
Technical Abstract: Lehmann lovegrass is an introduced grass. This grass is a very aggressive competitor and is not preferred by livestock. As a result it has invaded areas where it was not sown and displaced native grasses. It is a problem in some rangelands. Wind, water and animals are means by which seeds arrive and colonize new areas and the precipitation is a key factor in the establishment of new seedlings. In order to understand the process by which Lehmann lovegrass is being dispersed it is necessary to understand the role that domestic animals and precipitation play in this process. The objective of this study was to evaluate if the domestic animals are dispersing seed of this grass through its consumption and deposition of the seeds in the feces and how the precipitation affects the establishment of new seedlings. The study was carried out at the USDA/ARS Jornada Experimental Range located 37 km north of Las Cruces, NM. Two means of seed dispersion were evaluated (seed dispersed through feces and seed broadcasted) under two levels of precipitation (long term average (average) and long term average + 50% (high)). The broadcasted seed treatments had the highest number of emerged seedlings averaging 21.9 and 19.9 seedlings m**2 for the high and average precipitation levels respectively. On the other hand the treatments of seed dispersed through feces produced only 2.7 and 1.4 seedlings m**2. At the end of the growing season the mortality rate fluctuated 80 to 100%. The amount of rainfall had no effect on the number of established seedlings. The main mean of Lehmann lovegrass seed dispersion is the seed broadcasted by the wind. The results show that the domestic animals also disperse the seed of this grass contributing to the fast colonization of new areas located far away from the seed source.