Effects of elevated carbon dioxide on Bromus rubens and nutritional consequences for the desert tortoise

The purpose of this research was to determine the effect of elevated atmospheric carbon dioxide conditions on forage quality for the desert tortoise (Gopherus agassizii), using a common diet component, Bromus rubens. Nitrogen balance was monitored for tortoises fed pelleted diets reflecting the nitrogen levels of Bromus plants grown under elevated and ambient CO2 conditions, with varying potassium levels (3.5% and 1.4% DWB). Nitrogen content in the diet approached a positive correlation with total diet intake (p = 0.11), and was positively correlated with nitrogen loss at alpha = 0.10 (p = 0.08) and yet remained positively correlated with nitrogen retention (p = 0.07) in high potassium diets. When consuming lower potassium diets, no significant responses were seen with respect to nitrogen content of diets, although nitrogen retention approached significance (p = 0.11). These results, suggest that under elevated CO2 -conditions, if dietary nitrogen levels decrease, nitrogen retention abilities are likely to be compromised, especially when plants simultaneously contain large amounts of potassium.

Name thesis:degree_name

Master of Science (MS)

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Biological Science

Grantor dc:publisher

University of Nevada, Las Vegas

Year

2003

Author dc:creator

• Murphy, Kristen Marie

Contributors dc:contributor

• Stanley D. Smith

Statement dc:rights

• IN COPYRIGHT. For more information about this rights statement, please visit http://rightsstatements.org/vocab/InC/1.0/

Language dc:language

English

Identifier

https://oasis.library.unlv.edu/rtds/1500

OAI identifier oai:identifier

oai:oasis.library.unlv.edu:rtds-2499