Resource 1: Literature Review
Abella, SR. 2008. A systematic review of wild burro grazing effects on Mojave Desert vegetation, USA. Environmental Management 41(6): 809-819. doi: 10.1007/s00267-008-9105-7
Many ecologists believe that wild burros cause harm to plant communities and ecosystems through grazing on desert forage plants. This can be seen as one of the major controversial environmental problems in southwestern America. This review focuses particularly on the Mojave Desert region. The author had five categories of research to classify his 24 documents: (i) diet analyses of what the burros consumed, (ii) utilization studies of individual species, (iii) control-impact comparisons, (iv) exclosure studies, (v) examining chemical characteristics of forage plants. Eighty-three percent of these documents originated from 1972 to 1983. Ten of the diet studies and two enclosure studies concluded that the wild burros preferred to consume graminoid and for plants over shrubs. Furthermore, burros tend to prefer certain types of plants within the shrub group, as made known by the utilization studies conducted by the author. It is important to study burro grazing patterns in order to assess grazing management situations. This review deals with the plant life and the effect of burro grazing in the Mojave Desert, one of the three deserts the make up the California Desert ecosystem. It allows one to understand the plant and burro communities of the ecosystem and their relationship with each other.
Resource 2: Primary Literature
Mooney, HA, Berry J, et al. 1982. Comparative photosynthetic characteristics of coastal and desert plants of California USA. Boletin de la Sociedad Botanica de Mexico (42): 19-34.
This article focuses on the comparison between native plants from the hot desert climate of Death Valley in California and native plants from the coastal climate of Bodega head. Plants can either have C3 or C4 photosynthetic pathways. The desert plants in this study exhibited both types of pathways, as well as drought tolerance and intolerance. The desert plants also have many favorable outcomes with different thermal measures and high photosynthetic capabilities. On the other hand, the coastal plant species all had the same photosynthetic pathway, similar favorable outcomes, and low photosynthetic rates. The author concluded that each plant group follows these characteristics because of the large variation of temperatures and precipitation seen in desert habitats and the uniformity of such factors in the coastal habitat. It is important to take note of these conclusions because they can explain why certain plant species are present in the California Desert ecosystem. Such plants can play a role in the food chain by being a sustainable source of food for grazers.
Resource 3: Primary Literature
Sieg, AE, Gambone, MM, et al. 2015. Mojave desert tortoise (Gopherus agassizii) thermal ecology and reproductive success along a rainfall cline. Integrative Zoology 10 (3): 282-294. doi: 10.1111/1749-4877.12132
This article focuses on the species of tortoise native to the Mojave Desert, Gopherus agassizii, and how its reproductive success is affected by the thermal environment and rainfall. Reproductive success is typically exhibited as a result of increased resources, in this case desert plants. In order to test these factors, the authors observed the tortoise at two different ends of a 250-m elevation-related rainfall cline: the upper-elevation Cima and the lower-elevation Pumphouse. It was predicted that the Pumphouse environment would limit reproductive output because it would have higher temperatures and less rainfall, which would lead to a resource-poor environment. On the other hand, Cima would be expected to have higher reproductive success with its lower temperatures and greater rainfall. This allowed Cima to have more vegetation and therefore larger-bodied females (due to the increase in resources) and larger eggs. However, predatory interactions differed between the two ends, with Cima experiencing a higher depredation over Pumphouse (90% eggs depredated in Cima vs., 11% in Pumphouse). Overall, more eggs were safely hatched per individual female in Pumphouse. This study informs us as to which environmental factors are favorable for the survival of a species that plays a pivotal role in the California Desert ecosystem.
Resource 4: Other Resource
Morris, LR, Rowe, RJ. 2014. Historical land use and altered habitats in the Great Basin. Journal of Mammalogy 95 (6): 1144-1156. doi: 10.1644/13-MAMM-S-169
This article provides information on the historical use of the land in the Great Basin. While the vegetation of the land has been continually changing as a result of the change in climate, human interaction with the land has had such a tremendous change on the vegetation of the Great Basin. The author introduces human interactions that have influenced this change to include the introduction of livestock, mining, introduction of nonnative species, and increased CO2 levels, among other factors. Along with the changes in the vegetation of the land comes the altering of habitats. Altered habitats change the way ecosystems function and can have long lasting effects on the species and populations that live there. The article offers an extensive report of historical land usage of the Great Basin since European settlement, and how it has affected the wildlife and plant communities residing in the habitat. It also highlights the need to consider historical ecology as well as wildlife ecology to pave a path towards restoration and conservation. This article was published in 2014, which was relatively recent. It also has to do with historical usage of land and its effects, meaning it is up to date with the most recent major changes in land use. Furthermore, it is primary literature in a peer-reviewed scientific journal, making it a trustworthy source.
Resource 5: Other Resource
National Park Service. 2016. Mojave Desert. NPS. (26 March 2016; https://www.nps.gov/jotr/learn/nature/mojave.htm)
This website provides some general information on the Mojave Desert, one of the three deserts that make up the ecosystem of the California Desert. It describes the Mojave Desert as a rainshadow desert, and divides the information presented into four sections: elevations, temperatures, geology, and vegetation. The Mojave is located between the Great Basin Desert and Sonoran Desert (north and south, respectively) and is home to Telescope Peak (11,049 ft.) and the lowest point in the US, which sits at 282 feet below sea level. The temperatures in the desert depend on both the latitude and altitude of the location of interest. The Mojave is in a location where mountain ranges and their adjacent basins alternate. The Mojave Desert is said to be synonymous with Joshua Tree, because of the many Joshua trees that make up part of its vegetation. Many of the plants in the Mojave Desert are native to that area. Aside from the Joshua trees, low, widely spaced shrubs characterize the vegetation of the Mojave Desert. The website provides a map of the desert for reference as well as various inks throughout the text for further reading. The website does not have any literature citations or a credited author, but because it is a government website published by the National Parks Service, it can be viewed as a trustworthy source.