John Mull

Relationship between cheatgrass coverage and the relative abundance of snakes on Antelope Island, Utah

ABSTRACT. Cheatgrass (Bromus tectorum) is an invasive annual known to negatively impact many shrub-dependent organisms; however, relatively little research has examined how it affects snake communities. Bromus tectorum is abundant at Antelope Island State Park, Davis County, Utah, and could be a possible threat to snake populations. Study sites representing different B. tectorum coverage percentages were established to measure relative abundance of snakes. Snakes were captured from June to September 2005 primarily by using funnel traps attached to drift-fence arrays. Linear regression revealed a negative relationship between B. tectontm coverage (%) and the relative abundance of the Great Basin gopher snake (Pituophis catenifer deserticola) and the western racer (Coluber mormon). These results (1) suggest that B. tectorum invasions result in reduced snake abundance in shrubsteppe habitat on Antelope Island and (2) add to our understanding of the relationships between B. tectorum and native fauna.

Reproduction and Pollination of the Endangered Dwarf Bear-Poppy Arctomecon humilis (Papaveraceae) across a Quarter Century: Unraveling of a Pollination Web?

Abstract.— Arctomecon humilis, a rare gypsophile of the extreme northeastern Mojave Desert, is restricted to a few isolated populations in Washington County, Utah, USA. At several times in the past quarter century, we have studied the breeding system and reproductive success of this endangered species, recorded its pollinators, and tested the feasibility of human-assisted gene flow by performing reciprocal crosses between 2 isolated “populations” approximately 4 km apart. Arctomecon humilis possessed a mixed breeding system in the population studied (Beehive Dome in 1988); some plants exhibited self-compatibility but produced significantly fewer fruit/flowers and seeds/fruit for geitonogamous self-pollinations than for cross-pollinations. Few fruits and seeds were produced in the absence of pollinators. The results of cross-pollination treatments did not differ from unassisted open-pollinations (controls), suggesting that pollinators were not limiting reproductive success. Our more recent results (2012) suggest that some populations may be more at risk than others. Although all 7 populations surveyed produced ≥70% fruits/flower, they differed significantly in fruit set and in average seed number/fruit and seed weight. Possible reasons for these differences (i.e., inbreeding, genetic load, insufficient mating types, pollinator scarcity, etc.), are all potentially important for conservation management and should be investigated. Over the past 2 decades, the pollinator community appears to have changed dramatically from one composed of specialist and generalist bees to one where pollination is presently being accomplished by generalist foragers alone. The health of one of these generalists, the honey bee Apis mellifera, is a current global concern, and its future presence as a pollinator of A. humilis is unclear. Our reciprocal crosses between the White Dome and Webb Hill populations provide support for our proposal that human-mediated gene flow through interpopulation cross-pollinations be undertaken every 5 years to increase the genetic variability of populations. We make several other recommendations for research that would improve the ability of land managers to conserve this species.

Solutions from the Wild Side@@@Wild Solutions: How Biodiversity Is Money in the Bank

We live on an unexplored planet, ignorant of more than eighty percent of the species that share our world. In this fascinating and abundantly illustrated book, two eminent ecologists discuss the biological diversity of the Earth, showing how the natural systems that surround us play an essential role in protecting our basic life-support systems. Andrew Beattie and Paul Ehrlich tell us about the millions of species providing ecosystem services that maintain the quality of our air and water and the fertility of the soil, dispose of domestic, industrial, and agricultural waste, and protect crops from pests. The authors also describe how biological diversity opens the way for new medicines, pharmaceuticals, construction materials and designs, and manufactured goods. They point to innovative industries that harness species for the biological repair of damaged landscapes, biological mining, biological pest control, and biomonitoring of the environment. The organisms upon which these activities are founded - although often microscopic, obscure, or bizarre - provide natural capital that is worth infinitely more than anyone has previously guessed. The authors urge us to protect the biological wealth of our Earth and keep it from being destroyed by human activity.