Ecology and Evolutionary Biology Commons^™

Water Stress Strengthens Mutualism Among Ants, Trees, And Scale Insects, Elizabeth G. Pringle, Erol Akc¸Ay, Ted K. Raab, Rodolfo Dirzo, Deborah M. Gordon

Ted K. Raab

Abiotic environmental variables strongly affect the outcomes of species interactions. For example, mutualistic interactions between species are often stronger when resources are limited. The effect might be indirect: water stress on plants can lead to carbon stress, which could alter carbon-mediated plant mutualisms. In mutualistic ant–plant symbioses, plants host ant colonies that defend them against herbivores. Here we show that the partners’ investments in a widespread ant–plant symbiosis increase with water stress across 26 sites along a Mesoamerican precipitation gradient. At lower precipitation levels, Cordia alliodora trees invest more carbon in Azteca ants via phloem-feeding scale insects that provide the …

Evaluation Of The Utility Of Deciduous Molar Morphological Variation In Great Ape Phylogenetic Analysis, Anna M. Hardin, Scott S. Legge

Scott Legge

Non-metric dental traits are well- established tools for anthropologists investigating population affiliation and movement in humans. Nonetheless, similar traits in the great apes have received considerably less attention. The present study provides data on non-metric trait variability in the deciduous molars of great apes from museum context. Twenty-eight traits are observed in the upper and lower deciduous molars in specimens of Pan troglodytes, Pan paniscus, Gorilla gorilla, and Gorilla beringei. These groups are compared based on trait frequencies and mean measures of divergence. This study demonstrates the variability of non-metric traits in the deciduous molars of chimpanzees and gorillas. These …

The Contribution Of Fe (Iii) And Humic Acid Reduction To Ecosystem Respiration In Drained Thaw Lake Basins Of The Arctic Coastal Plain, David A. Lipson, Ted K. Raab, Dominic Goria, Jaime Zlamal

Ted K. Raab

Previous research showed that anaerobic respiration using iron (Fe) oxides as terminal electron acceptor contributed substantially to ecosystem respiration (ER) in a drained thaw lake basin (DTLB) on the Arctic coastal plain. As DTLB age, the surface organic layer thickens, progressively burying the Fe-rich mineral layers. We therefore hypothesized that Fe (III) availability and Fe reduction would decline with basin age. We studied four DTLB across an age gradient, comparing seasonal changes in the oxidation state of dissolved and extractable Fe pools and the estimated contribution of Fe reduction to ER. The organic layer thickness did not strictly increase with …

Metagenomic Insights Into Anaerobic Metabolism Along An Arctic Peat Soil Profile, David A. Lipson, John M. Haggerty, Archana Srinivas, Ted K. Raab, Shashank Sathe, Elizabeth A. Dinsdale

Ted K. Raab

A metagenomic analysis was performed on a soil profile from a wet tundra site in northern Alaska. The goal was to link existing biogeochemical knowledge of the system with the organisms and genes responsible for the relevant metabolic pathways. We specifically investigated how the importance of iron (Fe) oxides and humic substances (HS) as terminal electron acceptors in this ecosystem is expressed genetically, and how respiratory and fermentative processes varied with soil depth into the active layer and into the upper permafrost. Overall, the metagenomes reflected a microbial community enriched in a diverse range of anaerobic pathways, with a preponderance …

Real And Perceived Damage By Wild Turkeys: A Literature Review, Scott R. Groepper, Scott E. Hygnstrom Dr, Brandon Houck, Stephen M. Vantassel

Scott R Groepper

As populations of wild turkeys (Meleagris gallopavo) have increased, the number of complaints about damage has increased. We conducted a literature review to determine real and perceived damage caused by wild turkeys in North America. Wild turkeys can cause damage to agricultural crops, such as corn (Zea mays L.), soybeans (Glycine max [L.] Merrill), wheat, and hay crops but the majority of actual damage is usually minor or caused by other wildlife, thus estimates of damage by wild turkeys often are inflated. Occasionally, wild turkeys damage specialty crops, turfgrass, or ornamental flowers that may have higher value than common agricultural …

The Hudson’S Bay Company Brigades Of 1832-33 And The Malaria Epidemic In California, David A. Bainbridge

David A Bainbridge

The ecological and cultural impacts of the Hudson’s Bay Company fur brigades to California were long term and important, but the expedition of 1832-33 caused a catastrophe by introducing the intermittent fever. The “intermittent fever” led to mortality rates from 50-90 percent or more, and it is likely more than 30,000 people died from the fever in the affected areas of California.

West Nile Virus West Nile Virus Infection In American Robins: New Insights On Dose Response., Larry Clark

Larry Clark

West Nile virus (WNV) is a vector-borne pathogen that was first detected in the United States in 1999. The natural transmission cycle of WNV involves mosquito vectors and avian hosts, which vary in their competency to transmit the virus. American robins are an abundant backyard species in the United States and appear to have an important role in the amplification and dissemination of WNV. In this study we examine the response of American robins to infection with various WNV doses within the range of those administered by some natural mosquito vectors. Thirty American robins were assigned a WNV dosage treatment …

Diversity Of Plants And Animals In Mountain Systems In Tajikistan, Victor Roy Squires Dr, Neymatalo Safarov Dr

Victor Roy Squires Dr

Tajikistan, a landlocked country, is one of the world's centers of origin of cultivated plants and has a special role in the conservation of mountain biodiversity. The richness of biodiversity shows up at the genetic, species, population, and ecosystem levels. There are many relic and endemic species, with most of the components of biodiversity vulnerable to anthropogenic factors. Close cooperation across borders will be required for conservation of unique and threatened ecosystems in the Central Asian region. Proximate threats such as poaching, overfishing, illegal logging and overgrazing are causing irreversible damage to biodiversity in the Tajikistan hotspot. Threats stem from …

Use Of Anecdotal Occurrence Data In Species Distribution Models: An Example Based On The White-Nosed Coati (Nasua Narica) In The American Southwest., Jennifer K. Frey, Jeremy C. Lewis, James S. Stuart, Rachel K. Guy

Jennifer K. Frey

No abstract provided.

Review Of Mark Bekoff's Ignoring Nature No More: The Case For Compassionate Conservation, Ian Werkheiser

Ian Werkheiser

No abstract provided.

Classification Of The Alterations Of Beaver Dams To Headwater Streams In Northeastern Connecticut, U.S.A., Denise Burchsted, Melinda D. Daniels

Denise Burchsted

Of the many types of barriers to water flow, beaver dams are among the smallest, typically lasting less than a decade and rarely exceeding 1.5 m in height. They are also among the most frequent and common obstructions in rivers, with a density often exceeding ten dams per km, a frequency of construction within a given network on a time scale of years, and a historic extent covering most of North America. Past quantification of the geomorphologic impact of beaver dams has primarily been limited to local impacts within individual impoundments and is of limited geographic scope. To assess the …

Divergence In Thyroid Hormone Concentrations Between Juveniles Of Marine And Stream Ecotypes Of The Threespine Stickleback (Gasterosteus Aculeatus), Jun Kitano, Sean C. Lema

Sean Lema

Background: Hormones regulate the expression of multiple phenotypic traits. Therefore,

divergence in hormone concentrations may lead to evolutionary changes in the coordinated

physiological and behavioural traits that comprise an organism’s integrated phenotype. Adults

of marine ecotypes of threespine stickleback (Gasterosteus aculeatus) have higher concentrations

of the thyroid hormone thyroxine (T4) than adults of stream-resident ecotypes (Kitano

et al., 2010). Thyroid hormones are well-established mediators of osmoregulation and migratory

behaviours in fish, and the difference in T4 concentrations indicates that changes in thyroid

hormone signalling may underlie the evolutionary and ecological divergence of migratory and

non-migratory ecotypes.

Questions: Is the variation …