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Life Sciences

2002

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Incentives Toward Conservation Of Argaii Ovis Ammon: A Case Study Of Trophy Hunting In Western China, R. B. Harris, Dan H. Pletscher Oct 2002

Incentives Toward Conservation Of Argaii Ovis Ammon: A Case Study Of Trophy Hunting In Western China, R. B. Harris, Dan H. Pletscher

Wildlife Biology Faculty Publications

We investigated management of wildlife, habitat and the hunting programme in Aksai County, Gansu Province, People's Republic of China, during 1997-2000. Argali Ovis amnion is the focal species both for conservation and hunting. The hunting programme is intended to produce incentives to conserve wildlife and habitat. Poaching, a serious concern throughout western China, has been reduced in recent years in Aksai. Wildlife population trends are unknown because standardized surveys were begun only in 2000. Threats to argali in Aksai include livestock grazing, placer gold mining, and development of a dam, reservoir and aqueduct. The number of hunters participating in the …


Red Rock Desert Learning Center & Wild Horse And Burro Facility: Oliver Ranch Feasibility Study, Yosemite National Institutes Aug 2002

Red Rock Desert Learning Center & Wild Horse And Burro Facility: Oliver Ranch Feasibility Study, Yosemite National Institutes

Oliver Ranch Project

Yosemite National Institutes, a private, non-profit national environmental education leader, has been running successful residential science programs in national parks for 30 years in partnership with the National Park Service. The mission of YNI is to provide educational adventures in nature's classroom to inspire a personal connection to the natural world and responsible actions to sustain it. Early in 2000 in Las Vegas, a new organization, the Outside Las Vegas Foundation (OLVF), was forming. The OLVF is dedicated to preserving the federal public lands surrounding Las Vegas, enriching the experience of its visitors, enhancing the quality of life for local …


Reseeding Of Grazing Gastropods And Bivalves Into The Marine Environment In Western Australia, Jane Borg Aug 2002

Reseeding Of Grazing Gastropods And Bivalves Into The Marine Environment In Western Australia, Jane Borg

Fisheries management papers

The Department of Fisheries does not want to embark on what is ‘new territory’ in Western Australia without a policy framework to define what is to happen, why it is to happen, and what will happen if the project does or does not succeed. This paper therefore attempts to do three things. 1. It sets in place accepted definitions of reseeding and stock enhancement within the general context of fisheries management in Western Australia. 2. It discusses the policy issues associated with reseeding grazing gastropods and bivalves into the natural environment. 3. It proposes a framework or process to be …


Parallel Characterization Of Anaerobic Toluene-And Ethylbenzene-Degrading Microbial Consortia By Pcr-Denaturing Gradient Gel Electrophoresis, Rna-Dna Membrane Hybridization, And Dna Microarray Technology, Yoshikazu Koizumi, John J. Kelly, Tatsunori Nakagawa, Hidetoshi Urakawa, Said El Fantroussi, Saleh Al-Muzaini, Manubu Fukui, Yoshikuni Urushigawa, David A. Stahl Jul 2002

Parallel Characterization Of Anaerobic Toluene-And Ethylbenzene-Degrading Microbial Consortia By Pcr-Denaturing Gradient Gel Electrophoresis, Rna-Dna Membrane Hybridization, And Dna Microarray Technology, Yoshikazu Koizumi, John J. Kelly, Tatsunori Nakagawa, Hidetoshi Urakawa, Said El Fantroussi, Saleh Al-Muzaini, Manubu Fukui, Yoshikuni Urushigawa, David A. Stahl

Biology: Faculty Publications and Other Works

A mesophilic toluene-degrading consortium (TDC) and an ethylbenzene-degrading consortium (EDC) were established under sulfate-reducing conditions. These consortia were first characterized by denaturing gradient gel electrophoresis (DGGE) fingerprinting of PCR-amplified 16S rRNA gene fragments, followed by sequencing. The sequences of the major bands (T-1 and E-2) belonging to TDC and EDC, respectively, were affiliated with the family Desulfobacteriaceae. Another major band from EDC (E-1) was related to an uncultured non-sulfate-reducing soil bacterium. Oligonucleotide probes specific for the 16S rRNAs of target organisms corresponding to T-1, E-1, and E-2 were designed, and hybridization conditions were optimized for two analytical formats, membrane and …


Fine Root Vitality And Its Application In A Minirhizotron Study Of A Co2 Enrichment In A Florida Scrub Oak Ecosystem, Brandon Todd Herbert Jul 2002

Fine Root Vitality And Its Application In A Minirhizotron Study Of A Co2 Enrichment In A Florida Scrub Oak Ecosystem, Brandon Todd Herbert

Biological Sciences Theses & Dissertations

Minirhizotron images are assigned color codes to approximate the age of individual roots in situ. Triphenyl-tetrazolium chloride (TTC) has been used to measure the vitality of plant tissue by detecting dehydrogenase activity. TTC was used to assess the vitality of root tissue by color in a scrub oak ecosystem at Kennedy Space Center in central Florida. Roots were excavated, sorted into four color classes and stained with TTC. The product of the reduction of TTC by dehydrogenase enzyme, formazan, was extracted and its absorbance recorded using a spectrophotometer. A significant difference (p2 enrichment being conducted on a scrub oak …


The Future Of Stock Enhancements: Lessons For Hatchery Practice From Conservation Biology, Culum Brown, Rachel L. Day Jun 2002

The Future Of Stock Enhancements: Lessons For Hatchery Practice From Conservation Biology, Culum Brown, Rachel L. Day

Aquaculture Collection

The world’s fish species are under threat from habitat degradation and over-exploitation. In many instances, attempts to bolster stocks have been made by rearing fish in hatcheries and releasing them into the wild. Fisheries restocking programmes have primarily headed these attempts. However, a substantial number of endangered species recovery programmes also rely on the release of hatchery-reared individuals to ensure long-term population viability. Fisheries scientists have known about the behavioural deficits displayed by hatchery-reared fish and the resultant poor survival rates in the wild for over a century. Whilst there remain considerable gaps in our knowledge about the exact causes …


Biological Synopsis Of The Black Bream, Acanthopagrus Butcheri (Munro) (Teleostei: Sparidae) In Western Australia With Reference To Information From Other Southern States, Jeffrey V. Norriss, J E. Tregonning, Rod C J Lenanton, Gavin A. Sarre Jun 2002

Biological Synopsis Of The Black Bream, Acanthopagrus Butcheri (Munro) (Teleostei: Sparidae) In Western Australia With Reference To Information From Other Southern States, Jeffrey V. Norriss, J E. Tregonning, Rod C J Lenanton, Gavin A. Sarre

Fisheries research reports

This synopsis presents a review of the literature and research to April 2001on the biology of black bream, Acanthopagrus butcheri (Sparidae), particularly in relation to Western Australian populations. A. butcheri is a commercially and recreationally important species, and is endemic to the coastal lakes, estuaries, river systems and sheltered coastal waters of southern Australia, including Tasmania. Separate stocks reside within each river/estuarine system in southwestern Australia, and there is considerable variation in feeding, growth rates and age at maturity among stocks. For rivers/estuaries that are seasonally flushed in winter, downstream movement with the flush is followed by the annual upstream …


Coyote Foraging Ecology, Vigilance, And Behavioral Cascades In Response To Gray Wolf Reintroduction In Yellowstone National Park, T. Adam Switalski May 2002

Coyote Foraging Ecology, Vigilance, And Behavioral Cascades In Response To Gray Wolf Reintroduction In Yellowstone National Park, T. Adam Switalski

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Vigilance behavior can aid in the detection of predators and may also play a role in observation of conspecifics, in food acquisition, and in the prevention of kleptoparasitism. However, in most occasions, vigilance is most important as an antipredator function. Generally, factors that increase the risk of predation also increase the amount of vigilance. We examined whether the reintroduction of the large predator, the wolf, in Yellowstone National Park (YNP) would influence coyote vigilance and foraging ecology. From December 1997 to July 2000, we collected 1743 h of coyote activity budgets. Coyote home ranges occurred within wolf territories (termed high-use …


The Ecology Of Lianas And Their Role In Forests, Stefan A. Schnitzer, Frans Bongers May 2002

The Ecology Of Lianas And Their Role In Forests, Stefan A. Schnitzer, Frans Bongers

Biological Sciences Faculty Research and Publications

Recent studies have demonstrated the increasingly important role of lianas (woody vines) in forest regeneration, species diversity and ecosystem-level processes, particularly in the tropics. Mechanisms responsible for the maintenance of liana species diversity could yield new insights into the maintenance of overall species diversity. Lianas contribute to forest regeneration and competition, not only by competing directly with trees, but also by differentially affecting tree species and thus changing how trees compete among themselves. In addition, they contribute considerably to ecosystem-level processes, such as whole-forest transpiration and carbon sequestration. As the rate of tropical forest disturbance increases, they are likely to …


Statmod: A Tool For Interfacing Arcview® Gis With Statistical Software To Facilitate Predictive Ecological Modeling, Christine M. Garrard May 2002

Statmod: A Tool For Interfacing Arcview® Gis With Statistical Software To Facilitate Predictive Ecological Modeling, Christine M. Garrard

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

As geographical information systems and spatial data become more accessible, predictive spatial modeling in ecology is becoming more common. Unfortunately, not all ecologists possess the necessary skills to successfully combine statistical models and geographical information systems. In response to this problem, I wrote an extension for ArcView® GIS called StatMod. This extension interfaces ArcView GIS with SAS® and S-PLUS® statistical software and walks the user through creating and mapping logistic regression and classification and regression tree models.

StatMod was then used to run a series of analyses that would have been difficult without such a tool. A …


Anting Behavior In Birds: Ant Selection And Effect Of Ant Chemistry On Feather Ectoparasites, Hannah Carrington Revis Apr 2002

Anting Behavior In Birds: Ant Selection And Effect Of Ant Chemistry On Feather Ectoparasites, Hannah Carrington Revis

Biological Sciences Theses & Dissertations

Active anting behavior occurs when songbirds apply ants to their feathers. During anting displays, a bird draws its wings forward in front of the head and swings its tail around to the far right or left. Both wing and tail feathers are then rubbed with ants held in the bird's beak. The potential associations among ants, feather ectoparasites and birds make anting behavior an important community-level interaction. Although this behavior is cosmopolitan in distribution and occurs in a wide variety of passerine birds, it remains poorly understood. This dissertation tested hypotheses about anting behavior through controlled experiments with captive songbirds …


Summer Vertical Phytoplankton Distribution In The Lower Chesapeake Bay, Mollie Jill Weinstein Apr 2002

Summer Vertical Phytoplankton Distribution In The Lower Chesapeake Bay, Mollie Jill Weinstein

Biological Sciences Theses & Dissertations

Autotrophic picoplankton and phytoplankton composite samples were collected from the surface, pycnocline, and bottom water layers at three stations in the lower Chesapeake Bay between June and September 1993. Using light microscopy a total of 170 phytoplankton taxa were identified. Utilizing epifluorescent microscopy, the picoplankton taxa were distinguished by size, representing species with cells less than 2 microns. Diatoms were the dominant taxa during this period, with lesser representation by the other phytoplankton components. Within the picoplankton category, cyanobacteria were dominant. Statistical analyses of the data indicated the vertical composition and abundance of the phytoplankton was not significantly different over …


Endangered Species Bulletin, March/June 2002 - Vol. Xxvii No. 2 Mar 2002

Endangered Species Bulletin, March/June 2002 - Vol. Xxvii No. 2

Endangered Species Bulletin

In this issue:
4 Lands of Contrast, Diversity, and Beauty
8 Endangered Species and the Arizona-Sonora Desert Museum
12 The Sonoran Desert Conservation Plan
16 The Chihuahuan Desert: Diversity at Risk
18 Restoring a Desert Oasis
20 Desert Fish: Life on the Edge
22 Life in Mauna Kea’s Alpine Desert
24 The Tarahumara Frog: Return of a Native
27 Leading-edge Science for Imperiled Bonytail
28 Las Vegas Places its Bets on Habitat Plan
30 Arizona Tribal Partnerships for Wildlife
32 New Mexico’s Little Known Treasures
34 Rio Grande Silvery Minnow
36 Black-footed Ferrets Return to Mexico
38 Regional News and …


Daft Plan Of Management For The Proposed Miaboolya Beach Fish Habitat Protection Area., Department Of Fisheries Western Australia Mar 2002

Daft Plan Of Management For The Proposed Miaboolya Beach Fish Habitat Protection Area., Department Of Fisheries Western Australia

Fisheries management papers

The aims of the proposal outlined in this draft management plan is to protect and rehabilitate the aquatic habitat of Miaboolya Beach, the associated mangrove ecosystem, and involve the community in their management. By setting the area aside as a FHPA, the Department of Fisheries will establish a framework to promote and actively conserve all the habitats within the Miaboolya system, as described in Section 3 of this document.


Leaf Size, Specific Leaf Area And Microhabitat Distribution Of Chaparral Woody Plants: Contrasting Patterns In Species Level And Community Level Analyses, D. D. Ackerly, Charles A. Knight, S. B. Weiss, K. Barton, K. P. Starmer Feb 2002

Leaf Size, Specific Leaf Area And Microhabitat Distribution Of Chaparral Woody Plants: Contrasting Patterns In Species Level And Community Level Analyses, D. D. Ackerly, Charles A. Knight, S. B. Weiss, K. Barton, K. P. Starmer

Biological Sciences

We examined variation in leaf size and specific leaf area (SLA) in relation to the distribution of 22 chaparral shrub species on small-scale gradients of aspect and elevation. Potential incident solar radiation (insolation) was estimated from a geographic information system to quantify microclimate affinities of these species across north- and south-facing slopes. At the community level, leaf size and SLA both declined with increasing insolation, based on average trait values for the species found in plots along the gradient. However, leaf size and SLA were not significantly correlated across species, suggesting that these two traits are decoupled and associated with …


The Detection Of Bacillus Endospores During Low Heat Skim Milk Powder Processing Using Nucleic Acid Technology, Amy J. Rife, Rafael Jiménez-Flores, Chris Kitts, Mark Kubinski Jan 2002

The Detection Of Bacillus Endospores During Low Heat Skim Milk Powder Processing Using Nucleic Acid Technology, Amy J. Rife, Rafael Jiménez-Flores, Chris Kitts, Mark Kubinski

Dairy Science

Abstract of paper presented at the 2002 Joint Annual Meeting of the American Dairy Science Association & the American Society of Animal Science.


Effects Of Management Practices On Grassland Birds: Wilson’S Phalarope, Jill A. Dechant, Douglas H. Johnson, Lawrence D. Igl, Christopher M. Goldade, Amy L. Zimmerman, Betty R. Euliss Jan 2002

Effects Of Management Practices On Grassland Birds: Wilson’S Phalarope, Jill A. Dechant, Douglas H. Johnson, Lawrence D. Igl, Christopher M. Goldade, Amy L. Zimmerman, Betty R. Euliss

Effects of Management Practices on Grassland Birds

Information on the habitat requirements and effects of habitat management on grassland birds were summarized from information in more than 4,000 published and unpublished papers. A range map is provided to indicate the relative densities of the species in North America, based on Breeding Bird Survey (BBS) data. Although birds frequently are observed outside the breeding range indicated, the maps are intended to show areas where managers might concentrate their attention. It may be ineffectual to manage habitat at a site for a species that rarely occurs in an area. The species account begins with a brief capsule statement, which …


Effects Of Management Practices On Grassland Birds: Savannah Sparrow, David A. Swanson Jan 2002

Effects Of Management Practices On Grassland Birds: Savannah Sparrow, David A. Swanson

Effects of Management Practices on Grassland Birds

Information on the habitat requirements and effects of habitat management on grassland birds were summarized from information in more than 4,000 published and unpublished papers. A range map is provided to indicate the relative densities of the species in North America, based on Breeding Bird Survey (BBS) data. Although birds frequently are observed outside the breeding range indicated, the maps are intended to show areas where managers might concentrate their attention. It may be ineffectual to manage habitat at a site for a species that rarely occurs in an area. The species account begins with a brief capsule statement, which …


Effects Of Management Practices On Grassland Birds: Henslow’S Sparrow, James R. Herkert Jan 2002

Effects Of Management Practices On Grassland Birds: Henslow’S Sparrow, James R. Herkert

Effects of Management Practices on Grassland Birds

were summarized from information in more than 4,000 published and unpublished papers. A range map is provided to indicate the relative densities of the species in North America, based on Breeding Bird Survey (BBS) data. Although birds frequently are observed outside the breeding range indicated, the maps are intended to show areas where managers might concentrate their attention. It may be ineffectual to manage habitat at a site for a species that rarely occurs in an area. The species account begins with a brief capsule statement, which provides the fundamental components or keys to management for the species. A section …


Planetary Bioresources And Astroecology 1. Planetary Microcosm Bioassays Of Martian And Carbonaceous Chondrite Materials: Nutrients, Electrolyte Solutions, And Algal And Plant Responses, Michael Noah Mautner Jan 2002

Planetary Bioresources And Astroecology 1. Planetary Microcosm Bioassays Of Martian And Carbonaceous Chondrite Materials: Nutrients, Electrolyte Solutions, And Algal And Plant Responses, Michael Noah Mautner

Chemistry Publications

The biological fertilities of planetary materials can be assessed using microcosms based on materials in martian and carbonaceous chondrite meteorites. Their biological fertilities are rated based on soluble electrolyte nutrients, on the growth of mesophile and cold-tolerant algae, and of plant tissue cultures. The Murchison CM2 carbonaceous chondrite meteorite and DaG 476 martian shergottite contain high levels of water-extractable Ca, Mg, and SO4–S. The martian meteorites DaG 476 and EETA 79001 also contain high levels of extractable nutrients NO3–N (0.013–0.017 g kg1) and PO4–P (0.019–0.046 g kg1). The yields of most of the water-extractable …


Millipeds (Arthropoda: Diplopoda) Of The Ark-La-Tex. Ii. Distributional Records For Some Species Of Western And Central Arkansas And Easter And Southeastern Oklahoma, Chris T. Mcallister, Rowland M. Shelley, James T. Mcallister Iii Jan 2002

Millipeds (Arthropoda: Diplopoda) Of The Ark-La-Tex. Ii. Distributional Records For Some Species Of Western And Central Arkansas And Easter And Southeastern Oklahoma, Chris T. Mcallister, Rowland M. Shelley, James T. Mcallister Iii

Journal of the Arkansas Academy of Science

We collected millipeds between November 2001 and March 2002 at several sites in the Ouachita Provinces of western (Garland, Hot Spring, Pike, and Polk counties) and central Arkansas (Pulaski County) and the Ouachita and Kiamichi Provinces of southeastern Oklahoma (LeFlore and McCurtain counties). The following millipeds were found: Eurymerodesmus dubius, Auturus louisianus louisianus, Pseudopolydesmus pinetorum, and Cambala minor in Garland County; Eurymerodesmus sp., A. I. louisianus, P. pinetorum, and juveniles of the family Parajulidae (tribe Aniulini) from Hot Spring County; E. dubius, A. I. louisianus, and juveniles of the family Cleidogonidae from Pike County; Brachycybe lecontei, A. I. louisianus, Abacion …


Livelihood Security And Protected Area Management, Stephen F. Siebert, Jill M. Belsky Jan 2002

Livelihood Security And Protected Area Management, Stephen F. Siebert, Jill M. Belsky

Ecosystem and Conservation Sciences Faculty Publications

No abstract provided.


Species Richness, Latitude, And Scale-Sensitivity, S. Kathleen Lyons, Michael R. Willig Jan 2002

Species Richness, Latitude, And Scale-Sensitivity, S. Kathleen Lyons, Michael R. Willig

School of Biological Sciences: Faculty Publications

The latitudinal gradient of species richness is well documented for a variety of taxa in both terrestrial and aquatic environs. Moreover, a number of recent attempts to assess the effects of scale on the relationship have concluded that the latitudinal pattern is scale-invariant. Nonetheless, the power of those approaches is predicated on precise knowledge of the forms of the latitudinal gradient, the area relationship, and their interaction. We used a model developed by J. Pastor, A. Downing, and H. E. Erickson for assessing the effects of scale on the productivity–diversity gradient to avoid such complications. More specifically, for 253 sets …


Surface Reflectance Properties Of Antarctic Moss And Their Relationship To Plant Species, Pigment Composition And Photosynthetic Function, C. E. Lovelock, Sharon A. Robinson Jan 2002

Surface Reflectance Properties Of Antarctic Moss And Their Relationship To Plant Species, Pigment Composition And Photosynthetic Function, C. E. Lovelock, Sharon A. Robinson

Faculty of Science - Papers (Archive)

We investigated how surface reflectance properties and pigment concentrations of Antarctic moss varied over species, sites, microtopography, and with water content. We found that species had significantly different surface reflectance properties, particularly in the region of the red edge (approximately 700 nm), but this did not correlate strongly with pigment concentrations. Surface reflectance of moss also varied in the visible region and in the characteristics of the red edge over different sites. Reflectance parameters, such as the Photochemical Reflectance Index (PRI) and Cold Hard Band (CBH) were useful discriminators of site, microtopographic position and water content. The PRI was correlated …


Uncertainties In Sediment Quality Weight-Of-Evidence (Woe) Assessments, Graeme E. Batley, G. Allen Burton, Peter M. Chapman, Valery E. Forbes Jan 2002

Uncertainties In Sediment Quality Weight-Of-Evidence (Woe) Assessments, Graeme E. Batley, G. Allen Burton, Peter M. Chapman, Valery E. Forbes

Valery Forbes Publications

Uncertainties in sediment quality assessments are discussed in five categories: (1) sediment sampling, transport and storage; (2) sediment chemistry; (3) ecotoxicology; (4) benthic community structure; and (5) data uncertainties and QA/QC. Three major exposure routes are considered: whole sediments, and waters in sediment pores and at the sediment-water interface. If these uncertainties are not recognized and addressed in the assessment process, then erroneous conclusions may result. Recommendations are provided for addressing the identified uncertainties in each of the key areas. The purpose of this paper is to improve the reporting of sediment quality assessments.


Strategies For Controlling House Fly Populations Resistant To Cyromazine, Diana C. Crespo, Roberto E. Lecuona, Jerome Hogsette Jan 2002

Strategies For Controlling House Fly Populations Resistant To Cyromazine, Diana C. Crespo, Roberto E. Lecuona, Jerome Hogsette

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

The objectives of this study were to compare, from both biological and economic viewpoints, the impact of various control strategies and evaluate their effect on cyromazine-resistant Musca domestica L., and beneficial house fly pupal parasitoids on caged-layer farms (240,000 hens) in Argentina. The strategies evaluated were: chemical, chemical + cultural, and chemical + cultural + biological (integrated management). The products used were: cyromazine 1% and 50%, DDVP, azamethiphos with and without z-9-tricosene, lime, and the parasitoids Spalangia endius Walker and Muscidifurax raptor Girault & Sanders. In the absence of control measures, fly density increased quickly and the average parasitism rate …


Plumeless Thistle (Curled Thistle, Bristly Thistle), L.-T. Kok, A. Gassmann Jan 2002

Plumeless Thistle (Curled Thistle, Bristly Thistle), L.-T. Kok, A. Gassmann

USDA Forest Service / UNL Faculty Publications

Plumeless thistle, Carduus acanthoides L., is an introduced Eurasian noxious weed in pastures, rangelands, croplands, and along highways in 19 of the contiguous states in the United States (Frick, 1978). Carduus acanthoides and Carduus nutans L. in the northeastern United States often occupy the same habitats, such as overgrazed pastures and disturbed roadsides, and these species sometimes occur as mixed stands.


The Unionid Mussels Of The Upper Iowa And Turkey River Watersheds, Jim Eckblad, Brett Ostby, Karis Tenneson Jan 2002

The Unionid Mussels Of The Upper Iowa And Turkey River Watersheds, Jim Eckblad, Brett Ostby, Karis Tenneson

Journal of the Iowa Academy of Science: JIAS

The Iowa driftless region occupies an area of about 9,000 km2 in the northeastern corner of Iowa and is drained by relatively old entrenched meandering streams. The Upper Iowa River and Turkey River are the largest of these streams. During the period from June, 1999 to October, 2000, a total of 193 sites were surveyed for mussels from the Upper Iowa River, the Turkey River, and their main tributaries. Surveys were conducted by hand using a 10 m bank-to-bank search at each site. Data analysis was facilitated using ArcView GIS. The presence of mussels was recorded at 75% of …


Growth Increment Analysis Of Marine Bivalves From The North, Stephen D. Houk Jan 2002

Growth Increment Analysis Of Marine Bivalves From The North, Stephen D. Houk

Electronic Theses and Dissertations

This study aids in developing a sea surface temperature (SST) proxy with monthly temporal resolution using a combination of growth increment and stable isotope analyses of marine bivalves from the north coast of Peru. Faunal assemblages from the Siches and Ostra Base Camp archaeological sites contain shells of warm-tropical mollusks that currently live farther north in Ecuador. The presence of warm-tropical species in these sites and others as far south as 10"s latitude and dating prior to 5730 cal yr B.P. indicates a stable warm-water regime in the eastern tropical Pacific which subsequently changes to a modern temperate-water regime after …


Effects Of Cattle Grazing On Woodlands In Central Iowa, Cathy Mabry Jan 2002

Effects Of Cattle Grazing On Woodlands In Central Iowa, Cathy Mabry

Journal of the Iowa Academy of Science: JIAS

Iowa's forests have undergone a dramatic decline in area since settlement by Europeans. Most of the remaining forests have been degraded by an assortment of human impacts, with cattle grazing the most prominent among them. Using a matched pairs study designed to control for environmental differences among plots, I examined the impact of cattle grazing on the forest understory, canopy trees, and tree regeneration. There were distinct groups of understory species associated with ungrazed and grazed plots. Species associated with ungrazed plots were all native and tended to be perennial herbs with fleshy roots. Ungrazed plots also had species preferring …