Due to the inconveniences associated with under ice population studies, most aquatic population studies are made during the spring, summer, and fall seasons. Like most lakes little is known about the fall and winter popu-lations of the Utah Lake invertebrates. The purpose of this study is to classify, determine quantitative fall and winter population fluctuations, and obtain life history and ecological information of the macro-invertebrates at . Lincoln Beach, Utah Lake. This lake is the largest, natural occurring body of fresh water in the state and has a high potential for the production of gamefish and water-fowl. As Smart (1960) points out, an estimate of the amount of bottom fauna is the most important single stand-ard for evaluating the potential of a lake to produce fish. It is also an important consideration in the evaluation of waterfowl habitats (Barnett, 1964).

>Magister Scientiae - MSc / Urbanisation and storm water input in the Kuils River catchment changed the flow of the river from ephemeral to perennial. This led to flooding problems in the Kuilsrivier central business district. The river was channelised in 2000 to increase the carrying capacity of the channel and thus to reduce the flood risk. This study aims to monitor the impacts of channelisation on the geomorphology and ecology of the Kuils River. This was done by selecting representative study sites upstream, within and downstream of the channelised reach. The geomorphological and ecological characteristics of the river were recorded in detail with changes tracked over a year period incorporating channelisation activities and winter floods.

Fujimoto, S. (2015) Quisarctus yasumurai gen. et sp. nov. (Arthrotardigrada: Halechiniscidae) from a submarine cave, off Iejima, Ryukyu Islands, Japan. Zootaxa. 3948 (1): 145-150. Fujimoto, S. (2014) A new Stygarctus (Arthrotardigrada: Stygarctidae) from Japan, with entangled seminal receptacle ducts. Zootaxa. Magnolia Press. 3784 (2): 187-195. / 京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第19533号 / 理博第4193号 / 新制||理||1602(附属図書館) / 32569 / 京都大学大学院理学研究科生物科学専攻 / (主査)教授 疋田 努, 教授 沼田 英治, 教授 曽田 貞滋 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM

No description available.

Coastal meadows are important habitats for many animals, but the habitats are threatened by changes in land use such as abandonment of grazing. On the Swedish East coast, many coastal meadows can be found and they are highly influenced by the brackish marine environment which supports large populations of spiders. Spiders are the most abundant carnivorous arthropods on coasts of Uppland, and it is known that spider communities are closely associated with the vegetation. This study aims to investigate the spider communities in coastal meadows in Uppland and Sörmland, Sweden, and spiders were collected with pitfall traps and vacuum suction sampling. The meadows are under varying management either grazed by cattle, abandoned or has never been managed, and this is expected to influence the vegetation structure. The vegetation was on average higher in the abandoned sites, but the coefficient of variation in height was similar. The Lycosid community was not influenced by the vegetation structure, but was extremely abundant. Mean height of the vegetation had a positive influence on species richness, and a higher number of species were found in the abandoned and grazed meadows compared to the non-managed meadows, in the analysis of the vacuum sampled community. The communities were distinctly different in meadows under different management, and this was influenced by the height of the vegetation. Management of costal meadows is therefore also important for conserving diverse communities of spiders, but clearly some spiders prefer the less species rich un-managed habitats, so consideration should be taken to this.

No description available.

No description available.

In forested ecosystems, salamanders occupy important ecological roles as predator, prey and as potential regulators of ecological processes. The effects of forest management, particularly clearcut harvesting, on salamanders have been well documented; removal of overstory trees negatively affects abundances of salamanders. However, the length of time that salamander populations remain depressed following forest harvesting and factors limiting population recovery have been a source of controversy in the literature and are the goal of this dissertation. As part of the Southern Appalachian Silviculture and Biodiversity (SASAB) project (Chapter 1), a long-term replicated field experiment designed to evaluate a range of silvicultural treatments on biodiversity, I evaluated specific hypotheses related to salamander populations, their prey, and their habitat. First, I examined long-term trends in salamander abundances across a range of silvicultural treatments to determine whether negative effects of forest harvesting persisted for 13-years after harvest (Chapter 2) and to document the effects of multiple harvests on salamanders (Chapter 3). The relative abundances of terrestrial salamanders were quantified in six silvicultural treatments and an unharvested control and on six replicated field sites with night-time, area-constrained searches. Across 13-years of post-harvest data, terrestrial salamander abundances generally were lower in silvicultural treatments with some disturbance to the canopy (group selection harvest through silvicultural clearcut). Further, a comparison of demography of common species of salamanders suggested that differences in habitat quality existed between harvested and unharvested experimental units (EUs). A second harvest in the shelterwood plots to remove overwood had a cumulative negative effect on salamanders at one of two sites studied. Additionally, I conducted a sensitivity and elasticity analysis for eastern red-backed salamanders (Plethodon cinereus) and modeled population growth to evaluate the contribution of demographic parameters to population recovery. These analyses indicated that adult survival was the parameter with the greatest influence on the population growth rate and that >60 years would be required for recovery of salamander populations to preharvest levels even if habitat conditions were restored to preharvest conditions immediately. Next, I quantified the bioenergetics of salamanders across a disturbance gradient to evaluate whether changes to (1) invertebrate prey, (2) energy expenditure for basic maintenance costs, and or (3) an index to body condition could help explain observed changes to abundances or demography of salamanders from forest harvesting (Chapter 4). Although I did not detect a difference in abundances of invertebrates along the disturbance gradient, I determined that salamanders in recently disturbed forest stands expended approximately 33% more energy for basic maintenance costs in an active season and the body condition of salamanders was greater at one of two sites in disturbed EUs. Thus, the bioenergetics of terrestrial salamanders may have been affected by increasing temperatures from silvicultural disturbance and may cause salamanders to allocate less energy to reproduction or growth because of increased maintenance costs. In collaboration with Eric Sucre, Department of Forestry at Virginia Tech, I examined the effects of salamanders on invertebrates and ecosystem processes, specifically leaf litter decomposition. We constructed 12 in situ field mesocosms and I manipulated densities of red-backed salamanders into zero, low, and high density treatments. From June 2006-June 2008, I estimated invertebrate abundances, rates of leaf litter decomposition and food habits of salamanders across treatments. I found that invertebrate abundances were more affected by season than by the density of salamanders and that rates of leaf litter decomposition did not differ among salamander treatments. Salamanders were euryphagic and consumed more (by abundance and volume) herbivorous invertebrates than predators or detritivores. Finally, I modeled habitat relationships of terrestrial salamanders at two spatial scales on the SASAB study sites (Chapter 6). I quantified abundance of salamanders with area-constrained searches during warm rainy nights and measured forest characteristics related to foraging or refugia habitats or that described the overstory and understory of forest stands. At the scale of the 30 m2 transect and the 10 m2 sub-transect, abundance of salamanders was best described by models that incorporated descriptors of canopy cover and woody and herbaceous understory vegetation. Thus, terrestrial salamanders may have responded positively to forest stands with a mature overstory and structurally diverse understory for foraging habitat. Collectively, these data suggest that recovery of salamander populations after forest harvesting will take approximately 60 years, and that life history characteristics (low fecundity, late sexual maturity) and possibly changes to bioenergetics may contribute to the slow recovery. Further, silvicultural practices that retain some canopy trees through a rotation may have a more rapid return of salamander populations to preharvest levels and may encourage development of understory structure for salamander foraging. Although these data fill some gaps in knowledge of relationships between silviculture and terrestrial salamanders, many questions about long-term effects of disturbances on populations and habitats remain. My modeling of recovery of salamander populations depended on estimates of a survival from a congener, and I did not document whether forest harvesting decreases survival of terrestrial salamanders. Lastly, the influence of stochastic events on population dynamics particularly in disturbed stands was not examined in this dissertation. Therefore, future research on the SASAB study sites should continue to track abundances and demography across the disturbance gradient, acquire age-specific estimates of survival, determine whether salamanders exhibit density dependence, develop estimates of entire energy budgets, and use manipulative laboratory experiments to describe the role of plethodontid salamanders in ecosystem functions. / Ph. D.

I studied life history parameters of 5 taxa of aquatic insects in the orders Ephemeroptera and Odonata, successional patterns over 2 years of pond development, and precision of 15 biological metrics in a series of 6 replicate experimental ponds from March 1989 to April 1990. I determined voltinism, emergence patterns, larval growth rates and annual production for Caenis amica (Ephemeroptera: Caenidae), Callibaetis floridanus (Ephemeroptera: Baetidae), Anax junius (Odonata: Aeshnidae), Gomphus exilis (Odonata: Gomphidae), and Enallagma civile (Odonata: Coenagrionidae). Growth rates ranged from 0.011 to 0.025 mg DW/d for Ephemeroptera and from 0.012 to 0.061 mg DW/d for Odonata. Annual production ranged from 5 to 11 mg DW/sampler/yr for Ephemeroptera and from 10 to 673 mg DW/sampler/yr for Odonata. Comparison of the benthic macroinvertebrate community at the end of year 1 to the benthic macroinvertebrate community at the end of year 2 showed no significant differences for community summary measures (total density, taxa richness, diversity, Bray-Curtis similarity index); however, some individual taxa densities were significantly lower at the end of year 2. Physicochemical parameters measured indicated that the ponds were oligotrophic. Submerged macrophytes colonized and became established in most of the ponds during year 2. A few noninsect taxa were not present in expected numbers, probably due to lack of efficient dispersal mechanisms. Fifteen metrics were analyzed by a statistical procedure that indicates the percent change that must occur (detection limit) to detect true differences between two means. The metrics with the lowest detection limits (usually < 20%) were taxa richness, EOT index (number of taxa in the orders Ephemeroptera, Odonata, and Trichoptera), proportion of Chironominae/Orthocladiinae, and proportion of collector-gatherers. Detection limits of < 20% on all dates were also obtained for taxa richness and EOT index metrics when analyzed using dip net samples. Density metrics only allowed detection limits of about 50% on most dates. This study provided needed information on the life history of taxa important in shallow, lentic ecosystems, ecological succession in newly created ponds, and statistically sound and ecologically meaningful metrics. This study also provides a valuable baseline for impact assessment work in experimental ponds. / Ph. D.

This study was undertaken to assess the effectiveness of implanted substrates in sampling aquatic macroinvertebrate assemblages associated with stone dikes on the Lower Mississippi River and to obtain basic information on assemblage composition, structure, and patterns of distribution over a dike. For study purposes, stone-filled baskets were implanted into a dike near Vicksburg, Mississippi, in February 1979, and retrieved four months later. The resulting data indicated the presence of a diverse and productive assemblage (38 taxa; average of 101,968 organisms/m²), characterized by net-spinning caddisflies, tube-building chironomids, isopods, and clinging mayflies. The caddisfly, Hydropsyche spp., accounted for over 60 percent of the total organisms collected. A comparison of assemblage data obtained from the surface stones of the implanted substrates with data obtained from adjacent surface stones of the dike indicated close agreement in estimates of both assemblage composition and structure. However, on an average basis, over seventy percent of the total organisms collected in the substrate implants were found below the surface layer of substrate. The importance of this finding to future sampling efforts is discussed. Statistically significant differences in assemblage estimates were encountered over both the length and width of the structure sampled. These findings are discussed both in terms of their potential ecological significance and in terms of future sampling design considerations. / Master of Science