Spelling suggestions: "subject:"ecosystem management"" "subject:"cosystem management""
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Ecological factors influencing the survival of the Brenton Blue butterfly Orachrysops niobe (Trimen) (Lepidoptera: Lycaenidae) / David A. EdgeEdge, David Alan January 2005 (has links)
The Brenton Blue butterfly, Orachrysops niobe (Trimen) is currently only known to be extant at
one locality in the southern Cape (the Brenton Blue Butterfly Reserve = BBBR), and currently
globally Red Listed as "Critically Endangered". This research investigates the life history and
ecological interactions of o. niobe and recommends management techniques for the BBBR.
Adult nectar sources and female oviposition behaviour are described. The first two larval instars
feed on the leaflets of the host plant Indigofera erecta Thunb., and the 3rd and 4th instar larvae feed
on this plant's woody rootstock, attended by ants Camponotus baynei Arnold. Cannibalism takes
place in the early larval stages. Adults emerge from late October - early December, from late
January to early March, and occasionally there is a third brood in April. Morphological and
behavioural features of the larvae are described, and larval growth patterns are compared to other
polyommatines. The nature of the myrmecophilous behaviour is assessed and the phylogenetic
relationships between Orachrysops, Euchrysops, Lepidochrysops, and other polyommatine genera
are discussed.
Ant assemblages at the BBBR are described from pitfall trap sampling and field observations of
interactions between O. niobe larvae and ants. The ant assemblages at the BBBR, Nature's Valley
Fynbos Reserve (NVFR) and Uitzicht 216/ 40 are compared. The potential impact of the
Argentine ant at the BBBR is discussed.
Adult and egg counts are used to study the population dynamics of O. niobe, leading to an
estimate of the adult butterfly population and its fluctuations. A population dynamics model is
constructed, and several factors impacting fecundity and mortality are assessed. Population studies
on other polyommatines are compared and discussed.
The morphology, reproductive biology and autoecology of the papilionoid legume I. erecta are
described. An explanation is offered why the larvae of O. niobe are monophagous on this plant.
Microhabitat variations cause changes in its vegetative morphology and this further explains the
restricted range of O. niobe. The population dynamics of I. erecta is investigated and the effects of
biotic and abiotic factors (including fire) assessed.
Braun Blanquet methodology is used to sample and classify the vegetation communities at the
BBBR. Ordination techniques are used to confirm the classification and to diagnose for
environmental gradients. Hypotheses are generated about the ecological processes functioning at
the site, and the environmental niche occupied by I. erecta. Correlations between the occurrence
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of vegetation types and other plant species and I. erecta are sought and a strong association with
Pterocelastrus tricuspidatus is demonstrated.
Three study sites are described and the ecological history of the region is reconstructed.
Ecosystems are no longer fully functional because natural fire regimes and megaherbivores are
absent. It is suggested that O. niobe currently inhabits an interglacial refugium under stress from
the current global warming trend. The remaining suitable habitat is threatened by coastal property
development and environmental degradation. An increased population of o. niobe at the BBBR,
and establishment of new populations is essential to avoid extinction. Management techniques are
evaluated and a management strategy for the BBBR is proposed. / Thesis (Ph.D. (Environmental Science))--North-West University, Potchefstroom Campus, 2006.
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The impact of willow encroachment on water and carbon exchange in the vegetation of a subtropical wetlandUnknown Date (has links)
Shortened periods of inundation due to water management have led to the encroachment and expansion of Carolina willow (Salix caroliniana) in sawgrass (Cladium jamaicense) marsh communities. Morphologic and physiologic differences between sawgrass and willow have potential consequences for microhabitat conditions and ecosystem function such as a reduction in temperatures and light availability and changes in primary productivity. Since it is a woody shrub, willow is often assumed to exhibit higher rates of transpiration than non woody plants, which in turn can affect photosynthesis and carbon exchange and ultimately wetland water management. In this study willow was found to have higher rates of stomatal conductance (gs) and photosynthesis (Anet) than sawgrass. However, sawgrass had greater intrinsic water use efficiency (WUE) than willow. This suggests that willow is capable of greater gas exchange and carbon assimilation than sawgrass but requires more water. Understanding the implications of willow expansion will improve landscape models of wetland water and carbon exchange and inform water management decisions. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2015. / FAU Electronic Theses and Dissertations Collection
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Effect of external pH on cyanobacterial pigment expressionUnknown Date (has links)
Cyanobacteria are classified as alkalophiles despite their preferential uptake of the acidic form of dissolved inorganic carbon. Long term impacts of external pH on the expression of photosynthetic and structural pigments in Schizothrix calcicola were investigated as potential contributing factors to this phenomenon. More robust cell walls in S. calcicola at pH <7 are suggested by significantly greater expression of myxoxanthophylls. Direct and indirect physiological costs of altering cell walls may contribute to S. calcicola's depressed growth at acidic pH. Comparison of chlorophylls expression suggests that alkaline rather than neutral external pH is only beneficial for S. calcicola growth in absence of nutrient limitation. While the cyanobacterial biomarker ratio of chlorophylls to echinenone was stable across the pertinent pH range of 6-8, other pigment ratios in S. calcicola were affected by pH with an approximately two week lag between the change of pH and the corresponding change of pigment expression. / by Maria West. / Thesis (M.S.)--Florida Atlantic University, 2010. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2010. Mode of access: World Wide Web.
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Deep-Water Biogenic Sediment off the Coast of FloridaUnknown Date (has links)
Biogenic “oozes” are pelagic sediments that are composed of > 30% carbonate
microfossils and are estimated to cover about 50% of the ocean floor, which accounts for
about 67% of calcium carbonate in oceanic surface sediments worldwide. These deposits
exhibit diverse assemblages of planktonic microfossils and contribute significantly to the
overall sediment supply and function of Florida’s deep-water regions. However, the
composition and distribution of biogenic sediment deposits along these regions remains
poorly documented. Seafloor surface sediments have been collected in situ via Johnson-
Sea-Link I submersible along four of Florida’s deep-water regions during a joint research
cruise between Harbor Branch Oceanographic Institute (HBOI) and Florida Atlantic
University (FAU). Sedimentological analyses of the taxonomy, species diversity, and
sedimentation dynamics reveal a complex interconnected development system of
Florida’s deep-water habitats.
Results disclose characteristic microfossil assemblages of planktonic foraminiferal
ooze off the South West Florida Shelf, a foraminiferal-pteropod ooze through the Straits of Florida, and pteropod ooze deposits off Florida’s east coast. The distribution of the
biogenic ooze deposits is attributed to factors such as oceanographic surface production,
surface and bottom currents, off-bank transport, and deep-water sediment drifts. The
application of micropaleontology, sedimentology, and oceanography facilitate in
characterizing the sediment supply to Florida’s deep-water regions. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2017. / FAU Electronic Theses and Dissertations Collection
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Three Essays in Economics of Prey-Predator RelationGo, Dong-Hun 01 May 2018 (has links)
This dissertation explores how natural ecosystem can be integrated with economic system through two case studies of multiple species interactions, or predator-prey relations. By the inclusion of biological, ecological and economic aspects, the integrated approaches aim at more clearly understanding of how regional ecosystem and economy interact with each other, given threats of resource extinction and environmental shock. I also explain strategies and policy regimes that can be considered to achieve efficient and sustainable ecosystem management in those circumstances.
The first case study focuses on a predator-prey relation in the Pacific Ocean between the United States and Canada, where endangered/threatened predators feed primarily on commercially valuable species as prey. Accounting for the importance of those predators as critical natural resources for whale watching industry, this case study synthesizes the species biological and the regional economic systems, and analyzes possible management strategies for both ecosystem conservation and sustainable economic growth.
A long-term drought and fragmented management has been one of the critical issues in the Great Salt Lake (GSL) ecosystem that is linked with its regional economy in Utah. For this issue, the second case study builds an integrated model for describing how the lakes main natural resources, such as water, brine shrimp, and migratory birds, are related to primary industries in the region including agriculture, mining, fishery, and recreation. With the model framework, the study presents how the prolonged drought affects both the GSL ecosystem and its rigional economy, and suggests economic management strategies for the lakes ecosystem recovery in the presence of drought.
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Implementation of the European network: Natura 2000 : Determined according to overarching EU directives or through compromising ecological aspects?Westfahl Backlund, Martina January 2008 (has links)
<p>Global biodiversity is currently being lost at an unprecedented rate, posing a threat to vital ecosystems and hence the generation of ecosystem services that human society is entirely reliant upon. Within the European Community, the EU has set a target of halting biodiversity loss within the territory by 2010. This goal is intended to be operationalized by the implementation of the Habitats Directive and the Birds Directive. These directives constitute the framework for the establishment of a coherent ecological network, referred to as the Natura 2000 network.</p><p>This study examines and analyses the socio-ecological complexities surrounding the designation of Natura 2000 sites in Östhammar municipality, Sweden. The use of a case study-approach to focus on this area is applied in pursuit of identifying and explaining the inherent intricacies in the designation processes and linking them to the broader global context. Throughout Europe, biodiversity exists in a rich variety of grasslands, but only a few studies have been performed to establish appropriate conservation management strategiesrequired for each habitat. This study makes a significant contribution towards shedding light on the Natura 2000 designation process, a phenomenon which has previously been only modestly documented, especially in Sweden. Ecosystem management is discussed and utilized as the theoretical basis for managing ecosystems sustainably, and an important aspect of note is the recognition that the distinction between man and nature needs to be understood as artificial and arbitrary.</p><p>The study explains how social-ecological factors have had a prominent effect on the designation process of Natura 2000 sites. The main determining factor behind the designation process has been the time-constraints, which have affected the designation of SCIs as well as the interaction between the Uppsala CAD and local stakeholders. The lack of adequate participatory approaches used during this process has heightened the risk of compromising the aim of the network: to achieve Favourable Conservation Status (FCS) for natural habitat types as well as species.</p> / <p>Biodiversiteten världen över minskar i en tidigare aldrig skådad hastighet vilket resulterar i ett hot mot fundamentala ekosystem, samt dess produktion av de ekosystemtjänster som det mänskliga samhället är beroende av. På grund av detta har EU satt upp målet att stoppa förlusten av biodiversitet inom unionens gränser tills 2010. Detta mål skall uppnås genom implementeringen av Habitat- och Fågeldirektivet. Dessa direktiv utgör ramen för etableringen av ett sammanhängande ekologiskt nätverk, det så kallade Natura 2000 nätverket.</p><p>Denna studie utreder samt analyserar de socio-ekologiska aspekter som omger utpekandet av Natura 2000 områden i Östhammars kommun, i Uppsala län i Sverige. Genom appliceringen av en fallstudie av området söker denna uppsats att identifiera samt förklara inneboende svårigheter i processen av dessa utpekanden, samt att sätta dem i ett globalt sammanhang. Inom Europa existerar biodiversitet bland annat i olika typer av ängar, dock har endast ett fåtal studier tagit sig an uppgiften att formulera anpassade förvaltningsstrategier för dessa habitat. Denna studie bidrar till att sprida ljus över implementeringen av Natura 2000, ett fenomen som tidigare endast studerats i blygsam utsträckning, speciellt i Sverige. Den teoretiska grunden utgörs ekosystemansatsen, som appliceras för att utvärdera ett uthålligtförvaltande av ekosystem. Vidare understryks vikten av att betrakta ekosystem och mänsklig aktivitet som ett och samma system, och att synen på dem som skilda system bör anses artificiell och motsägelsefull.</p><p>Denna uppsats förklarar hur socio-ekologiska aspekter har påverkat utpekandeprocessen av Natura 2000-områden i Östhammars kommun. De avgörande faktorerna bakom detta är en identifierad tidsbrist, vilket har influerat utpekandet av områden av gemenskapsintresse samt interaktionen mellan Länsstyrelsen i Uppsala och lokala markägare. Bristen på samverkan och information har resulterat i en förhöjd risk av att målet med nätverket inte kommer att nås: att åstadkomma gynnsam bevarandestatus för arter och habitat.</p>
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The potential of dynamic segmentation for aquatic ecosystem management : Pacific lamprey decline in the native lands of the Confederated Tribes of Siletz Indians (Oregon, USA)Palacios, Kelly C. 02 June 2000 (has links)
The Lamprey Eel Decline project conducted by the Confederated Tribes of
Siletz Indians (CTSI) combined traditional ecological knowledge, scientific research
and geographic information science. CTSI wanted to learn why the Pacific lamprey
(Lampetra tridentata), a culturally and ecologically important species, was declining
in the streams within their native land area. The project included interviewing native
elders, characterizing stream habitat, monitoring water quality, creating a geographic
information system (GIS) and educating tribal members on the cultural and ecological
importance of the Pacific lamprey. Dynamic segmentation, a GIS data structure, was
used to link standard stream survey data on the river unit scale to a base stream
coverage (1:24,000). Dynamic segmentation efficiently associates georeferenced data
to a linear feature, thus allowing the data to be readily assessable on desktop computer
systems. To be more useful to the tribal and local resource managers, it is
recommended that these GIS coverages of aquatic habitat should be used in conjunction with additional data coverages and basic regional models for watershed
analysis and better management of aquatic ecosystems. / Graduation date: 2001
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Cost-effective land development with a spatially-realistic ecosystem constraint /Bauer, Dana Marie. January 2005 (has links)
Thesis (Ph. D.)--University of Rhode Island, 2005. / Typescript. Includes bibliographical references (leaves 220-234).
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Pre-harvest water quality of ephemeral streams in Missouri Ozark forestsSmith, Abraham J. January 2006 (has links)
Thesis (M.S.)--University of Missouri-Columbia, 2006. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (February 23, 2006) Includes bibliographical references.
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Landscape controls on the hydrology and nitrate removal effectiveness of riparian zones in Southern Ontario /Vidon, Philippe Gilles Francois. January 2004 (has links)
Thesis (Ph.D.)--York University, 2004. Graduate Programme in Geography. / Typescript. Includes bibliographical references (leaves 182-194). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://wwwlib.umi.com/cr/yorku/fullcit?pNQ99255
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