Spelling suggestions: "subject:"mountain"" "subject:"fountain""
891 |
Estrutura espacial das comunidades de Ephemeroptera HAECKEL, 1896 (Insecta) em riachos da Serra da Mantiqueira e da Serra do Mar, Estado de São Paulo / Spatial structure in assemblages of Ephemeroptera Haeckel, 1896 (insecta) in streams of Serra da Mantiqueira and Serra do mar, State of São PauloAna Emilia Siegloch 26 March 2010 (has links)
Este estudo teve como objetivos, i) investigar a composição taxonômica das duas vertentes da Serra da Mantiqueira (Parque Estadual de Campos do Jordão e Região de Pindamonhangaba) e da Serra do Mar (Núcleos Santa Virgínia e Picinguaba), com base na coleta de larvas e alados, ii) analisar quais as escalas espaciais (mesohábitat, riacho, vertente e serra) que melhor estruturam as comunidades de Ephemeroptera e iii) identificar e quantificar as variáveis ambientais que influenciam as comunidades de larvas de Ephemeroptera. Considerando o esforço conjunto de todos os métodos de coleta foram registradas oito famílias 33 gêneros e 21 espécies, das quais oito famílias 28 gêneros e 18 espécies na Serra da Mantiqueira e sete famílias 30 gêneros e 15 espécies no Parque Estadual da Serra do Mar. As duas serras apresentaram uma porção bastante significativa da riqueza taxonômica do Brasil, 41% e 45% dos gêneros e 80% e 70% das famílias, respectivamente. A alta riqueza registrada no estudo pode ser relacionada à metodologia de coleta empregada que abrangeu a coleta de larvas e alados e explorou diversos mesohábitats e riachos. Considerando todo o modelo hierárquico, houve variação significativa da riqueza e abundância das comunidades entre as quatro vertentes e os mesohábitats pedra e folha/corredeira. No entanto, a maior variação ocorreu entre as réplicas de um mesmo mesohábitat, refletindo o padrão de distribuição agregada das comunidades de Ephemeroptera. A maior riqueza foi encontrada no mesohábitat pedra/corredeira e na vertente que abrange o Núcleo Santa Virgínia. A ordenação mostrou tendência de segregação das amostras de cada vertente e tipo de mesohábitat. Essa tendência de segregação foi corroborada pela análise de variância multivariada (Permanova). Assim, a estrutura espacial das comunidades de larvas de Ephemeroptera parece predita pelos fatores ambientais da escala local ligadas aos mesohábitats e pelos fatores de maior magnitude da escala regional, associados às vertentes. A Análise de Redundância (RDA) evidenciou a altitude, condutividade elétrica, temperatura da água e Resumo Geral 10 largura como as variáveis ambientais locais que mais contribuíram para explicar a estrutura das comunidades. No entanto, as variáveis ambientais locais explicaram apenas 19,3% da variabilidade na abundância dos gêneros, 7,9% da variabilidade foi explicada pelas variáveis ambientais indissociáveis da matriz geográfica, 23,4% foi explicada pela posição geográfica dos riachos e 49,4% permaneceu inexplicada. Os resultados encontrados nesse estudo destacam a contribuição semelhante das variáveis ambientais locais e da posição geográfica dos riachos na estruturação das comunidades, indicando que além das variáveis ambientais locais os processos biológicos contagiosos, como dispersão, também influenciaram a estrutura das comunidades de larvas de Ephemeroptera na região estudada / The purpose of this study was to i) inventory the taxonomic composition the mayfly fauna, larva and adult, in two slopes of the Mantiqueira Mountains (Campos do Jordao State Park and Pindamonhangaba Region) and of the Serra do Mar (Santa Virginia and Picinguaba Nuclei), located in São Paulo State, ii) analyze the spatial scales (mesohabitat, stream, slope and mountain) that best explain the spatial structure of Ephemeroptera assemblages and iii) identify and quantify the environmental variables that affects the communities of Ephemeroptera larvae. In all, 8 families, 33 genera and 21 species of Ephemeroptera were recorded. In the Serra da Mantiqueira 8 families, 28 genera and 18 species were found and in the Serra do Mar, 7 families, 30 genera and 15 species. Both mountains had a very significant portion of the genera reported to Brazil (41% and 45% of genera and 80% and 70% of families, respectively). The high Ephemeroptera richness in the areas may be related to the sampling methodology used, that included the collection of larvae and adults and explored several kinds of mesohabitats and streams. Considering the entire hierarchical model, there was a significant variation in both richness and abundance of the assemblages among the four slopes and between stone and leaf mesohabitats. Moreover, the highest variation in richness and abundance occurred among the samples from the same mesohabitat, which reflects the clumped distribution pattern of the assemblages of Ephemeroptera. Stone was the mesohabitat with the highest estimated richness, similarly Santa Virgínia Nucleus was the slope with highest estimated richness. The ordination showed a trend of segregation of samples from slopes and mesohabitats, this trend was confirmed by multivariate analysis of variance (Permanova). Thus, the spatial structure of the assemblages seems predicted by environmetal factors of local scale related to mesohabitats and the features of regional scale, associated with slopes. The Redundancy Analysis (RDA) showed elevation, electrical conductivity, water temperature and width as the local environmental variables that contributed most to explain the spatial structure of communities. However, local enrironmental factors explained only 19.3% of the data variability, 7.9% of the General Abstract 12 data variability was explained by environmental variables inseparable from the geographical matrix, 23.4% was explained by the geographical location of streams and 49.4% remained unexplained. The results of this study showed the similar contribution of local environmental variables and the geographic location in the community structure, indicating that the biological processes, as dispersal, also influenced the structure of the assemblages of Ephemeroptera larvae.
|
892 |
The light at the end of the tunnel: photosensitivity in developing mountain pine beetle (Dendroctonus ponderosae)Wertman, Debra 11 December 2017 (has links)
This research explores the capacity for functional photoreception in larvae of the
mountain pine beetle (Dendroctonus ponderosae), an extremely important forest pest
insect that is well adapted for development beneath the bark of pine trees. Phototaxis
tests, gene expression analysis and development experiments were integrated to assess
mountain pine beetle larvae for light sensitivity. When presented with a phototaxis
choice test, larvae preferred dark over light microhabitats, revealing that larvae sense and
respond behaviourally to light. Long wavelength opsin transcription was identified in all
life stages, including eggs and larvae, suggesting that D. ponderosae possesses
extraretinal photosensitive capabilities across its life cycle. The long wavelength opsin
could function in phototaxis or the development phenology of immature beetles, while
the ultraviolet opsin, only found to be expressed in pupae and adults, is likely to function
in dispersal via the compound eyes. Results from two development experiments reveal
an effect of photoperiod treatment on beetle development rate when reared from the egg
stage, but not when reared from mature larvae, indicating that a critical photosensitive
life stage(s) must occur in D. ponderosae prior to the third larval instar. An effect of
photoperiod on adult emergence rates, however, appears to be independent of larval
rearing conditions. The discovery of opsin expression and negative phototaxis in eyeless
mountain pine beetle larvae, in addition to an effect of photoperiod on immature
development and adult emergence rates, suggest that light and photoperiodism likely
function in survival and life cycle coordination in this species. / Graduate / 2018-10-17
|
893 |
Species Endemism: Predicting Broad-Scale Patterns and Conservation PrioritiesZuloaga Villamizar, Juan Gerardo January 2018 (has links)
Do thermal barriers limit biotic composition and community similarity, potentially helping to shape biodiversity patterns at continental scales? Are environmental variables responsible for broad-scale patterns of species endemism? Are these patterns predictable? And, how can patterns of endemism can inform global conservation strategies? These are some of the questions that I attempted to answer during my doctoral research.
In the first chapter, I tested one of the most contentious hypotheses in ecology: Do thermal barriers, which grow stronger along elevational gradients across tropical mountains, create a dispersal barrier to organisms and consequently contribute to the isolation and divergence of species assemblages? If so, do patterns potentially generated by this mechanism detectably relate to dissimilarity of biotic assemblages along altitudinal gradients across the mountains in the Americas? We found that mountain passes are not only higher in tropical realms, as initially thought by Janzen (1967), and extensively popularized and assumed in further research, but they are also present in temperate regions along the western coast of North America. We also found that the stronger the thermal barrier, the higher the dissimilarity between communities. However, the variance explained was low, suggesting thermal barriers play a minor role in creating and maintaining patterns of biodiversity.
The second chapter raises the question of why are there more small-ranged species in some places than in others. I tested four macroecological hypotheses (H1: climate velocity; H2: climate seasonality; H3: climate distinctiveness or rarity; and, H4: spatial heterogeneity in contemporary climate, topography or habitat) to predict broad-scale patterns of species endemism, using a cross-continental validation approach. We found that there is no empirical reason, from the standpoint of model fitting, parameter estimates, and model validation, to claim that any of these hypotheses creates and maintains broad-scale patterns of endemism. Although we found statistically significant relationships, they failed stronger tests of a causal relationship, namely accurate prediction. That is, the hypotheses did not survive the test of cross-continental validation, failing to predict observed patterns of endemism. Climate velocity was dropped from some models, suggesting that early correlations in some places probably reflect collinearity with topography. The effect of richness on endemism was in some cases negligible, suggesting that patterns of endemism are not driven by the same variables as total richness. Despite low explained variance, spatial heterogeneity in potential evapotranspiration was the most consistent predictor in all models.
The third chapter is aimed to evaluate the extent to which global protected areas (PAs) have included endemic species (species with small range size relative to the median range size). We measure the relative coverage of endemic species by overlapping species geographic ranges for amphibians, mammals, and birds, with the world database of PAs (1990-2016). Then we measure the rate of expansion of the global PA network and the rate of change in endemic species coverage.
We found that ~30% of amphibian, ~6% of bird and ~10% of mammal endemic species are completely outside PAs. Most endemic species’ ranges intersect the PA network (amphibian species = 58%; birds = 83%; mammals = 86%), but it usually covers less than 50% of their geographic range. Almost 50% of species outside the PA network are considered threatened (critically endangered, endangered and vulnerable). We identified that ecoregions in tropical Andes, Mesoamerica, Pacific Islands (e.g., New Guinea, Solomon), Dry Chaco, and Atlantic forests are major conservation priorities areas.
The historic rates of new PAs added every year to the network is between ~6,000 to ~15,000. In contrast, we found that rates of including endemic species within the PA network have been fairly slow. Historic data shows that every year, the entire geographic range of 3 (amphibians) to 6 (birds and mammals) endemic species is 100% included inside the PA network (amphibians = from 162 to 233; mammals = 10 to 84; and, amphibians = 16 to 99). Based on these trends, it is very unlikely PAs will include all endemic species (14% total endemic species, that is ~1,508 out of 11,274) currently outside the PA network by 2020. It will require five times the effort made in the last two decades. However, projections also showed that is very likely that some portions of the geographic ranges for all endemic birds and mammals, but not for all endemic amphibians, will be covered by the future PA network.
I sum, I found that none of the hypotheses tested here can explain broad-scale patterns of total species richness and total species endemism. My main contribution on this research area is clearly rejecting these hypotheses from potential candidates that may explain biodiversity patterns. By removing them, we advance in this field and open possibilities to test new hypotheses and evaluate their mechanisms. I proposed that other drivers and mechanisms (whether biotic and biotic) acting at local scales, and escaping the detection of macroecological approaches, might be responsible for these patterns. Finally, in terms of conservation planning, I proposed that the international community has an opportunity to protect a great number of endemic species and their habitats before 2020, if they strategically create new PAs.
|
894 |
Caractérisation des systèmes hydro-climatiques à l'échelle locale dans l'Himalaya népalais / Characterization hydro-climatic systems at the local scale in the Nepalese HimalayasEeckman, Judith 30 October 2017 (has links)
La partie centrale de la chaîne himalayenne présente d’importantes hétérogénéités, en particulier en termes de topographie et de climatologie. La caractérisation des processus hydro-climatiques dans cette région est limitée par le manque de descriptif des milieux. La variabilité locale est alors difficilement représentée par les modélisations mises en œuvre à une échelle régionale.L’approche proposée dans ce travail est de caractériser les systèmes hydro-climatiques à l’échelle locale pour réduire les incertitudes liées à l’hétérogénéité du milieu. L’intégration de données localement précises est testée pour la modélisation de bassins versants peu instrumentés et fortement hétérogènes.Deux sous-bassins du bassin de la Dudh Koshi (Népal) sont utilisés comme échantillons représentatifs des milieux de haute et moyenne montagne, hors contribution glaciaire. Le schéma de surface ISBA est appliqué à la simulation des réponses hydrologiques des types de surface décrits à partir d’observations de terrain. Des mesures de propriétés physiques des sols sont intégrées pour préciser la paramétrisation des surfaces dans le modèle. Les données climatiques nécessaires sont interpolées à partir des observations in situ disponibles. Une approche non déterministe est appliquée pour quantifier les incertitudes liées à l’influence de la topographie sur les précipitations, ainsi que leur propagation aux variables simulées. Enfin, les incertitudes liées à la structure des modèles sont évaluées à l’échelle locale à travers la comparaison des paramétrisations et des résultats de simulation obtenus d'une part avec le schéma de surface ISBA, couplé à un module de routage à réservoir et d'autre part avec le modèle hydrologique J2000. / The central part of the Hindukush-Himalaya region presents tremendous heterogeneity, in particular in terms of topography and climatology. The representation of hydro-climatic processes for Himalayan catchments is limited due to a lack of knowledge regarding their hydrological behavior. Local variability is thus difficult to characterize based on modeling studies done at a regional scale. The proposed approach is to characterize hydro-climatic systems at the local scale to reduce uncertainties associated with environmental heterogeneity.The integration of locally reliable data is tested to model sparsely instrumented, highly heterogeneous catchments. Two sub-catchments of the Dudh Koshi River basin (Nepal) are used as representative samples of high and mid-mountain environments, with no glacier contribution. The ISBA surface scheme is applied to simulate hydrological responses of the surfaces that are described based on in-situ observations. Measurements of physical properties of soils are integrated to precise surface parametrization in the model. Necessary climatic data is interpolated based on available in-situ measurements. A non deterministic approach is applied to quantify uncertainties associated with the effect of topography on precipitation and their propagation through the modeling chain. Finally, uncertainties associated with model structure are estimated at the local scale by comparing simulation methods and results obtained on the one hand with the ISBA model, coupled with a reservoir routing module, and on the other hand, with the J2000 hydrological model.
|
895 |
Understanding the Sunrise Ceremony as a repository of cultural traditions and values: an exploration of ritual as a means for studying the health of the Apache peopleWitt, Michelle Pambrun, Witt, Michelle Pambrun January 1996 (has links)
The intent of this exploratory study was to discover the cultural significance of an Apache ritual, the Sunrise Ceremony, as it relates to the physical, mental, and emotional well-being of the Apache individual, family, and community at large. The ethnographic methodology was used to gather data because this design provided the most systematic and flexible process to generate the widest range of information necessary for describing this culture from the native's
point of view. Four culturally relevant domains were developed and analyzed to reveal five cultural themes, including "It's my strength," "Women are the core of living here," "It Tells You the Story of the Beginning," and "Change is Sad--Alcohol is Bad." The findings suggest that because the Sunrise Ceremony is central to the Apache way of life, its values and culture, an understanding of the Sunrise Ceremony can assist in the development of accurate nursing assessments and successful interventions to improve the collective health and well being of the Apache people. Additionally, recommendations for nursing practice and further research are proposed.
|
896 |
Hydrologické sucho v pramenných oblastech šumavských toků / Hydrological Drought in Headwaters of Šumava MountainSkála, Vít January 2017 (has links)
This master thesis if focused on the phenomenon of hydrological drought in the Šumava (Bohemian/Black Forrest) region. Hydrological drought is defined on seven hydrological stations (Modrava (CZ), Rejštějn (CZ), Sušice (CZ), Zwiesel (DE), Teisnach (DE), Chamerau (DE), Kalteneck (DE)) during period 1931-1937 and 1949-2014. The aim is in finding suitable hydrological dought indexes and other methods and apply them od the data. Results are compared each other and also are compared with studies that were proceed in non-mountainous region. For hydrological drought evaluation the threshold concept and method according Gumbel 1963 were used and deficite volumes were calculated. Seasonality graphs and graphs for nuber of drought days in hydrological years were constructed, For trends defining, Mann.Kendall and Hisch-Slack tests were used. Hydrological drought sesonality is different on german and czech side, it means effect of exposition towards southwest winds. Hydrological drought is concetrated in autumn at german stations and in winter on czech stations. Number of drought episodes decreases with decreasing elevation. There were found significant decreasing trends in drought episodes occurance in time. Monthly trends aren't so clear. On czech side there is significant decreasing trend in winter months,...
|
897 |
Montane Wetlands of the South African Great Escarpment : plant communities and environmental driversJanks, Matthew Richard January 2015 (has links)
Wetlands provide a number of valuable functions to both the surrounding environment and society. The anaerobic conditions created by flooding in wetlands provide a habitat that supports unique assemblages of plant life. High altitude wetlands are amongst the most species-rich in South Africa. They house a number of rare species and play a vital role in the supply of water to lower lying areas. These are some of the reasons that mountain wetlands are of high conservation value. A phytosociological study was undertaken on the high altitude wetlands of the Great Escarpment with the aim of classifying the plant communities and identifying the environmental drivers of plant community patterns within these ecosystems. Data collection was focused in the Eastern Cape and was supplemented with data from existing studies to gain a more complete understanding of the wetlands of the Great Escarpment of South Africa. Using the Braun-Blanquet approach, Hierarchical Cluster Analysis and Indicator Species Analysis; five broad wetland groups were identified, comprised of 33 individual plant communities and 81 indicator species. Multivariate analysis, including Canonical Correspondence Analysis revealed that the effects of altitude, such as temperature and rainfall, are the most significant large-scale drivers of vegetation patterns. Smaller scale drivers include wetness and soil nutrients including nitrogen, phosphorus, electrical conductivity, sodium, and organic content. The identification of indicator species served to reveal potentially important wetland species across different areas of the Great Escarpment. The effects of altitude on plant community patterns highlights the susceptibility of the high altitude specific communities to upward temperature zone shifts resulting from global warming. Other threats include livestock trampling, water extraction, and land use change for agricultural purposes. The relative absence of alien species in these wetlands gives an indication of their pristine condition and therefore their importance as a reference from which they may be monitored. A large proportion of the wetlands studied here occur outside protected areas, and given the rate of wetland loss in South Africa, it is important that continued effective land management is practiced to ensure that these ecosystems are conserved in the future .
|
898 |
Artillery and Warfare 1945-2025Bailey, J P A 24 November 2009 (has links)
For millennia battles were essentially affairs of linear encounter. From the 10th
Century to the 20th Century, artillery generally fired directly in the two dimensional
plane,limiting potential effects. The development of indirect fire changed this ,
two-dimensional model. Warfare became not so much a matter of linear encounter
as one of engagement as cross and throughout an area; and artillery dominated land
operations in both the First and Second World Wars as a result.
Firepower was subsequently often applied in even greater weights, but its effects
were frequently excessive and high-value targets proved elusive. During the Cold
War in Europe,the importance of field artillery wanded relative to other arms.
Artillery could only regain its utility by acquiring the highest-value targets and
engaging them effectively with the appropriate degree of force in time and space true
precision, as opposed to mere accuracy at a point. Improvements in target
acquisition and accuracy will enable land systems once more to engage targets
effectively throughout the battlespace with implications for warfare analogous to
those precipitated by the introduction of indirect fire a century ago.
Land operations will become increasingly three-dimensional and Joint. The effects
of fire will increasingly be applied in, not merely via, the third dimensions, since
targets themselves will increasingly be located, not just on the area of a battlefield,
but in the volume of three-dimensional battlespace with values of indetermined
by considerations of the fourth dimension, time. Fire, lethal and non-lethal, will
also be targeted in other less tangible dimensions such as cyber-space and new
types of 'virtual counterfire' will also emerge in the forms of legal and moral
restraint. All will be viewed through the lens of perceptions.
The burgeoning of firepower from all sources now becomes the spur for changes in the relationship between the land and air components, mindful of those novel factors that will increasingly inhibit the application of that firepower.
|
899 |
Timber supply and economic impact of mountain pine beetle salvage strategiesMoreira-Munoz, Simon 05 1900 (has links)
To address the scale mountain pine beetle (MPB) outbreak in British Columbia, salvage has become fully integrated with timber supply strategies. The objective of this thesis is to assess the economic impact of different salvage strategies depending on different attack levels, decay rates, and stakeholder discount rates. The study area is located in N.E. British Columbia where the MPB has not yet reached its peak and where susceptible to attack stands account for 40% of the area. Salvage strategies were modelled with a timber supply model (Woodstock) which uses a linear programming type II optimization approach. Performance of the model was assessed over a range of indicators such as NPV, profit, salvage proportion, species composition, inventory levels, and non-recoverable volume. Sensitivity analyses were conducted on harvest flow, discount rate, and ending inventory. The model was very sensitive to the intensity of attack and less sensitive to the decay level. The high level of attack resulted in large volume losses, mostly as un-salvaged inventory.
Although allowable annual cut (AAC) uplifts have an economic benefit, they do not necessarily maximize the salvage of pine. Non-pine species are an important component of the salvage and these species are also essential for the future timber supply. If the objective is to ensure quality and quantity of the future forest, policies have to complement AAC uplifts by strongly encouraging the salvage of mainly pine-leading stands and management options that minimize the “by-catch” of non-pine species and minimize destruction of advanced regeneration during salvage. However, this has an opportunity cost for the private industry where the objective is to maximize profit. If the salvage strategy focuses on decreasing the impact on cash flows, achieving desirable ending inventory levels, avoiding salvage of stands after shelf-life, and reducing impact on non-attack species, then the current harvest level will likely lead to a mid-term timber supply fall-down. Using the fibre for bioenergy production is an alternative if managing for bioenergy can be integrated into harvest operations. However, unlike mill residues, the bioenergy supply has to fully account for harvest and transportation costs of dead wood to the mill. / Forestry, Faculty of / Graduate
|
900 |
High-resolution Permafrost Distribution Modelling for the Central and Southern Yukon, and Northwestern British Columbia, CanadaBonnaventure, Philip P. January 2011 (has links)
Basal Temperature of Snow (BTS) measurements were used as the primary inputs to a high resolution (30 x 30 m grid cells) empirical-statistical regional permafrost probability model for the southern and central Yukon, and northernmost British Columbia (59° - 65°N). Data from seven individual study areas distributed across the region were combined using a blended distance decay technique, with an eighth area used for validation. The model predictions are reasonably consistent with previous permafrost maps for the area with some notable differences and a much higher level of detail. The modelling gives an overall permafrost probability of 52%. North of 62°N, permafrost becomes more extensive in the lowland areas whereas farther south permafrost is typically common only above treeline.
Significant differences exist between the mountain environments of the Yukon and the Swiss Alps where the BTS method originated and as a result different modelling approaches had to be developed. This work therefore: (1) develops additional explanatory variables for permafrost probability modelling, the most notable of which is equivalent elevation, (2) confirms the use of ground truthing as a requirement for empirical-statistical modelling in the Yukon and (3) uses a combination of models for the region in order to spatially predict between study areas.
The results of this thesis will be of use to linear infrastructure route-planning, geohazard assessment and climate change adaptation strategies. Future work employing the model will allow the effects of scenario-based climate warming to be examined.
|
Page generated in 0.7609 seconds