51 |
Vegetation Characteristics of Wyoming Big Sagebrush Communities Historically Seeded with Crested Wheatgrass in Northeastern Great Basin, USAWilliams, Justin Rodney 01 May 2009 (has links)
Crested wheatgrass (Agropyron cristatum [L.] Gaertn.) is one of the most commonly seeded grass species in the western United States and dominates thousands of hectares in the Great Basin. Although many degraded Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis) plant communities have been seeded with crested wheatgrass, successional pathways, influence of soil attributes, and cultivation history on the vegetation of these communities have not been fully characterized. I sought to identify community phases, vegetative differences, and soil attributes that explain variation among 35 Wyoming big sagebrush communities historically seeded with crested wheatgrass. All communities were more than 30 years old and had not experienced fire, or received subsequent chemical or mechanical treatments following their original seeding. Species richness, diversity, vegetation cover, and soil samples were measured in four 20 x 5 m intensive Modified Whittaker plots per community. Hierarchical clustering and principal component analysis of three indicator species (crested wheatgrass, Sandberg bluegrass, and Wyoming big sagebrush) identified four distinct community phases. Community phase 1 was dominated by crested wheatgrass and had the lowest species richness and cover of big sagebrush. Phases 2 and 3 had the highest species richness and cover of native species. Phase 4 was dominated by big sagebrush and had the lowest cover of crested wheatgrass. Community phases differed significantly for soil texture, soil nitrogen, and ground cover characteristics. Bare soil was almost double on loam-textured soils and rock cover was higher on clay loam texture soils (P < 0.05) as well as native plant cover. Communities previously cropped occurred on more coarse-textured soils and had 6-fold lower native species cover and double exotic herbaceous and crested wheatgrass cover. Cropping occurred on favorable, low rock, fine-texture soils, the same soils that favor crested wheatgrass production and reduce resilience of native plant composition. Delineation of community phases provided a new, empirically based state-and-transition model, while the characterization of soil attributes and disturbance history provided information about feedback mechanisms influencing dominant species that delineate community phases and effect community structure. This information can be used to assist in the development of management strategies in crested wheatgrass seeded communities.
|
52 |
Experimental Investigation On Sharp Crested Rectangular WeirsGharahjeh, Siamak 01 June 2012 (has links) (PDF)
This study is an experimental research to formulate the discharge over sharp-crested rectangular weirs. Firstly, a series of measurements on different weir heights were conducted to find the minimum weir height for which channel bed friction has no effect on discharge capacity. After determining the appropriate weir height, weir width was reduced to collect data on discharge-water head over weir relationship for a variety of different weir openings. Then, the data was analyzed through regression analysis along with utilization of global optimization technique to reach the desired formulation for the discharge. By taking advantage of a newly-introduced &ldquo / weir velocity&rdquo / concept, a simple function was eventually detected for the discharge where no discharge coefficient was involved. The behavior of the weir velocity function obtained in the present study illustrates the transition between the fully contracted and partially contracted weirs. In addition, the proposed weir velocity formulation is simple and robust to calculate the discharge for full range of weir widths.
|
53 |
Achievement and maintenance of dominance in male crested macaques (Macaca nigra)Neumann, Christof 18 November 2013 (has links) (PDF)
Dominance rank often determines the share of reproduction an individual male can secure in group-living animals (i.e. dominance rank-based reproductive skew). However, our knowledge of the interplay between individual and social factors in determining rank trajectories of males is still limited. The overall aim of this thesis was therefore to investigate mechanisms that underlie individual dominance rank trajectories in male crested macaques (Macaca nigra) and to highlight potential individual and social determinants of how males can achieve and maintain the highest rank possible. Data for this thesis were collected on 37 males during a field study on a natural population of crested macaques living in the Tangkoko-Batuangus Nature Reserve in Indonesia. In study 1, I validate Elo-rating as a particularly well suited method to quantify dominance hierarchies in animal species with dynamic dominance relationships. In studies 2 and 3, I suggest a personality structure for crested macaque males consisting of five distinct factors and further demonstrate that two personality factors determine whether males will rise or fall in rank. Finally, in study 4, I present results on how males utilize coalitions to increase their future rank. Together, these results shed light on how individual attributes and social environment both can impact male careers. Ultimately, in order to understand what determines rank-based reproductive skew, we need to consider the complexity and likely diversity of the mechanisms underlying rank trajectories of individual males which are likely to differ across different species.
|
54 |
Analýza vybraných aspektů hnízdní biologie potápky roháče (Podiceps cristatus) / Analysis of selected aspects of the breeding biology of Great Crested Grebe (\kur{Podiceps cristatus})MARKOVÁ, Kateřina January 2016 (has links)
The aim of the thesis was monitoring abundance and distribution of nests of Great Crested Grebe (Podiceps cristatus) during the season on the Naděje fishpond system. Further observation included factors that could affect nesting success of the Great Crested Grebe. Attention was concentrated on Wild Duck (Anas platyrhynchos) which is bred by man on the fishpond system and might negatively affect nesting success of Great Crested Grebe. Part of this study was the detailed observation of selected pairs during the nesting season by using camera traps. Temperature measurement in the nests was done by temperature data logger. The investigation was realized on the Naděje fishpond system near the village Frahelž. The research took place from the 14th of April to the 28th of October in 2015. In 2015 were found and investigated 37 nests on the Naděje fishpond system. On the fishpond Skutek were monitored 34 nest, on the fishpond Láska 2 nests and on the fishpond Rod only 1 nest. Majority nests (30) were found on a free surface and 7 nests were situated in the bushy vegetation. Parameters of 111 eggs were obtained altogether. On the fishpond Skutek were found 100 eggs, on fishpond Láska 8 eggs and in the only nest on fishpond Rod 3 eggs. Using the camera traps during the observation proved negative effect of wild duck on Great Crested Grebe nesting. The nest was destroyed group of wild duck. The maximum temperature in the nest reached 33,8 °C.
|
55 |
COMPARAÇÃO ENTRE DOIS SISTEMAS HIDRÁULICOS DE MEDIÇÃO DE AGUA DE IRRIGAÇÃO DE ARROZ / COMPARISON BETWEEN TWO HIDRAULICS SYSTEMS OF MEASUREMENT OF RICE IRRIGATION WATERLuz, Glauco de Oliveira da 24 February 2011 (has links)
The irrigated farm crops are the main users of water. With this, in places where there is a water
shortage to attend all sorts of use, this kind of activity is characterized like as a potentially conflicting,
once that to produce one hectare of rice, are necessary thousands cubic meters of water. To work out
this conflict, many actions are been developed, as giving rights and tax to use water. Although, to the
effectiveness of that actions, is necessary an effective inspection over all of the producers and users,
monitoring each volume used. Being a inspection this kind unsustainable to the manager, is necessary
the study of methodologies to determine water flow and volumes of irrigation, which shall be easily
understood and applied, to be used by the producers themselves. Were tested, comparatively, two
sorts of hydraulics systems, sharp crested Weirs and Velocimetric Hydrometers, measurers of water
flow and volumes respectively, for monitoring the volumes of irrigation of two parcels of irrigated rice in
the harvest 2009/2010, located in Cachoeira do Sul city, in Capané locality. In each parcel, one with
Direct tillage and area of 0,66 ha and another one with Conventional tillage and area of 0,80 ha, the
monitoring of water occurred simultaneously by using the Weirs and Hydrometers installed in
sequence and confined, in other words, the monitored water was the same in both systems. Was used
Pluviometer to monitoring the total volume of rain fall, in order that, with the irrigation volume was
calculated the total volume necessary to that rice parcels. The results of the comparative monitoring
between Weirs of Thin Wall and Velocimetric Hydrometers showed a small difference in the final
results, been the difference of 1,15% bigger by the Hydrometer in relation to Weir in the parcel with
Direct tillage and 6,75% smaller by Hydrometer in relation to Weir in Conventional tillage. However,
Were verified daily variations between the Weirs and Hydrometers that reached 82% in the Direct
tillage and 39% in the Conventional tillage. The total volume monitored to each parcel was 8565,15
m³/ha in the parcel with Direct tillage and 9987,25 m³/ha in the conventional tillage, both considering
the results of Weirs. With the results found and the characteristics of operation and maintenance of
the analyzed systems, is checked the availability of using sharp crested Weirs for monitoring water
quantity in rice crops, although by the comparatively study oh both systems, is not recommended to
use hydrometers in these ways. / As lavouras de arroz irrigado são as principais usuárias de água durante o seu ciclo produtivo. Com
isto, em locais onde existe escassez de água para atender a diversos usos este tipo de
empreendimento se caracteriza como um potencial conflitante, uma vez que para produção de um
hectare de arroz são necessários milhares de metros cúbicos de água. Para resolver estes conflitos,
muitos instrumentos estão sendo desenvolvidos, como a outorga e a cobrança pelo uso da água. No
entanto, para a efetividade destes instrumentos, é necessária uma fiscalização extensiva sobre todos
os produtores e usuários, monitorando os respectivos volumes utilizados. Sendo uma fiscalização
deste tipo insustentável para o órgão gestor se faz necessário o estudo de metodologias de
determinação de vazões e volumes de irrigação que sejam de fácil entendimento e aplicação, para
que possam ser utilizadas e monitoradas pelos próprios produtores rurais (automonitoramento).
Foram testados comparativamente dois tipos de sistemas hidráulicos, Vertedores de parede delgada
e Hidrômetros Velocimétricos, medidores de vazões e volumes respectivamente, para monitoramento
dos volumes de irrigação de duas parcelas de arroz irrigado na safra de 2009/2010, localizados na
cidade de Cachoeira do Sul, na localidade de Capané. Em cada uma das parcelas, uma com sistema
de plantio Direto e área de 0,66 ha e outra com plantio Convencional com área de 0,80 ha, o
monitoramento da água ocorreu de forma simultânea através da utilização de vertedores e
hidrômetros instalados em série e confinados, ou seja, a água monitorada por um era a mesma que a
monitorada pelo outro. Foi utilizado Pluviômetro no monitoramento do volume total de precipitações,
para que juntamente com o volume de irrigação fosse determinado o volume total necessário ao
cultivo do arroz naquelas parcelas. O resultado do monitoramento comparativo entre Vertedores e
Hidrômetros apresentou pequena variação no resultado final, sendo a diferença de 1,15% monitorada
a mais pelo Hidrômetro em relação ao vertedor na parcela com plantio Direto e 6,75% a menos pelo
Hidrômetro que o Vertedor na parcela com plantio Convencional. No entanto, foram verificadas
variações diárias entre os Vertedores e os Hidrômetros que alcançaram 82% no plantio direto e 39%
no plantio convencional. O volume total monitorado para cada parcela foi de 8565,15 m³/ha na
parcela com plantio Direto e 9987,25 m³/ha no plantio Convencional, ambos considerando os
resultados obtidos com os vertedores. Com os resultados obtidos e as características de operação e
manutenção dos sistemas analisados, verifica-se a viabilidade da utilização de Vertedores de parede
delgada para o automonitoramento de água em lavouras orizicolas, no entanto, através do estudo
comparativo dos dois sistemas, não se recomenda a utilização de Hidrômetros Velocimétricos neste
meio.
|
56 |
Helminto e artropodofauna de Paroaria coronata (Miller, 1776) (Passeriformes: Emberzidae) / Helminth and Arthropodfauna of the Paroaria coronata (Miller, 1776) (Passeriformes: Emberezidae)Mascarenhas, Carolina Silveira 22 July 2008 (has links)
Made available in DSpace on 2014-08-20T14:31:33Z (GMT). No. of bitstreams: 1
dissertacao_carolina_mascarenhas.pdf: 23937030 bytes, checksum: 4ede460c8b3f9046c6af286984b4b306 (MD5)
Previous issue date: 2008-07-22 / Paroaria coronata (red-crested cardinal) occurs only of South America. The species
is not in danger of extinction, but it is appreciated by the illegal trade in wild animals.
His parasite fauna is little known and has been recorded only one Nematoda and
three Phthiraptera. The diet is mainly based greasses seeds, but can consume small
fruit and insects. The study aimed to identify helminths and arthropods associated
with red-crested cardinal and for that were examined wild birds, captives and of
undetermined origin, totaling 40 specimes. The wild birds and undetermined origin
were the most parasitized. The helminthfauna was composed of Aproctella carinii,
Dispharynx nasuta, Capillaria sp. Diplotriaena sp. (Nematoda); Tanaisia oviaspera,
Tanaisia valida, Tanaisia sp., Prosthogonimus ovatus (Trematoda); Orthoskrjabinia
sp. (Cestoda); Mediorhynchus sp. (Acanthocephala). Tanaisia sp. was most
prevalent (10%) and more abundant (0.48), D. nasuta and Orthoskrjabinia sp.
occurred with greater mean intensity of parasitism (5 helminths/host). The
arthropodfauna was represented by Myrsidea coronatae, Philopterus sp. and
Brueelia sp. (Phthiraptera); Ptilonyssus sairae and Sternostoma pirangae
(Gamasida), where M. coronatae and P. sairae were the most prevalent with 65%
and 50%, respectively. All helminths are reported for the first time in P. coronata,
Orthoskrjabinia sp. is recorded for the first time in Brazil; A. carinii, Diplotriaena sp.,
T. valida, T. oviaspera and Mediorhynchus sp. are cited for the first time in the Rio
Grande do Sul state. The helminthfauna found in P. coronata, indicates that the
species is omnivorous eating habits. Among the arthropods, Philopterus sp., Brueelia
sp., P. sairae and S. pirangae have your first record infecting P. coronata; M.
coronatae is recorded for the first time in Brazil, this report marks the first occurrence
of S. pirangae in Brazil and the first of P. sairae in the Rio Grande do Sul state. / Paroaria coronata (cardeal) ocorre apenas na América do Sul. A espécie não está
em perigo de extinção, mas é visada pelo comércio ilegal de animais silvestres. Sua
fauna parasitária é pouco conhecida, tendo sido registrado somente um Nematoda e
três Phthiraptera. A dieta desta ave baseia-se principalmente em sementes de
gramíneas, mas pode consumir pequenos frutos e insetos. O estudo teve por
objetivo identificar os helmintos e artrópodes associados à P. coronata e para tal
foram examinadas aves silvestres, cativas e de origem indeterminada, totalizando 40
espécimes. As aves silvestres e de origem indeterminada foram as mais parasitadas.
A helmintofauna esteve composta por Aproctella carinii, Dispharynx nasuta,
Capillaria sp. Diplotriaena sp. (Nematoda); Tanaisia oviaspera, Tanaisia valida,
Tanaisia sp., Prosthogonimus ovatus (Trematoda); Orthoskrjabinia sp. (Cestoda);
Mediorhynchus sp. (Acanthocephala). Tanaisia sp. foi mais prevalente (10%) e mais
abundante (0,48), D. nasuta e Orthoskrjabinia sp. ocorreram com maior intensidade
média de parasitismo (5 helmintos/hospedeiro). A artropodofauna esteve
representada por Myrsidea coronatae, Philopterus sp. e Brueelia sp. (Phthiraptera);
Ptilonyssus sairae e Sternostoma pirangae (Gamasida), onde M. coronatae e P.
sairae foram os mais prevalentes com 65% e 50%, respectivamente. Todos os
helmintos são relatados pela primeira vez em P. coronata, Orthoskrjabinia sp. é
registrado pela primeira vez no Brasil; Aproctella carinii, Diplotriaena sp., Tanaisia
valida, Tanaisia oviaspera e Mediorhynchus sp. são citados pela primeira vez no Rio
Grande do Sul. A helmintofauna encontrada em P. coronata, indica que a espécie
tem hábito alimentar onívoro. Entre os artrópodes, Philopterus sp., Brueelia sp., P.
sairae e S. pirangae são citados pela primeira vez parasitando P. coronata; M.
coronatae é registrado pela primeira vez no Brasil; este relato caracteriza a primeira
ocorrência de S. pirangae no Brasil e a primeira de P. sairae no Rio Grande do Sul.
|
57 |
Shaping an Iconic Species : From the giant panda to the red panda and the Tibetan antelope / Skapandet av en ikonisk art : från jättepandan till den röda panda och den tibetanska antilopenHuang, Kefan January 2020 (has links)
This thesis is based and developed on the ambiguous and open conception, iconic species, which reveals the relationship between human society and non-human species that goes be- yond its biological status. From the case of the giant panda, I attempt to deconstruct the shap- ing process of an iconic species from multiple perspectives, which includes how a specific cultural context, or a specific historical period contributes to the shaping process and how the government and the public diverge or even clash around the shaping process. Then, I introduce my fieldwork where I through observing both giant pandas and red pandas in the exhibition centres called panda bases to analyse the encountering an iconic species in reality and their different influences on public awareness of the wildlife conservation. I also attempt to explore the various representative forms of an iconic species such as the Tibetan antelope ranging from the mascot to the film and follow the changes of its symbolic meanings in different forms. In conclusion, the thesis is aimed to reflect the hybrid features of the iconic species and pro- vide in-depth interpretation of the endless interactions between the human beings and other species.
|
58 |
Amphibia : Living on both sidesNielsen, Elvira January 2023 (has links)
Mariestad municipality participated in a global competition to become Volvo’s site for a new lithium-ion battery factory. The competition was between eleven different countries and three different locations in Sweden. Aer declaring Mariestad and the site Korstorp as winners, extensive surveys of the site were initiated during which they did a rare find of the protected species the great crested newt. However, Volvo is still planning on going through with building the factory the way they planned, which implies asphalting an area of 140-150 ha and constructing a box like factory of one or two floors. The newts are now under great threat and will have to be moved in order to make room for the factory. Building battery factories is something we strive for on a global scale, but what happens when global sustainability opposes local? In the example of the battery factory in Mariestad Agenda 2030’s sustainable development goals biodiversity and economic growth seem to be in opposition to each other and here it becomes clear that the value of humans and non-humans are different. How are we to remedy the unequal distribution of power and how can we turn the conflict zone in Korstorp into a zone of diplomacy? The convention of the rights of the child became Swedish law in 2020 and here it is relevant taking a look at article 12, which says; “All children have the right to express their opinions, adults shall listen and consider the children’s opinions”. The children are our future and they have to live with our choices. Building in a sustainable manner implies listening to who will be affected. The society’s measurement of success needs to be altered from economic growth to one which everybody has the right to be part of. To reach that place we have to practice at an early age to think and act in a democratic manner. If children feel as if they have been heard they could come to appreciate democratic processes in which they trust their ability to alter the society and feel obligated towards it. Furthermore, the unlimited imagination of children and the fact that they are not yet indoctrinated in the routines and customs of our society might bring the innovation needed to create a new kind of factory in symbiosis with the local environment.
|
59 |
Piscivorous colonial waterbirds in the Columbia River estuary : demography, dietary contaminants, and managementSuzuki, Yasuko 13 January 2012 (has links)
Caspian terns (Hydroprogne caspia) and double-crested cormorants
(Phalacrocorax auritus) nest in large colonies on East Sand Island in the Columbia
River estuary, the largest known colonies for the two species in the world. Both
species of piscivorous colonial waterbirds have been identified as predators with a
significant impact on the survival of juvenile salmonids (Oncorhynchus spp.) listed
under the U.S. Endangered Species Act. To better understand and address issues
related to seabird-fisheries interactions in the Columbia River estuary, I conducted
studies related to the ecology, conservation, and management of these two species of
piscivorous waterbirds.
I evaluated the demographics and inter-colony movements of Caspian terns
belonging to the Pacific Coast metapopulation, with special emphasis on two breeding
colonies, one on East Sand Island in the Columbia River estuary and the other on
Crescent Island in the mid-Columbia River, based on re-sightings of color-banded
individuals. Apparent annual adult survival at both colonies was high, and age at first
reproduction was greater than previously reported for the species. Colony site
philopatry of breeding adults at both colonies was high; however, some individuals
prospected for breeding colonies over much of the Pacific Coast region and moved to
other colonies over distances of up to 3,000 km. Some terns from the large colony in
the Columbia River estuary responded quickly to the availability of new colony sites
as distant as 550 km from the estuary, and established successful breeding colonies
within less than a year of the new sites becoming available. The Caspian tern colony
on East Sand Island appears to be an important source colony for a number of smaller,
less productive colonies distributed over an extensive area from the Salton Sea,
California to the Copper River Delta, Alaska, an area with limited and ephemeral
nesting opportunities.
Environmental contaminants have been a conservation concern for wildlife in
the Columbia River estuary, especially species that consume fish and are therefore
likely to bioaccumulate persistent organic pollutants. I measured and compared levels
of polychlorinated biphenyls (PCBs) in eggs and chicks of Caspian terns and doublecrested
cormorants, as well as their primary prey fish types, at colonies on East Sand
Island and farther up-river. Based on differences in tern and cormorant diet
composition at the various study colonies, higher PCB levels in eggs and chicks were
associated with diets dominated by resident freshwater and estuarine fishes. PCB
levels in prey fish were positively correlated with lipid content; however, PCB levels
in the livers of chicks were negatively correlated with chick fat scores, suggesting that
chick fat reserves are a sink for ingested PCBs. Lower PCB levels in terns and
cormorants from East Sand Island compared to colonies farther up-river reflected diets
with a higher proportion of marine forage fishes at East Sand Island; marine forage
fishes had lower average levels of PCBs than their resident freshwater and estuarine
counterparts.
In order to explore non-destructive techniques for managing nesting colonies
of double-crested cormorants, I evaluated habitat enhancement and social attraction,
two techniques that have proven effective for relocating Caspian tern colonies to sites
where impacts on fish stocks of conservation concern would be minimal. Cormorants
were attracted to nest and successfully raised young at test plots on East Sand Island
and on islands in the estuary with a previous history of cormorant nesting or
unsuccessful nesting attempts. On an island with no history of cormorant nesting or
prospecting, however, no cormorants were attracted to nest. My results suggest that
attraction of nesting cormorants using these techniques is dependent on the previous
history of cormorant nesting or nesting attempts, the frequency and intensity of
disturbance by potential predators, and the presence of breeding cormorants nearby.
While habitat enhancement and social attraction have potential as methods for
redistributing nesting cormorants away from areas where fish stocks of concern are
highly susceptible to predation, successful establishment of new colonies using these
techniques will likely require a focus on sites with a history of cormorant nesting.
Findings from this dissertation raise some concerns over the management of
Caspian tern and double-crested cormorant colonies on East Sand Island in order to redistribute
parts of these colonies to alternative sites and mitigate the impact of those
piscivorous colonial waterbirds on ESA-listed salmonids. East Sand Island has
supported source colonies of piscivorous colonial waterbirds for many smaller
colonies throughout the region and is close to an abundant and relatively
uncontaminated food supply. Also, alternative colony sites that can substitute for East
Sand Island are not readily apparent, especially for double-crested cormorants.
Therefore, management of Caspian tern and double-crested cormorant colonies on
East Sand Island to benefit Columbia Basin salmonids needs to proceed cautiously and
reversibly because of the implications for the region-wide populations of these
piscivorous colonial waterbirds. / Graduation date: 2012
|
60 |
Populační dynamika zrzohlávky rudozobé (Netta rufina) / Population dynamics of Red-crested Pochard (Netta rufina)Poláková, Klára January 2014 (has links)
This study is aimed at analysis of long-term and short-term changes in numbers of Red-crested Pochard (Netta rufina) in Třeboň region. This species is increasing in long-term period and it is also spreading into new localities in the Czech Republic. There were recorded two waves of arrival of Red-crested Pochard arrive, i.e. in April and in May. The total numbers were decreasing at the end of breeding season (from the beginning of July) in study area. The water surface area and area of littoral vegetation were found to be the most important factors affecting preference of individual ponds in pre-breeding season. Furthermore, water transparency seems to be important factor affecting numbers of broods, ducklings and adults in post-breeding season. Low numbers of broods per 1 female were recorded in years with high numbers of Red- crested Pochard at the start of breeding season. However, the frequency of brood parasitism was higher in these years. Key words: Netta rufina, Red-crested Pochard, population dynamics, ducks, breeding, numbers, brood parasitism, south Bohemia
|
Page generated in 0.0706 seconds