Spelling suggestions: "subject:"lead toughness""
1 |
Feeding ecology of black and white colobus monkeys from south coastal Kenya: the influence of spatial availability, nutritional composition, and mechanical properties of food itemsDunham, Noah T. 27 June 2017 (has links)
No description available.
|
2 |
Influência da estrutura da vegetação de cerrado na assembleia de ácaros plantícolas / Influence of cerrado vegetation structure in the assemblage of plant mitesNunes, Samuel Nascimento 18 March 2016 (has links)
Submitted by Cláudia Bueno (claudiamoura18@gmail.com) on 2016-07-13T19:53:24Z
No. of bitstreams: 2
Dissertação - Samuel Nascimento Nunes - 2016.pdf: 1360269 bytes, checksum: cf4cac437479400d2487692196f0e700 (MD5)
license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2016-07-14T13:33:20Z (GMT) No. of bitstreams: 2
Dissertação - Samuel Nascimento Nunes - 2016.pdf: 1360269 bytes, checksum: cf4cac437479400d2487692196f0e700 (MD5)
license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2016-07-14T13:33:20Z (GMT). No. of bitstreams: 2
Dissertação - Samuel Nascimento Nunes - 2016.pdf: 1360269 bytes, checksum: cf4cac437479400d2487692196f0e700 (MD5)
license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5)
Previous issue date: 2016-03-18 / Fundação de Amparo à Pesquisa do Estado de Goiás - FAPEG / Plant inhabiting mites are little known in Natural Ecosystems since the most studies with
these animals were held in agroecosystems. Cerrado biome presents several
phytophysiognomic types with distinct environmental characteristics, ranging from open
areas (Campo Cerrado) to forest (Cerradão). The phytophysiognomy can be crucial in
organizing assemblage of plant-dwelling arthropods because they have differences in
physical and chemical characteristics of the microenvironment, and in the floristic
composition, richness and abundance of plant species. In the present study we evaluated
Cerrado vegetation structure effect in the organization of mites assemblage on Miconia
albicans (Sw.) Triana plants from Emas National Park, which represent the largest
Cerrado protected area. We sampled 21 10x10 m-plots, being 12 distributed in Campo
Cerrado (CC) and nine in Cerrado Sentido Restrito (CSR). In each plot, one M. albicans
individual was marked for mite sample, preferably, those located closer to the plot center.
We collected 10 leaves around median extract canopy of each marked plant, which in turn
were washed in 70 % alcohol for extracting mites. In the laboratory, the mites were observed under dissecting microscopy, mounted on microscope slides and identified
under phase constrast microscopy. We sampled a total of 463 mites, being 347 in CSR
and 116 in CC, distributed in 44 species and 14 families. We reported three genera for the
first time to Brazil, namely, Phytoptipalpus (Tenuipalpidae), Paraciota (Eriophyidae) e
Idiolorryia (Tydeidae). Miconia albicans plants from Cerrado Sentido Restrito showed
greater richness and abundance of mites than those in Campo Cerrado. These results were
significant when all mites were analyzed together and also when only considered the
phytophagous mites. These results can be explained by two mechanisms: (i) Cerrado
Sentido Restrito presents greater host plant richness and abundance, what allowed support
more individuals, and consequently greater species richness; or (ii) plants from Campo
Cerrado have greater leaf toughness, which difficult the establishment and development
of phytophagous mites on their leaves, thus interfering in occurrence and abundance of
other trophic levels. Therefore, the vegetation structure and leaf characteristics, typical of
each vegetation formation, may have been decisive in occurrence and establishment of
mites on M. albicans leaves, mainly for Phytophagous. / Os ácaros plantícolas são poucos conhecidos em ecossistemas naturais, uma vez que a
maioria dos estudos com esses animais é realizada em sistemas agrícolas. No Bioma
Cerrado são encontrados vários tipos fitofisionômicos com distintas características
ambientais, variando desde áreas abertas (campo cerrado) às florestais (cerradão). A
fitofisionomia pode ser determinante na organização da assembleia de artrópodes
plantícolas por apresentarem diferenças nas características físico-químicas do
microambiente, na composição florística, riqueza e abundância de espécies vegetais. No
presente estudo foi avaliado o efeito da estrutura da vegetação do Cerrado na organização
da assembleia de ácaros em plantas de Miconia albicans (Sw.) Triana no Parque Nacional
das Emas, que é a maior unidade de conservação deste Bioma brasileiro. Avaliamos 21
parcelas, sendo 12 em áreas de Campo Cerrado (CC) e nove em Cerrado Sentido Restrito
(CSR). Em cada parcela foi marcado um indivíduo de M. albicans, preferencialmente,
aquele localizado mais próximo ao centro da parcela. Foram coletadas 10 folhas ao redor
do extrato mediano da copa de cada planta marcada, que por sua vez, foram lavadas em
álcool 70% para extração dos ácaros. Em laboratório, os ácaros foram triados, montados
em lâminas de microscopia e identificados sob microscópio com contraste de fases. Foi
amostrado um total de 463 ácaros, sendo 347 em CSR e 116 em CC, distribuídos em 44
espécies e 14 famílias. Três gêneros foram relatados pela primeira vez para o Brasil, sendo
eles Phytoptipalpus (Tenuipalpidae), Paraciota (Eriophyidae) e Idiolorryia (Tydeidae).
Plantas de M. albicans de Cerrado Sentido Restrito apresentaram maior riqueza e
abundância de ácaros do que aquelas em Campo Cerrado. Esses resultados foram
significativos quando todos os ácaros foram analisados em conjunto e também quando
somente os fitófagos foram considerados. Os resultados encontrados podem ser
explicados por dois mecanismos: (i) Cerrado Sentido Restrito apresenta maior riqueza e
abundância de plantas hospedeiras, o que possibilita a ocorrência de maior número de indivíduos de ácaros, e consequentemente uma maior riqueza de espécies; (ii) As plantas
de Campo Cerrado apresentam maior dureza foliar, o que dificulta o estabelecimento e
desenvolvimento de ácaros fitófagos sobre as plantas hospedeiras, interferindo dessa
maneira na ocorrência e abundância dos demais níveis tróficos. Portanto, a estrutura da
vegetação e as características foliares, que variaram entre as fitofisionomias avaliadas,
podem ter sido determinantes na ocorrência e estabelecimento de ácaros em M. albicans,
principalmente para os fitófagos.
|
3 |
Exotic vs. native: global and urban investigations of leaf litter decay in streamsKennedy, Kimberly Theresa May 30 August 2016 (has links)
Exotic species alter the streamside plant community by changing the resources available to the stream food web, causing cascading changes throughout the entire aquatic ecosystem. To better understand the impacts of exotic litter species on stream communities, investigations were made at global and local levels. A meta-analysis was performed to understand which environmental and litter quality factors impact native and exotic litter decay rates on the global scale. It was found that exotic species are likely to decay faster than native species at larger mesh sizes, and in warm temperature environments because high quality exotic leaves have a lower C:N ratio than native leaves. An urban litter decay experiment in Victoria, B.C. streams contrasting Alnus rubra, Salix sitchensis, Hedera sp., Rubus armeniacus and plastic trash found that trash decays more slowly than leaf litter, but leaf species all decay at the same rate, and stream invertebrates colonize all litter types equally. Significant differences in litter decay rates and invertebrate community alpha and Shannon diversities were also observed across the four different streams. The more that is learned about the impacts of exotic leaf litter, the better we are able to respond to keep streams as healthy and as biodiverse as possible. / Graduate / 2017-08-10 / 0329 / 0793 / kimkenn@uvic.ca
|
Page generated in 0.0576 seconds