Submitted by Valquíria Barbieri (kikibarbi@hotmail.com) on 2018-04-09T21:08:02Z No. of bitstreams: 1 DISS_2014_Angélica Francisca Mendes Mamede.pdf: 690362 bytes, checksum: 992dd831bb86f670485b28ddc3c8df3c (MD5) / Approved for entry into archive by Jordan (jordanbiblio@gmail.com) on 2018-04-26T16:45:41Z (GMT) No. of bitstreams: 1 DISS_2014_Angélica Francisca Mendes Mamede.pdf: 690362 bytes, checksum: 992dd831bb86f670485b28ddc3c8df3c (MD5) / Made available in DSpace on 2018-04-26T16:45:41Z (GMT). No. of bitstreams: 1 DISS_2014_Angélica Francisca Mendes Mamede.pdf: 690362 bytes, checksum: 992dd831bb86f670485b28ddc3c8df3c (MD5) Previous issue date: 2014-03-13 / CNPq / A variação no uso de recurso é muito comum e pode ocorrer de diferentes formas dentro de uma população natural. Dentre essas se destacam a exploração de recursos diferenciada entre machos e fêmeas, jovens e adultos, ou pode estar relacionada à mudança na morfologia em resposta ao uso de recurso e especialização individual (essa por sua vez pode ser afetada pela competição intra ou interespecífica). Desse modo o objetivo desse trabalho é descrever o padrão de uso de recurso alimentar dentro de uma população do peixe jeju (Hoplerythrinus unitaeniatus), um peixe predador comum em ambientes lênticos, na planície de inundação do Pantanal. As coletas foram realizadas na planície de inundação localizada na região do Pantanal de Poconé nos anos de 2009, 2010 e 2011. De cada indivíduo foram tomadas medidas morfológicas, tiveram seu sexo determinado e o estomago retirado. Os itens alimentares de H. unitaeniatus e seu possível competidor Hoplias malabaricus foram identificados. Para quantificação foi utilizado o método numérico. Verifiquei se machos e fêmeas, e/ou jovens e adultos (classificados segundo estimativa de primeira maturação) e/ou variações na morfologia estavam relacionadas à composição da dieta dentro dessa população através de uma PERMANOVA. Então calculei o grau de especialização individual na população (IS) e o aninhamento (NODF), separadamente para grupos que diferiam na dieta. Utilizei uma PCA para reduzir a dimensionalidade dos dados de cobertura vegetal, para então saber se existiu efeito da competição intra ou interespecífica e cobertura vegetal no IS através de uma regressão multipla. Foram analisados os conteúdos estomacais de 145 exemplares de H. unitaeniatus: 56 machos (CP variando entre 49,02 e 200,22 mm) e 89 fêmeas (CP variando entre 64,13 e 204,50mm). O comprimento médio da primeira maturação estimado foi de 105,8 mm. Desta forma, 82 indivíduos foram classificados como jovens e 53 como adultos. Os itens alimentares foram divididos em 22 categorias. Machos e fêmeas não diferiram na composição de recursos utilizados (pseudo-F1,143=1,46; p= 0,14). No entanto, a composição da dieta diferiu entre jovens e adultos (pseudo-F1,143= 5,26; p<0,01). Quando confrontados com a composição da dieta, encontramos relação entre a variação na dieta relacionada à morfologia (eixo 2, pseudo-F1,142=2,07, p<0,01; eixo 3, pseudo-F1,142= 0,57, p=0,87). De forma geral, a amplitude de especialização individual dentro desta população variou entre 0,22 e 0,62 e foi significativa somente na minoria dos casos. O aninhamento só foi significativo em dois casos, e variou entre 10 e 60,83. O modelo geral de regressão múltipla entre o IS e a abundância de jeju e de traíra e os eixos da PCA de cobertura vegetal, representou 12,6% da variação encontrada no IS e não foi significativo (F4,9= 1,47; R²ajustado=0,126; p= 0,29). O IS não foi afetado pela abundância de jejus (p= 0,12), pela abundância de traíra (p= 0,53) e nem pela cobertura vegetal (eixo 1, p= 0,94; eixo 2, p= 0,6). Em síntese, a população de Hoplerythrinus unitaeniatus da planície de inundação do Pantanal apresentou uma tendência em ter especialização individual em poucos casos, esta por sua vez não foi influenciada por interações competitivas. Também encontrei variação intrapopulacional no uso do recurso explicada pela ontogenia e por variações morfológicas. / The variation in resource usage is very common and can occur in different ways in a natural population. Among these, I highlight the differentiated exploitation of resources between males and females, young and old, or can be related to change in morphology in response to resource usage and individual specialization (that in turn can be affected by intra-or interspecific competition). Thus the aim of this study is to describe the standard of food resources usege within a population of jeju fish (Hoplerythrinus unitaeniatus), a predator fish common in lentic environments) on the floodplain of the Pantanal. The collections were made in the floodplain located in the Pantanal region of Poconé in the years 2009, 2010 and 2011. The measures of morphology of each individual were taken and they had their sex determined and their stomach removed. The food itens of H. unitaeniatus and its possible competitor Hoplias malabaricus were identified. To quantify the numerical method was used. I checked if males and females, and/or adults (classified according to estimate of first maturity), and/or variations in morphology were related to the composition of the diet within that population through a PERMANOVA. Then I calculated the degree of individual specialization in the population (IS) and nestedness (NODF), separately for groups that differed in the diet. I used a PCA to reduce the dimensionality of the data of vegetation cover, and then whether there was effect of intra and interspecific competition or vegetation cover in IS through a multiple regression. The food itens of 145 especims of H. uniteniatus were analized: 56 males (Standard Length between 49.02 and 200.22 mm) and 89 females (SL between 64.13 and 204.50mm). The average length of the first maturation estimated is 105.8 mm. Thus, 82 individuals were classified as young and 53 as adults. The food itens were divided into 22 categories. Males and females did not differ in the composition of resource used (pseudo-F1.143=1.46; p= 0.14). However, diet composition differed between young fishes and adults (pseudo-F1.143= 5.26; p<0.01). When confronted with the composition of the diet, we found relashionship between variation in diet linked to morphology (axis 2, pseudo-F1.142=2.07, p<0.01; exis 3, pseudo-F1.142= 0.57, p=0.87). In general, the amplitude of individual specialization within this population ranged from 0.22 and 0.61 and was significant only in a minority of cases. The nestedness was significant only in two cases, and range between 10 and 60.83. The general model of multiple regression between the IS and the abundance of jeju and traíra and the PCA axes of vegetal cover, represented 12.6% of the variation found in the IS and was not significant (F4.9= 1.47; R²adjusted=0.126; p= 0.29). The IS was not affected by the abundance of jeju (p= 0.12), by the abundance of traíra (p= 0.53) and not by the vegetation cover (axis 1, p= 0.94; axis 2, p= 0.6). In summary, the population of Hoplerythrinus unitaeniatus of floodplain of Pantanal, presented a tendency to have individual specialization in a few cases, this turn was not influenced by competitive interactions. I also found intrapopulation variation in resource use explained by ontogeny and morphological variations.

Anticipated increases in the frequency, duration or intensity of high temperature events ('heat waves') have the potential to significantly impact forest form and functioning, but these events remain virtually unstudied in forest ecosystems. This thesis presents the results of an event-driven research effort into the impacts of three days of record-setting high temperatures in late May 2010 on key ecophysiological parameters in Sugar Maple (Acer saccharum. Marsh). High temperatures reduced photosynthetic capacity by ~66% versus previous years and total end-of-season leaf litter production by ~33% versus prior measurements. It is predicted that these reductions substantially reduced productivity for Sugar Maple in 2010. These results constitute the first description of the impacts of a short-duration heat wave on productivity-related parameters in a temperate forest tree. The predicted increase in high temperature events could make such impacts a significant, though so far overlooked, pathway of climate change impacts on temperate forests.

Anticipated increases in the frequency, duration or intensity of high temperature events ('heat waves') have the potential to significantly impact forest form and functioning, but these events remain virtually unstudied in forest ecosystems. This thesis presents the results of an event-driven research effort into the impacts of three days of record-setting high temperatures in late May 2010 on key ecophysiological parameters in Sugar Maple (Acer saccharum. Marsh). High temperatures reduced photosynthetic capacity by ~66% versus previous years and total end-of-season leaf litter production by ~33% versus prior measurements. It is predicted that these reductions substantially reduced productivity for Sugar Maple in 2010. These results constitute the first description of the impacts of a short-duration heat wave on productivity-related parameters in a temperate forest tree. The predicted increase in high temperature events could make such impacts a significant, though so far overlooked, pathway of climate change impacts on temperate forests.