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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Modelagem da din?mica de crescimento de uma Floresta Ombr?fila aerta do estado de Rond?nia / Modelling of growth dynamics of tropical rain forest of State of Rondonia, Brazil.

Morokawa, Tokitika 05 February 2009 (has links)
Made available in DSpace on 2016-04-28T14:56:37Z (GMT). No. of bitstreams: 1 2009 - Tokitika Morokawa.pdf: 5650089 bytes, checksum: a8d1865101e3a9effdd865554b069415 (MD5) Previous issue date: 2009-02-05 / A model of the growth dynamics of forests was developed applying Bertalanffy growth model (BGM) y=a[(1 e bt)c] for individual trees. Based on linearized relationship with diameter and height equation LnH=b0+LnD and volume equation V=b0Db1Hb2 mutually compatible equations for diameter, basal area, height and volume were generated, adjusting parameters a and c of BGM. Additionally, it was developed a methodology based on DBH measurements in two occasions and the estimate value of parameter a to get the values of parameter c and b of BGM. The data of the inventory of 1,061 trees over 40cm DBH of 67.5 hectares of tropical rain forest of Aquariquara Extractive Reserve, located in State of Rondonia, Brazil, were used to test the developed model. These data were grouped in nine maximum diameter (Dmax) classes. The tree survival was estimated based on the frequency of trees by relative age class. The input and output of each tree was adjusted considering a closed and stable population with replacement of a dead tree by the ingrowth of the same specie of tree with 40cm DBH. Applying the model to such data and simulating the growth dynamics of the forest in a time frame of 1500 years (T1 → 1,500), the difference of simulated annual average, in relation to the observed values in the year T0 of the forest inventory was -2.09% in age, -0.33% in height, -0.96% in diameter, -3.41% in basal area, -3.81% in volume and +1.81% in merchantable trees value. The average values of T1→500, T501→1000 and T1001→1500 periods were equal for all variables by Kruskal-Wallis test (p=0.05). The simulation showed that one hectare of this forest maintains a total stock composed of 15.72 120-year-old trees, accumulated 4.35m2 of basal area and 37.98m3 wood volumes on average. The annual input flow of the system was 0.3457 88-year-old trees which accumulated 0.0441m2 of basal area and volume of 0.3265m3. The output of the system consists of 0.3459 132-year-old trees totaling 0,1127m2 of basal area and 0.9911m3 in volume. The annual input and output rates were, respectively, 2.20 and 2.20% in number of trees, 1.01 and 2.59% in basal area and 0.86 and 2.61% in volume. In addition, the simulation indicated that it is possible to sustain an average annual production of 0.5528m3 of merchantable timber generating R$5.50 (about US$1.49) annual income per hectare of forest. The simulation showed that the model developed describes growth dynamics of tropical forest. However, it needs to be properly adjusted based on real growth of each individual tree and flows of input and output of trees in the system. / Nesta tese foi desenvolvida a modelagem da din?mica de crescimento de uma floresta, aplicando-se o modelo de crescimento de Bertalanffy (MCB) y=a[(1 e bt)c] para ?rvores individuais. Baseando-se nas rela??es linearizadas entre o di?metro e altura da equa??o LnH=b0+LnD e do di?metro com volume V=b0Db1Hb2 foram geradas equa??es de crescimento reciprocamente compat?veis entre di?metro, ?rea basal, altura e volume, ajustando-se os valores dos coeficientes a e c do MCB. Adicionalmente, foi desenvolvida metodologia, baseando-se em medi??es de DAP de cada ?rvore em duas ocasi?es e com a estimativa do coeficiente a, para obter os valores dos coeficientes c e b do MCB. Para testar o modelo desenvolvido foram utilizados numa simula??o os dados de invent?rio de 1.061 ?rvores, com DAP≥40cm, de uma ?rea de 67,5ha de Floresta Omb?fila Aberta da Reserva Extrativista Aquariquara, localizada no munic?pio de Machadinho D?Oeste, estado de Rond?nia. Estes dados foram agrupados em nove classes de di?metro m?ximo (Dmax) compreendidas entre 50 e 240cm, mantendo-se uma amplitude entre elas de 10cm. A taxa de sobreviv?ncia da ?rvore foi estimada baseando-se na freq??ncia de ?rvores por classe de idade relativa. O sistema de entrada (input) e sa?da (output) de cada ?rvore foi ajustado considerando uma popula??o fechada e est?vel com substitui??o de uma ?rvore morta pela entrada de ?rvore da mesma esp?cie com DAP≥40cm. Em rela??o aos valores observados no ano T0 do invent?rio florestal, as m?dias anuais dos valores simulados da din?mica de crescimento dessa floresta num horizonte temporal de 1.500 anos (T1→1.500), apresentaram diferen?as m?dias de -2,09% em idade, -0,33% em altura, -0,96% em di?metro, -3,41% em ?rea basal, -3,81% em volume e +1,81% em valor da ?rvore em p?. As m?dias anuais dos valores simulados dos per?odos T1→500, T501→1.000 e T1.001→1.500 foram iguais para todas as vari?veis pelo teste de repetibilidade de Kruskal-Wallis (p=0,05), mostrando que o modelo ? est?vel no tempo. A simula??o mostrou que esta floresta mantem em m?dia um estoque total de massa em crescimento composta de 15,72 ?rvores.ha-1 com 120 anos de idade acumulando um total de 4,35m2.ha-1 de ?rea basal e 37,98m3.ha-1 de volume de madeira. O fluxo anual de ingresso no sistema foi de 0,3457 ?rvores com 88 anos de idade que somaram 0,0441m2 de ?rea basal e 0,3265m3 de volume, e de sa?da do sistema composto de 0,3459 ?rvores com 132 anos de idade que somaram 0,1127m2 de ?rea basal e 0,9911m3 de volume por hectare, resultando em taxas de ingressos e sa?das anuais, respectivamente, de 2,20 e 2,20% em n?mero de ?rvores, 1,01 e 2,59% em ?rea basal e 0,86 e 2,61% em volume. Al?m disso, a simula??o indicou que ? poss?vel sustentar uma produ??o m?dia anual de 0,5528m3 de madeira de valor comercial gerando renda anual de R$5,50 por hectare (a pre?o corrente de outubro de 2002) de floresta. A simula??o mostrou que o modelo desenvolvido descreve a din?mica de crescimento de floresta tropical, por?m ele necessita ser devidamente calibrado tomando os dados de crescimento real de cada ?rvore individual e dos fluxos de ingressos e sa?das de ?rvores do sistema.
2

Influence des variations des facteurs environnementaux sur la croissance de poissons de l’atlantique / Influence of the variation of environmental factors on growth of the fish in the Atlantic Ocean

Barrios rodriguez, Alexander José 21 February 2017 (has links)
Les paramètres de croissance de poissons pélagiques et démersaux ont été étudiés durant la période de 1990 à 2015 dans le but d’examiner l’impact de facteurs biotiques comme la densité-dépendance, le recrutement, la mortalité totale et de facteurs abiotiques tels que l’intensité d’upwelling, la température et la concentration en chlorophylle a. Les paramètres d’histoire de vie des espèces peuvent varier selon les espèces, d’une région à l’autre, et dans le temps au sein d’une même région en raison de leur plasticité et de la pression de la pêche. Une comparaison inter-espèces et inter-régions a été réalisée. Le modèle non linéaire à effets mixtes a été utilisé pour différentes populations de l’Océan Atlantique afin d’établir les paramètres de croissance aux niveaux individuel et de la population. Les variations des paramètres de croissance d’une sélection d’espèces ont été mises en corrélation avec des facteurs biotiques et abiotiquesLes espèces (Sardinella aurita, sardinelle ronde, Atherinella brasiliensis, tinicalo, Merlangius merlangus, merlan, Melanogrammus aeglefinus, églefin et Solea solea, sole) montrent des réponses différentes aux facteurs biotiques et abiotiques. Au niveau spatial pour le merlan et l’églefin, la croissance est affectée par la latitude et la température, tandis qu’au niveau temporel la croissance du merlan est affectée par la température et la densité. Il y avait un intérêt pour savoir si les variables morphométriques et le diamètre de l’otolithe de tinicalo étaient de bons indicateurs de la croissance : c’est la longueur standard qui a présenté / The impact of biotic factors such as density-dependent processes, recruitment, total mortality, and abiotic factors such as upwelling intensity, temperature and chlorophyll a concentration on the variation of growth parameters of pelagic and demersal fish were studied during the periods 1990 - 2008 (pelagic) and 1971 - 2015 (demersal). Life history parameters vary according to the species and from one region to another and over time within a given area because of their plasticity and the high fishing pressure. Interspecies and inter-regional comparison were carried out. Non-linear mixed effects models were used on different fish species of the Atlantic Ocean in order to estimate the growth parameters at the individual and population levels. Variations in growth parameters of selected species were correlated with biotic and abiotic factors.Selected species (Sardinella aurita, round sardinella, Xenomelaniris brasiliensis, tinicalo, Merlangus merlangus, whiting, Melanogrammus aeglefinus, haddock and Solea solea, sole) showed different responses to biotic and abiotic factors. Regardind the spatial component for whiting and haddock, the variation of growth parameters was affected by latitude and temperature. Concerning the temporal component, whiting was affected by temperature and density-dependent processes. There was also an interest to know if the morphometric variables and the diameter of the otolith of Atherinella brasilensis were good growth indicators. Among the morphometric parameters examined, the standard length-Age relationship showed the best fit (r2 = 0.90), foll

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