O desmatamento e conseqüente uso da terra para pecuária e agricultura são as principais atividades causadoras das emissões de gases do efeito estufa no território brasileiro. Nos últimos 30 anos essa prática tem sido mais intensa no arco do desmatamento da Amazônia, e em particular, nos Estados de Rondônia e Mato Grosso. Atualmente, essa região se constitui na maior área de expansão agrícola do mundo e por isso, faz-se necessário avaliações mais aprimoradas das emissões de gases do efeito estufa. Para avaliar essas emissões é necessário inicialmente, estimar os estoques de carbono do solo e vegetação, antes da intervenção humana. O objetivo desta pesquisa foi estimar os estoques de carbono dos solos dos Estados de Rondônia e Mato Grosso e assim, auxiliar nos cálculos futuros da emissão de gases do efeito estufa devido à mudança do uso da terra. A presente estimativa foi efetuada através das seguintes etapas: constituição de uma base de dados georreferenciados com informações compiladas da literatura, estimativa das densidades dos solos para os perfis onde essa informação é inexistente, padronização das camadas de solos avaliadas através ajuste vertical da profundidade do perfil e finalmente, cálculo dos estoques de carbono do solo. A superfície dos estados de Rondônia e Mato Grosso foi dividida em 11 ecorregiões geradas através da sobreposição de mapas temáticos sobre solos, clima, vegetação nativa, topografia entre outros utilizando-se um Sistema de Informação Geográfica. Essa divisão em ecorregiões é uma recomendação do manual, produzido pelo Painel Intergovernamental de Mudanças Climáticas, que trata dos procedimentos oficiais para estimativa de emissão de gases do efeito estufa em nível nacional. As estimativas dos estoques de carbono foram efetuadas para cada um dos 15 grupos de solos existentes para cada uma das 11 ecorregiões. Os estoques médios de carbono dos solos (expressos em kg C m-2) para cada ecorregião apresentaram os seguintes valores: Alto Xingu (8,7); Bacia Sedimentar do Paraná (9,6); Chapada dos Parecis (12,3); Depressão Araguaia (6,7); Depressão Cuiabá-Paranatinga e região Serrana (10,4); Depressão Guaporé (15,2); Nordeste do Mato Grosso (11,2); Norte do Mato Grosso (9,8); Norte de Rondônia (8,7); Pantanal (7,5) e Rondônia Central (10,4). A integração dos cálculos dos estoques de carbono dos solos de cada uma das 11 ecorregiões que cobrem 1.128.000 km-2 aponta valores de 5,7±0,7 Pg C e 10,4±1,3 Pg C, respectivamente para as camadas 0-30 cm e 0-100 cm. Considerando apenas a camada 0-100 cm pode-se inferir que o total de 10,4 Pg C representa 0,7% do total de carbono estocado nos solos do globo (1576 Pg C). Esse valor é expressivo uma vez que estão concentrados em uma área de 1,12 milhões de km-2, ou seja, 0,008% da superfície total (cerca de 135,21 milhões de km2) dos solos do mundo. As informações aqui geradas são fundamentais para o projeto temático em desenvolvimento no Laboratório de Biogeoquímica Ambiental do CENA/USP, que trata das emissões de CO2 para atmosfera, geradas a partir da decomposição da matéria orgânica devido ao desmatamento e uso agrícola do solo nos Estados de Rondônia e Mato Grosso. / Deforestation and consequent land use for agriculture and husbandry are the main activities that cause greenhouse gas emissions in the Brazilian territory. In the last 30 years these practices have been more intense at the Amazon deforestation arch, particularly in the States of Rondônia and Mato Grosso. Presently, the region represents the largest area of agricultural expansion in the world; therefore, it is necessary to better assess its greenhouse gas emissions. In order to evaluate those emissions it is initially necessary to estimate carbon stocks in soils and vegetations, previously to human intervention. The main objective of the present research was to estimate soil carbon stocks for Rondônia and Mato Grosso states and then assist in the future calculations of greenhouse gas emissions due to land use change. The present estimates were performed by developing the following tasks: constitution of a georreferenced data base with information compiled from the literature, estimate soil bulk density for profiles in which this information does not exist, standardization of soil layers through vertical adjustment of soil profile depth and finally, calculation of soil carbon stocks. The surface of Rondônia and Mato Grosso states was divided in 11 ecoregions generated by overlying thematic maps of soils, climate, native vegetation, topography and others through a Geographic Information System. This division in ecoregions is a recommendation from the guideline produced by the Intergovernmental Panel on Climate Change, that brings the official procedures to estimate the greenhouse gas emission for national scales. The soil carbon stock estimates were done for each one of the 15 soil groups in each of the 11 ecoregions. The mean soil carbon stocks (expressed in kg C m-2) for each ecoregion presented the following values: Alto Xingu (8.7); Bacia Sedimentar do Paraná (9.6); Chapada dos Parecis (12.3); Depressão Araguaia (6.7); Depressão Cuiabá-Paranatinga e região Serrana (10.4); Depressão Guaporé (15.2); Nordeste do Mato Grosso (11.2); Norte do Mato Grosso (9.8); Norte de Rondônia (8.7); Pantanal (7.5) e Rondônia Central (10.4). The integrated soil carbon stock calculations of each one of the 11 ecoregions that cover 1.128.000 km-2 showed values of 5.7±0.7 Pg C and 10.4±1.3 Pg C, for the 0-30 cm and 0-100 cm soil layers, respectively. Considering only the 0-100 cm soil layer it is possible to infer that the total of 10.4 Pg C represents 0.7% of the total carbon stored in the world soils (1576 Pg C). This is a meaningful value since it is concentrated in an area of 1.12 million km-2, i.e., 0.008% of the global soil surface (about 135.21 million km2). The information generated in the present research is essential for the thematic project that has been carried on by the Laboratório de Biogeoquímica Ambiental - CENA/USP, related to the CO2 emissions to the atmosphere, generated from soil organic matter decomposition due to deforestation and agricultural use of soils from Rondônia and Mato Grosso states.

Lightning-caused forest fires are one of the major natural disturbances in Ontario managed boreal forests. Survival of these forests with fires for centuries shows that such disturbances are integral to the boreal ecosystem and its ecological functioning. Characterizing the fire regimes defined by fire ignition frequency, fire sizes and their spatial distribution patterns etc. thus can help to improve our understanding of the boreal forest dynamics and provide guidance for management practices attempting to maintain biodiversity and achieve sustainability. In this thesis the lightning-caused fire ignitions data for four ecoregions in Ontario managed boreal forests (3E, 3W, 3S and 4S) for 1960–2009 were analyzed using pattern analysis and density estimation to determine the spatial nature of fire ignitions. These fire ignition spatial patterns were further used (as weighted ignition scenario) to simulate forest fire regimes in the study area. Fire regimes were also simulated using spatially unweighted ignitions (unweighted ignition scenario). Non-spatial (total number of fires, total burn area, number of fires by size classes, annual burn fraction) and spatial (spatial burn probability) indicators of the simulated fire regimes under both ignition scenarios were compared to test the null hypothesis that modeled forest fire regime is not affected by the spatial patterns of input fire ignitions. All data analysis were performed for individual ecoregions. Spatial pattern of ignitions were analyzed using the nearest neighbour index and Ripley’s K-function. Ignition densities were estimated using the adaptive kernel density estimation method and the fire regimes were simulated using BFOLDS (Boreal Forests Landscape Dynamics Simulator). Results showed that lightning-caused fire ignitions are clustered in all ecoregions. Fire ignition density also varied spatially within ecoregions. Overall fire ignition density was highest in the northwestern ecoregion (4S) and lowest in the eastern ecoregion (3E), which corresponds to the combined gradient of effective humidity and temperature in Ontario. For each ecoregion, comparison of non-spatial simulated fire regime indicators showed statistically non-significant differences between unweighted and weighted ignitions. The spatial burn probability however captured clear spatial differences between unweighted and weighted ignitions. Spatial differences in spatial burn probability between both ignition scenarios were more prominent in ecoregions of high fire occurrence. Results of the weighted ignition scenario closely followed the spatial patterns of the estimated fire ignition density in the study area. Based on these results this thesis rejects the null hypothesis and emphasizes that ignition patterns must be considered in simulating fire regime in Ontario boreal forests.

Lightning-caused forest fires are one of the major natural disturbances in Ontario managed boreal forests. Survival of these forests with fires for centuries shows that such disturbances are integral to the boreal ecosystem and its ecological functioning. Characterizing the fire regimes defined by fire ignition frequency, fire sizes and their spatial distribution patterns etc. thus can help to improve our understanding of the boreal forest dynamics and provide guidance for management practices attempting to maintain biodiversity and achieve sustainability. In this thesis the lightning-caused fire ignitions data for four ecoregions in Ontario managed boreal forests (3E, 3W, 3S and 4S) for 1960–2009 were analyzed using pattern analysis and density estimation to determine the spatial nature of fire ignitions. These fire ignition spatial patterns were further used (as weighted ignition scenario) to simulate forest fire regimes in the study area. Fire regimes were also simulated using spatially unweighted ignitions (unweighted ignition scenario). Non-spatial (total number of fires, total burn area, number of fires by size classes, annual burn fraction) and spatial (spatial burn probability) indicators of the simulated fire regimes under both ignition scenarios were compared to test the null hypothesis that modeled forest fire regime is not affected by the spatial patterns of input fire ignitions. All data analysis were performed for individual ecoregions. Spatial pattern of ignitions were analyzed using the nearest neighbour index and Ripley’s K-function. Ignition densities were estimated using the adaptive kernel density estimation method and the fire regimes were simulated using BFOLDS (Boreal Forests Landscape Dynamics Simulator). Results showed that lightning-caused fire ignitions are clustered in all ecoregions. Fire ignition density also varied spatially within ecoregions. Overall fire ignition density was highest in the northwestern ecoregion (4S) and lowest in the eastern ecoregion (3E), which corresponds to the combined gradient of effective humidity and temperature in Ontario. For each ecoregion, comparison of non-spatial simulated fire regime indicators showed statistically non-significant differences between unweighted and weighted ignitions. The spatial burn probability however captured clear spatial differences between unweighted and weighted ignitions. Spatial differences in spatial burn probability between both ignition scenarios were more prominent in ecoregions of high fire occurrence. Results of the weighted ignition scenario closely followed the spatial patterns of the estimated fire ignition density in the study area. Based on these results this thesis rejects the null hypothesis and emphasizes that ignition patterns must be considered in simulating fire regime in Ontario boreal forests.

No description available.

The classification of North American species of Prionus (Prionus) Geoffroy is reevaluated, with three subgenera recognized: P. (Antennalia) Casey, revived status, P. (Neopolyarthron) Semenov, revived status, and P. (Prionus). Prionus (Neopolyarthron) is revised and consists of P. imbricornis (Linnaeus), P. debilis Casey, revived status, and P. cuneatus Casey, revived status, with the latter two species removed from synonymy with P. imbricornis. Prionus robustus Casey, new synonymy, and P. fissicornis parviceps Casey, revised synonymy, are transferred from synonymy with P. imbricornis to synonymy with P. cuneatus and P. fissicornis respectively. Keys to North American subgenera of Prionus and to species of P. (Neopolyarthron) are provided. Species of P. (Neopolyarthron) are redescribed, diagnosed, and illustrated, and the distribution, hosts, habitat, and conservation status of each are discussed. Species distribution maps are provided, along with 26 new state records. Prionus fissicornis is diagnosed, and type specimens of its synonyms are reviewed and illustrated.

No description available.