388 research outputs found

    Gestión de bosques mixtos de pino y roble en escenarios de incertidumbre climática

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    The process-based forest growth model 4C (FORESEE - FORESt Ecosystems in a Changing Environment) was used to analyze the growth of a mixed oak-pine stand [Quercus petraea (Mattuschka) Liebl., Pinus sylvestris L.]. The oak-pine stand is typical for the ongoing forest transformation in the north-eastern lowlands. The pine and the oak trees are 104 and 9 years old, respectively. Three different management scenarios (A, B, C) with different thinning grades and a thinning interval of five years were simulated. Every management scenario was simulated under three different climate scenarios (0K, 2K, 3K) compiled by the regional statistical climate model STAR 2.0 (PIK). For each climate scenario 100 different realisations were generated. The realisations of the climate scenarios encompass the period 2036-2060 and exhibit an increase of mean annual temperature of zero, two and three Kelvin until 2060, respectively. We selected 9 model outputs concerning biomass, growth and harvest which were aggregated to a single total performance index (TPI). The TPI was used to assess the management scenarios with regard to three management objectives (carbon sequestration, intermediate, timber yield) under climate change until 2060. We found out that management scenario A led to the highest TPI concerning the carbon sequestration objective and management scenario C performed best concerning the two other objectives. The analysis of variance in the growth related model outputs showed an increase of climate uncertainty with increasing climate warming. Interestingly, the increase of climate induced uncertainty is much higher from 2 to 3 K than from 0 to 2 K.Se ha utilizado un modelo forestal basado en procesos denominado 4C (FORESEE - FORESt Ecosystems in a Changing Environment) para analizar el crecimiento de un masa forestal con mezcla de Quercus petraea y Pinus sylvestris. Ésta es una mezcla típica en las áreas de transformación forestal en las zonas bajas del noreste de Alemania. Los pinos y los robles tienen una edad de 104 y 9 años respectivamente. Se simularon tres escenarios diferentes de manejo (A, B, C) con diferentes grados de claras e intervalos de clara de 5 años. Cada escenario de manejo fue simulado bajo tres escenarios climáticos (0K, 2K, 3K) los cuales se calcularon por el modelo regional climático estadístico STAR 2.0 (PIK). Se generaron 100 diferentes realizaciones para cada escenario climático. Las realizaciones incluyen el período 2036-2060 y presentan un aumento de la temperatura anual de cero, dos y tres grados Kelvin hasta el año 2060, respectivamente. Seleccionamos 9 salidas del modelo relacionadas con la biomasa, crecimiento y rendimiento que se combinaron en un único índice de rendimiento total (TPI, total performance index). El TPI fue analizado para investigar los escenarios de manejo con respecto a tres objetivos de manejo (secuestro de carbono, máximo rendimiento maderero, y un escenario intermedio a ambos) bajo la influencia de cambio climático hasta el año 2060. Nuestros resultados indican que el escenario A muestra el TPI más alto con respecto al secuestro de carbono, y el escenario C tuvo el mejor resultado respecto a los otros dos objetivos. El análisis de varianza en las salidas relativas al crecimiento mostró que mientras más evoluciona el calentamiento global, más crece la incertidumbre climática. Cabe destacar que el aumento de la incertidumbre inducida por el clima es mucho mayor al aumentar de 2 a 3 K que de 0 a 2 K

    Padrões de deslocamento de Cebus nigritus (Cebidae, Mammalia) em mosaico de floresta nativa e plantios de Pinus e Eucalyptus.

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    Editores técnicos: Marcílio José Thomazini, Elenice Fritzsons, Patrícia Raquel Silva, Guilherme Schnell e Schuhli, Denise Jeton Cardoso, Luziane Franciscon. EVINCI. Resumos

    A transcription frame-based analysis of the genomic DNA sequence of a hyper-thermophilic archaeon for the identification of genes, pseudo-genes and operon structures

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    AbstractAn algorithm for identifying transcription units, independently regulated genes and operons, and pseudo-genes that are not expected to be expressed, has been developed by combining a system for predicting transcription and translation signals, and a system for scoring the triplet periodicity in ORF candidates. By using the algorithm, the 1.09 Mb sequence that covers approximately 60% of the genome of Pyrococcus sp. OT3 has been analyzed. The identified ORFs show the expected biological and physical characteristics, while the rejected ORF candidates do not. Frequent use of operon structures for transcription, and gene duplication followed by mutation or termination of the duplicated genes, are discussed

    Uncertainty of biomass contributions from agriculture and forestry to renewable energy resources under climate change

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    In the future, Germany's land-use policies and the impacts of climate change on yields will affect the amount of biomass available for energy production. We used recent published data on biomass potentials in the federal states of Germany to assess the uncertainty caused by climate change effects in the potential supply of biomass available for energy production. In this study we selected three climate scenarios representing the maximum, mean and minimum temperature increase for Germany out of 21 CMIP5-projections driven by the Representative Concentration Pathways (RCP) 8.5 scenario. Each of the three selected projections was downscaled using the regional statistical climate model STARS. We analysed the yield changes of four biomass feedstock crops (forest, short-rotation coppices (SRC), cereal straw (winter wheat) and energy maize) for the period 2031–2060 in comparison to 1981–2010. The mean annual yield changes of energy wood from forest and short-rotation coppices were modelled using the process-based forest growth model 4C. The yield changes of winter wheat and energy maize from agricultural production were simulated with the statistical yield model IRMA. Germany's annual biomass potential of 1500 PJ varies between minus 5 % and plus 8 % depending on the climate scenario realisation. Assuming that 1500 PJ of biomass utilisation can be achieved, climate change effects of minus 75 (5 %) PJ or plus 120 (8 %) PJ do not impede overall bioenergy targets of 1287 PJ in 2020 and 1534 PJ in 2050. In five federal states the climate scenarios lead to decreasing yields of energy maize and winter wheat. Impacts of climate scenarios on forest yields are mainly positive and show both positive and negative effects on yields of SRC
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