978 resultados para Ferdinand Maria, Elector of Bavaria, 1636-1679.
Resumo:
An incubation experiment at five different temperatures was used to assess the potential for adaptation of Calanus finmarchicus to future warming of the ocean. During a short term (3 h) and long term (6 day) exposure of individual females to a gradient of temperature stress, egg production and fecal pellet production were monitored to indicate secondary production and grazing rates. A longer term (10 day) exposure to elevated temperatures followed by a return to ambient sea temperatures was used to assess the potential recovery of individuals exposed to temperature stress. Females were picked out from WP2 net samples and acclimatised in 2 L bottles of GFF filtered seawater with Thalassiosira weissflogii as prey for >48 h at ambient SST. Experimental bottles were filled with filtered seawater (GFF filtered from non-toxic seawater supply) and acclimated to experimental temperature overnight (0, 5, 10, 15 and 20 °C). Individual females were transferred into bottles using forceps and the bottles were inoculated with T. weissflogii to a final concentration of 5 µg chl L-1. Bottles were then placed into water baths and incubated for 3h or 6 d, and monitored for egg and fecal pellet production rates. A 10 day exposure experiment was used to test the potential for recovery from temperature stress, by returning females incubated at 5, 10, 15 and 20 °C back to 10 °C for 24 h and counting egg and fecal pellet production.
Resumo:
Respiration rates and electron transport system (ETS) activities were measured in dominant copepod species from the northern Benguela upwelling system in January-February 2011 to assess the accuracy of the ETS assay in predicting in vivo respiration rates. Individual respiration rates varied from 0.06 to 1.60 µL O2/h/ind, while ETS activities converted to oxygen consumption ranged from 0.14 to 4.46 µL O2/h/ind. ETS activities were significantly correlated with respiration rates (r**2 = 0.79, p = 0.0001). R:ETS ratios were lowest in slow-moving Eucalanidae (0.11) and highest in diapausing Calanoides carinatus copepodids CV (0.76) while fast-moving copepods showed intermediate R:ETS (0.23-0.37). 82% of the variance of respiration rates could be explained by differences in dry mass, temperature and the activity level of different copepod species. Three regression equations were derived to calculate respiration rates for diapausing, slow- and fast-moving copepods, respectively, based on parameters such as body mass and temperature. Thus, knowledge about the activity level and behavioral characteristics of copepod species can significantly increase the predictive accuracy of metabolic models, which will help to better understand and quantify the impact of copepods on nutrient and carbon fluxes in marine ecosystems.
Resumo:
This study investigates the landscape evolution and soil development in the loess area near Regensburg between approximately 6000-2000 yr BP (radiocarbon years), Eastern Bavaria. The focus is on the question how man and climate influenced landscape evolution and what their relative significance was. The theoretical background concerning the factors that controlled prehistoric soil erosion in Middle Europe is summarized with respect to rainfall intensity and distribution, pedogenesis, Pleistocene relief, and prehistoric farming. Colluvial deposits , flood loams, and soils were studied at ten different and representative sites that served as archives of their respective palaeoenvironments. Geomorphological, sedimentological, and pedological methods were applied. According to the findings presented here, there was a high asynchronity of landscape evolution in the investigation area, which was due to prehistoric land-use patterns. Prehistoric land use and settlement caused highly difIerenciated phases of morphodynamic activity and stability in time and space. These are documented at the single catenas ofeach site. In general, Pleistocene relief was substantially lowered. At the same time smaller landforms such as dells and minor asymmetric valleys filled up and strongly transformed. However, there were short phases at many sites, forming short lived linear erosion features ('Runsen'), resulting from exceptional rainfalls. These forms are results of single events without showing regional trends. Generally, the onset of the sedimentation of colluvial deposits took place much earlier (usually 3500 yr BP (radiocarbon) and younger) than the formation of flood loams. Thus, the deposition of flood loams in the Kleine Laaber river valley started mainly as a consequence of iron age farming only at around 2500 yr BP (radiocarbon). A cascade system explains the different ages of colluvial deposits and flood loams: as a result of prehistoric land use, dells and other minor Pleistocene landforms were filled with colluvial sediments. After the filling of these primary sediment traps , eroded material was transported into flood plains, thus forming flood loams. But at the moment we cannot quantify the extent ofprehistoric soil erosion in the investigation area. The three factors that controlled the prehistoric Iandscapc evolution in the Ioess area near Regensburg are as follows: 1. The transformation from a natural to a prehistoric cultural landscape was the most important factor: A landscape with stable relief was changed into a highly morphodynamic one with soil erosion as the dominant process of this change. 2. The sediment traps of the pre-anthropogenic relief determined where the material originated from soil erosion was deposited: either sedimentation took place on the slopes or the filled sediment traps of the slopes rendered flood loam formation possible. Climatic influence of any importance can only be documented as the result of land use in connection with singular and/or statistic events of heavy rainfalls. Without human impact, no significant change in the Holocene landscape would have been possible.