Limiting the soil degradational impacts of wildfire in pine and eucalyptus forests in Portugal: A comparison of alternative post-fire management practices

In newly burnt and unburnt pine and eucalyptus forest in Portugal, overland flow and soil losses were monitored to assess the impacts of the following post-fire treatments: application of different quantities of logging litter; rip-ploughing compared with minimum tillage prior to planting eucalyptus seedlings; and clearance of pine needles and vegetation. Eucalyptus logging litter reduced soil losses by up to 95 per cent. The impact of pine logging litter was equivocal, but removal of pine needles increased soil losses elevenfold. Implications for soil longevity, soil quality and land management strategy are discussed.     

Influence of capture stress, salinity and reproductive status on zinc associated with metallothionein-like proteins in the livers of three marine teleost species

The influence of capture stress, salinity and reproductive status on zinc associated with the metallothionein-like (MT-like) proteins in the livers of three marine teleost species was investigated. In striped mullet, Mugil cephalus L., the zinc associated with the MT-like protein, as determined by gel-permeation HPLC, increased significantly from approximately 102 to 1162 nmol zinc bound/g wet wt 7 days following capture in the field, handling, transportation to the laboratory and transfer to holding tanks. Significant increases were also observed following exposure to reduced salinity for 7 days. Smaller increases were observed in cultured red drum, Sciaenops ocellatus, livers following exposure to reduced salinity and physical trauma for 7 days. Finally, there was approximately a 2·5-fold increase in the zinc associated with the MT-like protein in livers of female spotted seatrout, Cynoscion nebulosus, collected during the reproductive season compared to regressed animals. These findings emphasize the need for establishing the natural fluctuations in MT levels as well as the response to common physical environmental variables before measurement of MT can be used reliably as a biochemical indicator of environmental contamination.     

Astrometric masses of 21 asteroids, and an integrated asteroid ephemeris

We apply the technique of astrometric mass determination to measure the masses of 21 main-belt asteroids; the masses of 9 Metis (1.03 ± 0.24 × 10^-11 M_⊙), 17 Thetis (6.17 ± 0.64 × 10^-13 M_⊙), 19 Fortuna (5.41 ± 0.76 × 10^-12 M_⊙), and 189 Phthia (1.87 ± 0.64 × 10^-14 M_⊙) appear to be new. The resulting bulk porosities of 11 Parthenope (12±4%) and 16 Psyche (46±16%) are smaller than previously-reported values. Empirical expressions modeling bulk density as a function of mean radius are presented for the C and S taxonomic classes. To accurately model the forces on these asteroids during the mass determination process, we created an integrated ephemeris of the 300 large asteroids used in preparing the DE-405 planetary ephemeris; this new BC-405 integrated asteroid ephemeris also appears useful in other high-accuracy applications.     

Earthquakes in Switzerland and surrounding regions during 2006

This report of the Swiss Seismological Service summarizes the seismic activity in Switzerland and surrounding regions during 2006. During this period, 572 earthquakes and 91 quarry blasts were detected and located in the region under consideration. Of these earthquakes, two occurred in conjunction with the construction of the new Gotthard railway tunnel and 165 were induced artificially by the stimulation of a proposed geothermal reservoir beneath the city of Basel. With 20 events with M _L ≥ 2.5, five of which were artificially induced, the seismic activity in the year 2006 was far below the average over the previous 31 years. Nevertheless, six events were felt by the public, most prominently the strongest of the induced Basel events (M _L 3.4), which caused some non-structural building damage. Noteworthy are also the two earthquakes near Cortaillod (M _L 3.2), on the shore of Lake Neuchatel, and in Val Mora (M _L 3.5), between the Engadin and Val Müstair, as well as the 42 aftershocks of the M _L 4.9 Vallorcine earthquake, between Martigny and Chamonix, of September 2005. Editorial handling: Stefan Bucher     

Atlantic remote sensing land ocean experiment (ARSLOE): Overview

ARSLOE was a multiorganization experiment held October 6-November 30, 1980, near Duck, North Carolina. It provided a large number of wind-wave and related measurements to intercompare and develop wave measurement systems, to evaluate and improve wave models, and to provide basic information on wave mechanics in shallow water. This paper provides an overview of the experiment.     

Development of an observational error model

In calculating the orbit of a minor planet with a least-squares algorithm, current practice is to assume that all observations of a given era have the same uncertainty, and that the errors in these observations are uncorrelated. These assumptions are unrealistic; and they lead to sub-optimal orbits.Our objective is to develop and validate an observational error model that provides realistic estimates of the uncertainties and correlations in asteroid observations. When used to populate the covariance matrix of the least-squares algorithm, the resulting orbits are shown to more accurately and precisely represent asteroid trajectories.     

Mechanism of continental crust subsidence in the Alpine Belt

Formation of deep basins on continental crust in fold belts is often explained by stretching. This mechanism inevitably produces large deformations in the upper crust. No deformations typical of significant stretching were revealed in the predominant part of deep basins on continental crust in the Alpine Belt. This means that these basins were not produced by stretching. Most basins were formed during a short period of time of a few million years. The short duration of the subsidences eliminates thermal relaxation as the mechanism. The space and time relationships between the subsidence and orogeny and the profile of the basin floor exclude thrust loading as a cause of formation for practically all large basins. Gabbro to eclogite transformation is suggested as a mechanism of rapid subsidence. This occurs under the upwelling of hydrous asthenosphere at moderate temperature to the base of the crust. Eclogite sinking into the mantle results in a strong attenuation of the crust and lithosphere, which permits intense subsequent folding. The major part of deep basins in continental crust that formed by rapid subsidence was intensely shortened in the Alpine Belt. Significant crustal shortening did not spread over the cratonic lithosphere.     

A simple parameterization of sub-grid scale open water for climate models

The effects of small fractions ( < 30%) of open water covering a grid element are currently neglected even in atmospheric general circulation models (AGCMs) which incorporate complex land surface parameterization schemes. Here, a method for simulating sub-grid scale open water is proposed which permits any existing land surface model to be modified to account for open water. This new parameterization is tested as an addition to an advanced land surface scheme and, as expected, is shown to produce general increases in the surface latent heat flux at the expense of the surface sensible heat flux. Small changes in temperature are associated with this change in the partitioning of available energy which is driven by an increase in the wetness of the grid element. The sensitivity of the land surface to increasing amounts of open water is dependent upon the type of vegetation represented. Dense vegetation (with a high leaf area index) is shown to complicate the apparently simple model sensitivity and indicates that more advanced methods of incorporating open water into AGCMs need to be considered and compared against the parameterization suggested here. However, the sensitivity of one land surface model to incorporating open water is large enough to warrant consideration of its incorporation into climate models.