Morten Larsen

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Positions of individual trees in high-resolution aerial photographs are estimated by use of templates derived from an optical tree crown model and the geometry at image acquisition. The template is bounded by an ellipse, for which we ®nd the optimal size, eccentricity and translation along one axis. Tree top positions are estimated as local maxima of the(More)
Growth performance and heavy metal uptake by willow (Salix viminalis) from strongly and moderately polluted calcareous soils were investigated in field and growth chamber trials to assess the suitability of willow for phytoremediation. Field uptakes were 2-10 times higher than growth chamber uptakes. Despite high concentrations of cadmium (>/=80 mg/kg) and(More)
To estimate positions of individual trees in high–resolution aerial photographs we use circular templates derived from an optical tree crown model and the geometry at image acquisition. A straight–forward analysis method consists of finding local maxima of the correlation function for the successively transposed templates over the whole image. Three ways of(More)
The genetic composition of marine microbial communities varies at the microscale between particle-associated (PA; >1.6 μm) and free-living (FL; 0.2-1.6 μm) niches. It remains unclear, however, how metabolic activities differ between PA and FL fractions. We combined rate measurements with metatranscriptomics to quantify PA and FL microbial activity in the(More)
Templates derived from an optical tree crown model have been used with good results in the estimation of individual spruce tree top positions in aerial photographs. The method can nd tree tops from a wide range of viewing angles including extreme oo-nadir views, but a requirement has been that the number of trees was estimated in advance and that various(More)
A framework for analysing weather radar (DBz) images as spatial point processes is presented. Weather radar images are modelled for the purpose of predicting their evolution in time and thereby providing a basis for short-period precipitation forecasts. An observed image sequence is modelled as a set of individual rain cells that are the outcome of a marked(More)
In wetland-adapted plants, such as rice, it is typically root apexes, sites of rapid entry for water/nutrients, where radial oxygen losses (ROLs) are highest. Nutrient/toxic metal uptake therefore largely occurs through oxidized zones and pH microgradients. However, the processes controlling the acquisition of trace elements in rice have been difficult to(More)
Most commercially available optical oxygen sensors target the measuring range of 300 to 2 μmol L-1. However these are not suitable for investigating the nanomolar range which is relevant for many important environmental situations. We therefore developed a miniaturized phase fluorimeter based measurement system called the LUMOS (Luminescence Measuring(More)