Bayesian classification of vegetation types with Gaussian mixture density fitting to indicator values.

Question: Is it possible to mathematically classify relevés into vegetation types on the basis of their average indicator values, including the uncertainty of the classification? Location: The Netherlands. Method: A large relevé database was used to develop a method for predicting vegetation types based on indicator values. First, each relevé was classified into a phytosociological association on the basis of its species composition. Additionally, mean indicator values for moisture, nutrients and acidity were computed for each relevé. Thus, the position of each classified relevé was obtained in a three-dimensional space of indicator values. Fitting the data to so called Gaussian Mixture Models yielded densities of associations as a function of indicator values. Finally, these density functions were used to predict the Bayesian occurrence probabilities of associations for known indicator values. Validation of predictions was performed by using a randomly chosen half of the database for the calibration of densities and the other half for the validation of predicted associations. Results and Conclusions: With indicator values, most relevés were classified correctly into vegetation types at the association level. This was shown using confusion matrices that relate (1) the number of relevés classified into associations based on species composition to (2) those based on indicator values. Misclassified relevés belonged to ecologically similar associations. The method seems very suitable for predictive vegetation models

Farming for Nature : How does it work and what does it do?

Executive summary of Alterra report 247

the forest vegetation of the tolfa ceriti mountains northern latium central italy

The Forest Vegetation of the Tolfa-Ceriti Mountains (Northern Latium - Central Italy)The forests of the Tolfa-Ceriti mountains (Latium, central Italy) were investigated through a phytosociological approach. 249 relevés were performed and treated with multivariate analysis. 13 woodland communities were identified, of which 7 belong toQuercetalia pubescenti-petraeae, 1 toFagetalia sylvaticae, 1 toPopuletaliaand 4 toQuercetalia ilicis. The thermophilous Turkey oak-forests occurring on the trachytic hills of the Ceriti Mountains and on the flysch substrates of the Tolfa Mountains were included inRubio peregrinae-Quercetum cerridisass. nova.Quercus cerrisandFraxinus angustifoliasubsp.oxycarpawoodland communities of the footslopes have been ascribed toFraxino oxycarpae-Quercetum cerridis, while the widespread mesophilus Turkey oak forests have been ascribed toMelico-Quercetum cerridis. Cephalantero longifoliae-Quercetum cerridishas been restricted to acid and oligotrophic soils.Quercus petraeawoodlands, occurring on trachytic substrates have been described as a new association namedCarici olbiensis-Quercetum petraeaeass. nova. All these mixed oak woods have been included in the allianceCrataego laevigatae-Quercion cerridisArrigoni 1997. The nomenclatural problems concerning the prior nameTeucrio siculi-Quercion cerridisUbaldi 1988 are also discussed. The beech forests of the higher altitudes have been included inFraxino orni-Fagetum sylvaticae, while theAlnus glutinosaravine woodlands have been described as belonging to the new associationPolysticho setiferi-Alnetum glutinosae. Secondary communities ofAcer monspessulanumandAcer campestredeveloped on flysch substrates, and ofErica arboreaandArbutus unedo(Erico-Arbutetum unedonis) developed on trachytic substrates, have also been identified. Finally two types ofQuercus ilexwood have been identified:Cyclamino repandi-Quercetum ilicis, on sandstones, and the new associationArbuto unedonis-Quercetum ilicisass. nova on volcanic soils. This latter community can be considered as a coenological and geographical vicariant in central Italy of the sicilianErico-Quercetum ilicis

Heart rate measurement through PPG: Heartbeat measurement in a wireless headset

This thesis, assigned by Plantronics, proposes a solution to the motion artifacts that corrupt the results of PPG (Photo Plethysmo Graphic) signals and therefore the determined heart rate during physical exercises. An Infra-Red light emitting diode and phototransistor package was used to create a PPG signal that was amplified using an operational amplifier and filtered using a high pass and low pass filter. Research was done on PPG signals corrupted by motion with the help of an accelerometer. The fast Fourier transform of the signals showed that there is a relation between the frequency components of the PPG signal and motion signals. Based on this finding a working filter was designed in MATLAB that compares the frequency spectrum of the PPG to motion signals and removes any overlap. The experimental results for running motions prove the correct functioning of this system and showed that invasive sensing techniques are unnecessary.Electrical EngineeringMicroelectronics & Computer EngineeringElectrical Engineering, Mathematics and Computer Scienc

Boeren voor natuur past uitstekend tussen natuurbeheer en agrarisch natuurbeheer

Natuurbeheer kan effectiever door beheer in natuur- en landbouwgebieden beter op elkaar te laten aansluiten. Beide typen beheer vallen binnen dezelfde provinciale natuurbeheerplannen, waardoor boerencollectieven en terreinbeherende organisaties worden gestimuleerd tot afstemming. Landbouwbedrijven die werken volgens het concept Boeren voor Natuur kunnen deze aansluiting en afstemming goed vormgeven. Nu Boeren voor Natuur in de Catalogus Groenblauwe Diensten is opgenomen, is het een serieuze optie geworden voor integrale gebiedsplannen

Venster op km² Dreischor

Het project Venster op deWereld, waarin wetenschappers een vierkante kilometer bij Dreischor van alle kanten belichten, is inmiddels een eind op streek. Het leidt tot boek, documentaire en kunst. Hydrologen, landbouweconomen, ornithologen, meteorologen, bramendeskundigen, historici, archeologen, cultureel antropologen en andere deskundigen buigen zich over de vierkante kilometer, maar daarnaast worden de verhalen opgetekend van mensen die in het gebied wonen of werken, zoals de spruitentelers Gilles Klompe en Frans van der Linde, molenaar Bart van der Spek, René Perkins van de houtzagerij, Ria Geluk van museum Goemanszorg, vlaskenner Rinus Quist en Johan van de Velde van de wijnhoeve