Predicting the distribution of livestock grazing pressure in rangelands

Abstract Because grazing by livestock is one of the primary threats to rangeland biodiversity, but is unevenly distributed in space, rangeland monitoring programmes need to take account of the distribution of grazing pressure in order to distinguish between grazing‐induced change, seasonal fluctuations and changes that are a result of other threats. Livestock watering places are one of the major influences that give spatial expression to gradations in grazing activity. Using research results from the goldfields of Western Australia, we show how distance from water can be incorporated in spatial models to predict cumulative grazing pressure at different sites within paddocks. Two surrogates of grazing activity are illustrated: one relying on a commercially available model, and one developed from measures of track density. Factors other than distance from water can also have profound effects on the distribution of grazing pressure and its impacts at landscape and regional scales, and we review some of these briefly. Finally, we outline key spatial implications for the design of rangeland monitoring programmes.     

The quality of animal habitats estimated from track activity and remote sensing data

A method is proposed for estimating the quality of animal habitats from field counts with positioning routes and tracks by means of GPS, multichannel Landsat data, digital elevation model, and discriminant analysis. The distribution of American and European minks is analyzed to demonstrate the principle of choosing an optimal method for analyzing the environmental characteristics that determine the distribution of species and for mapping and estimating the quality of habitats and the probability of track detection. The outlook and some problems of implementation of the proposed approach are discussed.     

Une piste avec traces de soies épaisses dans le Trias inférieur a moyen de Lodève (Hérault,France): Cynodontipus polythrix nov. gen., nov. sp. les Cynodontes en France

A new ichnological genus, Cynodontipus species-type C. polythrix) has been created to define the unusual tract of a large but still unknown hairy Vertebrate of the Early to Middle Trias, Southern France. Horizon: just below the Chirotherium white sandstones slabs at Fozières (Hérault).This new type of footprint indicates that, as early as the Middle Trias, some Vertebrates were covered with an abundant protection of hair. A short systematic comparison is attempted with the last big Therapsids of that age, mainly the Cynodonts.