Learn More
A limnological survey of 15 lakes and 6 streams was carried out on Byers Peninsula (Livingston Island, South Shetland Islands, Antarctica) during austral summer 2001–2002. Most of the surface waters had low conductivities (20–105 μS cm−1) and nutrients (total phosphorus 0.01–0.24 μM), but some coastal lakes were enriched by nutrient inputs from seal(More)
In this paper we introduce two procedures for variable selection in cluster analysis and classification rules. One is mainly oriented to detect the " noisy " non–informative variables, while the other deals also with multicolinearity. A forward–backward algorithm is also proposed to make feasible these procedures in large data sets. A small simulation is(More)
Human activity and specifically tourism has been increasing in Antarctica over the last few years. Few studies have examined the indirect effects of human visits on Antarctic penguin rookeries. This work aims to study the differences between a highly visited (Hannah Point) and a rarely visited (Devil's Point, Byers Peninsula) gentoo penguin rookery on(More)
Aim There is an urgent need for conservation in threatened tropical forest regions. We explain and predict the spatial variation of α (i.e. within plot) and β (i.e. between plot) tree diversity in a tropical montane landscape subjected to a high deforestation rate. A major aim is to demonstrate the potential of a method that combines data from multiple(More)
A principal component method for multivariate functional data is proposed. Data can be arranged in a matrix whose elements are functions so that for each individual a vector of p functions is observed. This set of p curves is reduced to a small number of transformed functions, retaining as much information as possible. The criterion to measure the(More)
We propose a Bayesian procedure for multiple outlier detection in linear models avoiding the masking problem. The posterior probabilities of each data point being an outlier are estimated by using a new adaptive Gibbs sampling method, which modiies the initial conditions of the Gibbs sampler by using the eigen-structure of the covariance matrix of the(More)
Research in extremely delicate environments must be sensitive to the need to minimize impacts caused simply through the presence of research personnel. This study investigates the effectiveness of current advice relating to travel on foot over Antarctic vegetation-free soils. These are based on the concentration of impacts through the creation of properly(More)
The present study shows the occurrence of remarkable interannual variation in the meteorological conditions at Byers Peninsula (Livingston Island, South Shetlands Islands, Antarctica), in which one of the summers was significantly colder than the others. Within this climatic scenario, a limnological study was carried out at Lake Limnopolar during three(More)
In 2001 the LIMNOPOLAR Project was launched with the aim of addressing the suitability of freshwater ecosystems as useful sentinels of climate change. In this project, an automatic weather station was deployed on Byers Peninsula (Livingston Island, South Shetland Islands) near several freshwater ecosystems under research. Here the multi-year data recorded(More)