The patterns of genetic and morphological diversity a widespread species can be influenced by environmental heterogeneity the degree connectivity across its geographic distribution. Here, we studied Quercus havardii Rydb., uniquely adapted desert oak endemic to Southwest region United States, using genetic, morphometric, datasets over various scales quantify differentiation understand forces in...

We show how and why it makes sense to use a relational formalisation instead of the usual functional one in the treatment of term graphs. Special attention is paid to term graphs with bound variables, that have, to our knowledge, never been formalised with such a generality before. Besides the novel treatment of term graphs themselves, we present an innovative relational homomorphism concept th...

In many areas of science, scientists need to find distinct common characterizations of the same objects and, vice versa, to identify sets of objects that admit multiple shared descriptions. For example, in biology, an important task is to identify the bioclimatic constraints that allow some species to survive, that is, to describe geographical regions both in terms of the fauna that inhabits th...

Université d'Aix-Marseille III, Centre de Saint-Jérôme, Laboratoire de Botanique et d'Ecologie Méditerranéenne, 13397 MARSEILLE/CEDEX 4. Abstract: Methods of classifying ecosystems have developed differently in Europe and America. Individualization of bioclimatic zones and of altitudinal levels proved most valuable, particularly the role of edaphic factors. This methodology can be associated wi...

Ala~traet--Errors-in-variables problems are considered for the case of three variables, where the underlying relations among the noise-free variables are linear, and covariance information for the noisy variables is available. The static problem where the variables are complex (which can arise when narrowband filtering is used) is analysed in detail. Some results are also presented for the case...

The environmental causation of species' distributions depends on three general, interacting types of factors: the abiotic (or physical) environment, the biotic environment, and accessibility of areas across complex landscapes (Pulliam 2000; Soberón and Peterson 2005; Soberón 2007). Indirect variables, such as elevation, are those associated with the presence of species owing to correlation with...