Appréciation du bois de chêne (Quercus robur L, Quercus petraea Liebl) par les consommateurs et les professionnels français du bois

Regeneration Patterns of European Oak Species (Quercus petraea (Matt.) Liebl., Quercus robur L.) in Dependence of Environment and Neighborhood

Quercus robur L. (pedunculate oak) and Quercus petraea (Matt.) Liebl. (sessile oak) are two European oak species of great economic and ecological importance. Even though both oaks have wide ecological amplitudes of suitable growing conditions, forests dominated by oaks often fail to regenerate naturally. The regeneration performance of both oak species is assumed to be subject to a variety of v...

Three divergent rDNA clusters predate the species divergence in Quercus petraea (Matt.) Liebl. and Quercus robur L.

Quercus petraea and Quercus robur are two closely related oak species that frequently hybridize. We sequenced 70 clones containing the 5.8S and ITS2 regions of ribosomal DNA (rDNA) from these two species and did not detect a species-specific difference. Surprisingly, three divergent (up to 12.6%) rDNA families were identified in both species, indicating that they predate the speciation event. D...

A Simple Characterization of Du Bois Singularities

We prove the following theorem characterizing Du Bois singularities. Suppose that Y is smooth and that X is a reduced closed subscheme. Let π : e Y → Y be a log resolution of X in Y that is an isomorphism outside of X. If E is the reduced pre-image of X in e Y , then X has Du Bois singularities if and only if the natural map ØX → Rπ∗ØE is a quasi-isomorphism. We also deduce Kollár’s conjecture ...

The Sustainable Forestry Initiatives impact on stumpage markets in the US South

Using survey data and an equilibrium displacement model, we estimate the market and economic impacts of the American Forest and Paper Association’s Sustainable Forestry Initiative (SFI) on stumpage markets in the US South. We examine four timber product markets: softwood pulpwood, softwood sawtimber, hardwood pulpwood, and hardwood sawtimber. In each market we calculate changes in producer and ...

Fractionnement des lipides du sérum sanguin par les solvants organiques