This article gives insights on the complex balance between coalitions structure,
resource state or dynamics and agents’ heterogeneity to avoid bio-economic
collapses. A model bringing together coalition games and a viability approach
is proposed to focus on the compatibility between bio-economic constraints and
an exploited common stock dynamics. It is...
This paper deals with the sustainable management of a renewable resource
based on individual and transferable quotas (ITQs) when agents differ in terms of
harvesting costs or catchability. In a dynamic bio-economic model, we determine
the conditions under which the manager of an ITQ system can achieve sustainability
objectives which...
The coastal fishery in French Guyana is a challenging case study for the implementation of the ecosystem based fishery management. Although the current situation of this small scale fishery could be considered as satisfactory, the viability of the fishery can be questioned. Indeed according to demographic scenarios, the growth of...
Every wood anatomist knows that the wood near the center of a tree (juvenile wood) differs from the wood laid down at some distance from the pith (mature wood), and that the wood produced during the spring (earlywood) differs from the wood produced during the summer (latewood). There is a...
Recent work in the domain of fisheries ecology has shown that major
changes occur in fish communities exploited by commercial fisheries.
Selective fishing pressure on the more highly valued components of fish
communities is amongst the key factors proposed to explain these changes.
Under de facto open access conditions, it...
Our goals were to quantify how non-embolism-inducing pressure gradients influence trunk sapwood specific conductivity (ks) and to compare the impacts of constant and varying pressure gradients on ks with KCl and H2O as the perfusion solutions. We studied six woody species (three conifers and three angiosperms) which varied in pit...
The air‐seeding hypothesis predicts that xylem embolism resistance is linked directly to bordered pit functioning. We tested this prediction in trunks, roots, and branches at different vertical and radial locations in young and old trees of Pseudotsuga menziesii. Dimensions of bordered pits were measured from light and scanning electron micrographs,...
The Willamette Valley (WV) race of ponderosa pine (Pinus ponderosa) is being widely planted for timber in the Willamette Valley, western Oregon, because it grows in habitats that are either too wet or too dry for Douglas-fir (Pseudotsuga menziesii). Compared to the eastern Cascade Mountains (CM), the WV has 3...
• Premise of the Study: Tropical liana abundance has been increasing over the past 40 yr, which has been associated with reduced
rainfall. The proposed mechanism allowing lianas to thrive in dry conditions is deeper root systems than co-occurring trees,
although we know very little about the fundamental hydraulic physiology...
We determined the axial and radial xylem tension gradients in trunks of young Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) trees. Axial specific conductivity (ks-a) and sap flux density (Js) were measured at four consecutive depths within the sapwood at a stem height of 1 m. By definition, at a given position...