Genetic distance predicts trait differentiation at the subpopulation but not the individual level in eelgrass, Zostera marina.

Ecological studies often assume that genetically similar individuals will be more similar in phenotypic traits, such that genetic diversity can serve as a proxy for trait diversity. Here, we explicitly test the relationship between genetic relatedness and trait distance using 40 eelgrass (Zostera marina) genotypes from five sites within Bodega Harbor, CA. We measured traits related to nutrient uptake, morphology, biomass and growth, photosynthesis, and chemical deterrents for all genotypes. We used these trait measurements to calculate a multivariate pairwise trait distance for all possible genotype combinations. We then estimated pairwise relatedness from 11 microsatellite markers. We found significant trait variation among genotypes for nearly every measured trait; however, there was no evidence of a significant correlation between pairwise genetic relatedness and multivariate trait distance among individuals. However, at the subpopulation level (sites within a harbor), genetic (FST) and trait differentiation were positively correlated. Our work suggests that pairwise relatedness estimated from neutral marker loci is a poor proxy for trait differentiation between individual genotypes. It remains to be seen whether genomewide measures of genetic differentiation or easily measured "master" traits (like body size) might provide good predictions of overall trait differentiation

Temporal patterns of phytoplankton assemblages, size spectra and diversity during the wane of a Phaeocystis globosa spring bloom in hydrologically contrasted coastal waters

International audienc

The Transportation of Wood in Chutes

Artificial channels, known as chutes, in which logs and bolts may be transported down steep slopes by means of gravity, were devised several centuries ago in the mountainous regions of Europe and later were used by north American loggers, especially in New England, New York, and Pennsylvania. They operate most advantageously on grades that are far in excess of those on which wheeled vehicles or sleds can be used safely, and they are most serviceable for moving timber on terrain which is so steep or broken that the construction cost of suitable roads is prohibitive

The Transportation of Logs on Sleds

Heavy sleds, designed to transport timber from the forest to water courses down which it is floated or to haul it to mill or market, have been perfected chiefly in the United States and Canada. The importance of this method is indicated by the fact that it is used in transporting approximately 90 per cent of the annual log input of New England and New York, 80 per cent of that of the Lake States, and 100 per cent of that of Alaska and of Canada, exclusive of British Columbia. The credit for the development of sled-hauling methods in the logging industry is due chiefly to practical woodsmen

Oceanic distribution of inorganic germanium relative to silicon: Germanium discrimination by diatoms

Seventeen inorganic germanium and silicon concentration profiles collected from the Atlantic, southwest Pacific, and Southern oceans are presented. A plot of germanium concentration versus silicon concentration produced a near-linear line with a slope of 0.760 × 10−6 (±0.004) and an intercept of 1.27 (±0.24) pmol L−1 (r2 = 0.993, p < 0.001). When the germanium-to-silicon ratios (Ge/Si) were plotted versus depth and/or silicon concentrations, higher values are observed in surface waters (low in silicon) and decreased with depth (high in silicon). Germanium-to-silicon ratios in diatoms (0.608–1.03 × 10−6) and coupled seawater samples (0.471–7.46 × 10−6) collected from the Southern Ocean are also presented and show clear evidence for Ge/Si fractionation between the water and opal phases. Using a 10 box model (based on PANDORA), Ge/Si fractionation was modeled using three assumptions: (1) no fractionation, (2) fractionation using a constant distribution coefficient (KD) between the water and solid phase, and (3) fractionation simulated using Michaelis-Menten uptake kinetics for germanium and silicon via the silicon uptake system. Model runs indicated that only Ge/Si fractionation based on differences in the Michaelis-Menten uptake kinetics for germanium and silicon can adequately describe the data. The model output using this fractionation process produced a near linear line with a slope of 0.76 × 10−6 and an intercept of 0.92 (±0.28) pmol L−1, thus reflecting the oceanic data set. This result indicates that Ge/Si fractionation in the global ocean occurs as a result of subtle differences in the uptake of germanium and silicon via diatoms in surface waters