In the two decades following the 1980 eruption of Mount St. Helens in Washington State, the N2-fixing colonizer Lupinus lepidus is associated with striking heterogeneity in plant community and soil development. We report on differences in nutrient availability and plant tissue chemistry between older, dense patches (core) of L. lepidus and more recently established low density patches (edge). I...

Our understanding of plant growth in response to nitrogen (N) supply is mainly based on studies of mutants and transformants. This study explored the natural variability of Arabidopsis thaliana first to find out its global response to N availability and secondly to characterize the plasticity for growth and N metabolism among 23 genetically distant accessions under normal (N+), limited (N-), an...

We examined the tradeoffs between stand-level water use and carbon uptake that result when biomass production of trees in plantations is maximized by removing nutrient and water limitations. A Populus trichocarpa Torr. x P. deltoides Bartr. & Marsh. plantation was irrigated and received frequent additions of nutrients to optimize biomass production. Sap flux density was measured continuously ov...

We maintained a factorial nitrogen (N), phosphorus (P), and potassium (K) addition experiment for 11 years in a humid lowland forest growing on a relatively fertile soil in Panama to evaluate potential nutrient limitation of tree growth rates, fine-litter production, and fine-root biomass. We replicated the eight factorial treatments four times using 32 plots of 40 x 40 m each. The addition of ...

Plant identity and cover in coastal wetlands is changing worldwide, many subtropical salt marshes dominated by low-stature herbaceous species are becoming woody mangroves. Yet, how changes affect soil biogeochemical processes belowground biomass before after storms uncertain. We experimentally manipulated the percent mangrove (Avicennia germinans) 3 × m cells embedded 10 plots (24 42 m) compris...

Nutrient addition bioassay experiments were performed in the low-nutrient, low-chlorophyll oligotrophic subtropical North Atlantic Ocean to investigate the influence of nitrogen (N), phosphorus (P), and/or iron (Fe) on phytoplankton physiology and the limitation of primary productivity or picophytoplankton biomass. Additions of N alone resulted in 1.5–2 fold increases in primary productivity an...

Clonal growth allows plants to spread horizontally and to experience different levels of resources. If ramets remain physiologically integrated, clonal plants can reciprocally translocate resources between ramets in heterogeneous environments. But little is known about the interaction between benefits of clonal integration and patterns of resource heterogeneity in different patches, i.e., coinc...

The growth of the freshwater microalga Scenedesmus obliquus was studied at 30°C in a mineral culture medium with phosphorus concentrations of between 0 and 372 pro. The values for the specific growth rates, between So=0 #m and S,=298 pro, fitted a semistructured substrate-limitation model with #,,~ = 0.0466 h P.,,2 = 0.0256 h ~ and Ks = 0.2 ttm. The specific uptake rate of phosphorus reached a ...