Historically, the difficulty of obtaining pure cultures of abundant marine
microbial plankton has an obstacle to reconstructing the underlying
mechanisms of biogeochemistry in the ocean. While a number of dominant
marine species from the ocean surface have been cultured, the dominant
microbial plankton of the dark ocean proved far more...
The Oregon continental shelf waters are typically characterized by four to five major upwelling events that occur between May and October. The upwelled water is rich in nutrients, which fuels an increase in phytoplankton biomass. The onset of El Nino, however, can disrupt the normal physical processes along the Oregon...
Phytoplankton and microzooplankton comprise the base and the first link of the marine food web, respectively. These microbes are key drivers of marine carbon and nutrient cycles. Phytoplankton convert atmospheric CO₂ into organic carbon, and microzooplankton consume phytoplankton, packaging phytoplankton carbon into particulate forms that have a variety of fates:...
The purpose of this study was to understand the influence of organic material and nutrients from spawning salmon and supplemented salmon carcasses on stream food webs. My study objectives were to examine 1) assimilation of salmon-derived nutrients (SDN) by producers and consumers in the food web, 2) epilithic biofilm productivity,...
Research activities in the post-IBP phase of the Biome program prior to July 1975 were reported in Internal Report 162. Summaries of research and synthesis activities from July 1975 to August 1976 are presented here. The reports are arranged in the following order: Analysis of individual terrestrial ecosystems, which has...
Two native shrub species (Piliostigma reticulatum and Guiera senegalensis) are prominent vegetation components in farmers’ fields in Senegal. However, their role in nutrient cycling and ecosystem function has largely been overlooked. A study including both laboratory and field experiments was conducted to evaluate potential biophysical interactions of the two shrub...
Calcium (Ca) is an essential macronutrient that is increasingly recognized as a biogeochemical factor that influences ecosystem structure and function. Progress in understanding the sustainability of ecosystem Ca supply has been hampered by a lack of information on the various forms and pools of Ca in forest ecosystems. In particular,...
Although no formal project in mineral cycling was defined for 1972, three modeling efforts were begun: calcium cycling at Cedar River, litter decomposition, and miombo ecosystem. The calcium cycling model is a simple compartment model and was developed as a practice exercise. It demonstrates the inadequacy of linear-donor control formulation...