Woody vegetation encroachment threatens remaining native tallgrass prairie streams. Kings Creek is a prairie stream that was historically a mostly open canopy stream with little surrounding woody vegetation. Many reaches in Kings Creek have been subjected to woody expansion and now have a closed canopy. Closed canopy reaches receive less sunlight for primary producers and receive more leaf and wood material. Woody vegetation was removed from two 35 m reaches in order to determine the impact of woody expansion on stream ecosystem structure and function.

 The productivity of giant kelp forests is highly variable across time and space. Winter storms and summer periods of nutrient limitation act as bottom-up regulators of kelp abundance and growth in a geography-dependent manner. Our goal is to develop a predictive understanding of giant kelp forest dynamics in the nearshore waters of California using a combination of (i) bio-optical modeling of kelp productivity, (ii) high-resolution remote sensing of kelp cover, biomass and its physiological state.

Suspended solids in streams are important to monitor and manage because high levels of suspended solids have been shown to affect the primary and secondary production of a stream. The loading rate of total suspended solids (TSS) can greatly be influenced by the land management of a stream site’s catchment area. A computer-based geographic information system (GIS) was used to assess what land cover/land use variables were highly correlated to high levels of TSS in Kansas Flinthill streams on a long-term data set collected by the Kansas Department of Health and Environment.

Woody encroachment and its effects on terrestrial ecosystems have been well-studied. However, the effect on riparian and aquatic ecosystems, specifically denitrification, has been lacking. Riparian areas of headwater prairie streams were historically dominated by grasses, but have become increasingly covered by woody vegetation. To determine potential consequences of woody plant invasion on denitrification, three adjacent reaches were delineated from two branches of King’s Creek, which drains Konza Prairie Biological Station.

This study looked at the impact of high nutrient loads from non-point source pollution on the stoichiometry of detrital food webs in suburban streams: basal food resources, primary consumers, predators, and nutrient imbalances between food and consumer.

 The primary research focus of the Santa Barbara Coastal (SBC) LTER is on the relative importance of bottom-up processes and allochthonous inputs to giant kelp forests, a highly diverse and productive marine ecosystem that occurs on shallow rocky reefs at the interface of the land-ocean margin. Giant kelp forests are found along the temperate coasts of western North and South America, southern Africa, Australia and most sub Antarctic islands, including Tasmania and New Zealand.

This session is intended both for social and biophysical scientists who want to help develop a proposal for the kind of “multi-site, highly collaborative and integrated research initiative” envisioned by the LTER planning group. The focus will be on what the LTER planning process calls the “centerpiece” of the group's conceptual framework, as well as one of “Grand Challenges” to be addressed at the network level – “the dynamics of coupled human-natural ecosystems.”

Human settlements in both arid lands and cities must, of necessity, alter hydrological regimes and geomorphology to provide clean, reliable drinking water, water for agriculture, and protection from flooding. Additionally, people also create substantial modifications to provide water for manufacturing, recreation, aesthetics, and sense of place. All of these practices can result in elimination or degradation of existing aquatic ecosystems, as well as creation of new ecosystems such as artificial lakes, stormwater retention basins, mitigation wetlands, groundwater recharge ponds, etc.

Green Lake 4 is an alpine lake in the Silver Lake Watershed of Boulder Colorado. Many alpine lakes similar in productivity and elevation to Green Lake 4, have shown a recent shift in diatom species. Nitrogen has been shown to be increasing in alpine lake systems of the Rocky Mountain Front Range due to atmospheric deposition. Species associated with oligotrophic systems are being replaced with more common species that are tolerant of higher nutrient concentrations. However, little is known about the role phosphorous.

Stream microbial mats are dynamic communities of phototrophic and heterotrophic organisms that develop over intra-seasonal and inter-seasonal time scales. Diatom community composition is influenced by successional processes and physical and chemical gradients that together act to shape stream benthic habitats. In ephemeral streams of the McMurdo Dry Valleys (Antarctica, MCM LTER), previous work has demonstrated that in streams across the Fryxell Lake Basin, the diatom composition in microbial mat communities is determined largely by the annual and historical flow regime.