Shallow coastal bays such as those along the U.S. east coast are particularly vulnerable to changes in coastal zone activities that result in accelerated nutrient delivery rates. A major challenge in these systems is to understand how increased nutrient loading affects ecosystem structure and function. Much of the benthos in these shallow bays is illuminated by sunlight; as a result, benthic autotrophs such as seagrass, benthic microalgae (BMA) and macroalgae play an integral role in nutrient cycling.

In addition to seed deposition of both native and invasive plant species, birds may pollinate flowers, provide nutrient inputs, and deliver mutualistic or pathogenic microbes. Birds therefore may drive community assembly and succession, and play an especially significant role in the frequently-disturbed environments of barrier islands, where repopulation following storm and overwash events is critical to long-term species persistence.

 Phytoplankton production in the Santa Barbara Channel supports one of the richest marine ecosystems in the Southern California Bight. The climatology of chlorophyll biomass in the area reveals maxima over the Santa Barbara Basin in the western Channel and along the mainland in the eastern channel where the continental shelf broadens and where two rivers discharge seasonally.

The McMurdo Dry Valleys have no rainfall and most snowfall sublimates before wetting the soils significantly. Glacial melt streams are also seasonal, flowing for only 4 to 6 weeks per year. Consequently, hydrology does not provide significant connections among ecosystem components. Conversely, wind is a persistent daily feature of the McMurdo Dry Valleys environment throughout the year. In summer, cool air from the ice-covered oceans flows into the relatively warm valleys creating a strong thermal gradient in the valleys.

Analysis of twenty-five years of forest floor sampling on Watershed 6 (W6) at the Hubbard Brook Experimental Forest (Woodstock, NH, USA) shows no significant evidence of N accumulation in the forest floor (O horizon). The uncertainty in this estimate is high (2 ± 19 kg N ha^-1 y^-1) due to large spatial variation in forest floor mass, as well as interannual effects that can bias sampling depth. However, the C:N ratio of the forest floor has increased slightly (p = 0.05), which is unexpected under the “N saturation” hypothesis.

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.

 Seventy-four catchments, with a total area of 790 km2 (ranging from 1 to 50 km2), drain from the Santa Ynez Mountains along the northern coast of Santa Barbara Channel. The topography of these coastal catchments is characterized as mountainous headwaters and sloping coastal plains separated by transitional foothills. From west to east, there are both elevational and land use gradients. Headwater elevations increase from approximately 300 to 1400 m, and land uses on the coastal plain and foothills change from mostly rangeland to a combination of urban and agricultural lands.

Elevational Controls on Organic and Inorganic Nutrients in Stream Waters, Boulder Creek Watershed, Colorado Front Range

Jordan N. Parman and Mark W. Williams

Department of Geography and Institute of Arctic and Alpine Research, University of Colorado, Boulder, Colorado, USA

  Litter decomposition is an important process for nutrient and organic matter dynamics in forest ecosystem, and influenced by various biotic and abiotic factors. Ltter quality such as nitrogen and lignin contents is one of the important indicators to understand the difference of pattern and rate in the litter decomposition among different vegetation in forest ecosystem of northern Hokkaido, Japan. However, the pattern and rate in Sasa litter decomposition, their difference with the tree litter and their relations to the litter chemical property has not been clarified yet.

Diverse plant litter mixtures frequently decompose substantially differently than expected, compared to the average of the individual component species. These strong “non-additive” effects constitute an important way in which biodiversity influences key components of below-ground ecosystem function like soil C and N cycling, and it remains unclear which plant traits drive diversity effects on soil C and N cycling.