Microbes are of critical importance but are a poorly understood component of arctic stream ecosystems. They are responsible for recycling organic matter and regenerating nutrients that are essential to the food webs of aquatic ecosystems. We tested the hypothesis that differences in highly contrasting parent lithologies (non-carbonate and ultramafic), stream habitat (sediments and rocks), and stream biogeochemistry influence the structure of bacterial biofilm communities in arctic streams.

Viral-mediated cell lysis and microzooplankton grazing are both important sources of phytoplankton and bacteria mortality in the ocean, however, the magnitudes of these mortality sources are difficult to quantify. Using the modified (viral) dilution method, the effects of viral- and microzooplankton-mediated phytoplankton mortality can be examined simultaneously.

The objective of this work was to compare estimates of microbial and biogeochemical processes obtained from year round versus field season only data. We also aimed to capture the response of soils to simultaneous warming and nitrogen fertilization in both winter and summer months. Our research took place at the chronic Soil Warming and Nitrogen Fertilization experiment at the Harvard Forest Long Term Ecological Research site. The experiment includes four treatments in a completely randomized design: control, +heat, +N, and +heat +N.

The KBS LTER site is in a diverse, rural-to-semirural landscape typical of the U.S. Great Lakes and upper Midwest regions. Research at KBS asks how diverse plants, animals, and microbes in agricultural landscapes can contribute to farm productivity, environmental performance, and profitability. We study annual and perennial crops including corn, soybean, and wheat rotations, forage crops such as alfalfa, and biofuel crops such as poplars, switchgrass, and native successional communities.

The PAL study area encompasses a 200 x 500 km region extending from the nearshore coastal zone heavily influenced by seasonal sea ice cover to the open Southern Ocean, and from a northern area where sea ice cover is now limited to only the colder winters, to the south where perennial sea ice cover persists into summer months. In this region, primary production is dominated by unicellular phytoplankton and limited by light availability to the October-April period. The region is characterized by spring phytoplankton blooms that have declined by up to 90% in the northern region since 1978.

 The National Ecological Observatory Network (NEON) is a national-scale research platform for analyzing and understanding the impacts of climate change, land-use change, and invasive species on ecology. NEON features sensor networks and experiments, linked by advanced cyberinfrastructure to record and archive ecological data for at least 30 years. Using standardized protocols and an open data policy, NEON will gather essential data for developing the scientific understanding and theory required to manage ecological challenges.

This poster outlines molecular analyses of soil fungi within the Bonanza Creek LTER over the last six years. We examined community structure in three studies in mixed upland, black spruce, and white spruce forests. While fungal diversity is extremely high, and we were unable to saturate diversity in one quarter gram of soil with 5000 clone sequences, we were nevertheless able to saturate diversity across the 12 black spruce sites after combing over 2000 soil cores and 30,000 clone sequences.

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.

A majority of the research on the MCM LTER occurs during the austral spring and summer (October-January), a period of continuous sunlight, when field support is readily available. Through additional logistical efforts, we were able to collect the first data on the MCM lakes during the transition from summer to winter (October-April). These data allowed us to examine ecosystem responses as photosynthetic input of new carbon stopped. Protein biosynthesis (leucine incorporation) increased in the east lobe of Lake Bonney during March and April (p<0.05).

Microorganisms have confounded biogeographers because of their high dispersal capability, small size, and vast diversity and abundance. Here we use pyrosequencing, bioinformatics tools, and geospatial modeling to reveal that the genetic relatedness of soil bacteria varies in a predictable pattern across a landscape. Microbial communities showed strong spatial autocorrelation to a distance of 240 meters and this pattern was driven by changes in the genetic relatedness and abundance of specific clades across the landscape.