The Italian Long Term Ecological Research Network (LTER-Italy) was officially admitted to the International LTER Network (ILTER), during the general meeting held in Namibia in 2006. At present, LTER-Italy consists of an integrated group of 20 sites developing long term ecological research, a Secretary's Office, a group of sites managers and a Coordinating Committee. 9 research stations are CON.ECO.FOR. permanent plots under National Forest Service coordination, with many other sites and research stations in terrestrial, transitional, marine and freshwater ecosystems. CON.ECO.FOR.

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 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.

A conspicuous feature of the Western Antarctic Peninsula (WAP) continental shelf is the presence of deep submarine canyons that extend from the shelf break to the land margin, where during summer large colonies of breeding Adélie penguins occur.

Sea ice changes in the greater PAL LTER study region are occurring 29% faster than the fastest sea ice changes in the Arctic. Over 1979-2006, the sea ice season has become 83 days shorter in the greater PAL LTER area versus 59 days shorter in the greater Chukchi Sea area in the Arctic (though the latter includes twice the area effected). We review the physical processes and potential feedbacks contributing to these polar sea ice changes to better reveal high latitude climate sensitivity and its implications for polar marine ecosystems.

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.

Twenty year record of vegetation change from long-term plots in Alaskan tundra
William A. Gould¹, Joel A. Mercado Diaz^1,2, Jess K. Zimmerman²
1. USDA Forest Service, International Institute of Tropical Forestry, Río Piedras PR,
2. University of Puerto Rico, Río Piedras, PR

 In areas containing seasonal snowpacks, snowmelt contributes significantly to the hydrological cycle. Thus, quantifying the spatial distribution of flow through a snowpack is essential to accurate hydrograph interpretation and representation in snowmelt runoff modeling. Movement of liquid water through snowpacks is generally recognized to occur in distinct flow paths rather than as uniform flow through a homogeneous porous medium.

We have developed an autonomous underwater vehicle (AUV) capable of generating for the first time 3-D biogeochemical datasets in the extreme environment of perennially ice-covered Antarctic dry valley lakes. The ENDURANCE (Environmentally Non-Disturbing Under-ice Robotic ANtarctic Explorer) is in the middle of a two year campaign to map the under-ice lake dimensions of West Lake Bonney in the McMurdo Dry Valleys, and is equipped to measure a comprehensive suite of physical and biogeochemical indices in the water column.