Quantifying carbon and nutrient transformations in aquatic ecosystems at regional to continental scales in response to environmental change
Aquatic ecosystems regulate material transfer between terrestrial and coastal systems, and play a significant role in regional to global carbon (C) and nutrient cycles. The functioning of inland waters is being altered by human activities such as land use change, climate change, and hydraulic engineering.
The EcoTrends project was initiated in 2004 as a multi-site, individual investigator project that subsequently expanded into a network-wide initiative that directly supports the Decadal Plan and ISSE.
The Florida coastal Everglades (FCE) is a coastal wetland, which is characterized by a freshwater to marine gradient ranging from freshwater marshes, through mangrove fringe to the seagrass dominated Florida Bay estuary. Dissolved organic matter (DOM) in this system is am important biogeochemical component as most of the N and P are in an organic form. The dynamics of this DOM in the FCE is complex given its versatile sources and the effects of geomorphology, hydrology, water chemistry, and history of degradation on DOM composition and fate.
Inter-LTER collaboration – Chemical characterization of dissolved organic matter (DOM) from headwaters using a multi-analytical approach: Preliminary results from six different Biomes
Dissolved organic matter (DOM) is ubiquitous in a wide range in aquatic environments and plays important ecological roles by fueling the microbial loop, acting as a factor determining light penetration, as the substrate for photoproducts, as a pH buffer, and as a medium for the complexation of trace metals. In addition, DOM fluxes from terrestrial to marine environments have been reported to steadily increase due to climate change and anthropogenic influences. Thus, the chemical characteristics of DOM have extensive implications in aquatic environments.
Seasonal abundance and activity of microbes and mesofauna over a land-use intensity gradient in a Michigan agroecosystem
Microbial-mesofaunal interactions are known to play a significant role in the decomposition process and many researchers have examined interactions between microbes and common decomposer fauna (i.e. Acari and Collembola) under laboratory conditions. Biological succession in soil and litter has also been studied extensively in the field, however, few experiments have examined the concurrent succession of microbial and faunal communities. We propose that until this is done, our understanding of how microbial-faunal interactions influence decomposition will be incomplete.
Photo-induced generation of dissolved organic matter (DOM) from floc in the Shark River Slough of the Florida Coastal Everglades (FCE)
The Florida Coastal Everglades (FCE) is an oligotrophic wetland characterized by very low quantities of particulate organic matter (POM). POM in this environment occurs as a slow-moving, benthic layer of flocculent material (floc) that has been defined as biogenic, detrital and rich in organic matter. Although it is known that floc is an important component of the food web in the Everglades, still little is known about its biogeochemical dynamics in this environment. Floc has also been thought to be a potentially important source of dissolved organic matter (DOM).
Nitrous oxide (N2O) is a potent greenhouse gas (GHG) produced in soils primarily through the microbial processes of nitrification and denitrification. It is the major GHG emitted by US agriculture, with annual emissions from cropland greater than 1 million metric tons. Soil management activities, including nitrogen (N) fertilizer application, are the largest contributor to N2O emissions in the US, accounting for around 80% of total N2O emissions from the agricultural sector.
Potential production of biofuel feedstock by early successional grassland has large environmental sustainability
Accelerating demand for liquid fuel, together with concerns about anthropogenic influence on the environment and fossil fuels availability, resulted in an increasing interest in using renewable energy sources, which could be grown agriculturally. However, increasing demand for food and acceleration of land-use change have raised concerns about use of food-based bio-fuel (i.e. corn ethanol) and turned research to the direction of cellulosic feedstocks.
Global climate change is emerging as the single most important environmental issue of the 21st century. The direct and indirect effects of climate change on terrestrial and aquatic ecosystems are highly complex and poorly understood. High elevation watersheds can be a useful unit for studying climate-induced effects because they are sensitive to global change processes and may serve as a bellwether for more resistant ecosystems of higher order watersheds.
Hurricane Wilma Enhanced Vertical Accretion Rates and Soil Phosphorus Pools in Everglades Mangrove Forests
The distribution of mangrove biomass and forest structure along Shark River estuary in the Florida Coastal Everglades (FCE) has been correlated with elevated total phosphorus concentration in soils thought to be associated with storm events. The passage of Hurricane Wilma across Shark River estuary in 2005 allowed us to test this hypothesis by sampling chemical properties and spatial pattern of sediment deposits in mangrove forests along FCE sites in December 2005 and October 2006. The thickness (0.5 to 4.5 cm) of hurricane sediment deposits decreased with distance inland at each site.