Urban Streams Cycle Nitrogen as Fast as Unbuilt Systems

Urban watersheds—with their fertilized lawns, street runoff, treated and untreated wastewater—have proportionally more nitrogen flowing through them than undeveloped landscapes do. But are urban streams somehow less able to process that nitrogen? New research out of the Baltimore Ecosystem Study LTER says: no. The study, based on 385 urban watersheds and published in the journal FEMS Microbial Ecology, found that urban watersheds have similar, if not higher, nitrogen processing rates than natural areas.

Divergent water regimes influence algal diversity

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Wetlands exist on every continent save Antarctica and manifest as a variety of habitats, from salt marshes to mangrove forests. They provide important ecosystem services, such as water purification and flood protection—often tied to their high productivity and diversity.

Macrosystems ecology: A key subfield matures

Ecosystems ecology, landscape ecology, macrosystems ecology. It’s easy to think of these subdisciplines as big, bigger, biggest—but there’s a good deal more to the distinction than the scale of interaction they address. A recent “Idea and Perspective” article in Ecology Letters traces the origins and foundations of the field of macrosystems ecology, and advances a new hypothesis to describe how anthropogenic influences change the scales of ecological processes.

The grazing effect: How bison impact plant water use

When one envisions a grassland community, imagery of tall grasses and bison often come to mind. Bison are an iconic species on the landscape, and they also impact the structure and function of the grassland ecosystem in important ways.  Using natural variations in the abundance of oxygen isotopes, researchers at the Konza Prairie LTER found that  grazing influenced plant water use through changes in diversity.

Putting the “urban” in disturbance: Applying ecological frameworks to cities

The concept of “disturbance” is a core theme of the LTER Network and central to ecological science. How does the idea of disturbance need to change when applied to the interactions of an urban metropolitan region rather than a “natural” system? Ecologists often consider the process of urbanization itself to be a form of disturbance, but that is a habit that has to change, say the authors of a recent paper in Ecosystem Health and Sustainability. People, technology, and infrastructure have to be defined as part of the system when studying cities, they say.

Chronic Nitrogen Enrichment Slows Fungal Action

Fungi, often spotted in cold, damp locations, are responsible for decomposing the plant litter that falls to forest floors, enriching soils. Without fungi, dead plant material would inundate ecosystems and overwhelm other organisms. What would happen, then, if anthropogenic nitrogen altered the fungi’s ability to perform this vital ecosystem function? A recent study capitalized on a 28-year nitrogen enrichment experiment at the Harvard Forest LTER site in north-central Massachusetts to find out.  As nitrogen inputs to a system increase, researchers found, fungal decomposition slowed.

How Will Climate Change Affect Peak Firefly Activity?

A typical warm summer night is complemented with the familiar glow of fireflies and the light spectacle they create darting around and lighting up the night sky. However, the timing of these light shows might be affected by environmental changes. In order to better understand the life history of the firefly, researchers from the Kellogg Biological Station (KBS) LTER investigated the phenological patterns of fireflies from 2004-2015 to determine what explains the variability observed in their mating season.

Invasive Earthworms and Their Effects on Midwestern Soils

As ecosystem dynamics change with warming global temperatures, researchers have begun investigating the potential of further northward invasions from nonnative species like the Asian earthworm. Past studies have shown that nonnative earthworms can significantly alter ecosystem functioning, and this experiment confirms that Asian earthworms can do as much—if not more—damage as their better-researched European counterparts…. Read more »

2017 ASLO ABSTRACTS

logo from ASLO ocean science meeting 2017

From February 26-March 3, The Association for the Sciences of Limnology and Oceanography (ASLO) will hold its annual meeting in Honolulu, Hawai`i. The LTER Network sites will deliver oral and poster presentations on a wide range of topics, from blue carbon in salt marshes to impacts of the Eastern Pacific “warm blob” and El Niño. In… Read more »

ILTER Nitrogen Initiative 2016 Update

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The ILTER Nitrogen Initiative had a very good year in 2016. Hideaki Shibata, who leads the Nitrogen Initiative for ILTER, provided the following update. The Initiative produced many interactive activities, an international training course, publications, and firmed up links to other programs. The leaders of the Initiative truly appreciate the engagement, cooperation, and contributions of… Read more »