Snowshoe hares prefer many other plants to white spruce seedlings, but when the population of hares skyrockets—as it does about once a decade—they can decimate even a bumper crop of spruce seedlings. Researchers with the Bonanza Creek LTER reconstructed over 40 years of browsing history by analyzing the age and browse scars of thousands of seedlings and saplings at 18 locations on the floodplain of Alaska’s Tanana River.
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.
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.
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.
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.
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.
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.
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.
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 »
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 »
