Barrier islands’ harsh conditions, including nutrient and freshwater limitations and extremes of light and temperature, along with frequent large-scale disturbances, such as hurricanes, limit the number of plants species able to survive. As a result, successional trajectories can be convoluted.
The ice-covered lakes in the McMurdo Dry Valleys, a polar desert, rely on glacial melt for almost all their inputs. A recent study of Lake Fryxell suggests that in this environment even small changes in climate can impact biological productivity in the lake.
A recent experiment examined the impacts of increased nitrogen on salt marshes—and the all-important microbes within them.
Each forest reflects a legacy of past disturbances—from the literal detritus left behind a storm or fire to the prominence of particular species traits that enable species to bounce back after a specific type of disturbance.
How can researchers project the ways in which land-use changes will affect ecosystem services when they don’t yet know what course development will take? Integrated scenario analysis models several possible trajectories to examine the interactive effects that land-use change could have on ecosystem structure and function.
What information is needed to predict where fires will start in desert grasslands and how big they will get? Soil type turns out to play a larger role than expected.
Nitrogen enrichment can dramatically change the existing environment for plants and typically leads to increased productivity, decresed diversity, and shifts plant community composition. But what mechanisms are responsible for these changes? Researchers designed a multi-site experiment to find out, experimentally manipulating each of three possible drivers across mesocosms of three ecosystem types (tall grass prairie, alpine tundra, and desert grassland).
New analyses demonstrate that long-term nitrogen enrichment substantially changes the community composition of soil fungi in a temperate hardwood forest. The mix of fungal taxa that emerges appears to be better able to tolerate high nitrogen but less able to break down the lignin in organic matter, which contributes to an overall accumulation of soil carbon.
Ecologists know that nitrogen, phosphorus and leaf area play key roles in the productivity of plant communities. But how tightly are they tied together? And are those relationships sustained over different types of landscapes? A recent study of tallgrass prairie communities, building on a previous study of arctic tundra, found leaf area index (LAI) to be strongly correlated to both total foliar nitrogen and total foliar phosphorus in several plant functional types (grass, forb, woody, and sedge) and grazing treatments (cattle, bison, and ungrazed).
How sensitive are coastal ecosystems to sharp changes in temperature? Using a detailed spatial analysis in the Florida Everglades, researchers found that cold snaps reduced ecosystem productivity most dramatically in areas with low water levels that were located away from the coast. With more extreme weather events predicted in the future, knowing the likely effects of low temperature events on subtropical wetlands systems can inform management of these important ecosystems.