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.
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There are certain events, such as severe storms or a crash in financial markets, that catalyze transitions in social-ecological systems, in a process that is akin to the way a hurricane or insect outbreak might catalyze an ecological transition. To understand the patterns that emerge in social-ecological systems, ecologists must understand governance, a process rooted in the key social science concepts of power and networks.
In stratified lakes, a large portion of phytoplankton biomass is found—not at the surface, where sampling is easiest—but somewhere down the water column, in what is known as a subsurface chlorophyll maximum (SSCM). Researchers in Global Lake Ecological Observatory Network (GLEON) compared automated high-frequency chlorophyll fluorescence (ChlF) profiles with surface samples and discrete depth profiles. In 7 of the 11 lakes studied, automated sampling captured the presence of SSCM’s that would have been missed by conventional sampling.
How-and when-do ecosystems change character? Are those shifts reversible? And what signs might precede them? Such questions are hard enough to answer in a single place. One might think that incorporating different kinds of ecosystems would only complicate the problem. But a group of scientists in the Long-Term Ecological Research Network is finding a remarkably consistent pattern by combining models and data across several long-term ecological experiments.
Novel ecosystems can emerge through many kinds of changes, including changes in mean climate, species invasions, and increased or decreased variability. Researchers at Jordana Basin LTER have highlighted the role of interannual climate variability in changing the outcome when an exotic grass species invades dry shrubland. Using a process-based model, they predicted three outcomes, depending on the degree of variability and timing relative to invasion.
Climate-change is predicted to have a larger impact on Arctic regions than on temperate ecosystems. As a result, rural communities relying on local wild resources, or subsistence harvesting, are vulnerable to climate-change-induced environmental trends affecting the availability of fish, waterfowl, and other key resources.
Landscape ecologists and nature-lovers are well aware of the way that valleys collect deeper, moister soils than neighboring hill slopes and crests. Now, researchers at Coweeta LTER have have found that cool air, sliding downslope from higher elevations and pooling in mountain valleys, subsidizes productivity in a different way. The cold air drainage was most prevalent at night and in the evenings, so it had little effect on photosynthesis, but reduced plant and soil respiration by about 8 percent. Overall, the authors estimate it boosted annual net carbon uptake by about 15 percent.
Individuals—even individuals of the same species—don’t always respond to a stimulus in the same way. Studying calcification in a key coral species, Acropora pulchra, researchers at the Moorea Coral Reef LTER found greater variety in the corals’ response to temperature than to high levels of CO2 in seawater. Since individual variation is the raw material of evolution, the contrast suggests it may be easier for this coral species to adapt to rising temperatures than to increased ocean acidification.
How do you begin to approach wicked problems, those that span socioeconomic and ecological spheres, when solutions involve multiple and varied stakeholders? Researchers at the Kellog Biological Station LTER began to tackle one of U.S. agriculture’s greatest challenges, excess nitrogen pollution, by hosting “The N Roundtable,” to improve the flow of information through a farming landscape that has changed dramatically in the past few decades.