A recent meta-analysis found that aridity and low soil nitrogen levels seem to limit — rather than stimulate — plants’ ability to increase production of fine roots under elevated carbon dioxide conditions.
At the 2017 AGU Fall Meeting, held at the New Orleans Ernest N. Morial Convention Center in New Orleans, Louisiana, from December 11-15, 2017, dozens of LTER researchers will present new results on a range of topics, from how ecosystems recover from droughts and hurricanes to what manufactured ice storms can reveal about how to prepare for winter’s worst. Links to the abstracts for over 100 LTER presentations at AGU 2017.
If carbon is currency, wildfires are the brokers; that is, they distribute carbon between land and air. In the short-run, fire emits carbon dioxide into the atmosphere. Over time, it also strengthens subsequent carbon uptake through plant regrowth. This exchange is like a natural Ponzi scheme – the carbon offsets from yesterday’s fires take up today’s emissions…. Read more »
Recent research in Science concludes that high forest productivity relies on the presence of diverse tree species—a relationship that apparently hold true in biomes across the globe.
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.
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.
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).
This month’s Ecology Letters features the first global quantitative synthesis of under-ice lake ecology. In their analysis of 36 abiotic and biotic variables across 101 lakes, the authors issue a call to arms for more winter lake research—currently the focus of only 2% of freshwater publications. As the climate warms, they warn, temperate ecosystems are losing ice, and limnologists remain unsure what ecological processes are at stake. Though winter has long been understood as an inactive period, some data suggests that winter foodwebs and physical processes remain vigorous and that winter ecology can drive subsequent summer conditions.
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).
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.
International Drought Experiment" data-envira-gallery-id="site_images_45354" data-envira-index="0" data-envira-item-id="82314" data-envira-src="https://lternet.edu/wp-content/uploads/2020/01/Matta_rainout-533x400.jpeg" data-envira-srcset="https://lternet.edu/wp-content/uploads/2020/01/Matta_rainout-533x400.jpeg 400w, https://lternet.edu/wp-content/uploads/2020/01/Matta_rainout-533x400.jpeg 2x" data-title="Matta_rainout" itemprop="thumbnailUrl" data-no-lazy="1" data-envirabox="site_images_45354" data-automatic-caption="Matta_rainout - Researchers use rainout shelters at the Matta International LTER site in Israel to simulate extended droughts and observe changes in ecosystem productivity and species composition. The Matta site is part of a distributed network of over 100 sites across the globe inspired by long term experiments of the U.S. LTER Network. Similar structures without plastic panels serve as controls. Image courtesy of International Drought Experiment
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