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The latest updates on the LTER Network, new research papers, announcements, and jobs. 
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November 2016
 
LTER in the News
NSF News From Other News Outlets
Recent LTER Publications
Art and Humanities LTER Programs Build Empathy for Nature Journal of Environmental Studies and Sciences
Do arts and humanities programs at LTER sites further the Network’s mission? Recent research posits that art-humanities-science collaborations generate empathy – and associated emotions like inspiration, awe, and wonder – for the natural world. This empathy then drives society to engage with and care more broadly about nature.
 
Since HJ Andrews Experimental Forest began its annual writers’ residency in 2002, 21 LTER sites have hosted arts and humanities projects and six of those have established ongoing programs, including artists’ residencies, art and ecology workshops, and performing and visual arts exhibitions. Researchers explored the value and effectiveness of these collaborations via interviews with representatives from 15 LTER sites and an audience perception survey at an LTER-hosted art show. The authors make a case for the importance of creative inquiry in ecological contexts. They argue that beyond the direct contributions arts and humanities projects make to education and scientific outreach at the sites, they also illuminate ethical questions and foster relationships between humans and natural systems.
Chronic Nitrogen Deposition Restructures Soil Fungal Communities Fungal Ecology

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.
 
Using Harvard Forest’s 25+ year chronic nitrogen amendment study, researchers examined the impacts of nitrogen addition on functional and phylogenetic diversity. Results revealed a decrease in the relative abundance and diversity of ectomycorrhizal taxa (which dominate forest floors under “typical” nitrogen conditions) and a corresponding increase in saprotrophic ascomycetes, which specialize in decoposing dead plant tissue. One possible explanation: ectomycorrhizal fungi transport nitrogen to plant hosts in exchange for plant carbon; under high nitrogen conditions, plants are able to acquire enough nitrogen without assistance, so they direct carbon from photosynthesis to other activities. Observations of mounting soil organic matter in regions with long-term nitrogen deposition suggest that the effects may be at play across a wide variety of forest types.
A Framework for Understanding How Nitrogen Drives Change in Plant Communities Ecology Letters

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).

High nitrogen availability (1) reduces competition for nutrients and increases the struggle for light, so that even a small difference in size can (2) amplify a plant’s competitive ability (asymmetric competition). Abundant nitrogen also (3) changes the community composition of soil microbes and fungi, which in turn alters plant community structure via species-specific feedbacks.  

Researchers found that resource limitation strongly affected plant growth in all systems. In prairie and alpine systems, asymmetric competition drove diversity declines, while microbes were the driving force in desert grasslands. Species composition responded to a combination of different factors in each type of ecosystem. If this framework proves broadly applicable, it could give scientists a tool for tailoring strategies to management priorities.
Soil Type Strongly Influences Likelihood of Fire in Desert Grasslands Landscape Ecology
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.

As part of a study to understand the feasibility of reintroducing fire as a management tool in desert shrub- and grasslands, researchers examined 33 years of fire ignition data. They found that shallow and clayey soils, which support more continuous cover of perennial grasses, had higher fire frequencies than expected. Sandy and loamy soils supported fewer fires than expected. Other influences, such as mean annual precipitation, water holding capacity, and distance from roads are also important.

The study assessed the interactive effects of climate, urban development, and soil-landscape properties on fire distribution. The results can help refine landscape-level models of fire distribution, which land managers can use to develop long-term landscape management goals as well as short-term burn plans.
A Glimpse into the Future: How Land Use Decisions Will Impact Forest Function Ecological Society of America

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.

When applied for Massachusetts forests, the approach suggested that even in the face of considerable development, trees will absorb more carbon than they release. All the development scenarios increased surface water runoff and nutrient pollution and degraded interior forest habitat to varying degrees, but the “Opportunistic Growth” scenario, characterized by minimal government regulation, had the greatest negative impacts. 

The study’s scenarios varied the amount and pace of commercial and residential development, agricultural development, and timber harvest. Researchers assessed what impacts these changes, together with changing climate, would have over a fifty-year period (2010 to 2060). The research identified win-win scenarios that could increase both landowner and ecosystem benefits at the same time, though researchers acknowledge that tradeoffs between individual economic returns and ecosystem services are more common.
Announcements
LTER at AGU

LTER researchers will present over 100 talks and posters at the annual meeting of the American Geophysical Union, December 12-16. Find a list of LTER-related talks on the LTERNET web site. Topics include impacts of melting permafrost, fire in drylands and boreal systems, coastal geomorphology, blue carbon, and many others. Also see the related NSF press release.

FACULTY POSITIONS:
ILTER NEWS

Science of the Total Environment is planning a special issue on detecting and explaining natural and anthropogenic changes by making use of large extent, long-term ecological research facilities of the International Long-Term Ecosystem Research (ILTER) Network.

Editors are particularly interested in regional or global studies. To inquire about contributing a manuscript, email peter.haase@senckenberg.de by December 1, 2016, with: name of author(s), institute, country, indicative title, and abstract.
Photo Credits (top to bottom):  Jaime Schirmer (KNZ), Bernard Spragg, Konza GalleryDouglas I. Moore (SEV), Aleksandr Kozlovskii 
Copyright © 2016 LTER Network Office, All rights reserved.


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