Identifying Alternative Indicators for the Detection of Abrupt Transitions in Ecosystems: a Consideration of Time Scale and Community Parameters

Background: The potential for abrupt transitions in ecosystem processes may increase as climate change continues to accelerate1,2. While this trend is of great concern, our understanding of how to identify when and why abrupt transitions occur has been informed almost exclusively by theory. In order to enhance the prediction and management of these changes for… Read more »

Veg-DB Phase 2: Developing a cross-site system to improve development and access to synthetic vegetation databases

This working group will support the next stage of development for a LTER network-based system called Veg-DB that would provide improved access to vegetation data. LTER sites have become significant reservoirs of long-term data on changes in vegetation populations, structure, composition, and productivity. This information is essential to detect long-term trends, test hypotheses, and to… Read more »

The influence of precipitation variability on diversity and composition of North American grasslands

Predictions regarding future climate change vary greatly among regions, and these predictions include directional changes such as more arid conditions in the US Southwest (Seager et al. 2007), as well as an expectation of greater interannual variability (Easterling et al. 2000). Ecologists are charged with identifying biotic communities and ecosystems most at risk for declines… Read more »

Bi-stability in North American ecosystems: analyzing woody plant cover for temporal stable-state dynamics

Woody encroachment is occurring worldwide (Archer 1995), with negative effects on biodiversity in North America (Ratajczak et al. in press) and uncertain effects on ecosystem functioning (Barger et al. 2011). The spatial properties of tree and grass dominance are well-studied and strongly suggest that woody encroachment of grasslands represents a shift to an alternative stable… Read more »

Land Use Institutions, Land Use Land Cover Change, and the Distribution of Ecosystem Services

Zoning, building codes, subdivision ordinances, and neighborhood association rules are the most pervasive institutions affecting land use in the USA, yet their impact on land use change and ecosystem services and the distribution of these environmental goods and “bads” is highly variable and not well understood[1]. The purpose of this working group is to coordinate… Read more »

Quantifying Uncertainty in Wet Atmospheric Deposition

BACKGROUND      Monitoring nutrients in precipitation inputs and other ecosystem fluxes has advanced our understanding of biogeochemical cycling.  However, uncertainty due to variability or error in observations and models has rarely been reported in ecosystem studies. This makes it difficult to determine rates of change over time or compare results across multiple sites with quantitative confidence. … Read more »

Synthesizing long-term records and eco-hydrologic modeling to quantify structural legacy effects

Rationale:  While the importance of legacy effect characterization to interpreting long-term records of ecological conditions has continued to emerge (Bain et al. in review “Legacies in Material Flux: Structural Catchment Changes Pre-date Long-term Studies” BioScience) some early structural legacies (e.g. substantial soil losses to erosion) are challenging to characterize with controlled experiments.  However, the extended… Read more »

State Changes and Threshold Dynamics

A four-day workshop will use LTER data, including data from the EcoTrends project, to bridge the gap between the relatively mature theoretical understanding of thresholds and state changes in ecological systems and the emerging empirical databases that allow us to actually test models of state changes. Many of these changes represent “tipping points” or dramatic… Read more »

Development of a hydrochemical database – StreamchemDB

We are requesting Synthesis Working Group funds to support LTER participation in StreamchemDB. StreamchemDB is focused on aquatic chemistry data, and builds on former data synthesis projects ClimDB and HydroDB, all of which have been collaborative LTER-Forest Service cross-site synthesis and cyber-infrastructure projects.