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 state (Archer et al. 1995, Shaver et al.
2001, Briggs et al. 2005, Young et al. 2007, Bond 2008, Sankaren et al.
2005, Browning et al. 2008, D’Odorico et al. 2011, Staver et al. 2011).

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 changes in the states of the systems, and our workshop will use data from terrestrial, coastal, and open-ocean systems to illustrate common mechanisms underlying state changes and threshold dynamics.

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.

Quantifying Uncertainty in Ecosystem Studies

The goal of this synthesis is to evaluate uncertainty in hydrologic inputs, outputs, and net hydrologic flux of major elements across small watersheds with diverse characteristics.

The long-term goal of this project is to contribute to a cultural change in ecology that makes uncertainty analysis an accepted and expected practice in the construction of ecosystem budgets.