Tropical environments are changing fast due to deforestation and regrowth, urbanization, climate change, and other forces. The consequences are immense for the whole array of ecosystem services people require. The Luquillo Long-Term Ecological Research Program (LUQ) is tackling these issues in Puerto Rico. LUQ began in 1988 and focused on natural disturbances (hurricanes, landslides, droughts, floods) and ecosystem response. That work revealed patterns of resistance and resilience to cycles of natural disturbance.

Disturbance from fire can affect the abundance and distribution of shrubs and grasses in arid ecosystems. Specifically, fire may increase grass and forb production while hindering shrub encroachment. Therefore, prescribed fires are a common management tool for maintaining grassland habitats in the southwest. However, Bouteloua eriopoda (black grama), a dominant species in Chihuahuan Desert grassland, is highly susceptible to fire resulting in death followed by slow recovery rates.

Global change may alter the frequency and seasonality of temperate lake mixing, with unknown ecosystem consequences. Mixing disrupts vertical chemical and physical gradients, such as dissolved oxygen (DO) and temperature, which then influence biological dynamics. We conducted a mixing manipulation to observe whole lake response to episodic mixing, with a focus on the physical and chemical drivers of bacterioplankton communities. We mixed a temperate, dimictic bog lake during summer stratification.

 The primary research focus of the Santa Barbara Coastal (SBC) LTER is on the relative importance of bottom-up processes and allochthonous inputs to giant kelp forests, a highly diverse and productive marine ecosystem that occurs on shallow rocky reefs at the interface of the land-ocean margin. Giant kelp forests are found along the temperate coasts of western North and South America, southern Africa, Australia and most sub Antarctic islands, including Tasmania and New Zealand.

This session is intended both for social and biophysical scientists who want to help develop a proposal for the kind of “multi-site, highly collaborative and integrated research initiative” envisioned by the LTER planning group. The focus will be on what the LTER planning process calls the “centerpiece” of the group's conceptual framework, as well as one of “Grand Challenges” to be addressed at the network level – “the dynamics of coupled human-natural ecosystems.”

 Most climate change research has concentrated on the direct effects of environmental change for individual species and their interactions. By affecting key foundation species and ecosystem engineers, however, climate change may have a variety of indirect that may complicate our abilities to predict the response of communities and ecosystems. In California, climate change has increased the frequency and intensity of storms over the last half century.  Storms may directly alter the structure of kelp forest food webs via disturbance.

Join us for an update on the progress of the EcoTrends project, an introduction to the functionality of the new EcoTrends website (http://www.ecotrends.info), lessons learned during the project, and a description of plans for the future. We will also use this time to solicit and discuss ideas on how to better incorporate and display data via database design, web services and tools (e.g., mapping, analysis tools, modeling tools, and customizable features) that will further engage and support the research and information management community.
 

Disturbance ecology is a central theme at all LTER sites, yet disturbance datasets are often not standardized such that synthetic analyses and comparisons across sites are challenging. The goal of this workgroup is to bring together scientists collecting and maintaining long-term datasets on disturbance in an effort to develop effective formats for standardized datasets that can be included in the EcoTrends project. A second goal will be to initiate these multi-site comparisons across different disturbance events in the form of a draft manuscript.