Project Summary: Understanding factors that influence ecological stability is a key question in ecology. Population ecology has highlighted that synchrony within a species over space is an important indicator of species stability. Community ecology, in contrast, has highlighted that asynchrony between species within space may enhance the stability of aggregate properties (such as total productivity)…. Read more »
Cross site investigation using LTER Data.
Project summary: Although hundreds of short-term local experiments indicate that random changes in biodiversity can cause substantial changes in primary productivity, considerable debate remains regarding whether these influences of biodiversity are weaker or stronger at larger spatial and temporal scales in natural ecosystems. Given this knowledge gap, current models often implicitly assume no influence of biodiversity… Read more »
Soil organic matter is a massive storehouse for carbon, as well as a key regulator of nutrient cycling and soil quality in terrestrial ecosystems, yet ecology lacks a full understanding of the controls on stabilization and breakdown of soil organic matter. Two sets of competing theories underlie models that adequately predict site-specific dynamics, but result… Read more »
Project Summary: Many global change drivers (GCDs) lead to chronic alterations in resource availability. As communities change through time in response to these GCDs, the magnitude and direction of ecosystem responses is also predicted to change in a non-linear fashion. We propose to examine whether plant community dynamics are predictive of shifts in ecosystem function… Read more »
Project summary: Dissolved organic matter (DOM) provides a significant source of energy and nutrients to ecosystems and its biogeochemical cycling is inextricably linked to dissolved inorganic nitrogen (DIN). In stream ecosystems in particular, there is considerable spatial and temporal variation in the relationships between the different fractions of DOM (dissolved organic carbon and nitrogen) and DIN…. Read more »
Metacommunity ecology considers both the local- and regional-scale factors that influence community assembly. Previous work has identified dispersal, niche differentiation, and habitat heterogeneity as crucial parameters that determine metacommunity dynamics and stability in response to disturbance. However, it remains unclear whether the parameter combinations that are predicted to confer stability do so over long time… Read more »
This proposed effort will “stimulate cross-site and Network-level synthesis” by addressing issues of collaboration within the LTER network. Scientific synthesis should be promoted as we better understand the nature of that collaboration.
The concept that the LTER program works as a network of interacting sites and scientists is grounded in the earliest documents of the US LTER (Callahan 1984) through the most recent decadal plan (US LTER 2007).
The initiatives proposed in recent documents (US LTER 2007) cannot be achieved without this interaction.
We propose to organize a working group that will analyze and synthesize long-term data on the relationship between precipitation variability and the structure of North American (NA) grassland plant communities.
This project will build on prior LTER-related synthetic efforts that have evaluated the response of aboveground net primary productivity (ANPP) to precipitation variability [1-2] and the relationships among ANPP, plant community composition and resource availability [3-7] in NA grasslands.
We propose a new synthesis effort between the California Current Ecosystem (CCE) LTER, the Mo’orea Coral Reef (MCR) LTER and the Santa Barbara Channel (SBC) LTER to incorporate regional modeling of physical processes around islands in both the tropical Pacific and California Current regions.
While these LTERs are focused on two vastly different oceanic regions, they each contain a number of small islands that interfere with larger-scale ocean circulation by producing wakes, trapped circulation patterns and other island topographic effects.
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.