Cross site investigation using LTER Data.

Synthesizing population and community synchrony to understand drivers of ecological stability across LTER sites

Gammarid amphipod.

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 »

Scaling-Up Productivity Responses to Changes in Biodiversity

experimental plots with a variety of old field species

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 »

Advancing soil organic matter research: Synthesizing multi-scale observations, manipulations & models

deep soil profile, rich in organic matter, with grain growing on top

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 »

Global Patterns in Stream Energy and Nutrient Cycling

stream running through wetland

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 »

Integrating plant community and ecosystem responses to chronic global change drivers: Toward an explanation of patterns and improved global predictions

Three individuals collecting samples in desert brush.

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 »

Forecasting Rates of Riverine Leaf Litter Decomposition in Response to Inland Climate Change

Recent work has suggested that freshwater ecosystems may play a significant role in the global carbon cycle, potentially emitting 1.2 Pg C y-1 to the atmosphere [1, 2]. The majority of the CO2 that is degassed from streams and rivers comes from the decomposition of allochthonous leaf litter inputs [3, 4]. The process of decomposition fuels aquatic food webs, helps to regulate surface water acidity, and links biogeochemical cycles [5, 6].

A Data Synthesis Working Group: Disappearing Snow in the Western US: Ecosystem Implications for the Rain-Snow Transition Zone

Introduction and Goals:

In the Western US mountain regions, winter temperature increases will lead to the reduction and even loss of winter snowpacks.

A shift from snow to rain-dominated systems will alter seasonal patterns of streamflow, soil moisture, soil temperature, etc. affecting a myriad of ecosystem processes.

This proposed work will develop a working group and fund a student to aggregate and synthesize data relevant to the ecosystem implications of disappearing snow in the rain-snow transition of the Western US.

Understanding Interactions within the LTER Network for Improved Collaboration

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.

The Influence of Precipitation Variability on Diversity and Composition of North American Grasslands

Overview:

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.

Cross-Site Synthesis between CCE, MCR and SBC: Working group to develop comparative regional ocean modeling effort

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.