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 »
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: 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 »
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 »
Contrary to the predictions stemming from the nitrogen saturation hypothesis (Stoddard, 1994), some forested long-term research sites in Eastern North America exhibit peak streamwater nitrate exports during the growing season. Some initial hypotheses about climatic controls (Mullholland and Hill, 1997) have recently been questioned (Goodale et al., 2009). This is a proposal to fund a working group to advance a synthesis on the seasonal patterns of inputs, processing, and output of Nitrogen to watersheds across Eastern North America.
The goals of this proposed LTER Synthesis Working Group are (1) to initiate and coordinate the integration of data from multiple sites on stream ecosystem responses to nutrient amendment, (2) to synthesize these data with a quantitative evaluation of functional responses at the microbial, primary producer, consumer and whole-stream levels, (3) to produce an NSF Research Coordination Network proposal that will expand data integration and synthesis efforts to members of the broader national and international stream ecology communities and (4) to promote interaction between LTER and the NEON expe
Climate change alters ecosystem and community properties and although inter-annual variation occurs year-round (Dominguez et al. 2012), most research on the response of ecosystems to climate change occurs during the primary growing season (e.g. Knapp et al. 2002) or uses annual averages that homogenize across seasons (e.g. Knapp & Smith 2001, Hsu et al. 2012).
We are requesting funds to assemble a working group of scientists (primarily LTER and
ILTER) with interest and experience in designing and conducting climate change experiments. Our goal is to continue to design a network-level experiment, proposed previously as part of the LTER Decadal Planning process, to manipulate rainfall (i.e., impose drought) in terrestrial ecosystems.