Search Results for:

Fire and Aridland Streams

Quantifying interactive effects of fire and precipitation regimes on catchment biogeochemistry of aridlands Increases in the frequency, extent, and severity of wildfires could have long-lasting and wide-ranging effects on hydrology and biogeochemistry of catchments, with consequences for ecosystem services including provision of drinking water. In aridlands, effects of fire will depend on interactions with the… Read more »

Ecosystem transitions: increased variability and regime shifts

Human impacts on ecosystems can result in persistent compositional shifts that are difficult to reverse even after relaxation from perturbations. Considerable debate remains on whether these observed shifts in ecosystems are due to the existence of tipping points and systems with alternative attractors, or whether observed shifts in ecosystems represent communities in alternative trajectories that… Read more »

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

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

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

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

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 »

A synthesis to identify how metacommunity dynamics mediate community responses to disturbance across the ecosystems represented in the LTER network

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 »

Integrating plant community and ecosystem responses to chronic global change drivers

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 »

A global synthesis of multi-year drought effects on terrestrial ecosystems

Drought impacts on terrestrial ecosystems have increased globally over the last century with models forecasting that droughts will become more frequent, extreme, and spatially extensive. The goals for this project are to synthesize results from a unique global network of drought manipulations, focusing on how ecosystem productivity responds to drought over time and key mechanisms… Read more »

From poles to tropics: A multi-biome synthesis investigating the controls on river Si exports

Riverine exports of silicon (Si) directly influence global carbon (C) cycling through the growth of diatoms, ubiquitous autotrophs in marine and freshwater systems, which account for ~25% of global primary production. Rivers play essential roles in processing and supplying the Si necessary for diatom growth, but we have limited knowledge of the controls on river… Read more »