Fire and Aridland Streams

line of fire in a dark, open landscape

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 »

Selection across scales

birch forest

Selection across scales—merging evolutionary biology and community ecology to understand trait shifts in response to environmental change Selection acts on traits at both the community level, determining community assembly, and at the population level, determining the outcome of evolution. Selection at both scales combines with phenotypic plasticity to cause shifts in community-level mean trait values… Read more »

Soil phosphorus control of carbon and nitrogen

clouds, mountains, trees, and shrubs

Do actively cycling C and N pools depend ultimately on soil P supply? Across-biome synthesis In terrestrial systems the nitrogen cycle is more open than the phosphorus cycle. New N accumulates by biological N fixation and atmospheric deposition, and is readily lost from the system when N is in excess of biological demand. In contrast,… Read more »

Producers, Consumers and Disturbance

ground squirrel munches on nearby herbs

Response of Primary Producers and Primary Consumers to Environmental Change: from small-scale disturbances to seasonal and long-term changes This LTER SPARC Synthesis Working Group brings together LTER researchers interested in understanding how disturbances and environmental change across timescales are altering the production and transfer of organic matter from primary producers to herbivores. All ecosystems are… Read more »

Pelagic community structure

school of herring

Interannual variability and long term change in pelagic community structure across a latitudinal gradient Recent synthesis has shown both similarities and differences in how pelagic marine ecosystems have been influenced by cyclic and long term changes in the marine environment. The pelagic community structure synthesis group uses comparative data to test a series of conceptual… Read more »

The Flux Gradient Project

researcher recording data in flux tower overlooking coastal forest

The Flux Gradient Project: Understanding the methane sink-source capacity of natural ecosystems While biogenic CH4 emissions are thought to be of a similar magnitude to anthropogenic emissions, biogenic emissions remain the most uncertain source of the global CH4 budget. The vast areas with relatively small uptake and emission rates have been largely understudied but could… Read more »

Marine consumer nutrient dynamics

fish swimming through kelp forest

Consumer-mediated nutrient dynamics of marine ecosystems under the wake of global change Increases in the frequency and severity of disturbance events as a result of global change are altering population and community dynamics of marine animals. Given that animals are key recyclers of nutrients in many ecosystems, these ecological impacts may have consequences for ecosystem… Read more »

Identifying environmental drivers of plant reproduction across LTER sites

Reproduction is a key component of plant life cycles and is crucial for dispersal, however it has a surprisingly poorly understood relationship to environmental drivers. This is particularly true for plant species with highly variable reproduction over time, known as ‘mast seeding’. While mast-seeding patterns have been linked to weather (temperature, precipitation), describing past patterns… 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 »

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 »