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. This group’s goal is to refine and evaluate different soil organic matter stabilization theories and to produce a dataset that encompasses the impact of experimental manipulations on soil organic matter at different sites.
It seems like a simple question. Does biodiversity loss cause productivity loss? Most experiments to test the question are done on small plots. Scaling up to natural ecosystems introduces complications that could tip the balance toward a stronger—or a weaker—relationship. Drawing on data from biodiversity experiments at multiple LTERs and global observational and experimental networks, the Biodiversity and Productivity working group asks what role time scales, spatial scales, type of experiment, and ecosystem type have on the strength of this key relationship.
Populations of plants, animals, and microbes fluctuate all the time. Whether populations rise and fall in tandem, independently or alternately can affect ecological stability. Offset fluctuations between species can enhance ecosystem stability. Or alternate fluctuations of the same species in different regions can support species stability. Building on many sources of long-term data, the LTER Synchrony working group aims to understand the drivers and timescales of synchrony and its effect on ecological stability.
Many global change drivers (GCDs) lead to chronic alterations in resource availability, and scientists anticipate that the magnitude and direction of ecosystem responses to these changes will be non-linear. To predict responses to GCDs across a wide variety of ecosystems, the working group will take advantage of 101 similar experiments done across 17 LTER sites, all of which have examined plant community responses to changes in resource availability. The group aims to discover whether changes in plant community structure, productivity, and carbon storage are predictive of shifts in ecosystem function.
What factors impact the stability of ecosystems? Previous research has identified dispersal, niche differentiation, and habitat heterogeneity as crucial parameters that determine metacommunity dynamics and stability in response to disturbance. Researchers do not know, however, whether these factors confer stability over long time scales or across ecosystem types. Using LTER datasets, the working group will assess how well these parameters estimate stability across time and space–and in the process, identify the major predictors of metacommunity stability.
The working group will compare stream chemistry data from 19 sites, representing far-ranging biomes including tundra, desert, and tall-grass prairies, as well as boreal, temperate, and tropical rainforests. They aim to identify what factors affect the coupled breakdown and use of carbon and nitrogen in streams. While carbon and nitrogen are inextricably linked, scientists remain stymied by the considerable spatial and temporal variation in the relationships between the two. The unprecedented global database being assembled by the project will allow the team to examine energy and nutrient cycling across seasons and environmental and management gradients.