Sat & Sunday : Monday : Tuesday : Wednesday : Thursday : Friday

Returning soils to restoration ecology: rethinking the trade of structure for function
Friday, August 11, 8-11:30 am
Organizers: Mac Callaham, Christine Hawkes

Current strategies in restoration ecology generally focus on the restoration of vegetative structure, with the assumption that a restoration of whole-system function will follow. However, system function does not always accompany restored structure. This problem can often be traced to failure to establish essential aboveground/belowground linkages. Although restoration ecologists acknowledge the importance of soils, it is rare for soil to be considered, a priori, when restoration objectives are formulated. This situation seems unusual, as soils were a major focus of pioneering restoration ecologists who were motivated by massive degradations of soil resources during the dust-bowl era of the 1930s. Possible reasons for the tendency to overlook soils in restoration efforts include: 1) Soil is opaque and difficult to study; 2) Benchmarks for soil functions have been difficult to identify; and 3) Soil processes develop over a wide range of time-scales, including some that are too long to be practical to study given the relatively short duration of many restoration projects. This symposium will emphasize the importance of soils to restoration efforts and will help develop a framework for assessing soils in the restoration context. The objective of this symposium is to stimulate discussion between soil ecologists and restoration ecologists in hopes of moving closer to the ultimate goal of ensuring the ability of soils to sustain ecosystems and provide adequate supplies of food and fiber, while maintaining other critical functions into the foreseeable future. A panel discussion will follow.

Species invasion and species saturation: reconciling patterns of change in biodiversity
Friday, August 11, 8-11:30 am
Organizers: Thomas Stohlgren, Sara Simonson, Dov Sax, David Tilman

Species invasions are fundamentally altering ecosystems around the world. “Icons,” like Charles Elton, have suggested that communities become saturated in time. “Upstarts” have suggested that species-rich communities may be even more invaded than species-poor ones. Such evidence is difficult to reconcile with accepted theory, which suggests that resource limitations and competition should maintain species richness and abundance below some theoretical maximum. It follows that, where dispersal is not severely limited, over evolutionary time scales, niches should fill such that the amount of unused resources decreases and the number of species within an area stabilizes. However, modern trade and transportation greatly enhance dispersal, reduce barriers to species movement, facilitate the migration rates of native species within countries, and exponentially increase the introduction and exchange of non-indigenous plants, animals, and diseases among continents. Initially, such invasions may increase species richness; however, the long-term results of invasions are unclear and depend on the importance of species saturation and competition in structuring communities. What if other factors (e.g., facilitation) structure communities? These issues are not just of academic interest, as we are confronted with an unprecedented volume and number of species introductions. We debate findings from paleoecology, ecological theory, empirical observations, and experimental evidence to provide insights on invasion, migration, coexistence, and community saturation at different spatial and temporal scales. We span terrestrial and aquatic systems in various habitats and countries. Our speakers may not always agree. We hope to improve our understanding of species saturation in structuring ecological systems in light of invasions and better understand many basic issues in ecology: alternate stable states, regional and global homogenization, and invasion meltdown to name a few.

The ecological consequences of genetic diversity
Friday, August 11, 8-11:30 am
Organizers: Marc Johnson, Randall Hughes

Understanding the ecological and ecosystem-level consequences of biodiversity is a fundamental challenge in ecology. Decades of research and intense debate have given way to a growing consensus concerning the consequences of species diversity, as well as the mechanisms underlying the effects of diversity. Despite this advance in our knowledge, ecologists know very little about the ecological consequences of one of the most important sources of biodiversity—genetic diversity. By combining ecological and evolutionary approaches, the burgeoning field of community genetics has revealed that genotypic differences between individuals within populations can have large effects on communities and ecosystem processes. This suggests that genetic diversity can have consequences for communities of organisms similar to species diversity. Given the ubiquity of genetic variation in nature and its importance to basic and applied problems in biology, understanding the community and ecosystem consequences of genetic diversity is quickly becoming an important goal of ecological research. In this symposium, we will discuss and synthesize the recent conceptual and empirical advances in our understanding of the ecological consequences of genetic diversity. The symposium will focus on the effects of genetic diversity on individual species' demography, species interactions within and between trophic levels, and ecosystem dynamics, with the ultimate goal of determining when genetic diversity is likely to be most important. We will also examine how genetic diversity influences the interplay between ecological and evolutionary processes. Talks will feature experimental field and laboratory studies, observational research, and mathematical theory to explore how genetic diversity influences the ecology of organisms from microbes to dominant forest trees in both aquatic and terrestrial ecosystems.

Phenology and ecosystem processes
Friday, August 11, 8-11:30 am
Organizer: Asko Noormets

Vegetation phenology provides an integrative measure for quantifying the season-dependent shifts in ecosystem processes. It offers the promise of reducing uncertainty in quantitative assessments of ecosystem carbon and water cycles associated with the variation in growing season length. Understanding the phenological signals that correlate with different processes would allow: 1) the use of remote sensing technology to continuously monitor these changes; and 2) the application of remotely sensed information to improve the predictive capabilities of regional biogeochemical models. This session addresses the application of phenology for interpreting variations in ecosystem function and covers the following aspects: 1) phenological changes and fluxes of carbon, water, and energy; 2) feedbacks between surface phenology and atmospheric boundary layer processes; 3) use of remote sensing for continuous monitoring of phenological change; and 4) incorporating phenological information in regional biogeochemical models.

Application of behavioral principles for ecosystem stewardship
Friday, August 11, 8-11:30 am
Organizers: Mark Brunson, Fred Provenza

Ecology has contributed greatly to the conservation and restoration of managed ecosystems such as forests and rangelands by informing the design of management strategies that reflect our current understanding of processes and conditions of the abiotic and vegetation components of ecosystems. Less attention has been given to behavioral ecology and the interactions of animals and microorganisms within ecosystems. This session addresses how new ideas about behavior can be applied to improve ecosystem stewardship. If one assumes animal behavior is fixed in the genome, then improvements in vegetation or abiotic condition generally require removal of species (especially non-native or domestic animals) whose behaviors are associated with ecosystem degradation. This session will highlight research demonstrating that animal behavior is more plastic than traditionally thought—determined by learning as well as genome—and will describe how ecosystem managers have been able to take advantage of, and even influence, behaviors of both domestic and wild animals in order to achieve desired stewardship outcomes.