• Policy paper
  • Working title: Biological diversity is fundamental to the maintenance of basic human rights
• Abstract:
  1. Evidence now clearly shows that biodiversity maximizes the chance that any particular habitat will be dominated by the most productive species.
  2. While one species can sometimes maximize biomass in small areas (e.g., a farm field), a wide variety of species are needed to maximize biomass across an entire ecosystem (e.g., the ocean).
  3. While one species can sometimes maximize one ecosystem process, such as biomass production (again, in small areas), a wide variety of species are needed to maximize multiple ecosystem services simultaneously (e.g., food production, fiber production, drought resistance, pest suppression).
  4. There is now small but growing evidence that a wide variety of species are needed to maintain the production of biomass in a variable environment.
  5. The production of biomass is fundamental to nearly all ecological processes, and is the currency and transducer by which ecosystems provide food, clean water/air, and disease control for humani
  6. In sum …
  • IF biodiversity (i) maximizes the chance that the 'best' species will dominate individual habitats, (ii) maximizes the biomass of entire ecosystems over long time scales, and (iii) ensures the stable and sustainability of biomass
  • AND biomass is the fundamental currency by which ecosystems provide food, clean water/air, and the stability of these services to humanit
  • THEN diversity itself is fundamental to the maintenance of basic human rights.
    
• Participants: All at ASW3, core group includes Solan, Bunker, Cardinale and Duffy
• Timeline: Draft by January 2006
• Products: Science or Nature editorial, wallet card to hand out at ESA meetings

The BEF Index
• Working title: A standardized but flexible index of biodiversity-ecosystem functioning intactness.
• Abstract:

We are developing a Biodiversity-Ecosystem Functioning Index for two reasons. First, a standard measure of the deviation of an ecosystem/region/biome from a target may aid decision-makers. Although a standardized index is inevitably a simplification of the whole picture, it is a number that can be used by resource managers and policy makers for prioritizing various efforts (protection, maintenance, restoration, etc.). Second, an index which looks at both components instead of just biodiversity or just ecosystem functioning may provide an early warning of undesirable changes in an ecosystem. For example, denitrification rates in an isolated, small wetland remnant may be similar to those in a larger, less isolated wetland of the same type, thus having a high ecosystem functioning intactness. However, if the biodiversity of this small remnant has deviated considerably from a reference state, and experimental work has shown that such deviations in diversity negatively impact denitrification rates, the current rate of denitrification in the remnant wetland is likely a legacy effect of previous diversity; greater deviations of denitrification rates would be expected in the future. Conversely, the biodiversity of a forest may be largely intact at a certain time, but large amounts of nutrient loss from the system (compared to earlier times) may indicate an external stressor on the system (atmospheric nitrogen deposition) that, because of the longevity of the biota, has not yet affected biodiversity.

• Participants: All at ASWIII.
• Timeline:
  • Early October 2005: Leader shares notes from KK with entire group, soliciting additions and corrections.
  • October 2005: Participants respond with additions and corrections to notes, suggestions for improvement of indices (they need a lot of work).
  • Mid November 2005: Leader compiles additions, corrections, and suggestions from entire group into very rough draft of manuscript and submits to whole group.
  • November-December 2005: Group improves on rough draft.
  • January-March 2006: Leader struggles with making this into a submittable paper, with substantial input from whole group.
• April 2006: Submission to journal
  
• Products: 1) Science or Nature paper, 2) a chapter in "the book"

• Biodiversity scenarios
  • Working title: Predicting biodiversity change in the 21st century
  • Abstract:

  While BEF research has demonstrated that species diversity has strong impacts on ecosystem function, prior studies have relied on random or assumed extinction scenarios. BEF research has often been criticized for this disconnect between theory and real world changes in biodiversity. Reliable predictions for the effects of species loss on real-world ecosystem function must rely on accurate descriptions of compositional change. Our approach will be to compare three alternative methods for predicting compositional change in response to several global drivers, including habitat fragmentation, habitat degradation, invasive species, climate change, nitrogen deposition, resource extraction, and CO2 enrichment. The three methods include 1) a survey of biodiversity scenarios used in prior BEF research, 2) an expert opinion survey of the traits most strongly correlated with changes in abundance in response to several drivers, and 3) an empirical review of the traits correlated with a subset of drivers. For ecologists to make clear predictions about the effects of global change on ecosystem function, we must first be able to predict changes in community composition in response to these drivers.

  • Participants: Daniel Bunker, Jennie McLaren, Natalia Perez-Harguindeguy, Oliver Phillips, Chris Phillipson, Martin Solan
  • Timeline:
    • December 2005: Update of BEF bibliography. Begin BEF literature review. Construction of expert opinion survey. Identify empirical drivers to review (N-dep, fragmentation, ???).
    • January 2006: Complete BEF lit review. Launch expert opinion survey. Review empirical drivers.
    • Febuary 2006: Synthesize results.
    • March 2006 Submit manuscript.
  • Products: Paper for Ecology Letters

• Cross biome synthesis
  • Working title: Accounting for biodiversity impacts on ecosystem functioning across ecosystems.
  • Abstract:

  Empirical support for the linkage between changes in biodiversity and changes in ecosystem function consists largely of studies of constructed ecosystems that are small in scale, lacking in trophic complexity, and focused on single ecosystems, all of which limits their utility for forecasting the ecosystem consequences of biodiversity loss on natural ecosystems. If we wish to extrapolate the implications of current findings in biodiversity and ecosystem functioning research to larger scales typical of natural, degraded, and managed systems, we need appropriate methods. This need for a landscape-level approach motivates our present work. Here we use a mass-balance approach to develop an accounting model that incorporates species specific contributions to ecosystem function, and that includes trophic diversity and multiple, interacting biomes. This approach will allow for comprehensive simulations of the effects of changes in species composition on ecosystem functioning.

  • Participants: Katia Engelhardt, Jerome Chave, Sandra Diaz, Amy Symstad, Daniel Bunker, Daniel Flynn, Shahid Naeem.
  • Timeline:
    • October 2005: Draft of paper completed.
    • December 2005: Model exploration with simulated or empirical data.
  • February 2006: Incorporation of results into manuscript.
  • March 2006: submission.
    
  • Products: Manuscript for American Naturalist

• Multi-trophic interactions
  • Working title: Working title of the project: A meta-analysis comparing the top-down and bottom-up effects of species diversity at multiple trophic levels.
  • Abstract:

  The past decade has witnessed an explosion of interest in how species diversity, and particularly the widespread loss of diversity from natural communities, might alter rates of ecological processes that are fundamental to all life. Thus far, both experimental and theoretical considerations of species diversity have focused on how the richness of monotrophic groups of plants influences nutrient cycles and biomass production. But increasingly we have remembered that the species at greatest risk of extinction, and often those that have the greatest control over community and ecosystem-level properties, are those that occur at higher trophic levels. As we have sought to understand the functional role of diversity at higher trophic levels, predictions have proven to be mixed. Heuristic theory argues that species loss from higher trophic levels is likely to have greater impacts on community and ecosystem functioning than species loss at lower trophic levels. In contrast, mathematical theory suggests that any group of organisms consuming a common resource should have the same qualitative impact on resource pools and the production of biomass, regardless of trophic level. So which is correct?
  We propose to address this question with a meta-analysis of existing data. We distinguish between 6 types of 'diversity effects' that represent the combination of (i) the direction an effect can pervade through a food web (top-down effects of consumer diversity on a shared resource vs. bottom-up effects of resource diversity on a shared consumer), and (ii) the trophic position of the focal group of organisms (see figure below). We are now in the process of evaluating the existing diversity literature to decide whether enough experimental studies have explicitly manipulated diversity in 2 or more of these categories to allow a formal analysis. If there proves to be an insufficient number, we plan to broaden our scope to include single species deletion experiments, studies of invasion, and multi-species competition. One way or another, we expect to amass enough data to ask "does the addition or deletion of a single species from a higher (lower) trophic level have fundamentally different impact on resource (consumer) dynamics than the addition or deletion of a single species from a lower (higher) trophic level?"

  • Participants: Brad Cardinale, Amy Downing, Emmett Duffy, Claire Jouseau, Mahesh Sankaran, Diane Srivastava, Justin Wright
    
  • Timeline:
    • Oct, 05: First evaluation of available data. Participants summarize no. of BEF studies that have been performed at different trophic levels and then evaluate whether data must be obtain from other sources to address the hypothesis (e.g. studies of invasion, single species deletions, two species competition, etc.).
    • If there is a sufficient no. of BEF studies performed at contrasting trophic levels …
      Dec, 05: Complete formal meta-analysis.
      Feb, 06: Complete first draft of paper
      Jul, 06: Publication
    • If there is not a sufficient no. of BEF studies performed at contrasting trophic levels …
      Dec, 05: Complete data gathering from other sources
      Feb, 06: Complete formal meta-analysis
      Jul, 06: Complete first draft of paper
      Sep, 06: Publication
      
  • Products: Publication of meta-analysis in Ecology or Ecology Letters

ASW-III Participants

Dan Bunker
Brad Cardinale
Jerome Chave
Sandra Diaz
Amy Downing
Emmett Duffy
Katia Engelhardt
Andy Hector
Claire Jouseau
Jennie McLaren
Shahid Naeem
Natalia Perez-Harguindeguy
Oliver Phillips
Chris Phillipson
Mahesh Sankaran
Martin Solan
Diane Srivastava
Amy Symstad
Justin Wright