From Theory to Practice: Ecology and its Application
Plenary talks will be held Friday, March 22 in the Memorial Student Center’s Bethancourt Ballroom (MSC 2300) located on the 2nd floor of the MSC.
9:00 am – Introductory Remarks by Dr. Kevin Heinz, Assistant Provost for Graduate Studies
9:15 am – Dr. Thomas Brooks
Monitoring biodiversity: overall trends, and conservation benefits
With the 2010 establishment of the Convention on Biological Diversity’s Aichi Targets, the importance of development of rigorous approaches to monitor biodiversity trends, and the impacts of conservation actions, has become apparent. What can we discern about these trends as regards two of the highest profile of the Aichi Targets, preventing species extinctions (Target 12) and completing protected area coverage (Target 11)? IUCN mobilizes a number of globally standard data systems, of which three are particularly important in monitoring progress towards these targets, documenting extinction risk (the IUCN Red List of Threatened Species), protected area establishment (the World Database on Protected Areas), and significant sites for the global persistence of biodiversity (Key Biodiversity Areas). The data underlying these systems are delivered through IUCN’s expert commission structure (comprising >10,000 specialists worldwide) as well as the union’s >1,200 state and NGO members; and have become increasingly comprehensive over the last three decades. Regarding overall trends, extinction risk has increased over this period, but at rates varying widely among taxa, with corals and amphibians showing the greatest increases. While protected area coverage has increased overall, proportionate coverage of significant sites has actually slowed. Regarding conservation impact, we use counterfactual scenarios to examine what trends might have looked like in the absence of conservation action. For extinction risk, this approach reveals that the aggregate slide of species towards extinction would have been 20% faster over the period in the absence of conservation action. For protected area coverage, we find that the slide towards extinction for species well-represented in protected areas has been halved in comparison to that for poorly-represented species. Research challenges remain in how to increase the resolution and comprehensiveness of these measures, and to extend them to the other Aichi Targets. More generally, it is clear that while conservation actions are already delivering significant benefits, greatly increased efforts are essential to take these to the scale necessary to halt biodiversity loss.
10:15 am – Coffee Break
10:30 am – Dr. Gary Mittelbach
Productivity and species diversity: patterns and mechanisms
Robert MacArthur said “To do science is the search for repeated patterns, not simply to accumulate facts.” One of the most enigmatic patterns in ecology is the relationship between primary productivity and species diversity. At broad spatial scales the pattern is clear – areas of higher productivity support more species (e.g., the latitudinal diversity gradient). Species richness at these broad spatial scales is well correlated with the main climatic drivers of primary productivity (temperature, water availability), however, the mechanisms underlying the relationship remain unresolved. At smaller spatial scales, the relationship between productivity is more varied; positive, negative, and hump-shaped relationships abound. However, one small-scale pattern is very clear – when primary productivity is increased by nutrient addition (e.g., fertilization, eutrophication), species richness declines. But why? In this talk, I will explore what we know about the drivers of productivity-diversity relationships, focusing at the large scale on the latitudinal diversity gradient and at the small scale on experimental manipulations of plant communities.
11:30 am – Dr. Bruce Menge
Ecological forces shaping coastal marine ecosystems: the intermittent upwelling hypothesis, a test and possible application
The intermittent upwelling hypothesis (IUH) predicts that the strength of ecological subsidies, organismal growth responses, and species interactions will vary unimodally along a gradient of upwelling from persistent downwelling to persistent upwelling, with maximal levels at an intermediate or “intermittent” state of upwelling, and monotonic increasing functions with increasing intermittency. A test of this model involved investigating community and ecosystem dynamics at rocky intertidal study sites in Oregon, California, and New Zealand. Predictions of the IUH were supported via model selection analyses. On average, unimodal relationships of these processes with upwelling magnitude explained ~50% of the variance, and monotonic positive relationships against an index of intermittency explained ~42% of the variance. Results suggest that the IUH has geographic generality, and are also consistent with earlier arguments that bottom-up effects and propagule subsidies are strongly linked to the dynamics of higher trophic levels, or top-down effects, as well as to non-trophic interactions. Climate change models predict that upwelling regimes will change, and the IUH provides a tool to allow predictions of how coastal ecosystems will change in the future.
12:30 pm – Lunch Break
2:00 pm – Dr. Michael Willig
Elevational Variation in Population, Community, and Metacommunity Dynamics: Theoretical and Empirical Perspectives
Elevational variation in the Luquillo Mountains of Puerto Rico creates strong environmental gradients (temperature, precipitation, forest zones) that affect the abundance and distribution of animal species. Moreover, the geographic mappings of these environmental gradients will likely shift as a consequence of global climate change, subsequently altering patterns of biodiversity that require reconsideration of management practices and conservation actions. Because they are taxonomically diverse, numerically abundant, and potentially keystone heterotrophs (detritivores, herbivores, and carnivores), terrestrial gastropods represent a model taxon for exploring variation in biodiversity. I quantify spatial and environmental variation in multiple aspects of gastropod biodiversity at the population (total abundance as well as abundance of each of 14 species), community (richness, evenness, dominance, rarity, diversity), and metacommunity levels. The abundances of most species varies with elevation in a consistent manner along mixed forest (tabonuco – palo colorado – elfin forest) and a palm forest transects (i.e., decreasing toward lowlands), and are higher at palm than at non-palm sites. Similarly, community-level aspects of biodiversity vary with elevation in a consistent manner along mixed forest and palm forest transects (i.e., generally decreasing toward lowlands and higher in palm than at non-palm sites). Finally, based on analyses of coherence, range turnover, and boundary clumping, metacommunity structure along the mixed forest transect is Clementsian (i.e., compartmentalized distributions), whereas along the palm forest transect it is quasi-Gleasonian (i.e., idiosyncratic distributions). Elevational variation in population- and community-level attributes of biodiversity parallel variation in total gastropod abundance and net primary productivity. A single mechanism (more individuals hypothesis or random placement) accounts for elevational variation and the differences in biodiversity between mixed forest and palm forest transects. Moreover, the higher production and abundance of gastropods in palm-dominated forest patches compared to those in non-palm forest contribute to differences between metacommunity organization in the mixed forest and palm forest transects.
3:00 pm – Dr. Jorge Soberón
From practice to theory: areas of distribution as policy building blocks
The extent and history of the area of distribution of a species are fundamentally important in Macroecology and Biogeography. Moreover, distributional areas are closely linked to decision-making at many scales. Being able to answer where one is likely to find a species (to protect, to manage, to reintroduce, sometimes to eradicate), or what species are found in a place, is of crucial practical importance. For these reasons, modeling species distributions has become an exploding activity. In this talk I will discuss how sometimes it is practical need what drives conceptual and theoretical advances. Using mostly examples from the developing world I will illustrate how estimating distributional areas, for government purposes, required the development of theoretical concepts, mathematical understanding and increasingly powerful algorithms. I will end showing how this question-driven theorizing may perhaps differ from more conventional curiosity-driven theories.