Monday, August 19, 2013

INTECOL day 1: A day full of ecosystems #INT13

Note: These are some thoughts from the first day of INTECOL. –Sorry for the abruptness and lack of polish on these entries, there were many talks and I have little time for a proper composition.

*acronyms: BEF = Biodiversity and Ecosystem Function; GBIF = Global Biodiversity Information Facility

It is clear to me that INTECOL is the premiere ecological meeting. There are delegates from countries all over the world from 67 countries , with especially strong European contingents. The next INTECOL meeting will be in Beijing in 2017. This is a special INTECOL as this is the 100th anniversary of the British Ecological Society. The opening talk by Sandra Diaz was held in an immense auditorium at the ExCeL centre, with a couple of thousand in attendance.

Morning plenary:

Sandra Diaz: functional traits are at the core for understanding changes in biodiversity and how species contribute to ecosystem function. Theophrastus, Greek philosophers, created first functional groups. Looks at key traits for tens of thousands of species, only possible through TRY data base. Most variation explained by size ( height, seeds, etc.), second was leaf economy ( leaf N, Leaf area, etc). These traits define plant functional design. Densities low on the fringes of this trait space -physical challenges, and many of these species use human help for success (crops and weeds). Two dense areas in the trait space -big slow growing trees, and small species. Effect and response traits are important for linking environmental change to ecosystem services. These traits can be linked or decoupled, and could change management options.
Linking trait dispersion and values to ecosystem function is a new area, and so few studies. We just don't know enough to understand how functional diversity links to environmental change and ecosystem services.

 Sandra Diaz giving her plenary lecture

Tree of life in ecosystems symposium:

Lisa Donovan: how selective pressures influence evolution of biogeochemical cycling. Traits appear evolutionary labile, and reported on a common garden experiment to find genetic differences controlling traits. Nitrogen has phylogenetic signal but few differences between close relatives. Major differentiation within species and especially for different agricultural lines.

Erika Edwards: Need to move down to small scale to truly understand the evolution of traits that affect ecosystem function. She looks at the genus Viburnum. Need to think about whole organism traits. E.g., branching and growth pattern. This originates from tropics and reinvaded temperate regions repeatedly, and a mix of different and similar strategies emerged. growth patterns highly conserved, but leaf spectrum traits were not. Flowering time seems linked to carbon economy traits.

Amy Zanne: Evolution and biogeography of leaf and stem traits. Angiosperms originated in the tropics and understory woody species and spread everywhere and all types of morphologies. Most species are woody and not exposed to freezing, and lineages move back and forth in climate species but less so with growth form. lineages shift growth form first, followed by climate changes.

Cornwell. Evolution of decomposition. Differences in decomposition rates among different phylogenetic lineages. Did plant life go from fast cycling world to slow one during evolution. Experiment in common garden for decomposition rates. basal angiosperms (magnolias) has lower decomposition than eudicots, which has fast decomposition rates.

Afternoon plenary:

Joel Cohen. Taylor's law after half a century. Taylor's law has been verified but we don't understand it. Taylor's law states that the variance of a population is positively related to the mean population size. Further mean population size is correlated with body size. He showed that tree data supports a body size-variance relationship. Does it apply to food webs? Data from aquatic systems show this pattern across species. Why do we care about Taylor's law? Used for understanding fluctuations in epidemiology, conservation of endangered species and management of forestry resources. Can see the same variance-mean relationships in nonbiological data -computer data packets, weather data and stock market trades. No underlaying theory to explains these. Previous attempts, such as affects of competition, do not seem to affect pattern.

Biodiversity & Ecosystem function session:

Enrique Chaneton. Movement of large herbivores around the world, introduction of cattle versus reintroducing native extirpated herbivores. Little is know how these large herbivores influence forests. Multiple pathways of effect from changing plant composition and waste excretion, affects decomposition. Within an Argentinean park, sites on lake islands do not have introduced herbivores and compared to nearby mainland sites. Herbivores reduce vegetation cover by sixty percent. Trees and shrubs were particularly affected. Distinct composition shifts. Litter layer was substantially different. In dry sites, higher decomposition in ungrazed sites. Volcanic eruption during research 'sometimes shit happens' killed many of the cattle.

Carsten Meyer. Examined the completeness of species point data inventories. Looked at GBIF records and compare to known distribution maps. GBIF records are highly biased to North America, Europe and Australia. Species rich areas are almost absent from GBIF records. Not adequate for research or conservation. Funding, accessibility and human safety all at play for biases. These factors seem to differ among taxonomy, interestingly. Countries that under report are large emerging economies (china, India, Brazil, Russia) which could finance these efforts but for some reason do not.

Julia Koricheva. Tree species richness and genetic diversity on leaf miners. What is the relative importance of these two effects. Two experiments, one manipulating tree richness -up to five species, and another with up to eight clones of silver birch. Silver birch was in both experiments, so was the focus of leaf miner surveys. Tree richness affects miner richness, but not abundance. More leaf miner species with higher tree richness in first year, but not second. For genetic diversity, miner richness also increased with number of clones. Looked at effect sizes of two experiments and genetic diversity appeared to have a stronger effect on leaf miner richness.

Tommaso Jucker. Complementarity in functional groups enhances wood production. He noticed that there were eighty talks on BEF at INTECOL. Four species combinations two pines and two oaks. Biomass increased with richness, but looked at more detail, growth over the past ten years from wood cores. Both pines grew much better in mixture, but oaks only increase growth when other oak is present. Tree that benefit the most are small trees. For pines, wet year showed largest increase in growth, most room for complementarity.

Eric Allen. Direct and indirect effects of landuse on multifunctionality. Landuse intensity changes functions, it increases biomass but reduces bird diversity, flower cover, increases pathogens, etc. Used path analysis to compare landuse and biodiveristy as well as environmental variables. from this analysis, plant richness seems negatively correlated with multifunctionality. looked at groups of functions (e.g., production, soils, cultural). some plots shows strong indirect effects of richness for some functions.

Siobhan Vye. Responses to multiple stressor change. Examined stressors in coastal systems. Looked at how an invasive species affected community response to stress by experimentally combining species in mesocosms and manipulated nutrient enrichment and temperature. Invader increases productivity. The presence of the invader determined how the stressor influenced community functions.

Sebastian Meyer. BEF changes over time. A number of studies show that BEF experiments increase in strength over time. Examined how functions change over time using Jena experiment. How many different functions show changes over time? Over half of functions are influenced by diversity generally. He regressed the richness-function slopes across time, and about one third of functions showed increasing diversity effects over time. What are the mehanisms? The stronger relationships are driven by a combination of changes in high diversity treatments and changes in low diversity treatments.

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