Recap of the ESA annual meeting 2018

https://esa.org/neworleans/

Each year, thousands of ecologist gather in a city in the US for the ESA annual meeting.  It's a week filled with talks, meetings, meals, and lots of energy related to the field of ecology.  
Ecology is a relatively young discipline, tracing it roots back to the early twentieth century, taking influence from physics, engineering and systems science, and biology (just to name a few). The major motivation at that time was to understand "ecosystems" (a new concept at that time), as a working system of integrated parts.  That motivation continues unchanged to this day; what has changed is the range and sophistication of approaches available to the modern ecologist.  Thus, the depth and breadth of the field of ecology is ever increasing. 

That was reflected at the theme of the 2018 meeting: Extreme events, ecosystem resilience and human well-being.  The meeting kicked-off with two spectacular plenaries: Robert Twilley from LSU and Ariel Lugo from USFS IITF both spoke to the interdisciplinary nature of ecological/environmental resilience as they relate to urban areas.  Twilley addressed the long-term restoration of the Mississippi river delta, and some of the challenges that arise when conjoining ecological knowledge with water management at the state and regional levels.   His knowledge of the hydrology and landscape processes shaping the delta was impressive, and his willingness to work outside the traditional academic sector with politicians, managers and the public was inspiring.   

Ariel Lugo: "Holocene ecology needs revision in the Anthropocene" because humans are main actors.

On Monday morning, Ariel Lugo took the stage.  Admittedly, I am a fan of Ariel, but I think all in attendance were able to take something away from his plenary.  He spoke to many aspects of the changing nature of ecology, and showed how many of the old-school concepts from his graduate days in the 1970's (aka the Odum days) were still applicable today, with some re-thinking and re-furbishing.  One key point, is that the human can no longer be viewed as being separate from the ecological system.  In the past, disturbance was viewed as being separate from the [eco]system itself, and ecologists would study the resultant effects to gain understanding about the system.  Lugo proposed a paradigm shift (that is likely already underway), that incorporates disturbance, and system resistance and recovery from disturbance, as inherit properties to the system.  A deepening, contexutal, and holistic understanding of where the thresholds in ecosystem resistance and resilience are is required for building sustainable & flexible "socio-eco-techo"- logical systems in the Anthopoce.  buen mensaje!

After the plenaries, the meeting always gets going.  This was my 3rd ESA (I am on a 2 year cycle for ESA, 50th Baltimore, 52nd Ft. Lauderdale, and now 54th New Orleans).  A buzz engulfed the Ernst M. Moore Convention Center where the A/C was on full throttle amid the humid southern air and flavor of the Big Easy.  Folks ran to-and-fro, as did I.  Many old connections were re-kindled and new-ones were ignited.  Below I share some of my notes on the sessions I attended, mostly for my records, but if you were unable to attend they might serve as a highlight reel:

• Courtenay Ray (grad student in the Blonder Lab at ASU) delivered an animated and informative talk on the ecological explanations for and the demographics of an alpine plant community in Colorado.  She was interested in whether there is an ecological advantage to forming mat roots and whether this affects species vital rates.  Results were mixed, and she has some new experiments underway to tease the governing factors apart, including some ant seed-dispersal/seed-preference trials.  link to abstract
• Zoe Cardon (from Woods Hole) gave a very nice talk on hydraulic redistribution in plants and soil, and how incorporating proper representation of those processes into CLM models improves their predictions  link to abstract
• Zequing Ma (Chinese Academy of Sciences) presented his recent work on Global Root trait bio-geography.  A very nice talk on how root diameter is a key axis of root trait variation, globally.   link to abstract
• Alan Knapp (Colorado State) gave an excellent talk, where he acknowledged how all of us forest ecologists have "grassland envy" because of the relative ease in which NPP estimates can be obtained in grasslands vs. forests.  He also addressed whether precipitation experiments addressing climate change actually capture ecosystem responses (despite their variability).  link to abstract
• Martijin Slot (STRI Panama) gave a well-delivered talk on the drivers of the photosynthetic response to warming in Tabebuia rosea.  Stomatal conductance is main driver, but it a bit counter-intuitive, because of the "indirect effect of warming that causes stomatal closure through increasing VPD".  His results confirmed a stomatal closure limit of ~65% RWC or ~4MPa. Among his talk an the others in that session, there seemed to be a consensus building that you can get up to a 0.4 deg. C shift in Topt with warming, so there is some ability for plants to acclimate photosynthesis to increasing temperatures. link to abstract
• Pete Manning (Bik-F) presented work done with his team (SDiv-2, including Dylan Craven) on the nature of biodiversity and ecosystem function, specifically resilience and resistance and stability.  They tested the hypothesis that slow plant communities (sensu the Leaf Economics Spectrum) were more stable.  Results were supportive and nuanced, depending on community composition (phylogenetics) and community synchrony and compensatory trends in relation to ecosystem recovery.  link to abstract
• Benton Taylor (Columbia) showcased his results from some potted competition experiments with the N-fixing tree Pentaclethra macroloba and another non-fixing species done at La Selva Biological Station in Costa Rica.   Root nodule formation and N-fixation occurred to a greater degree in treatments with high light.  He presented biomass partitioning results, which led to his conclusion that "producing nodules is more than offset by the reduced fine root production" (i.e., there no structural cost to N-fixers to produce nodules).  pretty cool.  look for his paper to emerge in Nature Plants. link to abstract
• Andrew Quebbeman (Columbia) gave a very nice talk on how topographic heterogeneity influence our estimates of green house gas (GHG) fluxes in tropical forests.  He measured GHG emissions and soil moisture from soil across the Luquillo Forest Dynamics plot (which has high photographic variation), and concluded that both were important drivers of GHG fluxes. link to abstract
• Tim Perez (U Miami) gave a talk on the ecological consequences of heat tolerances in leaves of tropical trees.  Tim has measured the heat tolerances for hundreds of tropical tree species.  The heat tolerance is temperature at which photosynthesis the leaf breaks down, and Tim measures this by exposing leaves to high-temperature water baths and then measuring chlorophyll fluorescence.  He was interested in seeing if leaf-level photosynthetic heat tolerances could explain decelerating growth rates of trees in La Selva.  There were some promising results.  look for more to come from Tim and check out his website here.  link to abstract
• Freddie Draper (ITCB post-doc in collaboration with Greg Asner's lab) presented his work on the hyperdominance of Amazonian flora at different canopy strata.  His research (compiling data from the ATDN plots, Al Gentry's work and other sources) shows that few species are [hyper]dominant at all life stages in the Amazon.  Mytales, Piperales, and Melastomes dominate the understory, palms in the midstory.  link to abstract
• Rich Norby (Oak Ridge National Lab) gave a stimulating talk on the historical perspective of rising CO2 emissions.  He started in 1954 and walked through the developing understanding of the critical points of understanding in determining ecosystem responses to eCO2, mainly temperature effects on photosynthesis and growth and NPP.  Several seminal papers (Kramer 1981 Bioscience, Mooney 1991 Bioscience, and others) are now on my reading list. Thanks Rich... and, "If you know any millionaire friends that want to fund Amazon FACE", tell them to contact Rich.   link to abstract
• Colleen Iveresen (Oak Ridge National Lab) took attendees on a tour of three climate change experiments: Oak Ridge FACE, the SPRUCE project and the NGEE Arctic site.  One cool contrast between the Oak Ridge FACE and the SRUCE experiment she highlighted was that under elevated CO2 conditions the roots of the temperate trees increased biomass and depth, however in the boreal  bog, roots were found shallower in the flooded soil profile to maintain access to oxygen.  She also highlighted the FRED initiative (data available at http://roots.ornl.gov).  link to abstract
• Danien Bonal (CRNS INRA) summarized findings from Paracou, French Guiana, on water use between tree and lianas in a very cool talk.  Lianas had more negative deuterium isotopic values after they did a isotopic water injection into the soil, meaning that lianas were more efficient at taking soil water than trees.  Interestingly, they showed results that lianas effectively suck water away from the roots of trees.  link to abstract   link to paper here
  • On Thursday morning, I camped out for the NGEE Tropics session on model-data integration, which was killer.  I've said before, I am not a modeler, but Man, is that stuff intellectually awesome!  The FATES (Functionally-Assembled Terrestrial Ecosystem Simulator) model is published, check it out here.  github here for those more modeling inclined. 
  • Brad Christoffersen (U Texas) presented some interesting data from Panama on tropical tree hydraulic responses to the 2015-2015 El Niño drought.  He showed increasing variability in sap-flux with increasing water deficit, and a hump-shaped relationship of sapflow with increasing VPD  link to abstract
  • Xiantiao Xu (Harvard) presented a pretty intricate model of canopy leaf phenology for tropical forests integrating a sun-shade leaf model with a Vcmax and leaf lifespan model.  link to abstract
  • Jerome Chave (CRNS) talked about his model (the TROLL as he calls it) which is a dynamic IBM, that uses tree allometry, mainly and is able to model tropical forest dynamics (especially forest structure) well.  link to abstract
  • Jennifer Holm (Berkeley National Lab) - talked about model validation of FATES using data from ZF-2 in the Amazon.  She was testing AGB recovery of the model in response to logging.  The model performed relatively well, but underestimated the growth of large trees after timber harvest, leading her and Jeff Chamber to come up with the 'idling respiration' hypothesis for large trees in tropical forests.  I thought that was cool. link to abstract
  • Tom Powell (Berkeley National Lab) also presented on model testing with FATES and ED.  link to abstract
    • there were a few other talks in that session, apologies if I missed yours, the notes are convoluted there, I must have needed a coffee. 
  • David Medvigy (Notre Dame) switched it up in the session to talk about nutrient addition experiments in tropical dry forests.  He is currently part of a team doing the second known one ever.  The first, from Mexico, showed a doubling of stem biomass in response to added N&P. Their results did not show the same.  He spoke to the use of the MEND and N-Com models for modeling nutrient use by tropical trees.  He showed some results from simulations and concluded that there is probably no increase in wood production in dry forests under fertilization.  This is congruent with our understanding of tropical wet forests at the moment, but is likely context-dependent in relation to the severity of nutrient limitation.  link to abstract
• Ryota Aoyagi (postdoc at STRI Panama) showed some really cool experimental results on Phosphorus and Panamian trees (work he is doing with Ben Turner at STRI).  Species that are low-P specialists showed greater ability to uptake phosphorus and an increase in fine root biomass (allocation to fine roots) in response to increased levels of P.  This was one of my favorite talks of the conference, awesome work.  link to abstract
• Lars Hedin started his talk with Ma Nature paper on root traits and then presented a first-principles model on the evolutionary stable strategies of root-mycorrhizal associations.  The evolutionary simulations he showed return two divergent and stable strategies.  He showed that you can recover stable coexistence between AM and ECM trees with abundances that vary with latitude (recovering the natural distribution of trees in N. America).  link to abstract
• Brian McGill gave perhaps the most attended single 20-min talk at ESA.  The room (one of the bigger ones) was packed.  He presented the case on "why we have to unpack biodiversity and how to unpack it".  The basic premise was that S (sp. richness) is lousy" because it's 1-dimensional, scales non-linearly with increasing scale, and ignores abundance, spatial scale, and density in community data. He showcased of a new R package "mobr", which allows for several methods to "make S more multidimensional using rarefaction, N (number of individuals), and pi (probability of species encounter).  link to abstract
• Kelly Andersen presented the data up to date on the Amazon Fertilization Experiment (AFEX), where they have been adding N, P, and cations to the soil for about two-years now.  They are measuring lots of ecosystem responses including soil respiration, photosynthesis, growth and tracking nutrients.  At this point the fertilization has led to increased respiration and it is getting into the plants.  There should be some more results in the coming years, and the big question is will there be a growth response in this very-P-limited system.     link to abstract
• Kristine Cabuaguo was my last attended talk where I took notes (I had my talk shortly after).  She showed how the microbial community composition of the rhizophere can affect plant functioning, using experimental drought treatments with bacterial inoculations on potted Clusia pratens.  Proline, a protein associated with resistance to drought and other stressors, was highest in plants inoculated with all beneficial bacteria.  There was a lot more in there, with enzyme assays and other stuff; a very nice presentation.    link to abstract

​There were other talks that were awesome, too.  Some of which I was unable to attend (and wished I could), and a few of which I attended but my notes are either too disorganized to make sense or my chicken-scratch handwriting is illegible to decipher. 
Regardless, until the ESA (or whichever meeting you attend), take care, keep working, and research on! ​♠