The Kaspari Lab

Two More New Positions in Geographical Ecology

Our friends in the Department of Geography and Environmental Sustainability continue to grow, and have posted two hires out of the 19 total in Environmental Science at OU (including Biology’s own two in Geographical Ecology, Deadline 1 October!).  Join us as we build something great!

Tenure-track Assistant or Associate Professor in Geohumanities and Tenure-track Assistant or Associate Professor in Socio-Ecological Systems Modeling

OKLAHOMA, NORMAN 73019. The Department of Geography and Environmental Sustainability at the University of Oklahoma (http://geography.ou.edu/) is an actively growing and dynamic department. Over the past 5 years, undergraduate enrollment has more than tripled, research expenditures have doubled and the department has quintupled its computer resources for research and teaching.  As part of our ongoing growth, applications are being solicited for two tenure-track assistant or associate professors.

 

Position 1: Tenure-track Assistant or Associate Professor in Geohumanities

We seek a geohumanities scholar who studies environment-society relations, utilizes critical theory, and incorporates stakeholder/community engagement. An urban or regional specialization would be welcome. The successful candidate will have an opportunity to participate in new and established campus-wide efforts to support humanities scholarship. To raise our research profile, we desire faculty members who are strong in research in terms of suitable publications and grant success, as well as active within both professional and stakeholder communities and effective at bringing research insights into the classroom.

Teaching duties would include introductory geohumanities courses as well as a course on environment and society, and possibly regional courses within the candidate’s expertise.

Application Process: Candidates are invited to submit a statement of interest and qualifications, a full curriculum vita, up to five scholarly publications, and a list of three references. Screening will begin September 15th, 2015. To apply, please submit applications electronically in one PDF file to Dr. Laurel Smith, Chair, Human Geography Search Committee at laurel@ou.edu. Please copy Ms. Deborah Marsh at dmarsh@ou.edu.

 

Position 2: Tenure-track Assistant or Associate Professor in Socio-Ecological Systems Modeling

The successful candidate will be capable of research excellence in socio-ecological systems modeling as related to climate variability and change, and they must have demonstrated success in proactively leading and/or participating in interdisciplinary, collaborative teams. In particular, the candidate will fill an immediate need in coupled human-natural systems modeling, preferably through Bayesian hierarchical modeling or similar methodology.  The candidate will also be able to work within collaborative teams that examine challenging questions facing the social, natural, and physical sciences.

Application Process: Candidates are invited to submit a statement of interest and qualifications, a full curriculum vita, copies of up to five scholarly publications, and a list of three references. To apply, please submit all materials electronically in one PDF file to Dr. Bruce Hoagland, SES Search Committee Chair (Email: bhoagland@ou.edu) and copy Ms. Deborah Marsh (dmarsh@ou.edu).

Screening will begin October 1st, 2015. Applicants for both positions should have demonstrated a commitment to teaching at the undergraduate and graduate levels and a willingness to participate in Department, University, and professional service. We seek an outstanding candidate with a PhD in geography, or closely related field.

Persons from under-represented groups are strongly encouraged to apply. Initial appointment to this position will begin August 2016. Salary and remunerations are competitive and commensurate with qualifications.

 

Candidates interested in collaborative research will find many exciting opportunities on the campus. The University hosts the History of Science Collections, Digital Scholarship Lab in the Bizzell Memorial Library, Western History Collections, Carl Albert Congressional Research and Studies Center, and the Fred Jones Jr. Museum of Art. The College of Atmospheric and Geographic Sciences hosts the National Weather Center, South Central Climate Science Center, Southern Climate Impacts Planning Program, and the Center for Spatial Analysis. The Department is home to the Oklahoma Wind Power Initiative and the Land Use Land Cover Institute.

 

The University of Oklahoma (OU) is a Carnegie-R1 comprehensive public research university known for excellence in teaching, research, and community engagement, serving the educational, cultural, economic and health-care needs of the state, region, and nation from three campuses: Norman, Health Sciences Center in Oklahoma City and the Schusterman Center in Tulsa. OU enrolls over 30,000 students and has more than 2700 full-time faculty members in 21 colleges. In 2014, OU became the first public institution ever to rank #1 nationally in the recruitment of National Merit Scholars, with 311 scholars. The 277-acre Research Campus in Norman was named the No.1 research campus in the nation by the Association of Research Parks in 2013. Norman is a culturally rich and vibrant town of around 113,000 inhabitants located just outside Oklahoma City.  With outstanding schools, amenities, and a low cost of living, Norman is a perennial contender on “best place to live” rankings. Visit www.ou.edu/flipbook and www.ou.edu/publicaffairs/oufacts.html for more information.

The University of Oklahoma is an equal opportunity institution www.ou.edu/eoo.

 

10 Foundational Papers in Community Ecology

I suggest to students in Advanced EEB, our course for first semester Ph. D. students, that creativity is about fostering

  1. your ability to generate associations/ideas, and
  2. your judgement as to which ideas are worth pursuing.

Toward that end, I also encouraged them to ask professors for a list of ten influential papers (“papers everybody should read” is how I think I put it).

Then, of course, BeccaP immediately sends me an email asking for my list. Serves me right.

The following ten papers occurred to me on a Saturday morning, over 10 minutes or so, and in the middle of my third cup of coffee. I figured they must be important to me if they sprung up with no more prompting than a dose of caffeine. They are not my “Top 10” (an odd concept), but they certainly exist in my 99th percentile.

Turns out, these kinds of lists serve both elements of the creative enterprise. First, the papers below are all full of ideas (some ultimately more successful than others) and represent highly creative people at the height of the powers. I remember, or at least I think I do, reading each for the first time and feeling energized and a little bit jealous.  At the same time, they reflect my judgement as to the elements that combine to form a good science paper: clarity, ambition, stepping boldly into a knowledge gap, identifying and advocating a path forward. Each photocopy was highly scribbled upon. You can clearly see the fingerprints of these ecologists all over our lab’s work.  The first on the list made such an impression,  I deconstructed it.

MacArthur, R. H. 1958. Population ecology of some warblers of northeastern coniferous forests. Ecology 39:599-619.

Hutchinson, G. 1959. Homage to Santa Rosalia, or why are there so many kinds of animals? American Naturalist 93:145-159.

Hairston, N., F. Smith, and L. Slobodkin. 1960. Community structure, population control, and competition. American Naturalist 94:421-425.

Janzen, D. 1967. Why mountain passes are higher in the Tropics. American Naturalist 101:233-249.

McNaughton, S., M. Oesterheld, D. Frank, and K. Williams. 1989. Ecosystem-level patterns of primary productivity and herbivory in terrestrial habitats. Nature 341:142-144.

Power, M. E. 1992. Top-down and bottom-up forces in food webs: do plants have primacy? Ecology 73:733-746.

Holling, C. 1992. Cross-Scale Morphology, Geometry, and Dynamics of Ecosystems. Ecological Monographs 62:447-502.

Ritchie, M. E. and H. Olff. 1999. Spatial scaling laws yield a synthetic theory of biodiversity. Nature 400:557-560.

McGill, B. J., B. J. Enquist, E. Weiher, and M. Westoby. 2006. Rebuilding community ecology using functional traits. Trends in Ecology and Evolution 21:175-185.

Orians, G. H. and A. V. Milewski. 2007. Ecology of Australia: the effects of nutrient-poor soils and intense fires. Biological Review 82:393-423.

The tropics is just a big plate of scrambled eggs

Debby Kaspari is a featured artist at the Leigh Yawkey Woodson’s annual “Birds in Art” competition. Here is a brief video that captures the glories of painting birds in tropical forests.

Succumbing to the lure of the model organism: studying the imported red fire ant

Guest Post by Karl Roeder

Ants. The adorable arthropods that have captured my imagination for years have finally become the focus of my Ph.D. research. They are abundant, diverse, and ecologically important with a variety of castes that contain a range of alternative phenotypes that differ in body size, life span, societal role, and reproductive output. Quite simply, ants are awesome. But perhaps most importantly for my work, they occupy almost every trophic level in a community.

So what am I up to? Besides cataloging the ant diversity across Oklahoma, I am working towards understanding the factors that influence stable isotope signatures. Specifically, I will be looking at variation in Nitrogen (N) and Carbon (C) isotopes as these are routinely used to estimate the trophic position and carbon flow of organisms. Together N and C help piece together how energy flows through a food web. However stable isotope studies using ants are presented with a variety of challenges.

The tools of the trade

Tools of the trade when studying fire ants. All this, and a strong immune system. 

One challenge is size. In this case I am not just talking about body size but also colony and potentially population size. Understanding how and at what level size influences the intraspecific variation in isotopic signatures are first steps towards using stable isotopes to definitively map the trophic structuring of ant assemblages. In my mind it is vital to determine if a species’ isotopic signature is due to its diet or an artifact of morphological or behavioral mechanisms. Either way, the answer should be interesting!

Fire ants

After extracting ants from all that soil, Solenopsis invicta shows a range of sizes. 

This summer I am based at the University of Oklahoma Biological Station to work on these questions. And as an added bonus I am working with one of my favorite species, Solenopsis invicta. Having been intimately acquainted with the red imported fire ant for almost three years, I still find myself continually fascinated by their life history. Polymorphic workers, mono- and polygyne queens, unmatched aggressiveness, painful stings, and a behavioral escape mechanism to floods by rafting (and thank goodness given the amount of rain in Oklahoma this summer!). Perhaps it seems fitting that I continue to work in this system, as they appear to be the perfect model organisms to address my surplus of size based questions. Just remember to grab your shovel!

Exploring the role antibiotic compounds play in shaping tropical leaf litter invertebrate & microbial communities

Post by Jane Lucas

This summer (2015) I am working on furthering my exploration of the role antibiotic chemicals play in the structuring of leaf litter invertebrate and microbial communities. This work was inspired by a classic Janzen paper entitled “Why Fruit Rots, Seeds Mold and Meat Spoils” (1977). In this paper Janzen states:

“It is customary to view antibiotic production by microbes as adaptive in their competitive roles with each other… However, nowhere have I been able to locate a discussion of how antibiotics may render food uninteresting to animals”.

It is now my goal to shed light on Janzen’s question and begin to tease apart the complex relationship that occurs between microbial and litter invertebrate communities.

Rot

Rot. https://c1.staticflickr.com/3/2554/4174716675_3d2a30b554_b.jpg

In order to explore how antibiotic compounds shape invertebrate and microbial communities, I will be conducting a series of experiments on Barro Colorado Island in Panama, run by the Smithsonian Tropical Research Institute. In a common garden experiment, I am applying Streptomycin (a naturally derived antibacterial), Sulfonamide (a synthetic antibacterial) or Captan (a synthetic fungicide) to 0.25 meter-squared plots. By looking at both natural and synthetic compounds, I can begin to ask questions about whether there is an evolved history between litter invertebrates and the antibiotic compounds created by microbial communities. Over time, I will sample the invertebrate and microbial communities in these plots to examine how the presence of these various compounds affects community composition. It is my prediction that detritivore abundance should be lower in treated plots due to a markedly different and decreased microbial population.

Janel Lucas in the field

Jane Lucas setting up her field experiment in the litter of Barro Colorado Island, Panama. 

I will also conduct a mesocosm experiment that further tests litter invertebrates’ ability to sense and avoid antibiotic laden environments. By placing litter invertebrates in mesocosms that have half of the chamber treated with antibiotics and the other side untreated, I will be able to test whether certain taxa have developed a preference for one environment over the other. Previous tests have shown that detritivorous diplopods tend to avoid active antibiotic areas, suggesting a potential evolved ability to sense harmful compounds and move away from them. If this observation holds true across a variety of taxa, we may be able to explain part of the puzzle as to why the leaf litter is so patchy.

Lucas Experiment

Mesocosms are ideal venues to explore how invertebrates choose soil with or without antibiotics. 

Finally, I have the pleasure of working with Carolyn Gigot, an undergraduate student at Harvard University and an REU through STRI, on a project exploring how a few focal taxa respond to being raised in antibiotic laden environments. We hypothesize that invertebrates that rely on a healthy gut microbiome may suffer when raised in antibiotically active environments. Carolyn and I will monitor survival and growth rates of diplopods, isopods, oribatids and collembola over time, as well as extract their microbiomes, in order to test how our focal antibiotics influence individuals of a variety of detrivores.

Combined, these projects will shed light on Janzen’s 1977 inquiries, as well as provide important insight into a complex relationship that occurs across a large variety of environments.

Lightning strikes 14 times at a conference session: exploring multi-element limitation at the Association for Tropical Biology and Conservation meetings.

Reported by Mike Kaspari, Kyle Harms, and Jennifer Powers

Meetings are a vital part of the process of science. We meet with colleagues old and new, exchange ideas, schmooze, and testify. At the same time, these conferences are expensive in time, money, and carbon (who doesn’t feel a twinge of guilt when boarding a plane for an overseas meeting, or settling into the seat of an over-air-conditioned conference room?). Still, there isn’t a technology yet that can capture the feel of a lively discussion and reproduce the many random discoveries that arise in the hallways of a scientific congress.

Which doesn’t mean that we can’t be tweaking them a bit. There’s always room for improvement.

So here in Honolulu at the Association for Tropical Biology and Conservation meetings, we held a symposium “Exploring Elemental Limitation of Tropical Biological Processes Across the Entire Periodic Table”. But we decided to model it on the philosophy of Ignite/Lightning talks. The basic structure: 14 ecologists from a range of backgrounds were asked to prepare a 3-slide, 3 minute presentation of an idea or result that intrigued them and was relevant to the topic. After Kyle laid out the ground rules, the audience of 150 or so listened to a variety of points of view: both defenses and critiques of the traditional NP focus, evocations of neglected elements like B and Na, uneasy reports of little to show for multi-year experiments conducted on a shoestring, and confident long lists of findings in a 15-year experiment. The talks may have varied in their ultimate fit to the topic, but they certainly front-loaded the many facets of nutrient limitation in the minds of the audience. Jennifer diplomatically kept everybody to his or her 3 minutes. 50 minutes elapsed quickly.

Kyle called for a brief break to stretch our legs and partake in cheesy snack chips that rhyme with Bonitos . This was blatant bribery of participants and audience alike, and was amazingly effective.

Then I (Mike) moderated an hour’s give and take. For Jennifer and Kyle, and certainly for me, it seemed to start a little slowly (in retrospect, what discussion among people in a lecture hall doesn’t)? Silvia Alvarez-Clare’s presentation prompted early stab at a discussion catalyst: “What determines how long you wait for a fertilization experiment to show a response? That is, when do you give up?” The immediate reply from an audience member was “After your 3 year NSF grant is up”. Turns out, there’s nothing like a jaded riposte about grant funding to break the ice and warm up the crowd. All too soon, the hour was over.

Here are some nuggets that emerged from the discussion.

  1. It’s awfully obvious, but must be said, the answer to “What are the mechanics of nutrient limitation?” depends on the question.

Although there was a great diversity of interest in the audience (and among the organizers) the modal participant seemed to be an ecosystem ecologist with a big interest in the response of trees to plots that have been fertilized. This was best reflected by Joe Wright’s workmanlike summary of the results from the flagship fertilization plots on Gigante. However, when the synthesis question was posed “Well then, what have we learned about the role of nutrients on carbon sequestration in tropical forests?” (this for the benefit of global change modellers in the audience) you could hear the crickets. A definite uncomfortable silence. Which leads to…

  1. In a tropical forest ecosystem, decomposition is dominated by organisms about 20 o.m. smaller than the trees that are scrubbing CO2 out of the atmosphere. This has consequences for what responds to fertilization and when.

The number of bacteria in a few square meters of forest soil is on par with the number of trees in the Amazon basin. The generation times of the collembolans and oribatids in that soil can be measured in weeks and months. Not surprisingly, folks who work on microbial ecology and soil invertebrates—the brown food web—report rapid, repeatable responses to fertilization. We are talking hours, days, and weeks to see a bump in decomposition or oribatid densities. Moreover, over the course of months and years, these communities rearrange (and seem to continue to be rearranging) themselves. [And there is much more to do: imagine Lensky type experiments where chronosequences of soil communities are archived and revived over the course of a 10-year experiment]. So, large-scale fertilization plots continue to be enormously useful tools for studying the community and macro-ecology of soil bacteria, fungi, and invertebrates. Put another way, these plots have allowed us to study both direct effects of fertilization at the outset (i.e, a pulse experiment) and cascading indirect effects as the fertilizer application continues over time (i.e., a press experiment). In contrast, these same fertilization experiments, to the trees of a mature forest, even after 5 or 10 years, may reflect only the beginning of a pulse experiment. Which begs the question…

  1. So how do tree ecologists maximize the utility of fertilization experiments?

A number of ideas arose. First, exploit the considerable forestry literature for clues as to what nutrient mixes are most effective and the time scales of responses. Second, focus on the short-term plasticity. For example, we know that N, P, and K additions are relatively quickly reflected in leaf tissue (though the consequences of that reallocation are still unclear). Third, identify tree species a priori that should benefit from N, P, or some other nutrient, and experimentally explore nutrient niches of co-occurring populations. The last, and most intriguing idea to come out of this part of our discussion was to look at reproductive consequences. For example, does all that extra phosphorus and nitrogen wind up in the endosperm of seeds? This would have obvious consequences for seedling growth rates and hence the demography of the forest. An animal physiologist in the audience (who was obviously slumming it) prompted this avenue of inquiry when she brought up the notion of how early exposure to nutrients may, through developmental switches, have long-term consequences for the phenotype. But, of course…

  1. Fertilization plots are only one way to test hypotheses of nutrient limitation.

Chronosequences, geograpical gradients in biogeochemistry, and greenhouse experiments are all building the case for the role of nutrients in regulating the life history, community composition, and ecosystem fluxes in tropical forests. A mix of those data may ultimately be the most useful tool for studying the collective responses of trees to biogeochemistry. If so, the tree ecologists who started these plots were doing a mitzvah for those of us who study the small things. We owe them beer. And co-authorships.

  1. Stoichiometry varies at every organizational scale, and reflects, potentially, the demand side of the nutrient regulation equation.

Greg Asner showed how both growth form and taxon membership leaves a clear signal in the multi-element stoichiometry. Yadvinder Malhi suggests the canopy drives a plant’s stoichiometric signature.In a similar vein, Emma Sayer stressed that the diversity of resource use at every scale should cause us to question even the concept of nutrient limitation at the ecosystem scale. The symposium identified one clear hole in our knowledge: datasets that simultaneously map biogeochemical availability and elemental use at the individual, population, and functional level.

  1. It’s sometimes difficult to see the forest ecosystem for all the trees.

Given the modal audience member (see above), it was at times hard to conceive of a tropical forest as little more than large autotrophs embedded in a mineral matrix populated by critters whose job it was to turn detritus into plant food. But not always. Joe Yavitt made a case that nutrients can shape the way soil aggregates form. These aggregates, in turn, shape hydrology and represent the physical structure of the microbial world. Kyle Harms was a particularly strong advocate for exploring higher trophic levels and interactions based on the very cool work of Adriana Bravo. Bravo has shown that figs—packages of bat food that are bribes for the dispersal of fig seeds—often do not concentrate enough sodium, such that strict frugivorous bats need to seek sodium elsewhere. Kyle asked, how often is sodium used by plants, who don’t much need it metabolically, as a lure for the plant’s pollinator and disperser associates? Likewise, Nina Wurzburger and Sasha Reed showed why nitrogen fixation—with its dependence on Fe, Mo, and S (and lots and lots of carbon) is the poster process for multi-element limitation. One came away impressed with the huge opportunity to build nutrient limitation—from the structure of enzyme systems through the nutritional ecology of bacteria, fungi, and animals—into food webs and nutrient cycling.

  1. There’s more to life than N and P.

A number of participants, including Rebecca Ostertag and Ben Turner, argued why N and P co-limitation will remain focal points of ecology. Erika Marín-Spiotta shared patterns of key enzyme activity for N and P-cycling that varied by precipitation-season and habitat. One point of the symposium, however, was to explore the ecological implications of the 25 elements required for life. Lots of neat stuff here. Katie Heineman made the case for a sharper focus on calcium (where up to 50% in a tree may be sequestered in bark); Kyle argued for sodium; Brian Steidinger made the case for boron (and, more generally, metals like boron and selenium that yield a hump-shaped relationship between concentration and performance). Jennifer Powers combined the results from decomposition studies in the lab and nutrient use studies in the field to make a strong case for multi-element limitation as pervasive across tree species.

  1. And finally, the way ahead.

Two members of the organizing committee spent a good portion of their talks arguing for new, and very different, protocols to study multi-element limitation. Jennifer offered one protocol modeled on drug-screening: Step 1–start in the simplest mesocosms with the widest combination of nutrients. Step 2–Keep only the most promising nutrient combinations and test those nutrients in a more realistic mesocosm. Step 3–take the most promising results and test those in a longer duration field experiment. In that way, we should be able to winnow the 25 possible limiting elements, and their combinations/compounds, to something more manageable.

I went holistic, arguing that soil fertility (essentially, the first PCA in any analysis of soil biogeochemistry) can account for nearly 50% of the biogeochemical variation across tropical forest soils. This measure of fertility suggested the promise of “Kitchen Sink Experiments”: a fertilization treatment consisting of all possible nutrients at levels found in the richest soils. KSE’s (pronounced “Kissies” ™) test an alternate null hypothesis of nutrient limitation: not that no nutrient limits, say, decomposition, but that all nutrients, when increased together, produce the maximum result. Imagine a fertilizer based on the richest soils, the highest end of the PCA1 axis, applied from white sands to rich volcanic soils. Could be fun.

So, did it work?

As Kyle, Jennifer, and I debriefed each other, participants, and audience members, we came away feeling pretty good. Sure, there were some awkward silences, and certainly the moderator could use some training in fundamental social skills. But by and large, as the summary above attests, a fair bit of ground was covered in 2 hours. More to the point, the true gauge of success comes when comparing our Incite session to the alternative: eight 15-minute talks, each with from 0 to 5 minutes for questions, each with a rotating audience. Instead, we delivered a smorgasboard of ideas that the audience was able to select among; we identified knowledge gaps; had some good ideas (has anybody looked at how fertilizers influence seed nutrients and performance?) and offered some ways forward. And Kyle came through with the Doritos. Given the many costs of scientific conferences, we think this symposium model–lightening/incite talks followed by moderated discussion–offers more potential to generate new ideas in an efficient and fun way. It should be a basic feature of conferences in the future.

 

Canopy and understory microclimates – how are the ants handling them?

Jelena Bujan

The author, Jelena Bujan, in the canopy of Pseudobombax septenatum, a deciduous tree with smooth green bark. Jelena is completing her third field season on Barro Colorado Island, in Panama. 

In tropical forests, is frequently assumed that canopies are “deserts” in terms of their microclimate conditions when compared to the leaf litter far below. If indeed they are extremely hot and dry then animals living in the canopies must require a special suite of adaptations. But the truth is we don’t know to which extent tropical canopies and understory diverge in their microclimates. Temperature and relative humidity (RH) data measured across BCI’s canopy tower provide air measurements in a close proximity to the canopy. And while these data are incredibly valuable, they don’t capture the microclimates experienced by ants crawling on the canopy’s leaves and branches. Ants, only a couple of millimeters high, experience quite different environmental conditions from those measured by weather stations. To handle high temperature and low humidity they need to adapt. Desiccation resistance arises through a suite of mechanisms which may be variously costly, trading off against other aspects of organismal performance. My study focuses on desiccation resistance and the tradeoffs that ants potentially experience regarding regulation of water loss,  thus tolerating low humidity levels, and their critical thermal maximum (CTmax) – two traits necessary for surviving hot and dry environments. I am testing these ideas this in a community of tropical ants experiencing two microclimates—the tropical canopy and the understory of Barro Colorado Island (BCI).

First I needed to quantify the differences in microclimates of different habitats. This field season I placed data loggers in the canopies of 5 different tree species on BCI. Since I was trying to capture as many microhabitat variations as possible, I placed them above and below the branch, in the epiphytes, in the leaf litter, on lianas etc. To see how temperature and humidity changes in correlation with the surface distance I stacked them up.

stack Untitled

Data logger probes in different canopy microhabitats, and at different heights. Cephalotes atratus is here for scale.

The loggers are recording temperature and relative humidity (RH) every 10 min. After finding the loggers that will tolerate high humidity and deploying them, it turns out they are also interesting monkey toys. But they are also quite durable – so far they all still work (knock on wood).

monkeychewed datalogger

Data logger’s base station after a monkey attack

And yes, we are finding that the canopy is hotter, and more variable in terms of both temperature and RH, but the desert comparison seem to be exaggerated. Still, compared to the tropical litter is saturated with water, I predict that an RH under 60% found regularly in the tropical canopy should still be stressful to its ants. One way to avoid this stress is to be desiccation resistant.

To test ant desiccation resistance, we are first measuring how long ant workers from different habitats can survive in a 0% humidity air. Then, to see to which extent ants are regulating their water loss, we are exposing live and dead workers to 0% humidity, and measured their water loss over the same time interval. I expect to find no difference in water loss between live and dead ants from the understory (that is, understory ants don’t actively regulate water loss), because they do not need to invest in water regulation since they are living in 100% RH. Canopy ants, in turn, should actively regulate water loss. As of the time of this blog entry, I’m finishing the last runs of these experiments, and the data entry awaits….

A little known gem from the tropical ant/soil literature

A few days ago, a good friend wrote to ask what was known about the response of tropical soil invertebrates to drought. My first response was “precious little”, and then I remembered a cool article by Diana Wheeler and Sally Levings. The back story was that Levings did here dissertation work on BCI over a span of time that included a pretty awful El Nino drought. Back then BCI had a far-sighted program of ecological monitoring which included extracting soil litter for invertebrates. Wheeler collaborated with Levings years later to write the attached paper (as of this post, cited 4 times).

Funny, if this was published today, in an era of climate change, it would doubtless have wound up in a more high profile venue than Advances in Myrmecology. It is the curse of our times that understanding how ecosystems respond to highly unusual climate events is gaining traction. I attach Wheeler and Levings (1988) and another fine paper from Levings dissertation work that deserves to be more widely known.  Enjoy.

Wheeler and Levings Drought invertebrates on BCI

Wheeler, Diana E., and Sally C. Levings. “The impact of the 1983 El Nino drought on the litter arthropods of Barra Colorado Island, Panama.” Advances in myrmecology (1988): 309-326.

Levings seasonality arthropods JAE1985

Levings, S. C., and D. M. Windsor. “Litter arthropod populations in a tropical deciduous forest: relationships between years and arthropod groups.” The Journal of Animal Ecology (1985): 61-69.

Brian McGill visits the Kaspari Lab

Weiser, Kaspari, and McGillMacroEcologist extraordinaire Brian McGill visited the lab last week, visited with grad students, and gave two first rate seminars. The first laid out trends for the next 25 years of ecology. The second laid out a compelling framework for a top down theory of community organization. The most inspiring slide (out of many):

Screen Shot 2015-04-05 at 6.31.30 PM

 

 

What controls S?  Check. Climate limits? Check. Global abundance?  Check-a-rooni. Clumping and Traits? Sounds like we’re on the right track.

A splendid time was had by all by a handful of Rosenzweig lab alums.

Pictured Michael Weiser, Mike Kaspari, and Brian McGill.

Congrats to Professor Natalie Clay

Natalie Clay and Walking Stick (13 of 14)

Kaspari Lab alum Natalie Clay will be joining the Biology faculty of Louisiana Tech University this September. Good going Natalie, and Go Bulldogs!