Biodiversity Patterns in Melanesian Coral Reef Fish: New Research with Old Naturalists

Old naturalists are my jam. I dedicated my PhD dissertation to a 19th century botanist who had spent her childhood following Thoreau around the Concord woods. I have a soft spot for research that draws on the work of older ecologists, for data that was handwritten before the advent of ballpoint pens, for 21st century papers based on museum natural history collections. This nostalgia is well-timed: museum collections are increasingly digitized and freely available online, and the Biodiversity Heritage Library is doing the same for scientific literature on biodiversity.

Just as my kind of fieldwork no longer requires taking the steamship to downeast Maine and a buckboard on wild roads between logging communities, my scholarship is not dependent on scouring the library stacks for a particular volume or traveling to the archives of a natural history collection to comb through specimens for just the right sample. In the 21st century it is significantly easier to be an armchair laptop historical ecologist. Easier, but not easy.

“Natural history and collections seem to be a bit of a hard sell when it comes to the ecological literature, which surprised me,” says Dr. Kathryn L. Amatangelo. She and Dr. Joshua Drew just published a PLOS ONE paper using coral reef fish data from museum collections records, peer reviewed literature including fish check lists, and biological inventories. The biodiversity pattern they were attempting to analyze and understand — that reef fish diversity in the Indo-West Pacific decreases along a longitudinal gradient from species-rich Papua New Guinea to species-poor American Samoa — was described in 1906.

Amatangelo laments, “It seems almost passé to look at old collections and think about how and why long-dead historians collected their data. When you try to combine that with statistics and scientific analyses people seem to get a little squirrely.”

Drew and Amatangelo’s paper “Community Assembly of Coral Reef Fishes Along the Melanesian Biodiversity Gradient” applies modern ecological theory and big data statistical tools to observations recorded by David Starr Jordan, a Victorian-era ichthyologist who was both the founding president of Stanford University and a suspect in the possible murder of Jane Stanford. If that legacy is not problematic enough, he was also into eugenics.

Thanks to the efforts of Biodiversity Heritage Library (BHL), we can read Jordan’s 1906 paper “On a Collection of Fishes from Fiji” where he notes the diminishing diversity of fish as you travel across Melanesia. Drew remarks, “historical ecologists are always looking for old species lists, and it was super cool to find that he worked in my study system in Fiji.” Drew describes a Jordan as “an ichthyological hero of mine, a complex and not unproblematic figure”: Jordan’s writing on ichthyological biogeography and community change, his system for organizing ichthyological collections and his service on the US Fish Commission, a precursor of NOAA, provide a foundation for the kind of work that Drew and Amatangelo so beautifully execute here.

In the pursuit of quantitatively describing this biodiversity gradient, Drew and Amatangelo compiled presence/absence records for 396 fish species in five taxa across 7 countries. As Drew describes it, this dataset was created from “a massive literature search from collections-based and peer-review based lists that were then double-checked with FishBase.” They looked for agreement across all three datasets (collections, literature, and FishBase), which gave them more confidence in the data since it was not susceptible to the biases present in only one dataset. Amatangelo is a community ecologist with a plant background, she partnered with Josh Drew through a twitter connection, bringing statistical savvy to these new-to-her taxa and ecosystems. I asked her what it was like to work with unfamiliar study species in this project. “One downside was that things that were intuitive to Josh, such as why some traits are important, was a bit of a mystery to me. That could also be considered a positive, though, because it meant that Josh had to be able to explain WHY they were important, which helped in writing the paper.”

The paper’s ultimate goal was to illuminate the processes behind the reef fish biodiversity pattern to inform conservation efforts. Drew acknowledges that their conclusions are not ground-shattering — the biodiversity gradient was described 110 years ago, and likely broadly known before then in local communities. “But it’s nice to put a p-value on it,” he says. “Natural history and traditional ecological knowledge are not always recognized because they don’t come with a p-value, so here we did that. We probably could have told you the same result before, but this adds weight to the management recommendations.” Those management recommendations include collaborations across Melanesia to more efficiently share resources and partition the region into functional biodiversity groups.

Through the power of twitter, digitization, and online collections two modern ecologists were able to build on a paper from 1906 and study Melanesian coral reef fish diversity from their laptop screens in the United States. So much of this data would be instantly recognizable to Jordan, but so little of the actual process of collaborating, compiling and analyzing data, and writing a paper has remained constant since 1906.

Drew reflects on this revolution in his recent correspondence to Nature Ecology and Evolution: “Digitization of museum collections holds the potential to enhance researcher diversity.” He and coauthors write that “the advent of digitization (open access to images and specimen data) now makes a wealth of biodiversity information broadly available…Digitization allows access to museum holdings to those for whom collections have typically been out of reach.” The concentration of collections in the Global North is a reflection of our discipline’s role in the history of exploration and colonialism. Untangling this broader context of past research is perhaps the most impressive, thoughtful work that a historical ecologist could pursue.

In two papers this fall Drew has managed to both uphold the ichthyological legacy of Jordan, and articulately argue that the museum collections Jordan once organized in his spare time from being abhorrently racist, could be, in digital form, a force for increasing diversity in science. 

References:

Drew, Joshua A., and Kathryn L. Amatangelo. "Community assembly of coral reef fishes along the Melanesian biodiversity gradient." PloS one 12, no. 10 (2017): e0186123.

Drew, Joshua A., Corrie S. Moreau, and Melanie L. J. Stiassny. "Digitization of museum collections holds the potential to enhance researcher diversity." Nature Ecology & Evolution (2017):10.1038/s41559-017-0401-6

A Little Light Reading

As the leaves fall this October and the canopies bare their skeletal limbs, there’s suddenly more light filtering across the riverside trails in Maine and I’m wearing sunglasses on runs where I used to be totally engulfed in the shade. It’s hot toddy season, pumpkin spice season, submit-your-GRFP season. When the weather finally chills we’ll get into ugly sweater season, rush-to-take-family-photos-for-a-holiday-cards season, and grading-endless-finals season. Culturally, we humans divide the year into more than just autumn-winter-spring-fall. A recent PLOS ONE paper makes the case that understory plants probably do this too.

Janice Hudson and her coauthors explored the seasonal dynamics of sunlight in a temperate deciduous forest and the ecology of the common shade-tolerant shrub, spicebush. They were inspired, in part, by a relatively obscure 1977 Ecological Monographs paper* with the unassuming title “The Distribution of Solar Radiation within a Deciduous Forest,” in which the authors, Boyd A. Hutchison and Detlef R. Matt, outline the concept of phenoseasons.  

Get ready to update your calendars — the seven phenoseasons for life under a forest canopy are: winter leafless, spring leafless, spring leafing, summer leafing, summer fully-leafed, autumnal fully-leafed, autumnal partially-leafed. I only wish that Hutchison and Matt had dined with Tolkien. Imagine the invitation: “Let’s meet for second breakfast to celebrate the end of spring leafless.” [Insert ent joke here.] Hudson was interested in how changes in light availability affected understory plants like spicebush. As Hudson explains “broadly, this study was an attempt to better understand the pre-existing conditions of the forest…[are] light conditions...a controlling factor in the distribution and presence of plant species?” The phenoseason construct hasn’t taken off in ecology and the annual cycle of subcanopy light exposure is not well understood. Hudson and her coauthors stumbled on Hutchinson and Matt while working on a literature review, but the idea of phenoseasons — now update-able with a high-tech piece of equipment called line quantum sensors — seemed ecologically intriguing. Hudson’s background is in eco-hydrology and the link between seasonal changes in light and phenology had immediate implications for her. She wanted to know “how understory plants acclimate…[and] plant contributions to nutrient and water cycling during individual phenoseasons, and yet, the literature on the subject of phenoseasons is scant.”

Hudson’s team combined a year of intense field measurements with experimentally manipulated light conditions in growth chambers to explore light intensity through the phenoseasons. At Fair Hill Natural Resource Management Area in Maryland, Hudson and her team carried a light sensor through the forest of American beech and yellow poplar trees to measure light conditions above, within, and under the spicebush canopy, compiling over 4,500 measurements in a year across 26 sites (25 in the forest, one open area just outside the forest for comparison). 

When Hudson talks about light, she talks about photosynthetically active radiation (PAR) and, for this study, subcanopy photosynthetic photon flux density (PPFD), which is a measure of PAR. Unsurprisingly, the highest PPFD values under the beech and poplar canopy occur in spring leafing — the days are growing longer, the northern hemisphere is tilted toward the Sun, the trees are still mostly bare. During summer leafing, the subcanopy PPFD values drop, and continue to decrease into summer and autumnal fully-leafed, before a slight bump for the autumnal partially-leafed phenoseason. In a nod to Hutchison and Matt, Hudson recreates their 1977 figure mapping the contours of PPFD through the year at different canopy levels with her own data. It’s the scientific equivalent of siblings re-staging family photos as adults.

But what does it mean to be a spicebush living in the light environment depicted in these figures? In general, Hudson found that there’s almost 10 times more subcanopy light available during the leafless seasons than the leafing and leafed seasons. During the leafing and leafed seasons there are high-energy sun flecks and hot spots — think of a sun-dappled forest floor — which contribute to the variability of light measurements throughout the phenoseasons. But, mostly the understory species must make proverbial hay (read: Germinate! Flower! Leaf out! Photosynthesize like crazy!) while the sun shines in the short leafing seasons. Even in the leafless seasons, the open site received much more PPFD than the subcanopy: the woody surfaces of the trees were intercepting plenty of winter and early spring light.

The spicebush plants in the field and in the growth chambers grew best under the highest PPFD conditions found in the Maryland woods. This is the light niche. In the growth chambers, plants that received higher PPFD conditions were actually less healthy, produced fewer leaves and less biomass. Hudson wrote a beautiful explanation of this when we emailed and I have to let this paragraph speak for itself:

We know that all organisms have an ecological sweet spot, but very rarely are all conditions ideal. Canopy species are "less limited" in the sense that they may experience some shading by neighbors but are primarily subject to changes in light due to latitude, season, and sky conditions. This "light intensity niche" is especially important for shade-adapted and shade-loving plant species when you consider spectral filtration (one way that plants "communicate" with each other and adapt growth direction and strategy) and temporal sequences of incident radiation at both long and short time scales (the timing and amount of light availability is crucial for physiological and biochemical processes for these species). It puts a sort of "ceiling" on the amount of light that is useful for the understory plant, whereas for canopy species there really isn't such a thing as too much light – their growth is primarily limited by the lower boundaries of light availability.

 Finally, this study’s implications for climate change research are quite interesting. In the decades while the ‘phenoseasons’ concept was languishing, research in phenology has taken off: the timing of seasonal events like leaf out and flowering are almost universally creeping earlier in response to warming temperatures. This advancing spring phenology has been definitively tracked in temperate deciduous forests like Hudson’s study site. As the climate changes, leafing phenoseasons may bite into the leafless phenoseasons. The density of the canopy may change as the species composition, size, and height of canopy trees changes. As Hudson wrote, these are the pre-existing conditions in the forest from the perspective of an understory species. We often think about species migrations and no-analog communities when we talk about the ecological effects of climate change: now I think I’ll imagine the reshuffling of the pre-existing conditions, and the interactions between biotic and abiotic factors that create the “ecological sweet spots” that we study. And now, as we enter the autumn leafless, I’ll soak up the sun on my unseasonably warm October runs. 

*This paper’s obscurity is not helped by the fact that the google scholar pdf link takes you to a 627-page annual report hot off the mimeograph with old-timey typer-writer kerning; Hutchison and Matt’s paper is buried in this report (just scroll to page 327), though much easier to find via JSTOR.

Flying Foxes and Lilford’s Wall Lizards: At Your (Seed Dispersal) Service

I'm Dr. Caitlin McDonough MacKenzie, a new PLOS Ecology Community Editor. Last summer I was a PLOS Ecology Reporting Fellow at the 2016 Ecological Society of America meeting and I'm excited to join the team year-round! My first post as a Community Editor has me reflecting on my field site in the "off season", #poopscience, and the under-appreciated role of seed dispersers in ecology and conservation. Two papers dig into the seed dispersal services provided by charismatic megafauna in island ecosystems, and in both cases it's not much of an exaggeration to say: 'Save the Seed Disperser, Save the World.' 

I study plant phenology, specifically leaf out and flowering, on an island in Maine. I leave my field site just as flowers are senescing and unripe fruits are developing, and return again in early spring to catch the last patches of snow before the first green shoots emerge. I hardly ever think about what my plants are doing from July through April, but of course the ecological processes in these months — fruiting, seed dispersal, germination — underlie a fundamental assumption of my fieldwork: that there will be new plants each year when I return. I depart Maine and the seeds are just developing in green fruits, I arrive and new green stems are popping out of the soil, but in between seed dispersal was quietly a crucial, and perhaps overlooked, part of this circle of life. 

Two recentpapers in PLOS One highlight the seed dispersal services of charismatic megafauna in different study systems with implications for island conservation and habitat restoration. Both studies focused on the relationship between an animal seed disperser and a plant that prefers to grow in open, sunny environments. In Sa Dragonera Natural Park, on an islet in the Mediterranean off the coast of Mallorca, Dr. Constanza Neghme and her coauthors studied Ephedra fragilis, an evergreen shrub that produces pseudo-flowers and pseudo cones. E. fragilis is an early successional shrub, colonizing new areas and establishing in open ground without a “nurse” (for example, another plant) to provide shade and minimize water loss. So, E. fragilis seeds need to get to these open areas, away from the shade of their parents. In fact, seeds that were not dispersed, and landed below the parent plant, did not survive in Neghme’s study.

Dr. Ryszard Oleksy and collaborators worked in three forests in varying states of fragmentation and degradation across Madagascar, with a focus on fig trees: Ficus polita, F. grevei and F. lutea. These are all pioneer species, able to survive in degraded areas, and as their root systems penetrate hard substrates, they can improve aeration and drainage of the soil, facilitating the establishment of other plants. Fruiting fig trees depend on frugivores (fruit-eating animals) for seed dispersal, but rapid deforestation in Madagascar has decimated native wildlife populations, dramatically reducing animal-mediated seed dispersal. Dr. Neghme’s E. fragilis and Dr. Oleksy Ficus have particularly charismatic seed dispersers: wall lizards and flying foxes. The Lilford’s wall lizards (Podarcis lilfordi) are “superabundant” on Dragonera islet; they are endemic to the Balearic islands, but now extinct on nearby Mallorca and Menorca. Neghme reports that they are the only known seed dispersers of E. fragilis on the islet. In Oleksy’s research, the Madagascan flying fox (Pteropus rufus) is studied as a potential long-distance fig seed disperser. Madagascan flying foxes are the largest bat species on Madagascar. These frugivores crush fruit in their mouths to devour the fruit juice and soft parts (often including seeds), then spit out the fibrous fruit coating, not unlike my two-year-old eating blackberries. I’m sure she would love to eat figs with flying foxes if given the chance.

Both of these studies depend heavily on #poopscience. The #poopscience hashtag is popular among a certain segment of ecologists on twitter, and though the authors were unfamiliar with this term when I contacted them, they were universally enthusiastic to talk about their experiences in #poopscience. Neghme told me: “ My first time with poop science was when I was doing my bachelor thesis with lizard in high mountain ecosystems, I was helping a post doc and he encourage me to do questions by my own, then I saw the lizard poops carrying seed, and after reading an article from lizards as pollinators and seed dispersers in island ecosystems I started the journey in to poop.” Dr. Gareth Jones, the corresponding author on Oleksy’s paper, said that he’s “been into #poopscience for ages, initially using microscopic analyses to analyse prey of insectivorous bats, more recently using DNA barcoding to identify insects in poop to species level.”

To know what a seed disperser is eating, and to test the germination success of what Oleksy euphemistically calls “bat-processed seeds”, scientists collect and pick through lizard and bat faeces. Both studies planted “undispersed” (read: collected from parent plant) and dispersed (read: found in poop) seeds and tracked seedling emergence and seedling survival in a range of microhabitats. For both E. fragilis and the Ficus species, the “processed” seeds won. Lizard-dispersed and bat-dispersed seeds were much more likely to germinate, emerge, and survive as seedlings than the undispersed (non-faecal) seeds. Logically, the next question is where are the lizards and bats taking these seeds? We know you proverbially should not poop where you eat, but how far apart are the eating and pooping places of these lizards and bats? Neghme estimated how much time the lizards spent in different microhabitats on the islet, assuming that the proportion of time spent in each place would determine the probability of seed dispersal to those microhabitats. She and her colleagues walked transects and recorded if the lizards they spotted were in open areas, under Ephedra, or under other plants. The lizards spent most of their time in open habitats, and, unsurprisingly, this is where Neghme found the most lizard poop.

In Madagascar, 11 bats were outfitted with GPS devices, which tracked their movements overnight. These GPS tracks were combined with information about the bats’ gut retention time from a captive bat experiment. Basically, captured bats were fed a known quantity of fig seeds on banana slices and then researchers recorded the length of time between feeding and pooping, while counting the fig seeds present in each pooping event. (Ecology research can be especially glamorous.) Oleksy’s team then modeled the “seed shadow” of the bats’ flights — which is a nice way of saying they created a map showing where the bats were most likely to have pooped on the landscape. These “probable poop maps” confirm that Madagascan flying foxes are important long distance seed dispersers, and they frequently disperse seeds in degraded habitats as they fly between forest fragments. I love that both Neghme and Oleksy created sophisticated stochastic models of seed dispersal, and then ground-truthed them by walking through their field sites* and saying, “Yes. This is where the poop is.”

The ecosystem services provided by the E. fragilis shrubs on Dragonera and the Ficus fig trees on Madagascar are so important to habitat restoration and conservation. These early-successional species colonize open and degraded areas, and facilitate the growth and success of other, less-hardy plant species. But without their seed dispersers, they cannot access these open habitats and their seeds languish in the shade of parent plants. The Madagascan flying fox is listed as ‘Vulnerable’ in the IUCN Red List; Lilford’s wall lizard is ‘Endangered’. These seed-dispersing animals can act as super-conservationists: naturally maintaining and regenerating habitat through their poop. Neghme explained to me that the lizards are threatened by introduced predators and habitat loss, both “usual[ly] happen in island ecosystems to build tourist resorts.” In Madagascar flying foxes are legally hunted, and Oleksy notes that the “best protection would be to ensure that no one is allowed to hunt between August and December. Also no hunting at the roosting trees…Education would be a key to ensure local communit[ies] understand the role and importan[ce] of the bats.” The parallels between the lizards and the bats, the open-grown shrubs on Dragonera and pioneering fig trees in degraded Madagascan forests, run through these papers from study design to conservation implications. These strong relationships between plants and their animal seed dispersers highlight the importance of conserving species interactions for biodiversity maintenance and ecosystem functioning. Or as twitter might say: #poopscience can inform conservation! 

References:

Neghme C, Santamar ́ıa L, Calviño-Cancela M (2017) Strong dependence of a pioneer shrub on seed dispersal services provided by an endemic endangered lizard in a Mediterranean island ecosystem. PLoS ONE 12(8): e0183072. https:// doi.org/10.1371/journal.pone.0183072

Oleksy R, Giuggioli L, McKetterick TJ, Racey PA, Jones G (2017) Flying foxes create extensive seed shadows and enhance germination success of pioneer plant species in deforested Madagascan landscapes. PLoS ONE 12(9): e0184023. https://doi.org/10.1371/journal. pone.0184023 

*Note that ground truthing was limited by violence in Oleksy’s study. He explains: “at the time of the study south of Madagascar was at war with local rebels. I was based at Berenty Reserve which was rather safe, however due to the war we were not allowed to leave the reserve. We would still capture bats beyond its boundaries accompanied by a guard and ground truth in nearby areas. However, the more distant places to which bats flew were too dangerous to visit…Fortunately, we got enough data to analyse the GPS.” 

Science Communication, Simple Words, and Story Telling at ESA 2016

A guest post from PLOS Ecology Reporting Fellow, Caitlin McDonough, on research from the Ecological Society of America Scientific Meeting in Ft. Lauderdale, Florida, August 7-11, 2016.

On Tuesday afternoon at the Ecological Society of America 2016 Conference in Ft. Lauderdale, FL, amid the many Latin species names and varied sub-discipline jargon, it was possible to stumble upon a session of talks about blue flyers, spring pretty flowers, God’s creatures, and animals with six legs and no bone in their back. The audience fell in love with black back wood hitters, cheered for flying friends with six legs and four wings that like sweet things and help plants with sex and was touched by the sentiment that the land had memory made up of things in the dirtand much of the memory was lost. 

This was the Up Goer Five Ignite Session, where seven brave scientists took on the challenge made famous by xkcd comic author Randall Munroe and his Thing Explainer book and presented their research using only the 1,000 most common words in the English language, originating from Munroe’s eponymous example. In the ESA session, the phylogeny of grassland plants was reduced to grasses, grasssish, smells fresh, sun flowers, fixers, and roses and climate change was described as the whole earth surface is getting more and more hot. The presenters approached their talks with a high level of creativity and humor, and the audience responded with enthusiasm, empathy, and #UpGoESA tweets.

Rebecca Barak opened the session with a high-energy summary of grassland restoration research. Her talk featured the poetic land memory line and the hilariously simplified grass phylogeny, as well as the explanation that one piece of equipment used to study seeds was the special machine that doctors use to look inside of you.

Nick Haddad asked Can I light a fire to save those damn butter flies? With surprising dexterity he wove the story of Icarus and Daedalus into his research on fire adaptation and complex species interactions. Here, we noticed how difficult it is to mark temporal change and population dynamics of a butterfly species with only the 1,000 most common words: over five tens of years the numbers of these plants have gone down to zero. The stark phrasing that people may need to kill these animals to save them was very powerful in this pared down vocabulary.

Margaret Lowman may have smuggled in a few extra words, but her talk about working with priests in Ethiopia to save sacred forests (birds eye view of trees: in the center is a round house called a church) was a refreshing reminder that there are whole communities that ecologists traditionally neglect to engage with, and these have the potential to be fruitful partnerships.

David Inouye shared research from his field site (or where he spends his time playing while not teaching) and explained phenology models by asking the audience Can we guess when that will happen? His talk featured the memorably phrased description of his Colorado field site location as the place where people over 21 can buy grass to get high. Samuel Cowell regaled us with tales of the nesting behavior of blue flyers — their propensity for stealing some wood hitter homes, but also their territorial protection of other wood hitter homes, ultimately summarizing their complex interactions as blue flyers are bad and good to the wood hitters.

Jeff Atkins’s visuals — drawings commissioned from his and his colleagues’ children — strongly resonated with the audience. Pairing crayons and construction paper with the big green stuff and the small green stuff, in the mountains and the not so flat ground was a brilliant take on the simplified vocabulary.

Finally, Elizabeth Waring closed the session with her comparison of Old Green Things and New Green Things. The crowd loved her terms for nitrogen deposition (extra ground food to make green things for humans grow harder faster stronger) and greenhouse experiments (grown in a hot box, I changed how hot the grass got).

Science communication, language, and accessibility were at the center of the post-presentations discussion. Across all of the talks, the most memorable and successful Up Goer Five phrases didn’t just substitute simple words for scientific jargon, they were emotional and evocative compositions. Distilling one’s science into the 1,000 most common words was described as an opportunity to influence the connotation of common (but not top 1,000 words common) phrases with thoughtful word choice. The direct vocabulary has a sharp impact. As one audience member noted, this was not just an exercise in how good are you at using a thesaurus — the speakers found ways to be poetic, expressive, and clear.

Restricting word choice to the 1000 most common words highlights how few of our common words are ecological terms. In a way, this highlights the difficulty of science communication with the general public: our vocabularies do not always intersect. Meg Lowman wondered aloud if we could add 125 of “our words” back to the common vernacular. The loss of nature words from the Oxford Children’s Dictionary and our vocabulary in general has been noted. Is this a crusade for ecologists? What are the 125 words that we most miss? And what can we do to reintroduce these into words so that the next generation of Up Goer Five ecologists has the ability to say “trees”? 

Great story telling was not limited to the Up Goer Five session. At the Wednesday night Special Session “Engaging with the Wider World True Tales Told Live” four ecologists were given the whole range of the English language to speak to their experiences in diverse forms of engagement. During his tale Matthew Williamson confessed to fellow story-teller and ESA President Monica Turner that years ago, in a punk rock phase, he had joined her field team as kid with a Mohawk and a bad attitude. The narratives tracked births, deaths, career changes, and community building; they reflected on intersections of creativity, courage and advocacy. There were funny moments — Monica Turner admitted “I am not Stephen Colbert!” — and deeply poignant personal stories. In beautifully crafted prose, Annaliese Hettinger described the joy, isolation, and exhaustion she found in finishing her Ph.D. within a year of the birth of her son, while caring for her dying mother who, decades before, had defended her own Ph.D. when Annaliese was an infant. There was a real sense of craving in the audience as we watched these ecologists talking about science communication. We want more examples of successful science communication, and more opportunities to practice these skills ourselves. These opportunities are at ESA; among our ranks are excellent science communicators, our meetings feature multiple workshops focused on diverse engagement opportunities, and the Up Goer Five audience passionately embraced the idea of an annual Ignite Session. Hopefully this is an areas where we can continue to build and grow. 

Caitlin McDonough MacKenzie is a PhD candidate in the Primack Lab in the Biology Department at Boston University. She spends her field seasons in Acadia National Park, Maine studying leaf out and flowering phenology and patterns of historical species loss across plant communities. Her field methods include three ridge transects that are conveniently located adjacent to beautiful running trails and carriage roads. Away from Acadia’s granite ridges, she’s interested in underutilized sources of historical ecology data including herbarium specimens, field notebooks, photographs, and old floras; the potential for citizen science in phenology research; and the intersection of science and policy.  (Follow Caitlin on Twitter @CaitlinInMaine)

Common Gardens For All Your Climate Change Needs

A guest post from PLOS Ecology Reporting Fellows, Caitlin McDonough MacKenzie & Daniel E. Winkler, on research from the Ecological Society of America Scientific Meeting in Ft. Lauderdale, Florida, August 7-11, 2016. 

Experimental gardens are an old-school methodology. In perhaps the best known example in the 1930s and 1940s Clausen, Keck, and Hiesey transplanted Potentilla glandulosa across their range in the Sierras to explore the roles of environment and genetics played in determining growth form. Clausen, Keck, and Hiesey’s classic methodology of reciprocal transplanting has a contemporary application in climate change studies, whereby researchers relocate a plant (or seed) from its home and current climate to a transplant garden and new (and perhaps future) climate. Seven decades later, the Ecological Society of America’s 2016 Annual Meeting features experimental gardens that include species ranging from alpine forbs to douglas fir trees to a dune-loving annual—collected along latitudinal, elevation, and habitat gradients. 

Nicole Rafferty opened the Climate Change: Ranges & Phenology I session presenting her research on patterns of bumblebee visitation at the Rocky Mountain Biological Laboratory. As a part of this project, she installed a reciprocal transplant experiment with seeds from three elevations planted at 12 plots per elevation site. She wanted to test how alpine plant-pollinator relationships might change as plant communities experience new microclimates (for example, if a species is transplanted to a warmer site at a lower elevation). Unfortunately, the first year of this study coincided with a dry summer and low germination rates — as a result, in 2016 she switched to seedlings. In her 2015 seed study, the glacier lily seeds from mid-elevation had the lowest success in the transplants, suggesting that mid-elevation might be a barrier to plant migrations upslope for this species.  

Range shifts and phenological are also on the minds of researchers at the U.S. Forest Service. This time with an applied focus aimed at aiding land managers who will likely need to develop strategies to make Forest Service lands more resilient to climate change impacts. Sheel Bansal at the U.S. Forest Service’s Pacific Northwest Research Station and colleagues carried out a large-scale common garden study aptly named the Douglas-fire Seed-Source Movement trial. Their experiment used seeds from 60 sources throughout the species range in Washington, Oregon, and California and grew trees from each of the sources in 9 climatically-divergent field sites and also used artificial freeze experiments to test the impacts of changing environmental queues on Douglas fir cold hardiness and associated genetic linkages. They found strong differences in cold hardiness, with minimum winter temperatures and fall frosts as major predictors of cold hardiness based on seed source. Their results have important implications for the ability of species to shift their ranges by tracking climate envelopes, and further extend to land management efforts to maintain healthy forests experiencing future climates.

In the Great Lakes region, Elizabeth LaRue from the Emery Lab at the University of Colorado Boulder used a common garden to explore dispersal traits in American sea rocket (Cakile edentula var. lacustris). She knew that dispersal traits like pericarp, or seed wall, thickness and wet mass varied across the Cakile edentula range, but it was unclear if the variability was caused by environmental or genetic differences. Collecting seeds from across the range, and growing them together in a common garden isolated the role of genetic differences and revealed lower dispersal traits at the range edges. This data was used to inform species distribution models with different scenarios for starting dispersal genetics for Cakile edentula under climate change.

Kennedy Rubert-Nason in the Department of Entomology at the University of Wisconsin-Madison and his colleagues looked at the role of vernal freezes in determining aspen phenology and growth. They planted 6 aspen genotypes into common gardens at varying temperatures and examined a number of biological responses.  The number of days it took aspen to break bud accelerated in trees that experienced freeze-damage. Freeze-damaged trees were also stunted in their second year of growth when they experienced a freeze event during their first year. Defense compounds were also dramatically impacted, potentially indicating the negative effects of freeze events and the associated ability of the trees to defend against herbivores during their most vulnerable life stage. Their study nicely highlights the importance of the timing of environmental queues in dictating species susceptibility to a changing climate. 

Caitlin McDonough MacKenzie is a PhD candidate in the Primack Lab in the Biology Department at Boston University. She spends her field seasons in Acadia National Park, Maine studying leaf out and flowering phenology and patterns of historical species loss across plant communities. Her field methods include three ridge transects that are conveniently located adjacent to beautiful running trails and carriage roads. Away from Acadia’s granite ridges, she’s interested in underutilized sources of historical ecology data including herbarium specimens, field notebooks, photographs, and old floras; the potential for citizen science in phenology research; and the intersection of science and policy.  (Follow Caitlin on Twitter @CaitlinInMaine) 

Daniel Winkler is a PhD candidate at the University of California, Irvine and a recent National Park Service Young Leader in Climate Change. Daniel is a plant ecophysiologist interested in invasive species, evolutionary ecology, and climate change impacts on native communities in “extreme” environments. His field sites include much of the desert southwest, alpine regions of Colorado, the subalpine forests of Baja California, and the tundra of northern Japan. All of Daniel’s research focuses on climate change impacts on native systems, with an emphasis on parks and protected areas. You can follow him on Twitter @DanielEWinkler, his research on Facebook at www.facebook.com/GeoMustard/, or find more information on his website at www.winklerde.com.