Best New Papers

Summer Reading (Part 1)

We’re rushing out of the dog days of summer and into the start of a new semester — or in my case the start of parental leave, which is a little bit like embarking on a new semester at an unknown campus and while I completed the newborn syllabus three years ago, I have this sinking feeling that I don’t even know which classes I’m enrolled in yet. Regardless, I’m reflecting on my summer reading.

Over June, July, and August, I was all in on #365papers and I have a top ten list of scientific papers from these long summer days of slow reading. Because my “semester” might start at any moment, I’m breaking this post into two parts. First up: my favorite hot-off-the-press summer reads on mountains and phenology.

On Mountains

Think globally & way into the past…

1. Iglesias, V., Whitlock, C., Krause, T.R., Baker, R.G., 2018. Past vegetation dynamics in the Yellowstone region highlight the vulnerability of mountain systems to climate change. Journal of Biogeography 45, 1768–1780. doi:10.1111/jbi.13364

Fifteen pollen records covering 16,000 years and the 80,000 km2 mountainous Greater Yellowstone Ecosystem create an incredible review of elevational patterns of vegetation change in an iconic mountainous region. In this paper, Dr. Virginia Iglesias lays out the challenges of quanitifying pollen-vegetation relationships in mountain regions (aka what I didn’t know when I proposed my postdoc research) and then pulls in a staggering amount of modern and fossil pollen data to recreate the history of Yellowstone’s dominant conifers. These are stories of both stability and rapid change through past climatic changes with conservation implications for managers facing anthropogenic climate change. My favorite line: “The current vegetation distribution is, at best, a short and rather anomalous baseline for evaluating ecological responses to future climate change.” 

2. Elsen, P.R., Monahan, W.B., Merenlender, A.M., 2018. Global patterns of protection of elevational gradients in mountain ranges. PNAS 115, 6004–6009. doi:10.1073/pnas.1720141115

This study has it all: mountain biodiversity love, protected area planning, big data analysis, and beautifully designed maps of “elevational protection” across the globe. Full disclosure: Dr. Paul Elsen is a fellow Smith Fellow and I also got to see this paper as a speed talk at the North American Congress for Conservation Biology in July. The bottom line is this: when you zoom out, most of the world’s mountain ranges are narrowly protected — we need conservation across elevation gradients to effectively protect species under climate change. 

On Phenology 

Wherever you get your phenology data (maybe from TV?) scientists are asking some really interesting questions about community composition, temporal dynamics, and the implications of climate change on interspecific relationships…

3. Carter, S.K., Saenz, D., Rudolf, V.H.W., 2018. Shifts in phenological distributions reshape interaction potential in natural communities. Ecology Letters 30, 133–9. doi:10.1111/ele.13081

Amphibian breeding phenology is not the kind of phenology that I study — I don’t install recorders at ponds to capture EPs of overnight breeding calls, I don’t log hours listening to the audio to identify twelve different amphibian species and record the number of individuals per species calling during each recording session, and I certainly have not done this tirelessly for fifteen years. But I’m so glad that Dr. Shannon Carter and her colleagues did because their ingenuous analysis of changes in the timing of calling between pairs of amphibian species has huge implications for how we — plant phenology people included! — study phenological mismatch. The overlap (or "phenological distributions") of amphibian breeding calls has shifted in weird and non-uniform ways, and metrics like ‘first day of calling’ or ‘median call date’ don’t capture these changes well. This is just a great analysis of a grinder ball dataset (8 ponds in Northeast Texas, monitored consistently over 15 years) which opens up a window to these big questions — How do we monitor phenology? What information do we need to know that temporal mismatch is occurring?

4. De Frenne, P., Van Langenhove, L., Van Driessche, A., Bertrand, C., Verheyen, K., Vangansbeke, P., 2018. Using archived television video footage to quantify phenology responses to climate change. Methods Ecol Evol 149, 1791–9. doi:10.1111/2041-210X.13024

Dr. Pieter De Frenne and his coauthors have received tons of press coverage (best sub-headline: "ignore the lycra—look at the flowers") for this incredibly photogenic work. They basically watched 200 hours of TV (old coverage of the Tour of Flanders), justified this as “research” by grabbing screen shots of 46 shrubs and trees from along the cycling course, and found surprisingly strong advances in the timing of spring leaf out and flowering in these plants over the years. This is, on one level, the opposite of Carter et al listening to frog calls for fifteen years — the phenology monitoring here is opportunistic and there is only a single metric each year (what was happening on the day they filmed the Tour). But as De Frenne points out at the end of the paper: “Probably the most promising way forward for phenology research is to better integrate all types of phenology data…observational time series, experimental manipulations of climate, herbarium records, historical surveys of vegetation, historical maps, repeat photographs and other, yet unexploited, sources such as television video footage from broadcast archives.” 

5. Winkler, D.E., Butz, R.J., Germino, M.J., Reinhardt, K., Kueppers, L.M., 2018. Snowmelt Timing Regulates Community Composition, Phenology, and Physiological Performance of Alpine Plants. Front. Plant Sci. 9, 631–13. doi:10.3389/fpls.2018.01140 

Dr. Daniel Winkler, PLoS ESA Reporting Fellow 2016, tweeted out his new paper in July and he had me at “community composition, phenology, and physiological performance of alpine plants.” My “alpine-ish” communities include true alpine on Katahdin, but also Cadillac Mountain in Acadia, which is a whopping 1,530’ and more accurately described as ‘Northern Appalachian-Acadian Rocky Heath Outcrop’ by NatureServe. I’m definitely interested in the differences between alpine-restricted species and wide-ranging species. Winkler’s team recorded species diversity, flowering phenology, and physiological measurements including gas exchange, net CO2 assimilation, and stomatal conductance across plots along an elevation and aspect gradient in the Colorado Rockies. Two results jumped out at me: the alpine-specialists displayed less flexible flowering phenologies than the wide-ranging species, but there were not strong differences between these groups in physiology. This is the kind of paper that inspires mad grant writing — I'm interested but skeptical, will this hold up in my pet region/ecosystem/study system? I want to replicate this kind of research in the Northeast — and across a gradient of sites where phenology is tied to snowmelt (true alpine areas of Katahdin and the Presidential range), and where the two are (I think) decoupled (Cadillac Mountain). Winkler and I wrote a blog post together in 2016, I think I can convince him to collaborate on a larger scale — and get him to New England! 

Bonus “Reads”

Recent podcast episodes tangentially related to recent blogging