National Parks are Hot Spots

In this space, I’ve often shared my love for National Park-based research. I count myself among the researchers devoting time and energy to documenting how climate change affects the ecosystems and natural resources in U.S. National Parks; we study everything from pikas to forests, Joshua trees to birds. But, the underlying rate of warming in these National Parks was not on my radar and I had not given much thought to the climate exposure of National Parks versus the rest of the United States. It turns out, the parks are literal hotspots on the landscape.

Last fall, Dr. Patrick Gonzalez and coauthors from the University of Wisconsin published ‘Disproportionate magnitude of climate change in United States national parks’ in Environmental Research Letters. This study looked at historical and projected temperature and precipitation across all 417 U.S. National Parks. Between 1895 and 2010, mean annual temperature of the national park area increased at double the U.S. rate — parks warmed by 1.0°C (±0.2°C) per century, the rest of the U.S. land area by 0.5 °C.Dr. Gonzalez is a forest ecologist and Associate Adjunct Professor at the University of California, Berkeley. He is also the Principal Climate Change Scientist of the U.S. National Park Service, but he answered my questions here under his Berkeley affiliation, not for the Park Service.

I asked why he wanted to study a spatial analysis of historical and projected climate across all 417 US National Parks. What was the motivation for expanding on the earlier work of researchers who presented similar findings for the 289 large parks in the National Park System system?

“Up until our research, the severity of climate change across all the US national parks was unknown.” Gonzalez writes. “The previous work had only looked at subsets of parks. I work at a national level and it is important for me to give national policy-makers scientific information that is robust and comprehensive. The time-consuming parts of the work were the individual analyses by park and the computational tasks of downscaling all available general circulation model output of future climate projections to 800 m spatial resolution, which had not previously been accomplished for the U.S.”

In addition to the climate exposure of National Parks, Gonzalez and his team considered climate velocities. Climate velocity is the speed at which a plant or animal will need to move, migrate, or disperse — usually north or upslope — to “catch up” to their climate as it changes. Gonzalez found an interesting paradox in climate velocities: the park lands have experienced extreme temperature and precipitation shifts, but they also show lower climate velocity than the U.S. as a whole. They point out that this does not mean that plants and animals in National Parks are not in peril: “The lower climate velocities in the national park area are an artifact of that indicator being calculated as horizontal movement of areas of constant climate. Climate velocity can underestimate exposure in mountains.”

The National Parks are more mountainous than the rest of the United States. This is a reflection of our unsystematic history of serendipitous-style protection; we collect the pretty places as national parks, without considering the underlying biophysical diversity, and mountains are very pretty places. So while moving a couple meters upslope might seem easier than moving hundred of meters north to track a suitable climate, this is often an oversimplification. “Despite the computational artifact, our results indicate that projected climate velocities in national parks could exceed maximum natural dispersal capabilities of many trees, small mammals, and herbaceous plants.” Gonzalez elaborates, “Any new protection of natural areas, whether close to or far from national parks, can add to global conservation of ecosystems for biodiversity and human well-being.”

I asked Gonzalez if he had any thoughts on how the research could be interpreted for park visitors. I wanted to know if there is an effort to get this work not just to park managers on the ground, but to interpretive staff as well. “For national park interpreters, I’ve given many presentations directly to staff in individual parks, including interpreters,” he says. “I encourage all U.S. National Park Service staff to speak about the robust science of climate change and its human cause, which points us to solutions to saving America’s most special places.”

Finally, I noticed that both this paper and the earlier National Park System climate exposure study, which covered 289 large parks, were published in open access journals. I asked if this was an intentional pattern and these research teams were hoping to reach managers who may not have access to peer-reviewed journal articles.

Gonzalez confirmed that, “the open access of the journal of course enabled a much larger audience to directly download and read the original work. This greatly benefited national park staff and other natural resource managers, to whom we aimed to provide information useful for conservation under climate change. Intense interest immediately developed – people downloaded the pdf file more than once a minute in the first 24 hours of publication.”

But their outreach was not limited to open access journals. Gonzalez points out, “public media published over 40 individual stories, including in the Washington Post, on page 1 of the San Francisco Chronicle, on public radio stations, and on television." Gonzalez also wrote a concise summary for the website the Conversation. He says that the University of California, Berkeley, has greatly helped in the effort to reach natural resource managers by publicly posting the spatial data, and he directly provided customized analyses and maps for numerous individual national parks.

Finally, Gonzalez writes, "I just presented the results to the U.S. Congress in a hearing where I testified on human-caused climate change in U.S. national parks. The open access of the journal was critical, but we engaged a broader effort to widely communicate the science.”

Thank you to Dr. Gonzalez and his colleagues for providing the climate data that underlies so much ecological research across the National Park System! And thank you for modeling effective outreach and impressive science communication*! 

References:

Gonzalez, P., Wang, F., Notaro, M., Vimont, D. J., & Williams, J. W. (2018). Disproportionate magnitude of climate change in United States national parks. Environmental Research Letters, 13(10), 104001–13. http://doi.org/10.1088/1748-9326/aade09

Monahan WB, Fisichelli NA (2014) Climate Exposure of US National Parks in a New Era of Change. PLoS ONE 9(7): e101302. https://doi.org/10.1371/journal.pone.0101302 Banner image: photos by Jodi Kurtz, Via Tsuji, and Gabriel Millos, Creative Commons 

*if I ever publish a paper that averages one pdf download every minute, I will throw the biggest party and give everyone temporary tattoos of the figures.

Pikas Meet Cute: Two Subspecies, One National Park

The National Park Service is wrapping up celebrations on its 102nd anniversary this August. I’m unabashedly biased towards park science: my dissertation and my postdoc research are both Acadia-based, while cleaning out old papers last week I actually paused for a moment before recycling a torn up, coffee-stained copy of a National Park research permit from 2013. (Don't worry, the original pdf is safely stored on an external hard drive.)

I’d report on the hybridization of pikas in Rocky Mountain National Park even without the excuse of a belated happy birthday to the National Park Service, but clearly covering research on pikas and #poopscience is the perfect way to honor the stewards of our public lands. There are charismatic megafauna (mini-fauna?) and there are charismatic landscapes, and the scientists who study pikas in the western National Parks enviably have cornered the market on both. Dr. Jessica Castillo Vardaro just published new research on the population genetics of American pikas in PLoS ONE last month. In “Identification of a contact zone and hybridization for two subspecies of the American pika (Ochotona princeps) within a single protected area” Castillo Vardaro and coauthors analyze the DNA in pika poop to pinpoint where the northern and southern Rocky Mountain lineages of these rabbit relatives meet. Their pika #poopscience spanned samples from Grand Teton National Park, Great Sand Dunes National Park, and Rocky Mountain National Park.

Before Castillo Vardaro’s work, there was some evidence that the northern and southern Rocky Mountain pika subspecies had a historic contact zone somewhere near-ish Rocky Mountain National Park. However, Castillo Vardaro wasn’t looking for a contact zone or hybrid pikas when she began working on the Pikas in Peril (PIP) project — a team of National Park Service staff and academic researchers. Pikas are a bit of poster child for climate change vulnerability — “a climate indicator species” — because they cannot tolerate prolonged exposure to high temperatures. Castillo Vardaro’s initial genetic analyses of pika populations in western National Parks focused on signals of isolation by distance (IBD). She explains, “the further individuals are apart geographically, the less related they are genetically. Since pikas typically establish territories close to where they were born and mate with their neighbors, I expected to see strong signals of IBD. I did in all of my study sites except Rocky Mountain National Park (ROMO).” Comparisons of the pika samples and their sequences to Genbank showed that there were two genetic lineages represented in ROMO — Northern and Southern. Then, at a pika meeting (could there be a cuter meeting?) Castillo Vardaro met Preston Somers, a researcher who studied pika dialect in the Rockies in the 1970's. She notes, “His work suggested there might be a contact zone, but we were the first to actually show it and evidence of contemporary gene flow. So, we weren't initially interested in studying ROMO as a potential contact zone, but we are now.” The analyses in this research are steeped in #poopscience, or what the paper refers to as “fecal samples…through a combination of random, targeted, and opportunistic sampling.” I asked Castillo Vardaro about the trade offs of #poopscience versus tissue samples. As a plant ecologist, my Methods have never included gems like, “We avoided collecting old fecal pellets by preferentially collecting pellets with green plant material inside to avoid degraded DNA” — but I was curious to hear more. Castillo Vardaro expounded,

Fecal DNA is essentially the mucus and cells lining the digestive tract that then coat the fecal pellet as it passes through. There are very few cells compared to tissue (organ tissue or ear clips), there are other things present that can inhibit the PCR process like plant secondary compounds, and the feces has been sitting around outside for an unknown amount of time so the DNA can degrade. Each sample has to be genotyped multiple times to overcome the errors resulting from low quality/quantity DNA. My genotyping success rate was 50% - 75%, after removing samples that failed, contaminated samples, and multiple samples collected from the same individual unknowingly. That's a lot of work in the lab.

But, the #poopscience lab work pays off if you need lots of samples across a broad geographic area:

In contrast, I just got back from a week in Montana where I was helping my coauthor Chris Ray trap pikas at a site she has been monitoring for 30 years. In four days of effort (two trap days, but it takes a day to set up traps and a day to check traps/process pikas) we trapped 5 pikas. One person can collect 10-25 quality fecal samples in a day, plus anyone can collect fecal samples for genetic analyses after about 10 minutes of training. So while I would have preferred to have worked with tissue, there is no way to sample the number of individual pikas necessary for 10 high resolution genetic analyses if you had to trap every animal.

The collaborative nature of Castillo Vardaro’s research and the Pikas in Peril reminded me of an earlier blog post I wrote about the Biological Conservation paper “The importance of non-academic coauthors in bridging the conservation genetics gap.”  I noticed that Castillo Vardaro’s PLoS coauthors were all academics, but she pointed out that her coauthor and grad mentor, Clint Epps, designed the PIP project alongside National Park Service personnel and other academic researchers. “The questions, goals, and desired products were explicit from the beginning. These included National Park Service reports, summaries, briefs (publications on the web and available at the parks themselves), spatial data, and research that could be utilized in each of the parks.”

While Castillo Vardaro was doing field work, she worked with National Park Service and US Fish and Wildlife Service biologists, interns, and volunteers. She noted, “we worked with interpretive staff to prepare the park specific resource briefs. We (myself, Clint Epps, and Doni Schwalm) also wrote a note on the potential effects of a proposed quarry site in Grand Teton National Park on the pika populations there, which was provided to resource managers there.” Basically, this work (one of Castillo Vardaro’s dissertation chapters) is the exception that proves the rule to the non-academic coauthors paper: here, the coauthor list belies the strong partnerships with non-academic scientists and managers, and if you didn’t know about Pikas in Peril, you might think wow, these academics really know how to put together explicit management implications single-handedly! 

Finally, in Castillo Vardaro’s research I saw a mirror of my own dissertation work. I had no pikas or fecal DNA, but we both finished our dissertation field work in National Parks before the 2016 election. Her work could inform whether pikas are listed as endangered or threatened under the Endangered Species Act; my research supported a climate change vulnerability assessment; and after our halcyon days as PhD students under the Obama administration, we are now watching an administration and Secretary of the Interior generally disregard the National Park Service expertise on these issues.

I told Castillo Vardaro that I feel an extra sense of urgency in publishing my Acadia papers now — especially in open access venues. I wondered if this was a personal quirk or if she felt a similar sense of responsibility for her field sites and study species. She agreed that highlighting the work that we are doing on public and federally managed lands is even more important in the current political climate. “One of the main reasons I chose to publish in PLOS ONE was because I wanted the manuscript to be accessible (open access).” She also noted that, “the PIP project was funded as part of the NPS Climate Change Response Program. I do worry about continued funding for similar projects and initiatives under Zinke and the Trump administration. Pikas tend to live in places that aren't as directly impacted by development as other ecosystems (it would be difficult to put a subdivision on the steep, rocky, side of a mountain), but the policies and proposed changes to the Endangered Species Act under the current administration to make it easier for development and resource extraction on public lands could definitely impact pikas.” 

The flipside of non-academic coauthors bridging a conservation gap is this: when the federal government is hostile towards non-extractive natural resource management, the academic coauthors in these partnerships will continue to publish our findings, piling up the evidence to support our field sites and our study species. For those of us in academia who completed National Park fieldwork in what seems like another era, getting the writing done can seem both daunting and futile. It's not. Traditionally, the first wedding anniversary is the “paper” anniversary, but for the National Park Service’s 102nd I think papers are still an appropriate — and important — gift. 

References:

Castillo Vardaro JA, Epps CW, Frable BW, Ray C (2018) Identification of a contact zone and hybridization for two subspecies of the American pika (Ochotona princeps) within a single protected area. PLoS ONE 13(7): e0199032.

Hidden in Plain Sight: the Secret Tree Diversity of Cultural National Parks in the East

Last summer, my daughter received All Aboard! National Parks, a whimsical board book that devotes full-page spreads of colorful, kid-friendly illustrations to nine National Parks along a fictional railroad route. The National Parks skew western — Olympic, Yosemite, Yellowstone, Grand Canyon — with Acadia and Great Smoky Mountains representing the entire eastern half of the U.S. But, the book is a skewed representation of the National Park System in another way too: it only showcases the large, iconic, and “wild” national parks. Where are the National Battlefields, the National Recreation Areas, the National Scenic Rivers, and the National Historic Sites?

A recent paper from Forest Ecology and Management has me thinking that the cultural parks of the east that fall under the National Park Service umbrella deserve their own board book!

In the eastern United States, our National Parks dot the landscape as constellations of historic battlefields, homes of important historical figures, and wild islands of nature scattered across an eastern seaboard of cities, development, and fragmentation. But, it turns out that these small, cultural protected areas are harboring incredible tree species diversity. Dr. Kathryn Miller and colleagues from the National Park Service and University of Maine published “Eastern National Parks protect greater tree species diversity than unprotected matrix forests” after comparing tree species diversity measured in National Park Service Inventory & Monitoring plots to the species diversity recorded in nearby US Forest Service Forest Inventory and Analysis plots. Miller considered five metrics of diversity in each plot — number of individuals, tree species richness (how many species were in each plot?), Shannon evenness (are the species in the plot relatively as abundant as each other or are some super common and others very rare?), McNaughton Dominance (what is the relative abundance of the two most abundant species?), and Percent Rare N/S (what percent of species in a plot have fewer individuals than the average species abundance in that plot?).

The title of Miller's paper is a spoiler alert — the parks were more diverse than the matrix (non-park) forests — with park forests comprising higher species richness and a more even, less dominated distribution of abundance across species. She found this pattern of higher species diversity across the majority of the parks in the study, but it was most consistent in the lower latitude parks. Over a decade of publicly available data from the National Park Service’s Inventory & Monitoring plots and the Forest Service Forest Inventory and Analysis plots allowed Miller and her team to explore tree species diversity across 39 eastern National Parks, each containing between 4 (Sagamore Hill National Historic Site) and 171 (Acadia National Park) forest plots. Before Dr. Miller began her PhD at UMaine, she led field crews that collected some of the data in the National Park Service Inventory and Monitoring Program. Miller told me, “My field experience sampling and hiking around eastern forests has definitely helped me frame the types of research questions to ask, and interpret whether the results are meaningful. When I started this study, I suspected that at least some of our parks, particularly the larger ones (e.g. Delaware Water Gap National Recreation Area, New River Gorge National River), would have greater tree diversity. I was surprised, however, to find out that many of our cultural parks, which tend to be smaller and haven't been protected as long, also have greater stand-level tree diversity than matrix forests.”

Miller’s results are both expected and unexpected. First, there’s a general understanding among ecologists that eastern US forests today are smaller, younger, and more homogenous than they were before centuries of European settlement, land clearing, and timber harvesting. And, we know on a basic level that forests in US National Parks are largely protected from development and harvesting. So, it shouldn’t be shocking to find that forests managed by an agency that is dedicated to promoting ecological integrity and natural disturbance regimes are full of lots of species — not just the early successional ones. But, on the other hand, we often don’t imagine Minute Man Historical National Park — a battlefield replete with actors in Revolutionary War costumes — as bastion of biodiversity. Or, in the case of All Aboard! National Parks, we don’t imagine these cultural parks as national parks at all. So how did Miller land on this question — what made her interested in comparing the tree species diversity in parks and unprotected forests in the east? She muses that “this research question in particular was a follow-up to [our 2016 Ecosphere paper] "National parks in the eastern United States harbor important older forest structure compared with matrix forests" which compared metrics of forest structure in eastern national parks with surrounding matrix forests.” In that study, she found that “parks, regardless of park designation (e.g. National Park, National Recreation Area, or National Historical Park), had consistently older forest structure than matrix forests.” Were these older forests also more diverse? The same forest plot databases could answer that question as well! 

I asked Miller if her research changed her view of the ecological value of cultural national parks. “For me, the results of this study were very encouraging, and confirmed that our efforts to monitor and keep even the smallest parks' forests healthy are worthwhile. I am hopeful that the results of these studies are empowering to the resource managers in our cultural parks, and lead to stronger emphasis and additional resources for maintaining healthy forests in these parks. Ultimately our research also makes a strong case for the importance of protected areas in preserving forest biodiversity, even small urban parks.”

This research seems relevant to managers outside of National Parks as well — and Miller hopes that private landowners, state parks, and NGOs take note. She recognizes that resilience to global change is a big contemporary concern for many land managers. “In forests, tree diversity and structural complexity are important components of resilience, and our results demonstrate the positive influence that protection, particularly protection from logging, can have on forest resilience. In addition, park managers often receive pressure from well-meaning members of the public, and even other park staff to "clean up" forests after natural disturbances. In fact, this was typical management practice in the early days of national parks before we knew better.” She tied together her species diversity and forest structure research and reflected that, “coarse woody debris, dead and dying trees, and blow-downs all contribute to the overall diversity of a forest, and our research has shown that protected forests have more of these features than unprotected forests. Hopefully our research can help inform and support managers' decisions not to clean up after disturbances unless there is a concern about human safety (e.g. hazard trees).” Miller and I both work in Acadia — the kind of classic wild National Park that appears in our imaginations and children’s books as an iconic protected landscape. But as Miller points out, “Interestingly, Acadia National Park did not come out as being more diverse than surrounding matrix forests, particularly because the park has more extensive late successional forests that are largely dominated by red spruce.” She explains, “this isn't necessarily a bad thing, but it does suggest that the forests in Acadia may be more vulnerable to stressors than matrix forests, particularly stressors that could impact red spruce. While this isn't the greatest news, this is important information for park managers to know.”

Like many folks in the greater Boston area, I drive hours to Acadia and feel like I am stepping into a wilder, more biodiverse ecosystem when I lace up my hiking boots at the trailhead to Cadillac Mountain. But, there are pockets of protected tree species diversity hidden in plain sight across the eastern US. Miller’s research makes me rethink my summer road tripping plans — perhaps I should seek out some of those old, diverse forests in National Recreation Areas and Historical Parks, maybe some are actually accessible by railroad... I'm going all in on my research for the All Aboard! Cultural National Parks of the East board book pitch! 

References:Miller, K.M., McGill, B.J., Mitchell, B.R., Comiskey, J., Dieffenbach, F.W., Matthews, E.R., Perles, S.J., Schmit, J.P. and Weed, A.S., 2018. Eastern national parks protect greater tree species diversity than unprotected matrix forests. Forest Ecology and Management, 414, pp.74-84.

Miller, K.M., Dieffenbach, F.W., Campbell, J.P., Cass, W.B., Comiskey, J.A., Matthews, E.R., McGill, B.J., Mitchell, B.R., Perles, S.J., Sanders, S. and Schmit, J.P., 2016. National parks in the eastern United States harbor important older forest structure compared with matrix forests. Ecosphere, 7(7).