New publication - A 100 year history of succession

Our capstone paper of Cooper’s 100 year legacy is now available in Ecology (and on the publication page). It combined about 50 years of unpublished data, and incorporates a whole host of ancillary data including bird observations from the 40’s, moose from the 80’s, and more. It’s basically all the good stuff I could find, which will hopefully set us up for the next 100 years.

Abstract: The study of community succession is one of the oldest pursuits in ecology. Challenges remain in terms of evaluating the predictability of succession and the reliability of the chronosequence methods typically used to study community development. The research of William S. Cooper in Glacier Bay National Park is an early and well-known example of successional ecology that provides a long-term observational data set to test hypotheses derived from space-for-time substitutions. It also provides a unique opportunity to explore the importance of historical contingencies and as an example of a revitalized historical study system. We test the textbook successional trajectory in Glacier Bay and evaluate long-term plant community development via primary succession through extensive fieldwork, remote sensing, dendrochronological methods, and newly discovered data that fills in data gaps (1940s to late 1980s) in continuous measurement over 100+ years. To date, Cooper’s quadrats do not support the classic facilitation model of succession in which a sequence of species interacts to form predictable successional trajectories. Rather, stochastic early community assembly and subsequent inhibition have dominated; most species arrived shortly after deglaciation and have remained stable for 50+ years. Chronosequence studies assuming prior composition are thus questionable, as no predictable species sequence or timeline was observed. This underscores the significance of assumptions about early conditions in chronosequences and the need to defend such assumptions. Furthermore, this work brings a classic study system in ecology up to date via a plot size expansion, new baseline biogeochemical data, and spatial mapping for future researchers for its second century of observation.

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Kate wins Joint Fire Science Grad Research Fellowship

Congrats to Kate Hayes, who’s project, “Evaluating Flammability of Reburns in the Boreal Forests of Interior Alaska,” was selected for funding. Kate’s work is really fascinating, looking at how a sustained increase in fire frequency will shape future landscapes - and importantly, looking beyond first order feedbacks to longer term mechanisms. The work will go on for a couple years funded by the Joint Fire Science Program

From the proposal

Project Abstract:Temperatures in high-latitude environments are rising quickly, leading to increases in the frequency and intensity of wildfires (Kasischke et al. 2010). This trend is especially important in the boreal where fire return intervals have shrunk from between 100-300 years to often less than 20 (Zoltai et al. 1998, Brown & Johnstone et al. 2012, Caplat & Anand 2009, Johnstone & Chaplin III 2006). Shortening fire intervals have led to an increased presence of early to mid-successional deciduous species, with birch (Betula neoalaskana), alder (Alnus crispa), aspen (Populus tremuloides) and willow (Salix spp.) becoming dominant in stands previously dominated by black spruce (Picea mariana) (Hoy et al. 2016). Boreal deciduous species are considered less flammable than black spruce, so an increase in deciduous species has been hypothesized to reduce overall landscape likelihood of burning, creating a negative feedback loop (Astrup et al. 2018). The presence of deciduous species has been invoked as a landscape management solution to arctic and boreal warming, based on paleoecological evidence of declining fire activity found alongside increases in the presence of birch (Kelly et al. 2013, Brubaker et al. 2009). However, historical forest compositions were slightly different: past boreal environments were dominated by birch alone, while recent studies have found alder, aspen, and even willow in dominant quantities (Higuera et al. 2008). Furthermore, preliminary work (Hayes et al, in prep) demonstrates that fuel structures change dramatically across a 1-3 short interval fire gradient, with three burns resulting in more open, shrubby structure with increased willow. This indicates that paleoecological studies are not a perfect analogue for modern change, and that specific modern empirical landscape flammability data is required to inform future management directions.

Problem Statement
Current consensus holds that an increasing presence of deciduous species could act as a negative feedback to increasing fire, but that idea is based on the assumption that deciduous species lower landscape flammability. The rise in reburns across the state of Alaska is creating novel deciduous forest structures and compositions, configurations that may behave differently than paleoecological analogues and modern expectations.

Objectives
Quantify landscape flammability across a gradient of fire histories in the boreal forests of Interior Alaska.

Benefits
This research will help answer fundamental questions regarding the flammability of emerging boreal landscapes and will contribute directly to fire management strategies in Interior Alaska. The first benefit from this work will be specific standardized measurements of flammability of dominant boreal species across growth forms. These measurements will help resolve how landscape flammability may change with emerging changes to boreal forest structure as a result of multiple short interval fires.

The second benefit from this work will be quantification of fuel loads and structures across reburns in Interior Alaska. This dataset will include paired measurements of fuel type, quantity and spatial arrangement that can be analyzed against fire history, topography and regional climate. Quantification of the flammability of this emerging and apparently novel forest structure that results from long-term exposure to short interval fires is novel. The dataset produced will benefit both researchers and managers interested in changes occurring in boreal systems. Insights gained from this research will contribute directly to fire management: by knowing the relative flammability of different forest structures and compositions in reburned boreal forest, managers can better make decisions about restoration via prescribed fire, wildfire suppression and the dynamics of fire and vegetation.

The deliverable will be an actionable policy brief given to the Alaskan fire management community..

Lack of posts - sorry

A distinct lack of posts lately - the spring semester got busy, and then fieldwork took over. Since last posting (in February!!) there has been several new things:

New graduate students joining the lab - Arthur Link and Annelise Rue-Johns. Both are working on cedar and climate adaptation, but at distinctly different scales - from 20 degrees of latitude to lab work.

New publications - 5 of them. Nature Sustainability, Ecology, Ecology and Evolution, etc. See publication page for citations and links.

Fieldwork - Alaska is on fire (literally). Kate and Kyle were working hard all summer digging around southeast and central AK on different disturbance projects. More pictures soon.

REU students - I received a grant to host two REU students, who did amazing work in interior AK on soil and permafrost issues. Kristin Olsen and Vishnu Kodicherla - see their posters at AGU this fall.

Filming - we did quite a bit of filming in interior AK for educational materials this fall. Great stuff. Again, more soon…

New publication (3 of 4): What does resilience to fires really mean? A socio-ecological perspective

In mid 2018 I had the pleasure of attending a JFSP sponsored workshop that brought together half ecologists, half social scientists to talk about what resilience to fire really means in a truly linked perspective. It was fascinating. I believe we spent a full day arguing before we realized our basic definitions of what resilience actually means (bouncing back to the same state? adapting to new realities?)! It was highly instructive, and out of it came a really valuable way to think about resilience, adaptability, and dealing with (or avoiding change). I think it does an excellent job of bringing choice into our discussions of dealing with climate change, and brings a sense of agency back to ecological management discussions.

Higuera P, Metcalf A, Miller C, Buma B, McWethy D, Metcalf E, Ratajczak Z, Nelson C, Chaffin B, Stedman R, McCaffrey S, Schoennagel T, Harvey B, Hood S, Schultz C, Black A, Campbell D, Haggerty J, Keane R, Krawchuk M, Kulig J, Rafferty R, Virapongse A. 2019. Integrating subjective and objective dimensions of resilience in fire-prone landscapes. BioScience.  In press.

New publication (2 of 4): Emerging freeze and fire dynamics in temperate rainforests

Having just been in southern Chile for so long, I was struck how similar southern and southwestern Tierra del Fuego and the archipelagos are to southeast Alaska. Peat bogs (turbols), low treeline, and low evapotranspiration dominate, as does a general lack of fire (wind and landslides rule here).

Recently, a group of colleagues and I published a paper comparing the emerging changes in both regions, comparing and contrasting fire and snow dynamics in both areas as potential future stressors for forests. There’s a lot that can be learned from each area - snow loss up in the north, the emergence of fire in the south. Both areas are moving in the same direction, but in different ways, so a comparative approach is extremely valuable.

Buma B, Battelori E, Bisbing S, Holz A, Hennon PE, Mortiz M, Saunders SE, Creutzburg MK, DellaSala DA, Gregovich D, Krapek J, Zaret K, Bidlack A. Emerging freeze and fire dynamics in temperate rainforests. Austral Ecology. In press.

New publication (1 of 4): Dense forest carbon, mapped at unprecedented resolution and extent

A new paper describing the carbon status of the North Pacific temperate rainforests of southeast Alaska was just accepted for publication by PLOS ONE, and will be out soon. It’s the first study to every document and map the biomass C of the densest forest in the United States, the Tongass rainforest and surrounds. In this paper we used USFS data and machine learning, coupled with disturbance modeling, to build a climate, topography, and disturbance sensitive model. We then used the validated model to test if disturbances were driving down forest carbon across the region or if they were actually increasing baseline carbon (they are pretty rare). We found higher carbon in areas of higher disturbance exposure, to a point, indicating that infrequent disturbances do likely result in more productive landscapes compared to areas where disturbances are non-existent.

Buma B, Thompson T. Long-term exposure to more frequent disturbances increases baseline carbon in some ecosystems: Mapping and quantifying the disturbance frequency-ecosystem C relationship. PLOS One.  In press.

Figure 2 from the publication - the map, validation points, and what happens to predicted carbon stocks in the model if disturbances are set up their lowest setting.

Back from Cape Horn!

Sorry for no updates for a while - several new publications will come in a flurry of a few posts as I get time (really good month for that!). But, the lack of posts is due to the long, long time spent in southern Chile with National Geographic.

The trip to Cape Horn, to study forests and ecosystems at the end of the world, was amazing. Beautiful, windswept, austere, wind scoured, green and almost tropical, and wind blasted. It’s a windy place. Wind seems to shape everything we saw, from the distribution of cushion plants to tree structure to animal life. Storms blow in and out in 15 minutes - including snow, sun, rain, sleet, and mist.

It’s a wild place. 5m seas in a small boat, grumpy penguins (I got bit by one!), and difficult walking made movement exhausting - sometimes an hour to go a 1/4 mile. But we got it done - several new research plots, temperature loggers installed, stress measured, and more. Looking forward to a successful series of studies at the edge of the world!

Andres Holz (PSU) is collaborating, and endured all of this as well! Also, thanks to Craig Welch, Ian Teh, John Harley, Enzo Fermani, Ricardo Rozzi, Ivan Diaz, and many more for their work.

For some more pictures, check out Instagram:

@iantehphotography
@craigwelch
@brian.buma

New publication - linking neoecology and paleoecology

One of the most fun groups I’ve worked with over the past several years is the NSF RCN Novus network (https://novusrcn.wordpress.com/), a group that has tried to get together “neo” disturbance ecologists - those of us working in the short term, doing fieldwork in disturbed areas, all that - with paleo ecologists. It’s been fun trying to reconcile perspectives and come up with ways to ask interesting questions across timescales.

A new perspectives paper was just accepted in Landscape Ecology where we look at mixing the mechanistic understandings of neo ecology with the deeper time perspective of paleo, and suggest ways to strategically link the two. I think it’s interesting because it’s not talking about individuals - it’s suggesting ways to collaborate strategically and create study designs collaboratively. Not a “tack the paleo on” for a new perspective, but rather to deeply integrate it into the conceptual/proposal stage.

Buma B, Harvey B, Gavin D, Kelly R, Loboda T, McNeil B, Marlon J, Meddens AJH, Morris JL, Raffa K, Shuman B, Smithwick E, McLauchlan K.  The value of linking short and long-term perspectives to understand spatially-explicit ecosystem resilience. Landscape Ecology. In press.

The edge of the world in maps - eye candy

A couple great sketched maps of Isla Hornos, from the old to the new to the newest. Getting closer!

One of the first maps to show Tierra del Fuego as its region, separate from the mainland. This was after the Horn (really, the Hoorn due to the Dutchmen that named it) was doubled for the first time, but prior to several other exploratory firsts including the Falklands being completely described.

A gorgeous sketch map of Isla Hornos and Cabo de Hornos, edging into the Drake Passage and the goal of the expedition. For more amazing versions, see http://onezillustration.com/projects/

A gorgeous sketch map of Isla Hornos and Cabo de Hornos, edging into the Drake Passage and the goal of the expedition. For more amazing versions, see http://onezillustration.com/projects/

And the most modern view, courtesy of NASA.

New publication - High spatial resolution assessment of carbon reserves

Gavin McNicol, a postdoc in the lab (now at Stanford), has just published his work on coastal forest carbon. Coastal rainforests are the most biomass-carbon dense forest biome in the world, and Gavin focused on building a high spatial resolution/broad extent map of the soil/non-biomass portion of that - which is actually abut 60% of the total. He did a great job, working at 90m resolution across 10 degrees of latitude, a truly difficult task.

In total, we’re looking at approximately 4.5 Pg C in the top 1m, mostly driven by precipitation and topography.

One of the most interesting aspects of the project was Gavin’s comparison to global maps, which are used in global C budgets and models. Our work here is highly detailed, and works with an extensive soil observation network that was put together specifically for this task. So it’s useful to compare and validate global maps, since the scales are at least comparable (e.g., we’re not comparing one observation to a global map, but a huge region/part of the globe).

The global maps are generally pretty poor - 4 fold lower than SoilGrids250m, the finest resolution global map available and significantly more accurate against observations. That was true for other global maps as well.

This type of modeling, at this scale, is quite useful for evaluating global products that are so important for our global change research - they are produced at the right scale for comparison and thus far better for validation than just a series of points that may skew accuracy spatially. I think it’s fairly clear we need more of these types of studies and evaluations.

McNicol G, Bulmer C, D'Amore DV, Sanborn P, Saunders S, Giesbrecht I, Gonzalez-Arriola S, Bidlack AL, Butman D, Buma B. Large, climate-sensitive soil carbon stocks mapped with pedology-informed machine learning in the North Pacific coastal temperate rainforest. Environmental Research Letters. In press.

One of the truly big tasks was unifying the regional dataset, and perhaps the most work. Above is the extent of the NPCTR displaying the distribution of soil profile descriptions (light green circles) and the study extent (dark green pixels) used in the SOC stock assessment. Inset maps show global (small) and continental (large) extent of the full NPCTR along with the boundaries of climatic sub-regions.

One of the truly big tasks was unifying the regional dataset, and perhaps the most work. Above is the extent of the NPCTR displaying the distribution of soil profile descriptions (light green circles) and the study extent (dark green pixels) used in the SOC stock assessment. Inset maps show global (small) and continental (large) extent of the full NPCTR along with the boundaries of climatic sub-regions.

Soil organic carbon stock predictions to 1 m (Mg C ha-1) at 90.5 m resolution for small NPCTR watersheds across BC and SE Alaska.

Soil organic carbon stock predictions to 1 m (Mg C ha-1) at 90.5 m resolution for small NPCTR watersheds across BC and SE Alaska.