Judges’ Queries and Presenter’s Replies

  • May 20, 2013 | 09:02 p.m.

    It seems to me that Super Storm Sandy was a weather event, albeit an unusual one, whereas climate change, even abrupt, occurs on much longer multiple-year to decade time scale. Please explain if the focal bird in your study has a life span that is sensitive to unusual weather to climate change.

  • Icon for: Maureen Correll

    Maureen Correll

    Presenter
    May 22, 2013 | 07:56 a.m.

    I am not sure if you received this first reply since I posted it as a comment, not a direct reply to your question, so I am cutting and pasting it and sending it to you again. If you have already read this reply, please disregard!

    Our research group considers climate patterns to be 30+ year trends, where weather events and records tend to be below this scale. Superstorm Sandy was an extreme weather event, absolutely. Extreme weather events are predicted to increase in frequency and severity as climate change progresses, making events such as these longer-term concerns. It’s also important to note that Sandy occurred in October, after most of the birds that utilize tidal marsh in the summer had already left for the season through migration. Sandy primarily affected tidal marsh birds by modifying their summer habitat along the coast, not through direct mortality or stress linked with the storm event. Communities of tidal marsh birds include species from several clades; life spans of these birds can range from a few years (sparrows) to decades (loons). I am interested in observing reactions to extreme storm events at the community, not at the individual, level, so the life span of the individual birds in the community are not a primary concern of mine . Rather, I am interested in seeing if bird community stability (change in diversity over time) is higher in tidal marshes with larger area and connectivity to one another – this is measurable even if different individuals of the same species are utilizing the marshes under study from year to year. Please let me know if you have any other questions, or if my answer is unclear. Thanks for the interest!

  • Icon for: Maureen Correll

    Maureen Correll

    Presenter
    May 20, 2013 | 09:36 p.m.

    Our research group considers climate patterns to be 30+ year trends, where weather events and records tend to be below this scale. Superstorm Sandy was an extreme weather event, absolutely. Extreme weather events are predicted to increase in frequency and severity as climate change progresses, making events such as these longer-term concerns.

    It’s also important to note that Sandy occurred in October, after most of the birds that utilize tidal marsh in the summer had already left for the season through migration. Sandy primarily affected tidal marsh birds by modifying their summer habitat along the coast, not through direct mortality or stress linked with the storm event.

    Communities of tidal marsh birds include species from several clades; life spans of these birds can range from a few years (sparrows) to decades (loons). I am interested in observing reactions to extreme storm events at the community, not at the individual, level, so the life span of the individual birds in the community are not a primary concern of mine . Rather, I am interested in seeing if bird community stability (change in diversity over time) is higher in tidal marshes with larger area and connectivity to one another – this is measurable even if different individuals of the same species are utilizing the marshes under study from year to year.

    Please let me know if you have any other questions, or if my answer is unclear. Thanks for the interest!

  • May 21, 2013 | 01:22 p.m.

    How many of the questions you wish to ask have been addressed in other areas (e.g., Southeast) or other circumstances (if any) that may inform your work, and which aspect of the research do you expect will be most surprising?

  • Icon for: Maureen Correll

    Maureen Correll

    Presenter
    May 22, 2013 | 07:55 a.m.

    In general, disturbance ecology research is done at small scales due to the contraints of large-scale manipulations, and a large manipulative project on coastal marshes has not yet been attempted. Tiffany Schriever and collaborators have done previous work in herpetology in southeastern wetland habitats within Louisiana, and found generally a decrease in community diversity after extreme storm events such as hurricane Katrina, Ivan, and Rita. For bird populations in particular, some work again has been done at smaller scales (Askins and Ewart 1991, Wauer and Wonderle 1992) and overall found a decrease in species abundance after hurricane events. The question I aim to ask for my dissertation work involves the application of island biogeography theory to marsh systems, particularly vegetation and bird communities. This has been studied before both in my area and species assemblage of interest (Shriver et al 2004, Benoit and Askins 2002). These studies found higher species richness in marsh patches with higher overall area. This is a very brief intro into the literature review for this part of my research, please let me know if you have any more questions in this regard. As far as what I expect to be most surprising, I think the surprising things are the unexpected results! I am excited to identify the area threshold after which a dropoff in community stability occurs. The effects of spatial composition of marshes on bird and vegetation community stability over the last 15 years is a separate question I ask in another chapter of my dissertation, and I am excited to see how the results from this disturbance chapter line up with my results from my longer-term change study.

  • May 21, 2013 | 05:10 p.m.

    Take a bow on your video – it was terrific. My question is a pretty open-ended one. The BACI layout that you now have to work with is certainly serendipitous. So I wonder: what EXACTLY do you propose to do with it? You mention Bayesian Hierarchical modeling and “lessened resistance” in your poster, but can you go a bit further? Obviously, there will be all sorts of measurable, quantifiable variables that changed significantly in the wake of Hurricane Sandy. And so the BACI design almost makes your job, in a sense, trivially easy. Can you expand just a bit on what you really plan to do with your data and this unique opportunity?

  • Icon for: Maureen Correll

    Maureen Correll

    Presenter
    May 22, 2013 | 08:10 a.m.

    I’m glad you liked the video! As far as specifics are concerned, I will be exploring the spatial characteristics of tidal marshes and the degree of resistance both in vegetation and bird communities observed in marshes in varying degrees of marsh area, shape, and connectivity, as well as previous degree of disturbance (previous management history), proximity to human development, type of human development, etc. The list goes on! Another part of my dissertation (mentioned very briefly in my video) involves a longer-term evaluation of the relationship between community stability (change in bird diversity over time) and spatial characteristics of coastal marsh, over a 15-20 year window. I am excited to identify and compare the spatial characteristics that are important in this longer-term change to the characteristics identified in this disturbance ecology chapter. As for the statistical side of things, I still have much work to do. Because of the design of my study, almost all analyses will be hierarchical in design, which I think will result in my use of a Bayesian framework of mixed models. I hope to do analyses at the local, state, and regional levels as well as ecologically significant levels (Gulf of Maine vs. Long Island Sound, etc) to produce tangible products for conservation decision-making and management at various scales. These answers to your question are still quite general, and I know I will be limited in scope due to the time I have left to complete my degree, but hopefully this sheds some light onto my thought processes. Please let me know if you have any additional questions!

  • May 23, 2013 | 09:32 a.m.

    Thanks Maureen. Play your cards right and you just might get to spend the rest of your career tackling these sorts of questions!

  • May 21, 2013 | 10:05 p.m.

    Dear Maureen,

    Great video and poster! You sure got ‘lucky’ with hurricane Sandy, and its great that you are making the most out of that opportunity.

    What wasn’t clear to me was the link between an extreme event, such as a hurricane, and abrupt climate change. Don’t get me wrong, I understand that extreme events are predicted to become more frequent. But that isn’t in itself an abrupt climate change, is it? Or are you suggesting that the current rate of climate change is so rapid that it qualifies as abrupt? Is your question to test if what was experienced is an abrupt change? Or are you assuming that it is?

    Best,
    Volker

  • Icon for: Maureen Correll

    Maureen Correll

    Presenter
    May 22, 2013 | 08:23 a.m.

    I’m glad you enjoyed my video and poster, thank you! The application of this BACI setup to abrupt climate change research is twofold; recording how communities react both short-and long-term to extreme storm events such as this will be helpful in the development of both gradual and abrupt climate change policy. However, strictly speaking, yes we are in a period abrupt climate change due to the exponential (non-linear, or abrupt) increase in the amount of CO2 in the atmosphere over the last 120 years. The number of these storm events is predicted to increase over the next 50 years, the severity of which is unknown, but could very well be abrupt, not linear, in nature. This is where the idea of abrupt change enters the scene. Our question is not to see if what was experienced was an abrupt climate event; it was by definition an extreme weather event due to the timescale over which it occurred. Climate change is loosely defined as 30+ year trend changes in the weather record, where weather events can be defined as changes on timescales smaller than this. My question and interest in my Sandy work is 1) what is the initial reaction of bird communities to hurricane sandy 2) how is this effected by differences in marsh area, connectivity, and shape 3) using the information produced here, how can we plan and develop policy to prepare for a non-linear increase in extreme storm events such as Sandy, and what can we expect to see as an increase in these storms continues to occur? This third question is specifically where abrupt climate change comes into play.

  • May 22, 2013 | 12:27 a.m.

    This is a monumental and timely project! The fact that you have two established control areas and keen public interest in your research is also a plus. I liked that you explained why your team chose birds as the biological indicator to examine the health of the tidal marshes. My question may be premature, but has your team observed/documented any biological, chemical, or mechanical negative factors impacting birds in the tidal marshes that are specifically attributable to Huricane Sandy?

  • Icon for: Maureen Correll

    Maureen Correll

    Presenter
    May 22, 2013 | 08:32 a.m.

    We have just started surveys for 2013, and as of yet have no results from that data collection. However, anecdotally, many of our survey points form 2011/2012 have changed completely in cover type in 2013 from high marsh (marsh flooded ~ once a month, where saltmarsh sparrows commonly make their nests) to sandy beach, low marsh (flooded daily, where nest construction is impossible) or in some cases open water. This extreme change in habitat will definitely effect diversity of bird species in these areas since many birds will no longer be able to breed in these areas. Additionally, some barrier beaches changed configuration significantly due to Sandy, and may in some isolated cases promote marsh development and growth over time. An example of this is on Monomoy National Wildlife Refuge on Cape Cod in Massachusetts, where the large sandy peninsula is now no longer attached to the mainland, and has created several areas of coastal habitat newly protected from open ocean energy. Over the next few years it is probable that low marsh and eventually high marsh vegetation could colonize these areas, producing a marsh where open water and sand spits existed before. The next few months, and hopefully another year of surveys in 2014 will shed more light on answers to your questions!

  • May 22, 2013 | 10:06 a.m.

    What an open, thoughtful and audience-specific answer to my question. I especially liked the bird nesting impact example. I immediately went to read your other answers- thank you for all of them!
    Dr. Anderson

  • Further posting is closed as the competition has ended.

Presentation Discussion

  • Icon for: Brian Drayton

    Brian Drayton

    Faculty
    May 20, 2013 | 09:15 a.m.

    Nice plan to take advantage of Sandy, and a very clear statement of the research. But how will you quantify “resistance” or resilience to disturbance within the time constraint of your study? If you have some historical data sets, these probably have in them records of prior disruptive events that are helping you with this question?

  • Icon for: Maureen Correll

    Maureen Correll

    Presenter
    May 20, 2013 | 09:45 a.m.

    We hope to quantify resistance (initial reaction to the storm event), not resilience (degree of ability to recover over time), from this initial study, due to the time contraints of our current surveys. We hope to later use the 2013-214 data as baseline data for resilience studies down the road by comparing initial resistance to longer term recovery. We will quantify resistance to this extreme time event by measuring change in communities between 2011/2012 and 2013/2014. We will account and control for annual variability through use of data from control sites on either side of Sandy’s impact zone. While we do have historical data from 1997-2000 for many of these survey sites, we do not have comparable immediate before/after data like we will for hurricane Sandy.

  • Icon for: Amber Bratcher

    Amber Bratcher

    Trainee
    May 20, 2013 | 10:48 a.m.

    Nice work—good luck with this year’s surveys!

  • May 21, 2013 | 08:29 p.m.

    Best of luck! Very important work indeed. We are in NJ and NJ really suffered from Sandy. Hope that you can get the surveys done. Beautiful video!

  • Icon for: Maureen Correll

    Maureen Correll

    Presenter
    May 22, 2013 | 07:18 a.m.

    Thanks very much! Our surveys are underway for the season, so far so good! We started in early May, and hope to be done by August 1.

  • Small default profile

    Gillian Puttick

    Guest
    May 22, 2013 | 09:43 a.m.

    Nice work. What components of marsh communities will your measures of resistance focus on? Do you have hypotheses about what reactions you might see?

  • Icon for: Maureen Correll

    Maureen Correll

    Presenter
    May 22, 2013 | 10:59 a.m.

    I expect to see a decrease in community stability (change in bird diversity over time) after the event, and I expect to see a relationship between habitat patch size, shape, and connectivity and the degree of change we observe. I also expect to see a relationship between previous management practices in the marsh and resistance to the storm event. We’ll see!

  • Icon for: Timothy Waring

    Timothy Waring

    Faculty
    May 22, 2013 | 09:14 p.m.

    Mo, this is really well done! Nice to see you guys in here. Your natural experiment is amazing. What’s happening so far this season?
    Best,
    Tim

  • Icon for: Maureen Correll

    Maureen Correll

    Presenter
    May 22, 2013 | 11:36 p.m.

    So far so good… just hired on our last tech on Monday. We’ll see how it goes, but it looks like we have a great crew this year, I’m excited to see what we find.

  • May 23, 2013 | 04:21 p.m.

    HI Mo,

    very interesting that Sandy set you up with such a nice controlled experiment.

    Kate Beard

  • Further posting is closed as the competition has ended.

  1. Maureen Correll
  2. http://www.igert.org/profiles/5161
  3. Faculty: Project Co-PI
  4. Presenter’s IGERT
  5. University of Maine
  1. Bjorn Grigholm
  2. http://www.igert.org/profiles/5197
  3. Graduate Student
  4. Presenter’s IGERT
  5. University of Maine

Abrupt Climate Change in Atlantic Tidal Marsh Communities

Tidal marshes are one of North America’s most productive and dynamic habitat types. They also provide significant ecosystem services to the areas in which they are located by acting as a physical barrier between marine and terrestrial ecosystems, as well as providing critical habitat for fish and crustacean populations and various migratory birds. Marshes located along the Atlantic coast of the United States are particularly vulnerable to degradation and loss due to coupled human and natural systems. Climate change and sea-level rise have the potential to further this marsh loss through both linear and abrupt processes, particularly through increases in the frequency and intensity of storm-related flooding events. Collaborators with the Saltmarsh Habitat and Avian Research Program (SHARP) conducted bird surveys at over 1700 locations in the summers of 2011 and 2012 in between the Chesapeake Bay and the Canadian border. We plan to repeat these surveys in 2013, a season immediately following the extreme storm event Sandy, to define thresholds of vegetation composition, salt-marsh patch size, and marsh spatial arrangement on the landscape, beyond which marsh-bird communities will become unstable. The results of my anticipated dissertation research will enhance our current understanding of resilience of coastal wetland areas to abrupt climate change and identify ecosystem thresholds for abrupt losses in biodiversity.