The USGS and Delta Stewardship Council have been recruiting the next Delta Lead Scientist who is appointed by the Council after consultation with the Delta Independent Science Board. As part of the process, each applicant will give a seminar presentation on their research and experience and how it applies to the position as well as their vision for the Delta Science Program.
On April 30, the Delta Stewardship Council appointed Dr. Laurel Larsen as the new Delta Lead Scientist. Dr. Larsen is an associate professor in the departments of geography and civil and environmental engineering at UC Berkeley. Her work focuses primarily on how flowing water structures the form and function of landscapes with emphasis on the Florida Everglades, Southern Louisiana, and stream and watersheds across the US, including intermittent streams in coastal California. Dr. Larsen’s Environmental Systems Dynamics Laboratory takes a complex systems approach to environmental problems, seeking to understand the set of interactions and feedbacks that produce surprising or unanticipated behaviors. Her research has helped to identify the most critical drivers of landscape-scale change and generate predictions about how landscapes will respond to climate change or changes in management.
Dr. Laurel Larsen began by saying she approaches environmental challenges, many of which deal with restoration, from a systems perspective. The title of her presentation refers to the well-known reference of the Delta as a ‘wicked problem’, or one that cannot be solved in the traditional sense, but can be managed with appropriate knowledge and flexible institutions. This reference was first proposed by Riddle and Webber in 1972, who described a wicked problem as one where a linear traditionally scientific approach to problem solving would not capture the dynamics of complex system and their “waves of repercussions that ripple through systemic networks”.
“It would be naive of me to claim that the solution is ever just as simple as pouring water into the system,” she said. “I do hope to show how restoration science can melt away some aspects of these challenges, at least making these complex systems a little bit easier to understand or allowing us to better define our management objectives or anticipated outcomes. And yes, all of the examples that I’ll go through today do involve some form of hydrologic manipulation.”
Dr. Larsen presented a map showing the locations of the restoration projects she has worked on, which includes projects ranging from small in scale like these coastal salmon streams to large-scale projects in the Everglades and Chesapeake Bay. Her most intensive work so far is in the Everglades, where her initial work focused on using a variety of methods to understand the processes responsible for the ridge and slough landscape structure of the Everglades. Her work also focused on the processes responsible for the widespread degradation of the landscape which typically has led to a loss of open channel habitat.
Some of the methods developed in the Everglades became part of a project to evaluate how different types of vegetation communities differentially promote sediment accretion in one of the only parts of the Louisiana coastline experiencing land aggregation instead of net subsidence today. The objective was for the work to lead to the improvement of the numerical models being used to anticipate the long-term effects of engineered diversions and also to evaluate whether vegetation communities should and could be actively managed in such a way as to promote maximal sedimentation.
Dr. Larsen worked as part of a larger Chesapeake Bay restoration effort to understand how stream restoration within upper parts of the watershed influenced the downstream transport of nutrients, sediment, and carbon. She had the opportunity to work on understanding the biogeochemical and geomorphic impacts of two very different types of stream restoration used in an agricultural and an urban setting.
In Northern California, she worked on a project to understand how hydrologic manipulation of intermittent streams, which disconnect into a series of pools in the summertime, might enhance the survival of coho salmon and steelhead trout. Small coastal waterboards had secured funding for off-stream storage of winter flows and were interested in how best to use that water to balance agricultural needs with salmonid populations.
Currently, Dr. Larsen is working on sabbatical in Finland, which has peat soils covering about a third of its land area; about half of that area is drained for forestry operations. Collectively, boreal peatland hold about 60% of the total carbon that is in atmosphere and about a third of the carbon in soils, so they constitute a huge global store. In Finland, she is conducting a data-driven study of how carbon and water cycles interact in different types of peatlands, and control methane and carbon dioxide fluxes to the atmosphere.
She acknowledged that she has not worked in the Bay Delta, but many of the challenges faced in these other systems are quite similar to the challenges faced in the Delta, things such as land subsidence and species invasions in the Everglades and in Louisiana, loss of peat in the Everglades and the boreal landscapes, water quality concerns in the Chesapeake Bay and the Everglades, groundwater issues in coastal salmon streams, the need to promote habitat that supports wildlife, and the complexities of governance amidst many stakeholder groups and institutions.
“I believe that much of the insight and experience that I’ve gained in these other systems is quite transferrable to the Delta and may even infuse some new ideas into this community,” she said.
Her research methods have been wide-ranging. She has developed landscape scale and also small scale models of coupled flows, sediment, vegetation, and nutrient transport processes in wetlands. Her lab group is currently working on benchmarking an assessment of the national hydrologic model and the national water model that are both under development by government agencies for flow forecasting. She has conducted experimental studies in both the field and the lab involving some combination of flow manipulation and tracer introduction, as well as observational field studies ranging from the installation of new USGS gauging and water quality stations to sampling studies.
“In engaging all of these methods, my work has required substantive collaboration with people from many disciplines and also from government, academia, and industry, and methods that we have developed have in turn been useful for applied problems in other disciplines,” Dr. Larsen said, citing an example of a directional connectivity index she developed with colleagues as a performance indicator of landscape patterns in order to understand how spatially-explicit hydrological processes impacted fish movement in the Everglades.
THE MANY DIFFERENT DIMENSIONS OF WATER
“Water has many different dimensions and there are many complexities that come into play with considering hydrologic manipulation as a management tool,” Dr. Larsen said. “A lot of my thinking on this is informed by my work in the Everglades on CERP, also known as the Comprehensive Everglades Restoration Plan. The operational motto of CERP has been ‘getting the water right.’”
As in the Bay Delta, historic flows in the Everglades have been massively altered. The panel on the left shows the historic flows; the middle panel shows the flows after the water diversions and structural changes made to the system including the extensive construction of levees and canals.
The panel on the far right is the vision for the restoration, which involves balancing the needs of water for agriculture and urban areas with ecosystem needs. The tic-tac-toe graphic in the left corner of the diagram are the many dimensions to water: quantity, quality, timing and distribution.
“A big component of the much publicized stalling of restoration progress in the Everglades is the difficulty in figuring out how to enhance flow quantity to Everglades National Park in the southern part of the system, while ensuring that the water, which comes from the area around Lake Okachobee, a predominantly agricultural in the northern part of the system, is of adequate quality,” said Dr. Larsen.
The initial discussion didn’t involve flow velocity; one reason is that flows in the Everglades today are almost imperceptible – less than a centimeter per second. It’s very hard to even see this flow when you’re looking at the water, due to the drainage and compartmentalization by levees, so the importance of flow had to be formally demonstrated if it was going to be incorporated into management decisions in the restoration plan.
It’s challenging to evaluate the importance of a process for which there’s no modern reference, she said. At small scales, flows can be increased through extant vegetation communities using a combination of in situ flumes and pumps to pull water through in order to understand how vegetation controls flows and at what point the fluffy organic sediment at the bed begins to move.
“These processes are essential to include in large scale models of the Everglades but they are processes that you won’t find described in any fluid mechanics or geomorphology text book, so they needed to be tested and explored further in the field,” she said. “But then, how do we scale up this understanding to examine its impacts on the landscape? This is where modeling came in. Relatively simple models that captured the essential coupling between flow, vegetation growth, organic matter production, sediment transport, and nutrient dynamics suggested that only when flow transports sediment do we see a leveling off of vegetated area.”
On the plots on the slide, time is on the x axis and coverage of vegetation is on the y axis; the line on the graphs show that only when flows are sufficient to transport sediment can a patterned ridge and flume landscape be achieved that has a relatively high coverage of open water areas where the ridge coverage only gets to about 35%, she said.
A model was used to explore how the landscape would evolve over a range of flow conditions. The rectangular plots show the vegetation coverage; in this case, the x axis represents the flow conditions and the y axis is the vegetation coverage.
“The way to interpret this diagram is that any of the white parts of the plot represent places where vegetation coverage is expanding over time, whereas the black parts represent areas where vegetation is stable over time, and then the gray areas are whether either expanding or stable depending on how you approach that region,” said Dr. Larsen. “What this analysis showed is that there’s only a narrow range of flow velocities – about 2 to 5 centimeters per second – that promote the type of sediment redistribution needed to produce a ridge and slough landscape with broad channels and limited coverage of 30 to 50% of ridges.”
These findings were a key piece of information that was in planning an adaptive management experiment in which pulses of flow were reintroduced to a part of the landscape formerly isolated by two sets of levees that cutoff the from the rest of the Everglades.
The experiment, which is known as the DPM or Decompartimentalization Physical Model was designed as a ‘Before, After, Control, Impact’ experiment (or BACI). This was a statistical experiment where the effects of the impact of the introduced flow pulses are quantified by comparing an impacted site to control sites that did not experience the flow release and in which monitoring is completed from before the period of flow releases to after the period of flow releases, which are shown in blue.
The experiment was originally designed to take place over the six years, but still continues today due to continued funding. Part of the experiment was designed to test uncertainties associated with flow introduction and sediment redistribution while another part was designed to test practical engineering, and hence economic uncertainties about the extent to which the canals cutting across the flow path needed to be backfilled, Dr. Larsen said.
During the first flow release, they added green dye to visualize how the water moved through the affected area. The graph of the ridge to slough transect shows the results. The x axis is flow velocity; the y axis is the monitoring station, the blue line is the flow velocities before the flow release, and the orange line is the flow velocity after the flow release.
“We saw high velocities in the sloughs with the flow releases up to about 6 centimeters per second, whereas the flow release, flow velocities were only a fraction of centimeter per second,” said Dr. Larsen. “The flow release was accompanied by high bed shear stresses shown in the orange bars that were high enough to initiate flow transport represented by the orange bars being above this dashed line.”
The sloughs were covered with a type of vegetation that is ecologically important as it serves as the base of the ecosystem, but also creates a lot of drag on the flow. But what they saw was once they reintroduced flow, there was a rapid clearing which makes it even easier to achieve higher flows as clearing occurs.
“The question then was, does this actually transport sediment in a way that we believe is necessary for landscape development?” she said. “Our as of yet unpublished results suggest yes. What we see is that a few hours into the flow release, a lot of very small particles typical of epiphyten, or pond scum, become mobilized as evidenced by these high suspended sediment concentrations within the slough until there are none left to mobilize any more and we enter a period of forced depletion. At that point, the sloughs are very clear and we see an increase in the size of the particles being transported. The large fluffy organic floc is moving and this is what is needed to keep ridges from growing indefinitely wide over time.”
Water quality is a critical part of “getting the water right”, so they also monitored the concentrations of nutrients and conservative ions in the water, and then used a network modeling approach to understand the impacts of the canal backfill alternatives and the flow pulses.
“In short what we found is that only when canals are completely backfilled do you promote connectivity of both nutrients and conservative solutes across the gap,” said Dr. Larsen. “The other thing we found is that we found some evidence of phosphorous transforming the ecosystem a little bit further into the wetlands than before the flow release, but these effects did taper off, suggesting that appropriately engineered flow releases do constitute a viable means to restore the sediment redistribution process with only small ecological tradeoffs.”
“In the Everglades, just adding water ended up being a helpful process, but not one that was simple by any means to orchestrate, but well-coordinated restoration science ended up keeping that task from being impossible,” she said.
UNDERSTANDING ECOSYSTEM RESTORATION IN LARGER CONTEXT
Next, she turned to her work in the Chesapeake Bay to illustrate a project that underscores the importance of understanding ecosystem restoration in a larger context and particularly understanding networks of cause and effect from source points high in the watershed to sinks further downstream.
In the Chesapeake Bay watershed, stream restoration is often applied in hopes of helping management jurisdictions meet their TMDL requirements for nutrients or sediment. Stream incision is a pervasive phenomenon in many of the urban and agricultural subwatersheds of the Chesapeake Bay that is associated with rampant erosion.
“Most instances of stream restoration follow a highly prescribed physical template in which hard engineering structures are used to design channels of a particular slope, width, and meander wave length in order to ensure stability,” Dr. Larsen said.
These calculations are based on a prescribed physical template that was developed from observations of channel patterns of western rivers but are applied widely throughout the east. She worked on a comparative study on stream metabolism as an integrated measure of stream ecosystem health, and how it varied between neighboring watersheds with and without the instream restoration structures.
“What we found contributed to a much larger body of literature that suggests that this structural type of stream restoration often does not improve function – and this is key, particularly when it is done without stormwater controls higher in the watershed,” she said. “In our case, we found that the unrestored stream which did have watershed stormwater controls was more effective at retaining the amounts of organic matter and fine sediment needed to sustain critical biogeochemical functions in the streambed in comparison to the restored stream.”
“In the restored stream, we found high amounts of eroded bank sediment in transport during flow events, little retention of fines within the streambed between storm events, which is a conclusion that we reached through a combination of sediment fingerprinting studies and fine sediment tracer tests.”
In the next example, understanding hydrological connections between the watershed and what was happening in the stream was also critically important for addressing questions about how water management influenced the persistence of salmonids during the dry summer months.
“Seemingly identical pools would produce very different outcomes for fish with complete fish death in some pools and nearly complete persistence in other pools,” said Dr. Larsen. “Field surveys and statistical modeling by Cleo Woelfle-Erskine suggested that perhaps not surprisingly, dissolved oxygen is a critical determinant separating these two outcomes.”
“But what was surprising to us was the results of the water source tracking studies that followed,” she continued. “We were able to develop a statistical scoring system that indicated groundwater influence on pools, and what we found was that all of the pools which salmon recruited at the beginning of the summer and persisted in through the end of the summer had a persistent groundwater influence, and that shallow groundwater inflow actually helped maintain higher levels of dissolved oxygen in the pools, which was surprising to us.”
“We need to expand the study further but it seems a least here that the fish cued their behavior on the presence of groundwater inflow, so maintaining high levels of groundwater in those watersheds might be just as important if not more important to salmon conservation as surface water flows.”
NOVEL ECOSYSTEMS FOR NOVEL TIMES
“There’s been a lot of talk in the Bay about the role of novel ecosystems in restoration efforts, including in the Delta ecosystem,” said Dr. Larsen. “My experience with these restoration projects had led me to embrace the concept of novel ecosystems, given that the combination of stressors that these ecosystems are experiencing from climate change and other anthropogenic change is so radically different from anything in their immediate past. Restoration often focuses on restoring a historic ecosystem structure, but given the novel combination of stressors, restored function does not often follow. Rather, we often need to flip the equation on its head and design a novel ecosystem structure in order to restore function.”
In the Everglades, restoring historical landscape structure would have required removing the levees and canals, an approach that was strongly promoted or advocated for by some stakeholder groups, she said. If, however, the ultimate objective was restoration of the historic function of sediment redistribution for purposes of maintaining remnant ridge and slough habitat, that objective would not have been achieved by removal of levees and canals.
“For one, there are fewer available inputs of water to sustain those flows, which would result in lower overall water levels conducive to the choking of the waterways with even more emergent vegetation, including invasive cat tail,” said Dr. Larsen. “Secondly, flow velocities under these conditions would be slower than they would be historically because of vegetated drag from the existing emergent vegetation occupying former sloughs and likely not sufficient enough to redistribute sediment.”
“One of the key characteristics of non-linear environmental systems is that they are often characterized by irreversible trajectories of behavior such as this,” she continued. “Taking all of this into account, we could slightly redesign the compartmentalized structure of the Everglades to put in these gates culverts, and then use them to build up a head differential in the water that allows us to do pulse flow releases as in the DPM flow experiment. These short term releases do mimic historic short term flood pulses from the periodic overflow of Lake Okochobee up here and do have sufficient energy to redistribute sediment. So novel ecosystem structures aren’t always a bad thing when it comes to management for certain ecosystem functions.”
However, Dr. Larsen said that it’s often assumed that ecosystems composed of invasive species have diminished function, so there is a strong focus on eradication of those invasive species. While she acknowledged this approach seems entirely appropriate in the Delta based on the studies that have been done here, this approach diverges from approaches to ecosystem management elsewhere in the world, where abundant populations of invasives have been recognized as filling ecological niches in their own right and eradication is not pursued, perhaps because of its acknowledged impracticability.
How to quantify the function of invasives in novel ecosystems was a question that was pursued in a study of sedimentation and land building in southern Louisiana where they used LIDAR remote sensing imagery to gather spatially explicit information about the topography and the structure of wetland vegetation canopies and how they changed over a period of time with significant river flooding. They were interested in understanding the effect of vegetation communities on sedimentation and land elevations.
“We found that vegetation promoted sedimentation in place only in rooted native vegetation with extensive biofilm, but that invasive vegetation communities that replaced the natives, including water hyacinth, did not fulfill the same ecogeomorphic function,” Dr. Larsen said. “This finding may provide an even stronger impetus for management of invasive species in places like the Wax Lake Delta.”
HISTORY IS IMPORTANT
Historical knowledge leads to nature-inspired restoration designs and may expand ideas of what is possible in restoration efforts, Dr. Larsen said. In the Everglades, there was a lot of pushback around setting flow velocity targets to support maintaining the ridge and slough landscape as some thought that the landscape may have been naturally undergoing a gradual transition to a more homogenous state, and it seemed difficult to imagine flows in the very flat Everglades that were actually sufficient to transport sediment.
However, paleoecology and historical ecology provided some insights. Pollen records and sediment cores determined that the ridge and slough landscape features were persistent at the millennial timescale, while diving into the historical archive revealed that the Everglades experienced periods of substantial flow historically, and there were even rapids on the Miami River.
“These works expanded our idea of what may be possible for restoration to achieve,” she said.
In the Chesapeake Bay watershed, historical ecology inspired an innovative new approach to stream restoration that was quite different from the normal approach. Researchers working in the floodplains of incised streams noticed a black, organically rich layer that was present fairly ubiquitously in the incised banks throughout the East Coast. Sedge seeds preserved in the sediment suggested that formerly, these stream systems were relatively low energy, boggy wetland environments, rather than the typical meandering streams that are seen in the region today.
“By probing historical documents, they realized that the widespread construction of mill dams and the associated formation of mill ponds behind the mill dams had buried these historic wetlands,” Dr. Larsen said. “They determined much of the modern incision of streams is a result of the removal of these historic structures or as a result of them just falling into disrepair, which leaves a stair step in the floodplains that would then erode headward.”
“This realization led to the proposal of a radically different type of stream restoration in which the legacy sediment is fully removed from the floodplain. This reexposed the historical seeps and springs and in this plan, the channel was actually designed to go overbank and cut new paths through the floodplain rather than being held in place as a stable entity. This strategy for restoration was deployed as a pilot at Big Spring Run near Lancaster, Pennsylvania.”
“While our team is still collectively working up the results, the preliminary analyses are exciting. New channels have formed on the floodplain and sedges from the original hydric layer that were not planted as a part of the restoration are returning to the landscape. The stream reach has converted from a net source of sediment to a net sink, and it appears that rates of nitrogen and phosphorous retention and removal have increased substantially.”
“In addition to the brainstorming and horizon scanning that are so often discussed as integral to restoration science in a rapidly changing environment, I would argue that it is also important to scan your rear view mirror.”
BALANCING HUMAN AND NON-HUMAN NEEDS
“I would argue that the most exciting innovations in restoration science are nature inspired designs that balance human and non-human needs,” said Dr. Larsen.
She has been following closely the use of beaver dam analogs as a tool for increasing water storage in stream valleys in places like the Scott Valley in California. As discussed in a paper in Science, the initially simple human intervention of building beaver dam-like structures sets off a chain of naturally occurring reactions that eventually result in beavers reoccupying the floodplain, very high amounts of water storage and infiltration to groundwater, and a floodplain that is quite well connected to the channel.
Her group is now collaborating with an energy company from Alameda to investigate the possibility of using beaver dam-like structures to generate hydropower in a distributed fashion while also enabling fish passage and recreational activities, creating wetland and riparian habitat in a region upstream of these low head dams, and promoting groundwater recharge. This work is in response to a recent call from the Department of Energy to develop standard modular hydropower technology that achieves multiple diverse objectives.
VISION FOR THE DELTA SCIENCE PROGRAM
Dr. Larsen then outlined her vision for the Delta Lead Scientist position.
“First of all, the Science Action Agenda emphasizes the importance of synthesizing and integrating across and expanding upon existing modeling used in support of Delta science, and this is something I would eagerly work with the Integrated Modeling Steering Committee to achieve. Although the CASCADE modeling effort already uses some scenarios, I would hope to work with the larger community of modelers and non-modelers in the scientific community to outline more formal scenarios for management and climate alternatives, analogous to the RCP scenarios adopted by the climate modeling community.
“This scenario development would build upon the climate synthesis that was part of the ecosystem amendment to the Delta Plan, and would ideally be done in a coordinated two-way manner with the identification of adaptive management opportunities. I see one of my roles as being a bridge between the Integrated Modeling Steering Committee, CWEMF, and the Collaborative Adaptive Management Team, as well as a liaison between those teams and the broader scientific community.
“In my own career, I’ve done a lot of thinking about how to make modeling and model results more accessible, open, and reproducible, and in this respect, I’ve been inspired by what the Earth Surface Process Modeling community has achieved through CSDMS, which stands for the Community Surface Dynamics Modeling System, which is funded through NSF. In addition to chairing regular workshops and serving as a highly used repository for model code, CSDMS now includes a web-based interface that allows for coupling or daisy-chaining different types of earth system models, for instance, the sediment transport model with a flow or solute transport model.
“I look forward to working with the integrated modeling steering committee in their efforts to improve model interoperability and potentially seeking funding for model cyber infrastructure development, perhaps similar to what is available through CSDMS for using some of the tools available through this particular interface.
“One of the things that I’d very keen to advance, having been deeply immersed in this world at Berkeley for the past 5 years, is the reproducibility and accessibility of Delta science. This is really important because accessibility and reproducibility is essential in getting our science disseminated, understood, and used.
“I know that the passage of AB 1755 has galvanized a lot of great efforts in this community and in this area, but I would argue that we have the opportunity to break new ground here and go even further, particularly because of the Delta’s geographic location in the Bay Area, the data science hub. Berkeley recently received its largest donation in history earmarked for advancing data science initiatives, and even though I hate to admit it, Stanford ain’t so bad either in this respect. I can attest that there are many students who would like to use their data science knowledge to make a positive difference in the world and many of those show a strong interest in working on environmental challenges.
“One thing that may be beneficial to ongoing efforts in the Delta would be to assemble a panel of experts, both local and non-local, to periodically review and infuse with new ideas efforts in the areas of data reproducibility and data accessibility. A panel of experts might include someone like Deb Peters whose vision for open environmental science I found inspiring and who produced the graphics shown on this slide. She proposes using machine learning to analyze how people interact with data resources in order to predictably build efficiency and accessibility as more users undertake successful analyses, including things such as pre-fetching data or recommending datasets before they are requested, as well as the other strategies listed on the left hand side of the slide.
“I cannot overemphasize the importance of focusing on the whole pipeline of doing science and reproducibility initiatives, rather than just making the original raw datasets available. And I’m going to get on my soapbox here a little bit. In a reproducibility class that I taught at Berkeley in 2018, data science grad students tried to reproduce analyses in some of the papers that the instructors Max Offenhammer, an environmental economist and I had identified as being the best examples of peer reviewed, reproducible environmental science. Only rarely were the students successful mainly because the pipeline was often insufficiently transparent.
“One of these is the Pangeo initiative which is spearheaded by Fernando Perez at Berkeley. We’re currently collaborating on an NSF-sponsored project to build use cases for common data processing tasks on large datasets in the earth sciences and I can see a lot of potential for using tools such as this to promote utilization of the IEP and other monitoring and modeling datasets in the Delta as well. In these use cases, some of the tasks that are made available to the community are things such as fetching, data gap filling, and compiling data in a common format that’s then readily inputable to statistical analyses.
“Relatedly, once the datasets and commonly processing tools are readily available, it becomes increasingly easy to incentivize their utilization. There are good examples of this already in the California water scene, such as the California Water Data Hackathon recently run jointly by Berkeley and the State Water Resources Control Board. DWR has also sponsored water innovation contests, which turned out to make a great class project for undergraduate hydrology and water resources students. These crowd sourcing initiatives can be a great benefit to horizon scanning and also the production of useful data visualization tools or other tools that bridge the gap between scientists and stakeholders.
“While on the topic of the utilization of data, one additional thing that might be worth pushing for is the integration of data generation from the monitoring network with the display of results relevant to the identified performance measures. To the extent possible, it would be useful to visualize that information in a spatially explicit way, perhaps with near-real time integration and perhaps with an added layer of interpretation such as the red, yellow, green stoplight rating of nutrient effects on ecological processes seen here in this Everglades example. This is by my colleague Evelyn Geyser at Florida International University.
“One of my top priorities as Delta Lead Scientist would be to ensure the continuance of the funding programs started by John Callaway. As a possible mechanism for new funding, I would like to explore the possibility of partnering with program managers in the National Science Fountaion’s Coupled Natural and Human Systems program or with the National Socio-Environmental Synthesis Center or SESYNC in Annapolis, Maryland. At a minimum, I would also like to brainstorm how to provide some form of support or incentives to the scientific community to galvanize submission of coupled natural and human systems proposal by members of the community.
“I think it is important to have an ongoing, far-reaching discussion about what needs to be prioritized in future funding calls, and I know that John has done this in the most recent funding call. For example, riffing off of priorities already established in the Science Action Agenda, these include things like understanding the function of and anticipating novel ecosystems, understanding the impacts of changing water quality, and also topics that deal with Delta landscape ecology.
“Another thing that could be worth investing in is work on the optimal design or even the adaptive redesign of monitoring network. When I talk about adaptive redesign, I think Stephan Krause in the hydrologic community does a good job of outlining how monitoring networks that are adaptive in their spatial or temporal resolution are important in their ability to capture events that might be missed otherwise by traditional monitoring networks, so the idea here is to establish certain triggers that allow for more frequent sampling in time or spatially intensive sampling. Fortunately, the continued evolution of sensor and control technology makes these strategies increasingly more realistic to implement.
“Last, given the recent flux in water policy in California, I would be remiss not to mention plans to engage with the voluntary agreements to improve habitat and flow in the Delta and its watershed. While it is difficult to anticipate what that will look like at this time, thought that has been especially reinforced by my meetings thus far, I think it is quite possible that we may be asked to form panels and provide syntheses in support of the development of the agreements and that this could become a substantial part of my overall role as Delta Lead Scientist.
QUESTION: In the adaptive management experiment in which you have been involved, how was new information conveyed to stakeholders?
DR. LARSEN: “In the Everglades, this was done in several ways. I was a part of a science coordination team that had regular monthly meetings to discuss progress; managers at the Army Corps of Engineers in the South Florida Water Management District were also involved in those meetings and they were some of the people who had the power to determine how those on the ground efforts would adapt to the results that were emerging from those studies.
Another way that this two-way interaction happens in the Everglades is through regular meetings between the whole scientific community and the whole community of managers and that has actually been a pretty effective way to disseminate new science in the Everglades.”
QUESTION: How was this new scientific information acted upon by policy makers?
DR. LARSEN: “This is still an ongoing study. One of the plans in the comprehensive Everglades Restoration Project was to gradually decompartmentalize the Everglades. Initially one plan was to elevate the TamiAmi trail which cuts across the southern Everglades just upstream of Everglades National Park. It faced funding challenges so the length of that proposed project has gradually diminished from the whole length of the TamiAmi trail to a ten mile bridge to a two mile bridge to a one mile bridge. So there are these bureaucratic and funding related challenges, but the plan is for the decompartmentalization physical model to inform those larger scale decompartmentalization efforts.”
“One of the things that we learned that I didn’t talk about today, and we expected this first through the modeling, but then this was reinforced through the field experimentation we did, is that if you have a landscape that is already degraded in which emergent vegetation fully occupies the sloughs, it’s very difficult to go back to an open water habitat, so we’ve been seeing these pulse flow releases as a way to maintain existing landscape structure rather than to actually restore landscape structure that is considered degraded.”
“But one of the ideas that’s been floated around in the scientific community is the idea of doing more intensive management of that emergent vegetation, either through mechanically cutting new paths, new incipient sloughs, or through burning that vegetation. That’s something that we’ve had an opportunity to test with the continuation of the decompartmentalization physical model experiment. Some of our group underwent the very arduous task of using a machete to essentially cut a new incipient slough or waterway into a ridge in the area that is affected by these flow releases and found that flow velocities and sediment transport were quite high in that area. So whether this is a strategy that’s going to be deployed at much larger scales is still a topic that is under discussion.“
QUESTION: Can you give us another example of integrating monitoring network information into performance measures displays? The data visualization you spoke of.
DR. LARSEN: “I have spent a little bit of time on the Delta Stewardship Council’s webpage looking at the different performance measures and the graphs that area associated with them that display the extent to which they were met or not met over the past few years. One of the things that strikes me is that if someone was looking to obtain some of the most up to date information coming from the monitoring network, I don’t know if it was present or not, but it was difficult for me to find. And so one thought might be having visualizations that are maybe just as simple as showing the current position of the X2 for example, or showing concentrations of monitored nutrients which might be particularly important as we think about some of the upcoming water quality changes for the Delta region.”
“I think it would be particularly nice because if this was something that was accomplished, it could go a long way towards advancing some of the forecasting, both ecological forecasting, water quality forecasting, and water quantity forecasting that I know is a growing emphasis in this scientific community.”
“One of the scientific groups that I interact a lot with in my career right now is an ecological forecasting group. Real time ecological forecasting is a growing initiative nationwide and I think this is one relatively small thing, but one that takes a lot of infrastructure and a lot of work to implement that could really advance us towards doing near-real time ecological forecasting.”