Senior Scientist Robin Grossinger discusses the latest research working to develop tools and to understand how to build landscapes resilient to climate change and able to support native species into the future
The state of California has set ambitious restoration goals for restoration of the Delta’s ecosystem as embodied in the Delta Plan and other processes. Even with restoration planned now with the California Eco Restore program, significantly downscaled from the 100,000+ acreage originally envisioned with the Bay Delta Conservation Plan, the targets for restoration acreage still number in the tens of thousands of acres.
Preparing for large-scale restoration presents many challenges and the San Francisco Estuary Institute‘s Resilient Landscapes Program is working to address those, developing restoration and management strategies to reestablish and sustain key ecological functions and servicesm as well as integrate natural and human infrastructure to create systems that are more adaptive to climate change and other stressors.
At the May conference, New Approaches to Climate Change in the San Francisco Bay-Delta, senior scientist Robin Grossinger gave a presentation on how the Institute’s projects are working to translate science into data-driven, place-based, collaborative, and creative visions for resilient future landscapes in the Bay and the Delta.
Robin Grossinger began by noting that there are a lot of challenges faced by our ecosystems, but some of these challenges that we humans can control. Sea level rise is a challenge, but at least some of our systems do have the potential to respond positively to sea level rise, he noted. “The tidal amplification in the South Bay that makes sea level rise adaptation for marshes and people so challenging is largely of our own construction, and thus could be mitigated substantially by restoration,” he said. “That would make it easier for all the marshes to adapt and keep up themselves.”
Marshes can keep up with high rates of sea level rise if they have enough sediment – again something that we control, he said. “We manage our watersheds, we manage the shoreline—the shape and configuration—and then even megafloods could probably be good for marshes as they bring a lot of sediment. And then there’s fresh water and transition zones, so we’re starting to get glimmers at this point of what we could do that could make adaptive landscapes and systems,” he said.
But how do we get there? Mr. Grossinger said he’d be talking about some of the challenges, such as how to bring the different fields of science – ecology, population dynamics, landscape ecology, conservation biology, the physical sciences – and trying to be explicit about what is needed. “How much of those all different things do we need and where and how do they fit together and then, how do we actually implement those and be clear enough of what we need?,” he said. “Because right now we’re pretty vague about it. You know, we need transition zones, and we need fresh water and sediment. So, and then how do we do that at the scale that’s needed?”
The challenge is bigger than the individual projects, he said. “This challenge of translating our science from a lot of different areas and making visions that are explicit enough and compelling enough and really scientifically-based, but show what we can do and what we need to do,” he said.
So why resilient landscapes? “Because of the landscape scale, clearly we need to be operating at a bigger scale than we usually do to sustain ecological functions,” he said. “We’ve always known that, but now it’s really clear with migration and species needing to move and refuge and connectivity and populations needing to communicate and adapt; and then the physical drivers that are going to sustain the habitats and also drive the transformations that can actually be positive through sediment and flooding and fire – all those things need to happen at the appropriate scale.”
We’re going to need to integrate all the different elements across the landscapes, Mr. Grossinger said. “We’re going to need to integrate and interact with the infrastructure and the built environment too, more so than we typically have, and by this I mean aquatic and terrestrial systems as there’s a lot of interplay,” he said. “Resilient means in a flexible and adaptive way – I think of it as how do we give these ecosystems the best chance of adapting and surviving and thriving in the coming decades as they have to adjust and reconfigure? There will be some different species too we need to take care of coming from the south – it’s going to be a changing mix, but we do have the potential to make it much more resilient than it is today, to sustain these ecosystems much better.”
Mr. Grossinger said he was going to focus on ecological resilience with the idea that we as a scientific community have to figure out what we really mean by resilience, and what’s going to make ecosystems resilient. “That’s a big enough challenge for us,” he said. “But then we do also have to place it in this larger context if anyone else is going to listen to us and actually care about it and fund it.”
Historically, freshwater and sediment used to be delivered to the marshes, but with our modern infrastructure, it now bypasses the system, he noted. “In the future though, we could integrate our infrastructure, our wastewater infrastructure with our wetlands systems so that they work better,” he said.
“There are a number of reasons why we think that would be resilient and they’re all distinct, so I wanted to break out some of them. One is the idea that marshes can accrete faster under freshwater conditions, also with increased nutrients, and this could be a relatively reliable source of fresh water. We look at reservoirs that way for coldwater fisheries; it’s good to have a freshwater-dependent ecosystem actually near a societal infrastructure that’s likely to deliver that very confidently. People are going to be flushing their toilets. You can count on that probably more than most things.”
Habitat complexity is an important part of resilience. “It is good for the species in the system to be able to do different things under different conditions: in a drought, different habitats being available than there are when there’s more fresh water. Another theme is that creating bigger patch sizes by connecting these together reduces the chance of local extirpation.”
There are probably more elements here than just what this particular approach uses, he said. “We have a bunch of ideas of what resilience includes, what confers resilience, but we found that we wanted a more systematic framework through which to think through all of the dimensions from the physical to the ecological and the issues of scale and spatial and temporal scale, so we started developing this framework for landscape resilience. We’re still working on it, so I’m going to go through it fairly quickly but just to give you a flavor of how we’re thinking about this.”
The study’s approach is looking at the literature from a wide array of science to develop a framework. “The framework will be part of this toolset of how do we translate the science, and then you can apply that to a particular place with all of the expertise of that place and the existing understanding of it. And that helps us get towards visions which actually are explicit about what they’re trying to achieve ecologically.”
This is being developed in collaboration with Google’s new Ecology Program, as well as international and regional advisory teams. A number of the members of the international advisory team are quite involved in the international conversation about ecological resilience in this challenging time of changing climates, he said.
“It’s been actually slightly disconcerting how excited they’ve been about what we’re doing, and suggests that there’s not that much of quite what we’re doing happening around the world,” he said. “The regional advisory team has a lot of people who are experienced and knowledgeable about the ecosystems we’re working with, so that’s been a neat combination.”
There are seven attributes they are working with:
Setting: A ‘no-brainer’ but it’s actually very important, he said. “What resilience means and what you’re trying to make resilient to what varies from place to place, as the opportunities and the potential does, so you need to be really explicit about that from the beginning, and identify the potential.”
Processes: “True resilience over time is going to mean we have re-established processes at a variety of scale that will drive sustainable systems. For example, as we’ve been talking about creeks delivering sediment to the Bay but there are a lot of other driving processes for other components of this system.”
Connectivity: This means a lot of different things, from habitat patches to populations and the way different components interact. “It also needs to be appropriate connectivity; in many of our systems, aquatic systems in particular, they’re overly connected; there can be too much connectivity.”
Complexity and diversity: “Riparian corridors are a classic element; we combined complexity and diversity which are often talked about in overlapping ways, and that applies at a number of different levels, from genetic to the population and landscape scale.”
Redundancy: “It’s obviously really important that we need to have multiple elements. There are a few different levels in the literature of redundancy, from the role species play in the ecosystem to the number of habitats you have in case you lose one, so those are things that we can be explicit about: what we mean and how big and how many in a particular place. It’s also kind of tied in with modularity and trying to have not everything be contaminated by everything else. Like if something bad happens in one place, you want the other places to stay somewhat independent, so that’s where connectivity can be overly emphasized.”
Scale: It’s so important, we often have trouble thinking about how to consider it. “We need to think about the time scale and how we have to have plans that are different at different points in the next decades. And then there’s also the scale issue and the cross-scale issues,” he said.
People: “Our role at this point, and really probably always in human culture, is going to be essential to making these systems resilient through adaptive management and through the things we do. So we are obviously an essential part of how we shape the landscape.”
The Delta Landscapes Project
The Delta Landscapes Project is a multi-year project addressing the question of how to envision these landscapes in the future in all of their complexity, he said. “I’m going to just draw on this project as an example of how we can quantify metrics – spatial metrics and landscape ecology metrics in this case – that can reflect or quantify aspects of the system that we think ay relate to resilience, based on our literature and our knowledge of the system,” he said.
He gave an example of the connectivity of broad riparian corridors, which gets at scale as well as connectivity. “We’ve been able to identify the loss in that … it starts to suggest what one might do in the future to increase that dimension of resilience.”
“Similarly, the incredible transformation of floodplain habitat,” he said. “Different types of inundation from tidal to long-term, like seasonal inundation where you’d have freshwater flooding for months at a time to the more temporary flooding, all greatly reduced; we can link that to the attributes we think that confers on the system and then quantify it and set targets and then actually manage towards that.”
“We can use that guidance to develop landscape visions, using the concept of operational landscape unit, a term from the Dutch, which talks about how you bring together these different attributes of a system into a vision at the right scale that’s managed to some extent; it’s not a pure system but it is viable, it’s functional, it has metrics, things you can quantify and report and make performance measures and advise then all the individual pieces which will fit into that.”
Mr. Grossinger said they explored this idea in a conceptual way for the McCormack-Williamson Tract in the northeast Delta. They understood the setting of that spot with the particular opportunities that offered, how it had changed, and what the existing potential was. “There’s a fair amount of natural topography still present that could be used, and playing around with different scenarios of evolution over the next century and suggesting that you could develop a vision as part of a larger unit that would be much more resilient and adaptive. Then you could be explicit about what were the elements that you wanted to see, and then integrate that with all the different planning processes that would be needed to make that come into effect.”
“The only way we’re going to create these resilient landscapes is by having a vision that is longer term and larger scale,” he said. “We still almost always seem to have to do individual projects but they need to add up to something. Interestingly, some of the infrastructure barriers now will phase out at certain points in the future. So being ready when the highway is rebuilt, or the lease for the road to the radio tower is up, or all of these things. All these barriers do get redesigned or rebuilt at some cycle. Even the Bay Bridge gets rebuilt every once in a while. Maybe more frequently than we had hoped.”
Novato Creek, North Bay
“At Novato Creek in the North Bay, we’ve taken the idea a bit further, working with a lot of different people, and we’ve tried to develop a resilient landscape vision,” Mr. Grossinger said. “We’re pulling together a lot of the different elements like sediment delivery to a sort of deltaic marsh area, seepage levees, larger patch size, increasing tidal prism, and allowing the system to also provide some flood control benefits. Also bigger patch size, transition zone, a lot of the different elements we talked about, trying to integrate them in a place and show how that would look; then we actually have metrics that quantify that.”
The project was designed to also meet some other dimensions of resilience, such as flood protection, reduced sediment maintenance dredging costs, and wastewater benefits, he said. “Ultimately these transportation corridors have to be protected as well, and members of the project team are doing an economic analysis to see if it actually pencils out that this approach over the long run is similar cost or maybe even has cost benefits,” he said.
“Probably the ultimate challenge is this two-step of what do we think the ecosystem really needs, and how do we take our best science and deal with the uncertainty of all that but while still being specific enough that we can interact with engineers and planners and folks who actually need those specifics,” he said. “Then secondly, really design it in concert with these other sectors – where’s the sweet spot in the middle that will actually fund projects and have mechanisms that support them over time.”
“So, in closing I just want to thank all the different partners on these different projects, many colleagues, many of whom are in the room today, so thank you.”