Landscape Conservation Design (LCD) is somewhat akin to a multi-faceted gemstone: there are many sides to it, and each person’s view of it can change, depending on their perspective. LCD is both a process - how you make conservation decisions - and an end product: a map or scenario plan.
“Landscape Conservation Design is a bridge between biological planning and conservation delivery. We currently lack that bridge; that’s broadly where we are in the Gulf Coast Prairie,” says Ben Kahler, Science Coordinator for the Gulf Coast Prairie Landscape Conservation Cooperative (GCP LCC). “To better focus conservation on the ground, we need to know what our priorities are and focus on achieving our objectives in a way that maximizes our return on investment.”
The “coarse filter” approach
The way that the GCP LCC proposes to do this is through a two-pronged approach, called coarse filter and fine filter, respectively. “The coarse filter will produce maps that depict an aggregation of data for the entire GCP geography, and it’s habitat centric,” says Ben. “This approach focuses on the broadly defined habitats described in the LCC’s Science Strategy. For the majority of those habitats, we have data covering the entire Gulf Coast Prairie geography that can be depicted spatially (oyster reefs and karst not as much). Blair Tirpak, our GIS Specialist, is currently crunching data on tallgrass prairie.”
The Gulf Coast Prairie’s coarse filter LCD process will integrate the following data for each focal habitat type:
The resulting coarse filter design will be a representation of where broadly defined habitats are most aggregated or disaggregated, measured as a percentage of habitat within catchments (i.e. subwatershed areas of variable size). This is another way of measuring habitat connectivity as well.
Fine filter: Just because you have grasslands does not mean you have bobwhites
The fine filter approach is a different process with a different level of resolution. The fine filter LCD uses focal species to identify conservation priorities. “We have 28 focal species (6 are tier 1), which will drive the fine filter process,” explains Ben. “For example, instead of focusing where tallgrass prairie occurs or could occur, we will look at where tallgrass and other grasslands provide the conditions that are more or less suitable for focal species such as bobwhite.”
The fine filter approach requires biological planning objectives (i.e. population targets) and habitat models that explain how habitat conditions will influence species populations. “The problem is,” Ben pointed out, “Some of our focal species don’t have models yet. We already have models or sufficient data to model quail, mottled duck, some aquatic species (developed by the Southeast Aquatic Resources Partnership), black-capped vireo, northern pintail, and eastern meadowlark. On the other hand, we hardly know where freshwater mussels and oyster reefs occur.”
The fine filter approach will bring together data and current biological understanding, represented by species-habitat models. Then an optimization strategy needs to be applied to produce a design that maximizes the best habitat conditions across the landscape in the best configurations possible to achieve our landscape objectives for many focal species. Because the fine filter approach requires far more data and is far more time intensive, the GCP LCC has chosen the corridor from the Edwards Plateau to the Gulf of Mexico, encompassing the lower Colorado River watershed as its first fine filter design. This region includes not only a good cross-section of habitats, but also a good deal of partner interest due to issues such as water deficit, development threats, endangered species, and population growth.
LCD with and without population objectives
The ultimate goal of a LCD is to ascertain what kind, how much, and where habitat is needed to achieve species population objectives. The LCD answers the question, if we want 20,000 Bobwhite in this region, how do we achieve that? However, we are years away from having true biological objectives that are measurable for many species.
According to Ben, “In some cases, an objective could be as simple as stabilizing a population that’s declining. In other cases, objectives may exist, but they are measured differently. In the Gulf Coast Prairie, three bird conservation Joint Ventures are in the process of standardizing their various population objectives for bobwhite.”
What’s the timeline?
The GCP LCC’s first coarse filter design will be largely done by the end of the summer. “It’s essentially a ruleset on how to combine data products, and then we run the numbers.”
The fine filter, on the other hand, is still in its infancy. Ben sees himself as staffing an effort that includes the science team, the Steering Committee, and many others. They are still working through their first iteration of a fine filter approach.
Ben concludes, “The fine filter LCD will be a representation of how to achieve our common vision, but in consultation with many others, including private landowners and natural area managers. This leads us to the next step in this approach, which is to better understand our stakeholders - whether through surveys or some other approach - so that we can connect our biological priorities with the sites where landowner acceptance and capacity are most likely to result in lasting changes on the landscape.”