Why do a rapid ecological assessment?
Management actions to target desired conservation and restoration outcomes for any land unit or region should proceed from a sophisticated understanding of current and potential condition and configuration of the ecological system of interest. Spatial depictions of where to apply management actions in order to maximize their effectiveness are a cornerstone of conservation design. Open Pine Woodland and Savanna was historically a dominant vegetative cover for much of the East and West Gulf Coastal Plains, some portion of the Ozark Highlands, and much of the South Atlantic and Peninsular Florida Landscape Conservation Cooperatives. About 95% of the original habitat has been lost due to development, conversion to agriculture, and the timber industry. Historically, frequent fire played a role in maintaining the open, savanna-like forest structure and grassy understory, which, along with other characteristics, form an ecological niche utilized by many species, including Mississippi Sandhill crane (endangered), red-cockaded woodpecker (endangered), and gopher tortoise (candidate for most of its range, threatened west of the Mobile and Tombigbee Rivers in AL, MS and LA).
In 2013 the Gulf Coastal Plains and Ozarks Landscape Conservation Cooperative (GCPO LCC) Adaptation Science Management Team (ASMT) identified open pine woodland and savanna in the East and West Gulf Coastal Plain subgeographies as one of the nine priority ecological systems on which to focus initial science investments. From this the ASMT provided an initial set of “landscape endpoints”, or indicators, in their draft Integrated Science Agenda (ISA) related to amount, configuration, and condition that reflect the desired ecological state of the open pine system. After these were identified the next logical step was to identify where in the GCPO LCC landscape these desired conditions were being met, how much of the landscape was in the desired condition, and how much more was needed and/or could be provided by management to reflect those conditions. In essence, before we could go about prioritizing science investments we needed to know where open pine was located on the landscape. The GCPO LCC rapid ecological assessment takes a regional approach to identifying areas where priority systems are in the desired ecological state identified in the ISA and uses the most current, comprehensive, and consistently-derived geospatial data available in its process.
How was the ecological assessment conducted?
We assessed amount, configuration, and condition of this system within the GCPO boundary by evaluating spatial data layers representative of desired ecological states for the system and combining the layers in an additive mapping procedure. Input layers included a “pine mask” of ecological systems that are currently/potentially dominated by pine (derived from the USGS National GAP land cover data layer), estimations of basal area and canopy cover published by the USFS, and unpublished estimations of midstory density, midstory basal area, and average tree diameter per acre provided by USFS Remote Systems Application Center scientists. Each input layer in the additive mapping procedure is comprised of only those cells for which threshold values are met for each condition. Score values were assigned to each input layer, the layers were summed, and the output was processed further to identify areas where the greatest number of desired conditions occur in the greatest concentration.
What did we find?
The initial draft open-pine assessment suggests pine-dominant forests are common in the GCPO, covering about 47.8 million acres, or 27% of the total area. Less than 4% of the pine-dominant forest meets the endpoint condition thresholds representative of desirable habitat characteristics. The process identified 1.7 million acres of open pine on 7825 patches widely scattered throughout the GCPO, mostly in the East and West Gulf Coastal Plains. We identified 700,590 acres in 344 patches >600 acres in size and within 3 km of patches also >600 acres in size. The configuration of patches in the GCPO is most densely concentrated in Chattahoochie, Marion, and Taylor Counties, Georgia; Santa Rosa and Okaloosa Counties, Florida; Beauregard and Vernon Parishes, Louisiana; and Polk County, Texas. The draft assessment report has undergone initial partner review and draft open pine polygon patch layer and open pine conditions summarized by HUC12 basin layers are now available on the GCPO Conservation Planning Atlas. All products will be revised following a second round of reviews early this summer.
How can conservationists use this product?
Spatially explicit assessments of priority systems at large landscape scales can inform and direct the conservation efforts of land managers, agencies, NGOs and the broader conservation community. These data products can also be combined with models of urbanization and climate change to assess future threats to the priority systems, as well as habitat models to assess their value for wildlife. The map algebra process is fairly simple and repeatable, and in future iterations endpoint values and data layer input scores can be easily adjusted to estimate amount and configuration scenarios reflective of alternative forest conditions. We will follow this with a second installment that assesses relationships among open pine endemic species and their associated landscape endpoints in order to provide clear linkages among habitats and species in the system, help the LCC partnership identify and prioritize data needs, and lay the necessary groundwork for a comprehensive conservation design strategy in the GCPO.