Extinction & modeling articles from March BLN meeting

In Conservation Biology volume 35, issue 1 (Feb. 2021) is an article titled Vascular plant extinction in the continental United States and Canada, by Wesley M. Knapp, Anne Frances, Reed Noss, Robert F. C. Naczi, Alan Weakley, George D. Gann, Bruce G. Baldwin, James Miller, Patrick McIntyre, Brent D. Mishler, Gerry Moore, Richard G. Olmstead, Anna Strong, Kathryn Kennedy, Bonnie Heidel, and Daniel Gluesenkamp. Abstract: Extinction rates are expected to increase during the Anthropocene. Current extinction rates of plants and many animals remain unknown. We quantified extinctions among the vascular flora of the continental United States and Canada since European settlement. We compiled data on apparently extinct species by querying plant conservation databases, searching the literature, and vetting the resulting list with botanical experts. Because taxonomic opinion varies widely, we developed an index of taxonomic uncertainty (ITU). The ITU ranges from A to F, with A indicating unanimous taxonomic recognition and F indicating taxonomic recognition by only a single author. The ITU allowed us to rigorously evaluate extinction rates. Our data suggest that 51 species and 14 infraspecific taxa, representing 33 families and 49 genera of vascular plants, have become extinct in our study area since European settlement. Seven of these taxa exist in cultivation but are extinct in the wild. Most extinctions occurred in the west, but this outcome may reflect the timing of botanical exploration relative to settlement. Sixty-four percent of extinct plants were single-site endemics, and many occurred outside recognized biodiversity hotspots. Given the paucity of plant surveys in many areas, particularly prior to European settlement, the actual extinction rate of vascular plants is undoubtedly much higher than indicated here.

And, a new report by NatureServe finds over one-third of species and ecosystems in the United States are at risk of disappearing: “During a time when species are going extinct faster than any period in human history, the survival of species and persistence of healthy ecosystems requires science-based decisions. A new analysis by NatureServe addresses five essential questions about biodiversity–the variety of life on Earth–that need to be answered if we are going to effectively conserve nature. In the first report of its kind, Biodiversity in Focus: United States Edition reveals an alarming conclusion: 34% of plants and 40% of animals are at risk of extinction, and 41% of ecosystems are at risk of range-wide collapse. The analyses presented in the report inform how to effectively and efficiently use our financial resources to make the best conservation decisions.” Here’s the full report:

And from our March meeting as presented by Josh Albritton and published in Natural Areas Association volume 39, issue 4 (2019): Spatial modeling improves wetland inventories in Great Smoky Mountains National Park, by Alix Pfennigwerth, Joshua Albritton and Troy Evans. Abstract: Great Smoky Mountains National Park (GRSM) is home to over 800 wetlands, including rich montane seeps, bogs, montane alluvial forests, Appalachian canebrakes, alder swamps, rush marshes and beaver ponds. GRSM’s wetlands are typically small and occupy a relatively small fraction of the landscape, yet they harbor disproportionately high amounts of biodiversity and provide critical habitat for many rare species. Since 2010, the GRSM Inventory & Monitoring (I&M) Program has performed a comprehensive wetland inventory to aid in the protection and restoration of the park’s wetland resources. However, the expansive (816 mi2), topographically complex, and remote nature of the park presents several challenges to this work. Simple models based on low (<10%) slope have been informative to wetland surveys at low elevations (<3,500 ft), but such models have proven to be generally ineffective at locating wetlands in steep, high-elevation areas. As a result, despite their ecological importance, high-elevation wetlands have been largely underrepresented in our inventory: in 2015, less than over 92% 440/476) of wetlands in the inventory occurred below 3,500 ft. To address this problem, we used maximum entropy (Maxent) to model relative wetland habitat suitability throughout the park based on 24 environmental variables related to elevation, climate, vegetation and soils. Since applying the model in 2016, we have located over 140 new high-elevation wetlands, nearly quadrupling our previous high-elevation wetland inventory. Overall, Maxent habitat modeling is a relatively easy-to-use tool that, when coupled with existing protocols and institutional knowledge, can help land managers achieve a more efficient and effective workflow for planning, prioritizing and implementing field inventories. We encourage other parks and organizations to embrace similar spatial modeling approaches in their efforts to detect priority plant community locations.

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