Disentangling the potential effects of land‐use and climate change on stream conditions. (19th January 2020)

• Record Type: Journal Article
• Authors: Maloney, Kelly O.; Krause, Kevin P.; Buchanan, Claire; Hay, Lauren E.; McCabe, Gregory J.; Smith, Zachary M.; Sohl, Terry L.; Young, John A.
• Is Part Of: Global change biology. Volume 26:Number 4(2020)
• Page Start: 2251
• Page End: 2269
• Publication Date: 2020-01-19
• Subjects: benthic macroinvertebrates -- Chesapeake Bay watershed -- Chessie BIBI -- prediction -- projection; Climatic changes -- Environmental aspects -- Periodicals; Troposphere -- Environmental aspects -- Periodicals; Biodiversity conservation -- Periodicals; Eutrophication -- Periodicals; 551.5
• DOI: 10.1111/gcb.14961
• Languages: English
• ISSNs: 1354-1013

Abstract

Abstract: Land‐use and climate change are significantly affecting stream ecosystems, yet understanding of their long‐term impacts is hindered by the few studies that have simultaneously investigated their interaction and high variability among future projections. We modeled possible effects of a suite of 2030, 2060, and 2090 land‐use and climate scenarios on the condition of 70, 772 small streams in the Chesapeake Bay watershed, United States. The Chesapeake Basin‐wide Index of Biotic Integrity, a benthic macroinvertebrate multimetric index, was used to represent stream condition. Land‐use scenarios included four Special Report on Emissions Scenarios (A1B, A2, B1, and B2) representing a range of potential landscape futures. Future climate scenarios included quartiles of future climate changes from downscaled Coupled Model Intercomparison Project ‐ Phase 5 (CMIP5) and a watershed‐wide uniform scenario (Lynch2016). We employed random forests analysis to model individual and combined effects of land‐use and climate change on stream conditions. Individual scenarios suggest that by 2090, watershed‐wide conditions may exhibit anywhere from large degradations (e.g., scenarios A1B, A2, and the CMIP5 25th percentile) to small degradations (e.g., scenarios B1, B2, and Lynch2016). Combined land‐use and climate change scenarios highlighted their interaction and predicted, by 2090, watershed‐wide degradation in 16.2% (A2 CMIP5 25th percentile) to 1.0% (B2 Lynch2016) of stream kilometers. A goal for the Chesapeake Bay watershed is to restore 10% of stream kilometers over a 2008 baseline; our results suggest meeting and sustaining this goal until 2090 may require improvement in 11.0%–26.2% of stream kilometers, dependent on land‐use and climate scenario. These results highlight inherent variability among scenarios and the resultant uncertainty of predicted conditions, which reinforces the need to incorporate multiple scenarios of both land‐use (e.g., development, agriculture, etc.) and climate change in future studies to encapsulate the range of potential future conditions. Abstract : Maps showing small NHDplusV2 catchments (<200 km 2 in upstream drainage) across the Chesapeake Bay watershed predicted to be in Poor, Fair, or Good condition under baseline conditions (A), the A2 economic growth land cover projection combined with median climate 2090 projections from CMIP5 scenarios (B) and the B2 environmental sustainability land cover projection combined with median climate 2090 projections from CMIP5 scenarios (C). Upper focus area centers on region near the Hornell, NY, lower focus area centers on region near York Pennsylvania, and Bel Air Maryland.