Tree establishment in response to hydrology at IDOT wetland mitigation sites.

Details

• Creators:
  Matthews, Jeffrey W. ; Pociask, Geoffrey E.
• Corporate Creators:
  Illinois Center for Transportation
• Corporate Contributors:
  United States. Federal Highway Administration ; Illinois. Dept. of Transportation. Bureau of Materials and Physical Research
• Subject/TRT Terms:
  Field Studies Floods Hydrology Planting Recommendations Trees Wetlands
• Publication/ Report Number:
  FHWA¿ICT¿15 ¿005 ; ICT¿15¿005 ; UILU¿ENG¿2015¿2005
• Resource Type:
  Tech Report
• Geographical Coverage:
  Illinois
• Corporate Publisher:
  Illinois Center for Transportation
• Abstract:
  The Illinois Department of Transportation (IDOT) has compensated for unavoidable impacts to wetlands in transportation
  
  project corridors by restoring and creating wetlands throughout Illinois. As part of the IDOT Wetlands Program, monitoring
  
  of performance measures is conducted by the Illinois Natural History Survey (INHS) and the Illinois State Geological Survey
  
  (ISGS). The goals of this research were to determine the effect of flood events on the establishment of planted and
  
  naturally recruiting trees in IDOT mitigation wetlands and to make specific recommendations for tree planting and the
  
  establishment of mitigation performance standards. We compiled and analyzed existing data from INHS and ISGS
  
  monitoring reports and conducted additional field surveys to determine long‐term planted tree survival and assess natural
  
  tree recruitment. Based on our compilation of data from INHS wetland monitoring reports, we determined that the
  
  number of planted trees alive at mitigation wetlands by the end of mitigation monitoring was, on average, 57% the
  
  number of trees planted originally. We revisited ten older mitigation wetlands in 2014 and recounted surviving planted
  
  trees, and found that survival rate continued to decline beyond site monitoring periods. Tree mortality was clearly related
  
  to site exposure to flood disturbance during individual years, through the end of site monitoring, and beyond site
  
  monitoring periods. Depth and duration of inundation were more important than flood frequency in determining tree
  
  survival. Natural colonization greatly exceeded planting in terms of both stem density and basal area. However, natural
  
  colonization was not clearly related to site flood exposure. In sites that are exposed to long‐duration or deep flooding,
  
  planted tree survival is likely to be low regardless of species planted or the degree of on‐site management of plantings. We
  
  recommend that realistically attainable mitigation performance standards be developed on a site‐specific basis,
  
  considering the likely hydrologic regime of the site. In some situations, faster‐growing species provide tangible
  
  environmental benefits. In addition, natural tree colonization can supplement planting, even in sites where planted hard‐
  
  mast species are unlikely to persist.
  
  
• Format:
  PDF
• Funding:
  R27¿143
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha256:47f19f5879d4920810d69632e19b22177fc1e9c6864290b17e250e492849e843
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/28636/dot_28636_DS1.pdf
• File Type:
  [PDF - 3.80 MB ]