2017 Assessment of Native Plants in Treatment Plots

Transcription

1 15771 Creekside Lane Osseo, MN (651) Assessment of Native Plants in Treatment Plots Lake John (# ) Wright County, MN Surveyed June 8, 2017 Survey, Analysis, and Reporting by: James A. Johnson Aquatic Ecologist, Freshwater Scientific Services, LLC 2017 Freshwater Scientific Services, LLC Page 1 of 5

2 Purpose of Survey This survey was conducted to assess the native plant community present in the proposed treatment plots in the northern finger bay of Lake John (# ). These proposed plots supported dense in 2016, but treatment has not been allowed in order to protect beds of waterlilies and other native plants that would be affected by 2,4-D herbicide. The Lake John Association has recently expressed interest in trying a different herbicide (endothall rather than 2,4-D) to control the in these plots with the goal of controlling while also minimizing damage to the lilies and other native plants in the treated plots. This survey was requested by the Minnesota DNR as a part of the permit review process, but completion of this survey does not guarantee that a treatment will be permitted by the DNR. Survey & Analysis Methods Native Plant Survey Freshwater Scientific Services surveyed the two proposed treatment plots in the finger bay on June 8, During this survey, we conducted rake tosses at 14 locations, and assessed the abundance of native plants retrieved on the rake (collectively and for each species individually). We then calculated the frequency (% occurrence) and mean density for each of the encountered native plant species, and mapped the location and density of each species. Surveyed Path Native Plant Sample Sites Density (2016) Freshwater Scientific Services, LLC Page 2 of 5

3 Results Lake John Native Plants in Proposed plots: June 8, 2017 Sensitive to Common Name Scientific Name % Occ Mean Density Endothall? Yellow Lily Nuphar variegata 100% 1.21 No Sago Pondweed Stuckenia pectinata 93% 0.93 Yes Illinois Pondweed Potamogeton illinoensis 43% 0.50 Somewhat White Lily Nymphaea odorata 43% 0.43 No Chara Chara spp. 29% 0.50 No Water Crowfoot Ranunculus aquatilis 21% 0.43? Hardstem Bulrush Schoenoplectus acutus 21% 0.21 No Narrow Pondweed Potamogeton sp. 21% 0.21 Somewhat Wild Celery Vallisneria americana 21% 0.21 No Clasping-leaf Pondweed Potamogeton richardsonii 14% 0.14 Somewhat Bladderwort Utricularia vulgaris 7% 0.07? White-stem Pondweed Potamogeton praelongus 7% 0.07 Somewhat Flat-Stem Pondweed Potamogeton zosteriformis 7% 0.07 Yes Native Plant Diversity Native Species / Point 1 6 Density (2016) Freshwater Scientific Services, LLC Page 3 of 5

4 White Lily Yellow Lily Sago Pondweed Illinois Pondweed 2017 Freshwater Scientific Services, LLC Page 4 of 5

5 Chara Water Crowfoot Clasping-leaf Flat-stem Pondweed 2017 Freshwater Scientific Services, LLC Page 5 of 5

6 Online Resources & Contacts Minnesota Administrative Rules for Aquatic Plant Management Minnesota DNR Aquatic Plant Management Regulations & Permit Application Forms Christine Jurek Invasive Species Specialist Minnesota DNR (320) (ext 232) Steve Enger Aquatic Plant Management Program Coordinator Minnesota DNR 500 Lafayette Road Box 25 St Paul, MN (651) Freshwater Scientific Services, LLC Page 6 of 5