The Boquet and Au Sable River Associations are continuing to inventory non-native invasive plant species. In the fall, we concentrated on the top four invasive plants in NYS: purple loosestrife, Japanese knotweed, garlic mustard, and common reed (or Phragmites).
Up to this point, the search for these plants has been primarily at public access areas in the Boquet watershed. Sixty-four sites have been identified with invasive plants in all towns of the watershed. Fourteen of these sites contained more than one of the State's top invasive plant species.
To categorize and record for future comparisons, field data sheets were filled out referencing the sites by towns, GPS coordinates, landowners, elevation, proximity to water bodies and vehicular or public access, as well as the condition of invasive plants and their square yard abundance. The latter varied from just a few plants with a single square yard of abundance, to dense growth (more than 20 stems per square yard) covering 44,000 square yards or slightly more than 9 acres. So far, over 44 total acres of our watershed have been invaded by these nuisance species.
Perhaps more alarming than the total acreage to date, is the spreading potential. All four species either have hundreds or thousands of seeds per plant, or the ability to spread by plant fragments and root rhizomes. Put these plant propagation properties into locations conducive to dispersal of seeds and plant parts, and spreading will be rapid. All but 3 sites inventoried so far have either been next to a road, railroad, a water body, or near frequently used public buildings. The wind from passing vehicles is a great seed carrier. So, too, is water a great dispersal agent. We have seen entire plants torn from one stream section easily re-establish themselves downstream, and purple loosestrife seeds (as many as 300,000 for a mature plant) can stay viable after being submerged in water for 20 months. Clothing is yet another conveyance for seeds.
We'll keep you informed in future articles about our inventory work. This winter will be devoted mostly to obtaining names and addresses of riparian and wetland property owners so we can request permission to inventory these parcels in 2003.