Print PageUtricularia inflata is a submersed macrophyte expanding its range from the Atlantic Coastal Plain into the Adirondack Mountains of New York State. When found at high densities, this rootless plant may cause the local extirpation of native sediment-oxidizing isoetids, and consequently alter littoral zone chemistry by promoting both nutrient and metal release from the sediment into the water column. The spread of this invader is likely facilitated by its rootless morphology. Tagged U. inflata plants are readily dispersed by moving water, suggesting that this species may easily colonize downstream once introduced in a watershed. Surveys and vegetation sampling with SCUBA were conducted to investigate the distribution of U. inflata among and within Adirondack waterways. Trials in temperature-controlled fiberglass tanks in a greenhouse tested U. inflata’s ability to survive fragmentation because successful asexual reproduction may increase the spread of this species.
Results/Conclusions
Utricularia inflata continues to expand its range; it now occurs in at least 14 Adirondack lakes. This increased distribution includes sites downstream of previous findings as well as sites remote from them. Vegetation sampling confirms prior data that demonstrate U. inflata’s greater abundance at greater depth at relatively exposed sites. The dispersal ability of this macrophyte is promoted by survival of small fragments. Plants that were cut into 1.0 cm fragments exhibited an average of 6.1 cm of new growth, and all of the plants survived the duration of the 44 day experiment. The dispersal ability of U. inflata coupled with the success of fragments only 1.0 cm long provide further evidence that this plant may easily spread to sites downstream of an initial introduction or on vectors such as boat trailers or waterfowl.
