Lesser celandine (Ranunculus ficaria), an ephemeral perennial invasive plant brought over from Europe, is becoming widespread throughout the north eastern United States. This herbaceous buttercup is able to create extensive dense mats that limit native species growth during a spring window critical for native species growth. It takes advantage of an early growing season and rapid reproduction rates, which enable this species to create dense monocultures, threatening native communities and ecosystems. There is cause for concern as its high production of bulbils and tubers, linked with its ephemeral growth pattern, allow lesser celandine to outcompete, disperse and establish more rapidly than its local competitors. Elimination of native spring ephemerals results in decreased biodiversity.
We examined lesser celandine abundance and reproductive output (seed, bulbil and tuber production rates) in plants collected from plots spanning a disturbance gradient away from a river. Site characteristics (PAR, aspect, soil pH and moisture content) were investigated in order to examine site and quadrat differences. We hypothesize that reproductive output and lesser celandine abundance will be highest in moist floodplain at intermediate distances from rivers.
Results/Conclusions
There was high variability observed between sample sites, with average bulbil production ranging from 0.2 to as high as 6.1 per stem and tuber production ranging from 1.1 to as high as 8.5 tubers per plant. Densities of lesser celandine were found to be as high as 3100 plants/m2 in some areas. No seed production was observed. Some sites were consistent with our hypothesis, where maximal reproductive output and lesser celandine abundance were greatest at intermediate distances from the river; however reproductive output and lesser celandine abundance were not significantly greater at intermediate distances from rivers, thus we cannot support our hypothesis. PAR had a significant linear relationship with plant biomass (p<0.05). Light availability may play an important role in driving lesser celandine spread. This study was able to expand on the current limited understanding of lesser celandine, which can prove helpful in more effectively reducing population size and spread.