Using demographic findings to compare wild and translocated populations of Florida goldenaster (Chrysopsis floridana) in west-central Florida, USA

Evaluation of the success of rare plant introductions requires analysis of demographic success. We analyze the success of 10 wild and 8 introduced populations of Florida goldenaster (Chrysopsis floridana), a federally endangered forb endemic to west-central Florida, using demographic and stage-class data collected from 2017 to 2019. We also collected microhabitat data to characterize factors associated with this species' success. Introductions had higher annual survival rates and fecundity than wild populations; plants in scrub plots had higher survival than roadside plants, although fecundity was higher in roadside plants. Seedling recruitment was only higher for scrub plots in 1 year. Chrysopsis floridana occupancy was better predicted by lower soil nutrients and pH, but introduction success did not consistently vary according to soil conditions. Occupied plots had higher cover of bare sand, lichens, and forbs while unoccupied plots had higher cover of litter, shrub, and subcanopy. The presence of higher litter levels (>60%) appeared to significantly lower survival in 2018. Z-score site ranking suggested a slight disadvantage for wild populations overall, with the two highest ranked sites both being introductions. Conversely, stage-class data revealed that both wild and introduced populations had high counts across 3 years of sampling. Most of the healthiest populations had received recent fire, suggesting this may be crucial in providing conditions that promote recruitment and occupancy. More information is needed on aspects of fire and fire surrogates that are likely to affect the demography and distribution of this rare species.

Automated summary

The success of rare plant introductions, particularly for Florida goldenaster, depends on demographic factors. Introductions showed higher survival and fecundity rates compared to wild populations, with scrub plots having higher survival but roadside plants exhibiting higher fecundity. Soil conditions did not consistently affect introduction success, but plant occupancy was influenced by lower soil nutrients and pH. Fire events appeared to be crucial for promoting recruitment and occupancy of healthy populations.