Forest management practices, including prescribed burning, clear-cutting, and wildfires, influence vegetative structure and composition. Variation in vegetative characteristics can lead to differences in the vegetation-dwelling arthropod community. Arthropods often serve as bioindicators. Therefore, arthropod monitoring can be a useful tool to help determine which habitat management techniques are best for conservation efforts of endangered habitats, such as Florida scrub. We assessed how vegetation-dwelling arthropod abundance varied across different habitat conditions and management treatments in Ocala National Forest (ONF). ONF contains the largest remaining expanse of Florida scrub and is partially managed with clear-cuts and prescribed burns. We sampled arthropods on vegetation using a beat net at 54 sites in scrub habitat across ONF during summer 2019. We also measured habitat characteristics including average shrub height, percent bare ground, and pine understory cover. We used generalized linear models to assess relationships between environmental covariates and arthropod abundance and ranked models according to AIC values.
Results/Conclusions
The most common arthropods that were collected included spiders (Araneae), grasshoppers (Orthoptera), beetles (Coleoptera), and true bugs (Hemiptera). We found that treatment type (whether the stand was a clear-cut, prescribed burn, or wildfire) was the best predictor of arthropod abundance, followed by percent bare ground. Bare ground varied with treatment type at sampled sites. Prescribed burns had the most bare ground on average, followed by clear-cuts, then wildfires. It is worth noting that the wildfire stands were either six or ten years old, whereas the other treatment types had more age variation, but stand age was a poor predictor of arthropod abundance. Arthropod abundance was highest in stands managed by prescribed burning. Fires vary in intensity and can leave behind patches of unburnt vegetation and bare ground. This can result in differences in vegetation structure and ground cover and may alter arthropod abundance. These results suggest that increased bare ground produced by different treatments may result in a higher abundance of vegetation-dwelling arthropods. Arthropods can serve as strong environmental bioindicators. Therefore, future investigations on how treatment type alters arthropod diversity and abundance at other sites in Florida scrub, including young wildfire stands, is an important research direction.