Lloyd Center Samples Moth Population at Restoration Sites in Rhode Island

Nov 15, 2021

Part of this year’s contract to sample Lepidoptera (moth) populations in areas under recent restoration included sites in Rhode Island, a state the Lloyd Center for the Environment has conducted moth work at in the past. This year the work took us to Pratt Farm of Arcadia Management area in Exeter, and Nicolas Farm Wildlife management area in Coventry, where we assessed moth diversity using light traps, and quantified dominant vegetation that would attract moths, these indices being useful predictors of biodiversity response at habitats restored to an early successional stage.

Arcadia, at 14,000 acres, represents the state’s largest management and recreation area, and is a diverse mixture of forests, field, and wetlands. It contains Pratt Farm Conservation Area, historically farmed, but currently in various stages of succession and management. Similarly, Nicolas Farm at 1,439 acres, has a variety of habitats under various management regimes, including what was also once an actual farm. At both sites, recent forest cutting over the past year has occurred to maintain or restore the early successional (stages of vegetation such as open field and low shrub, prior to mature forest) habitats that have historically existed. The Pratt site and Nicolas Farm Site One were both cut recently, with Nicolas Farm Site One bordered with downed trees to act as a barrier to deer which would otherwise quickly browse the regeneration.

As usual, light traps were set at each site near sunset, with environmental data collected, including maximum and minimum temperature, relative humidity, and soil strength. Numbers of stems of dominant plants in bloom were tallied as well. The trap at the Pratt site was placed just over the crest of a hill, at the base of which was a small wetland that regularly hosted dragonflies of at least two species. Only a short walk was required to set this trap, but one had to watch their footing, as navigating fallen trunks and limbs from the recent harvest was the norm. At Nicolas Farm the footing was less treacherous but the walk longer, including the walk-through vegetation and around the deer barrier to the trap location for Nicolas Farm Site One.

Often the long walks occur near dark, especially early on when one fails to accurately gauge the length of daylight and finds themselves trapping in the dark. June was the perfect time for this circumstance, when Whippoorwills were sounding off during the trip back to the car. Birds in general were quite active overall, as expected in mixed habitats of open landscape surrounded by mature forest and wetlands. Moth catches were relatively low as expected in habitats with recent cutting when minimal regeneration has occurred, but a diversity of moths was caught at each site. Nicolas Farm Site Two had the highest catch, as expected from the site with most plant diversity and coverage. Overall plants of interest included American Burnweed, which appeared in late summer along with goldenrods, blueberries, and huckleberry, to name a few examples found in bloom.

This inventory is perhaps just a baseline indicator of what’s to come. It would be interesting to see what moths inhabit the area in the years to come, as the habitat gradually changes, and diversity slowly increases in these fascinating areas.

 by Lloyd Center for the Environment Research Associate Jamie Bogart