Land Use History and Wildlife – Hobart and William Smith Colleges \
The HWS Update

Land Use History and Wildlife

An article by Associate Professor of Environmental Studies Kristen Brubaker and Associate Professor of Biology Bradley Cosentino offers insights that may help habitat managers shape biodiversity in tracts of forested land. The article, titled “Effects of Land Use Legacies and Habitat Fragmentation on Salamander Abundance,” was featured in the September 2018 issue of the journal Landscape Ecology.

The article is based on extensive field research that Brubaker, Cosentino and their students undertook in 2013-14 on 95 separate sites in the Finger Lakes National Forest in Hector, N.Y. The research team measured the number of eastern red-backed salamanders, Plethodon cinereus, to determine if land that had been used for agricultural practices within the past five decades impacted the number of salamanders present on that plot.

“We need to consider history when trying to understand the abundance and distribution of wildlife today,” says Cosentino. “Historical land use has been underappreciated but can affect wildlife populations in many ways.”

Salamanders and other amphibians are good indicators of the health of an ecosystem because their permeable skin makes them sensitive to contaminants or extreme climate conditions. The biomass of salamanders in forests in the northeast, says Cosentino, is twice that of birds and equal to that of small mammals, “so these organisms are an important component of forest ecosystems.”

The study’s results were subtle, but telling. Previous use of a plot of land for agricultural purposes affected the landscape structure in numerous ways. Former agricultural plots, for example, are likely to have had rocks, dead trees and other impediments removed by the farmer looking for a smooth place to plant crops. Later, the lack of these objects, under which salamanders hide, may impact the size of the population.

Another indicator of the health of the salamander population was related to the way in which the land returned to a natural state. “We found the abundance of P. cinereus was greatest in forests with high basal area, canopy cover, leaf litter depth and low herbaceous cover,” said Brubaker and Cosentino in the article.

Despite these indicators, the team found viable populations on formerly farmed land, leading to a key insight. “To me, one of the interesting takeaways is that these sites that were formerly agricultural can still support populations of red-backed salamanders,” says Brubaker. “This tells me that we don’t have to focus all of our conservation efforts on pristine forests, but can also utilize second growth forests and forests that were formerly agricultural to meet important conservation goals.”