PS 6-57 - Effects of forest productivity and succession on the species and functional diversity of New England ant communities

Monday, August 12, 2019
Exhibit Hall, Kentucky International Convention Center
Maggie Anderson, Biology, Lawrence University, Appleton, WI, Israel Del Toro, Center for Macroecology Evolution and Climate, University of Copenhagen, Copenhagen, Denmark and Aaron Ellison, Harvard Forest, Harvard University, Petersham, MA
Background/Question/Methods

Functional diversity of ant communities describes the range of roles that ants fulfill within ecosystems. Ant functional diversity is an important component of ecosystem functioning as their activities often accelerate rates of decomposition and nutrient cycling in soils. Forest productivity has been shown to promote ant biodiversity by increasing species density through a phenomenon known as the Species-Energy Hypothesis. However, no research to date has examined the relationship between forest productivity and the functional diversity of forest ant communities of New England. As climate change brings warmer and wetter conditions to the region in the future, forest types are expected to change from less-productive coniferous stands to more-productive deciduous stands in a process called forest succession. This research aims to understand the effects of forest succession and subsequent changes in productivity on the functional diversity of New England ant communities.

My research took place in the summer of 2018 at the Harvard Forest in Petersham, MA. We sampled for ants around the bases of more than 300 deciduous and coniferous trees. We measured tree diameter and subtracted measurements from five years before to obtain productivity data. We also identified ants down to species and classified them further into functional groups.

Results/Conclusions

Although ant community composition did not vary significantly between coniferous and deciduous tree types, both increased significantly with forest productivity. Only functional diversity was positively impacted by deciduous stands. Although forest productivity and succession may change ant communities, ant functional diversity also has major effects on forest soils and nutrient cycling. Ants act as litter decomposers, soil movers, and seed dispersers among other roles. Their nesting is also known to increase levels of soil nitrogen and phosphorous and moderate pH. Thus, diversifying the functional roles of ants in a forest ecosystem could accelerate rates of decomposition and nutrient cycling. Climate change is only beginning to affect New England forest ecosystems. This study allows better anticipation of ant community responses to forest succession over time and better estimation of the effects of these changes on rates of nutrient cycling in the future.