STABLE CARBON AND NITROGEN ISOTOPES OF HARDWOOD FOREST AND THE PINE BARRENS IN NEW JERSEY

This research utilizes stable isotopes of both carbon and nitrogen to study the level of environmental impact climate change has on New Jersey's hardwood forest and the Pine Barrens. The inevitable effects of climate change will lead to rising temperatures, water scarcity, and changes humidity and atmospheric and soil moisture levels. Previous studies have utilized stable isotopes of carbon and nitrogen to study the effects of climate change in other locations, such as Australia, Arizona, and controlled lab settings. However, none of these environments mimic the Northeast American hardwood Forests or the Pine Barrens. Across New Jersey, at three different sampling sites (one North Jersey, one Central Jersey, and one South Jersey), a total of 65 leaf samples were taken from dominant tree species. Overall 23 unique tree species and 11 soil samples were collected from the three studied sites. Latitude, Longitude, light level, temperature, humidity, and air pressure were recorded using SoilWeb app by California Soil Resource Laboratory at UC Davis. After sample collection, leaves were cut into 1 square-centimeter sections for freeze drying. Freeze dried samples are then analyzed using a Thermo Delta V Advantage with a Flash Elemental Analyzer connected to a Conflo IV interface. Angiosperms (hardwood forests) have an average δ¹³C value ~3‰ lower than that of the gymnosperms (Pine Barrens), consistent with previous studies. The soil samples, which contain soil organic matter derived from the surrounding trees and bacteria, record the long-term averaged signal in the ecosystem. By comparing the δ¹³C and δ¹⁵N of the three sites, we find strong environmental control on the δ¹³C and δ¹⁵N of the northern and southern New Jersey.