Project SPRUCE

Spruce and Peatlands Responses Under Changing Environments (SPRUCE) site is the 8.1-ha S1 bog, a Picea mariana [black spruce] – Sphagnum spp. ombrotrophic bog forest in northern Minnesota, 40 km north of Grand Rapids, in the USDA Forest Service Marcell Experimental Forest (MEF). Two field research locations at the SPRUCE site were leveraged for this work. The South End bog, composed of 6 locations and no environmental treatments as well as the S1 enclosures. Within the enclosures, Deep Peat Heating (DPH) treatment was initiated in July 2014. This consisted of heating below ground at 2m depth to the target temperature above ambient. Whole Ecosystem Warming (WEW) treatments were initiated in June 2015. WEW treatments were preceded by approximately one year of deep peat heating (DPH) only. Approximately 10 months after WEW was initiated at 5 warming levels (+0, +2.25, +4.5, +6.75 and +9 °C), elevated CO2 treatments were initiated in June 2016, with treatment levels at +500 ppm above ambient. The goal of this project was to understand peatland microbial community responses to changes in their environment.