Multi-system passive warming chamber design and deployment

Heineke, Marcella; Fisichelli, Nicholas; Webber, Hannah; Zabilski, Brian; Locke, Henry

From the abstract: "Recently, there has been a large push for field based experiments in climate change research due to the complexity of community interactions and the extreme difficulty of modeling such interactions in the lab (Stewart et al. 2013). In areas with multiple ecosystems, there is an additional challenge of understanding the effects of climate change across the different systems. Acadia National Park (ANP) is one such place. We investigated the potential for building and deploying passive warming chambers in terrestrial and intertidal zones to better understand community-level effects of climate change. Passive warming chambers (PWC) are open or closed top chambers constructed of clear fiberglass that harness the power of the sun to raise ambient air temperature by 2-5 C inside the chamber. Our PWCs utilized different chamber designs, hexagonal for the blueberry plants and cone for the intertidal, to best suit the varying pressures exerted on the different ecosystems. In both terrestrial and intertidal settings, we deployed experimental PWCs, control chambers, and had control plots. The intertidal treatment cone was significantly effective at warming ambient air temperature inside the cone during low tide, while still allowing water flow during high tide (1-Way ANOVA, F = 385.4, df = 2, 48843, p-value < 2e-16). The experimental PWC (22.73 0.72 C ) was on average 2.83 C warmer than the control plot (19.9 0.52 C) during low tide, representing a more extreme climate change model; the control chamber (21.27 0.60 C) was on average 1.37 C warmer than the control plot, representing a moderate climate change model. The terrestrial PWCs were also effective at warming ambient air temperature, while keeping other abiotic factors the same, including: soil moisture and temperature and relative humidity. The ambient air temperature of the experimental PWC was significantly warmer than the control chamber and plot (1-Way ANOVA, F = 540, df = 2, 104563, p-value < 2e-16). During the day, the average ambient air temperature of the treatment PWC (26.12 1.67 C) was 4.02 C warmer than the control chamber and plot (22.10 1.53 C). We present initial abiotic data on warming within the chambers as well as planned future research on biotic responses to warming."