Examination of Surface Temperature Modification by Open-Top Chambers along Moisture and Latitudinal Gradients in Arctic Alaska Using Thermal Infrared Photography

Abstract

Passive warming manipulation methodologies, such as open-top chambers (OTCs), are a meaningful approach for interpretation of impacts of climate change on the Arctic tundra biome. The magnitude of OTC warming has been studied extensively, revealing an average plot-level warming of air temperature that ranges between 1 and 3˝C as measured by shielded resistive sensors or thermocouples. Studies have also shown that the amount of OTC warming depends in part on location climate, vegetation, and soil properties. While digital infrared thermometers have been employed in a few comparisons, most of the focus of the effectiveness of OTC warming has been on air or soil temperature rather than tissue or surface temperatures, which directly translate to metabolism. Here we used thermal infrared (TIR) photography to quantify tissue and surface temperatures and their spatial variability at a previously unavailable resolution (3-6 mm 2 ). We analyzed plots at three locations that are part of the International Tundra Experiment (ITEX)-Arctic Observing Network (AON-ITEX) network along both moisture and latitudinal gradients spanning from the High Arctic (Barrow, AK, USA) to the Low Arctic (Toolik Lake, AK, USA). Our results show a range of OTC surface warming from 2.65 to 1.27˝C (31%-10%) at our three sites. The magnitude of surface warming detected by TIR imagery in this study was comparable to increases in air temperatures previously reported for these sites. However, the thermal images revealed wide ranges of surface temperatures within the OTCs, with some surfaces well above ambient unevenly distributed within the plots under sunny conditions. We note that analyzing radiometric temperature may be an alternative for future studies that examine data acquired at the same time of day from sites that are in close geographic proximity to avoid the requirement of emissivity or atmospheric correction for validation of results. We foresee future studies using TIR photography to describe species-level thermodynamics that could prove highly valuable toward a better understanding of species-specific responses to climate change in the Arctic.

Changes in species abundance after seven years of elevated atmospheric CO2 and warming in a Subarctic birch forest understorey, as modified by rodent and moth outbreaks

“…Bryophytes reacted negatively to warming, which has been shown before ( Healey, Oberbauer & Hollister, 2016 ). However, a low number of hits for bryophytes, particularly in combination with many hits for vascular plants, does not necessarily mean that bryophytes have decreased in frequency when the abundance of vascular plants increased.…”

Effect of elevated [CO2] on yield, intra‐plant nutrient dynamics, and grain quality of rice cultivars in eastern India

“…This might be associated with the increase in the chamber temperature, particularly at grain‐filling stages (Fig. ) and reduced light transmittance (due to polycarbonate sheets) . Flowering has also been identified as the stage most sensitive to high‐temperature stress affecting fertilization and flower sterility.…”

“…1) and reduced light transmittance (due to polycarbonate sheets). 26 Flowering has also been identified as the stage most sensitive to high-temperature stress affecting fertilization and flower sterility. Moreover, high-temperature stress also impacts the sink potential under OTCs, which substantially reduced the grain yield, particularly in tropical environments.…”

A review of open top chamber (OTC) performance across the ITEX Network

“…The range of surface temperatures is greater within OTCs than in controls and results in higher maximum temperatures (Fig. 7; Healey et al 2016;Lindwall et al 2016) as well as lower temperatures due to shading (Jónsdóttir et al 2005;Dabros et al 2010). Elevated leaf temperatures have important consequences for plant water status through the increase in leaf to air VPD.…”

“…Similarly, handheld instrumentation has also provided analysis of unique spectral characteristics linked with growth, development and phenology that are undetectable to the human eye (May et al 2020). Our understanding of physiological impacts induced by OTCs has also been enhanced using thermal imaging technology (Healey et al 2016). Surface tissue and underlying soil or moss temperatures are key determinants of metabolic activity and monitoring such phenomena is vital for comprehensive analysis of subtle, yet complex, interactions among permafrost, surface moss, cryptogamic crusts and soils, and tundra vegetation.…”