Quantifying energy use efficiency via entropy production: a case study from longleaf pine ecosystems

Abstract

Abstract. Ecosystems are open systems that exchange matter and energy with their environment. They differ in their efficiency in doing so as a result of their location on Earth, structure and disturbance, including anthropogenic legacy. Entropy has been proposed to be an effective metric to describe these differences as it relates energy use efficiencies of ecosystems to their thermodynamic environment (i.e., temperature) but has rarely been studied to understand how ecosystems with different disturbance legacies respond when confronted with environmental variability. We studied three sites in a longleaf pine ecosystem with varying levels of anthropogenic legacy and plant functional diversity, all of which were exposed to extreme drought. We quantified radiative (effrad), metabolic and overall entropy changes – as well as changes in exported to imported entropy (effflux) in response to drought disturbance and environmental variability using 24 total years of eddy covariance data (8 years per site). We show that structural and functional characteristics contribute to differences in energy use efficiencies at the three study sites. Our results demonstrate that ecosystem function during drought is modulated by decreased absorbed solar energy and variation in the partitioning of energy and entropy exports owing to differences in site enhanced vegetation index and/or soil water content. Low effrad and metabolic entropy as well as slow adjustment of effflux at the anthropogenically altered site prolonged its recovery from drought by approximately 1 year. In contrast, stands with greater plant functional diversity (i.e., the ones that included both C3 and C4 species) adjusted their entropy exports when faced with drought, which accelerated their recovery. Our study provides a path forward for using entropy to determine ecosystem function across different global ecosystems.

Reviews and syntheses: Ongoing and emerging opportunities to improve environmental science using observations from the Advanced Baseline Imager on the Geostationary Operational Environmental Satellites

“…Furthermore, PAR estimated from satellites has been reported to underestimate PAR measured on the ground when the model assumed urban aerosol absorption over areas where maritime aerosols were more dominant (Janjai and Wattan, 2011). Despite these limitations, frequent estimates of PAR and incident solar radiation from geostationary satellites may be uniquely suited to drive the land surface models that are operating at increasingly fine spatial and temporal resolutions, providing a natural link for using geostationary satellite observations to improve our understanding of the carbon, water, and energy cycles (Williams et al, 2009). Terrestrial photosynthesis is particularly responsive to diffuse PAR, which penetrates plant canopies more efficiently than direct PAR (Emmel et al, 2020;Gu et al, 2003).…”

“…Effective energy dissipation results in a cooler surface (with less waste heat) for biological processes to occur. Diurnal patterns of LST can be used to quantify ecological complexity (Lin et al, 2009) and entropy production (Brunsell et al, 2011;Holdaway et al, 2010;Wiesner et al, 2019) and may be useful for monitoring the success of ecological restoration projects that seek to re-establish ecological function (Aerts et al, 2004).…”

Reviews and syntheses: Ongoing and emerging opportunities to improve environmental science using observations from the Advanced Baseline Imager on the Geostationary Operational Environmental Satellites

“…Effective energy dissipation results in a cooler surface (with less waste heat) for biological processes to occur. Diurnal patterns of LST can be used to quantify ecological complexity (Lin et al, 2009) and entropy production (Brunsell et al, 2011;Holdaway et al, 2010;Stoy et al, 2014b;Wiesner et al, 2019) and may be useful for monitoring the success of ecological restoration projects that seek to re-establish ecological function (Aerts et al, 2004).…”

Tropical Monsoon Forest Thermodynamics Based on Remote Sensing Data

“… Geophysical (land cover level). This direction, on the one hand, can be attributed to works related to the interaction of vegetation cover and climate [ 24 , 25 , 26 ], and on the other hand, research in which thermodynamic parameters are considered as integral indicators of the effectiveness of functioning [ 27 , 28 , 29 ], health [ 30 , 31 ], integrity/complexity/self-organization of ecosystems [ 32 , 33 , 34 ]. …”

“…At the same time, the development of scientific tools gives researchers new instruments for measuring thermodynamic parameters. In the last decade, the Eddy covariance biophysical complexes of the Fluxnet network was a basis for thermodynamic assessment and modeling at the landscape cover level [ 29 , 36 , 37 , 38 ]. However, despite high measurement frequency, these complexes are representative only for local conditions (up to 0.5 × 0.5 km) and, at best, characterize a type of system in which they are installed.…”