Diverse biosphere influence on carbon and heat in mixed urban Mediterranean landscape revealed by high resolution thermal and optical remote sensing.

Autor: Parazoo NC; Jet Propulsion Laboratory, California Institute of Technology, United States of America. Electronic address: nicholas.c.parazoo@jpl.nasa.gov., Coleman RW; Harvey Mudd College, Department of Biology, United States of America., Yadav V; Jet Propulsion Laboratory, California Institute of Technology, United States of America., Stavros EN; University of Colorado Boulder, United States of America., Hulley G; Jet Propulsion Laboratory, California Institute of Technology, United States of America., Hutyra L; Boston University, Department of Earth & Environment, United States of America.
Jazyk: angličtina
Zdroj: The Science of the total environment [Sci Total Environ] 2022 Feb 01; Vol. 806 (Pt 3), pp. 151335. Date of Electronic Publication: 2021 Oct 29.
DOI: 10.1016/j.scitotenv.2021.151335
Abstrakt: A fundamental challenge in verifying urban CO 2 emissions reductions is estimating the biological influence that can confound emission source attribution across heterogeneous and diverse landscapes. Recent work using atmospheric radiocarbon revealed a substantial seasonal influence of the managed urban biosphere on regional carbon budgets in the Los Angeles megacity, but lacked spatially explicit attribution of the diverse biological influences needed for flux quantification and decision making. New high-resolution maps of land cover (0.6 m) and irrigation (30 m) derived from optical and thermal sensors can simultaneously resolve landscape influences related to vegetation type (tree, grass, shrub), land use, and fragmentation needed to accurately quantify biological influences on CO 2 exchange in complex urban environments. We integrate these maps with the Urban Vegetation Photosynthesis and Respiration Model (UrbanVPRM) to quantify spatial and seasonal variability in gross primary production (GPP) across urban and non-urban regions of Southern California Air Basin (SoCAB). Results show that land use and landscape fragmentation have a significant influence on urban GPP and canopy temperature within the water-limited Mediterranean SoCAB climate. Irrigated vegetation accounts for 31% of urban GPP, driven by turfgrass, and is more productive (1.7 vs 0.9 μmol m -2  s -1 ) and cooler (2.2 ± 0.5 K) than non-irrigated vegetation during hot dry summer months. Fragmented landscapes, representing mostly vegetated urban greenspaces, account for 50% of urban GPP. Cooling from irrigation alleviates strong warming along greenspace edges within 100 m of impervious surfaces, and increases GPP by a factor of two, compared to non-irrigated edges. Finally, we note that non-irrigated shrubs are typically more productive than non-irrigated trees and grass, and equally productive as irrigated vegetation. These results imply a potential water savings benefit of urban shrubs, but more work is needed to understand carbon vs water usage tradeoffs of managed vs unmanaged vegetation.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2021 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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