Correlation of WorldView-3 spectral vegetation indices and soil health indicators of individual urban trees with exceptions to topsoil disturbance. (August 2021)

• Record Type: Journal Article
• Authors: Galle, Nadina J.; Brinton, William; Vos, Robin; Basu, Bidroha; Duarte, Fábio; Collier, Marcus; Ratti, Carlo; Pilla, Francesco
• Is Part Of: City and environment interactions. Volume 11(2021)
• Publication Date: 2021-08
• Subjects: Urban forest -- Street trees -- Urban ecosystem services -- Urban soil quality -- Soil disturbance -- Remote sensing; Metropolitan areas -- Environmental aspects -- Periodicals; Sustainable urban development -- Periodicals; Urban ecology (Sociology) -- Periodicals; Urban ecology (Biology) -- Periodicals; Land use, Urban -- Environmental aspects -- Periodicals; City planning -- Environmental aspects -- Periodicals; 307.3416
• DOI: 10.1016/j.cacint.2021.100068
• Languages: English
• ISSNs: 2590-2520

Abstract

Highlights: Remote sensing data assessing soil health at the individual (urban) tree level is understudied. SVIs correlate and are discerned dimensionally by PCA. Pearson's coefficient reveals the NDVI has stronger correlations than the NDRE. The NDVI is correlated positively with BD and LUM. The NDVI is correlated negatively with CO2, AF + AB, and TC. Abstract: Increasing recognition of the potential ecosystem services provided by urban forests suggests a need to examine soil quality under urban conditions. Soil quality assessment tools are presently mostly applied in agricultural production, but these approaches must also be evaluated in the urban context. This proof-of-concept exploratory study evaluates whether Worldview-3 spectral vegetation indices (SVIs) generated for individual tree crown (ITC) objects can be correlated to soil health attributes measured in the field in Metro Boston, Massachusetts, USA. While similar studies have completed such analysis for agricultural crops, none have done so for urban trees. The statistical analysis by Pearson correlation and principal component analysis (PCA) showed that SVIs, specifically the Normalized Difference Vegetation Index (NDVI), correlated significantly and positively with bulk density (BD) ( r = 0.536) and soil luminance ( r = 0.562) and negatively with CO2 respiration ( r = −0.536), active fungi and active bacteria ( r = −0.401), and total carbon ( r = −0.548). The negative correlations with parameters commonly considered positive for soil health in agricultural settings may indicate strong perturbation at the urban soil surface level; they also suggest soil health attributes measured at this study's 0–15 cm sampling depth may not be satisfactorily indicative of tree health as measured by SVIs. This study evidences the ground truthing of satellite-based urban SVIs, including their relationships with soil health attributes at the individual tree level.