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Greater aridity increases the magnitude of urban nighttime vegetation-derived air cooling
High nighttime urban air temperatures increase health risks and economic vulnerability of people globally. While recent studies have highlighted nighttime heat mitigation effects of urban vegetation, the magnitude and variability of vegetation-derived urban nighttime cooling differs greatly among cities. We hypothesize that urban vegetation-derived nighttime air cooling is driven by vegetation density whose effect is regulated by aridity through increasing transpiration. We test this hypothesis by deploying microclimate sensors across eight United States cities and investigating relationships of nighttime air temperature and urban vegetation throughout a summer season. Urban vegetation decreased nighttime air temperature in all cities. Vegetation cooling magnitudes increased as a function of aridity, resulting in the lowest cooling magnitude of 1.4 °C in the most humid city, Miami, FL, and 5.6 °C in the most arid city, Las Vegas, NV. Consistent with the differences among cities, the cooling effect increased during heat waves in all cities. For cities that experience a summer monsoon, Phoenix and Tucson, AZ, the cooling magnitude was larger during the more arid pre-monsoon season than during the more humid monsoon period. Our results place the large differences among previous measurements of vegetation nighttime urban cooling into a coherent physiological framework dependent on plant transpiration. This work informs urban heat risk planning by providing a framework for using urban vegetation as an environmental justice tool and can help identify where and when urban vegetation has the largest effect on mitigating nighttime temperatures. © 2021 The Author(s). Published by IOP Publishing Ltd.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]
Study of the dehydroxylation of kaolinite and alunite from a Mexican clay with DRIFTS-MS
Effects of fenoprofen and benoxaprofen on human lymphocytes: Inhibition of tritiated thymidine uptake
Bioprospecting insecticidal compounds from plants native to Mato Grosso do Sul, Brazil Bioprospecção de substùncias inseticidas de plantas nativas de Mato Grosso do Sul, Brasil
This paper reports on an evaluation of the insecticidal activity of extracts prepared from leaves of Tapirira guianensis Aubl. (Anacardiaceae), Attalea phalerata (Mart. ex Spreng.) Burret (Arecaceae), Eugenia uniflora L. (Myrtaceae), and Gomphrena elegans Mart. (Amaranthaceae) and from stems of Myracrodruon urundeuva AllemĂŁo (Anacardiaceae). Four extracts and 18 fractions with a range of polarities were tested. Ten-gram batches of wheat grains were each nebulized with 1 mL of a separate extract at 10% w/v. After solvent evaporation at 38 ÂșC, the grains were placed into flasks along with 20 unsexed 10- to 20-day old adult individuals of Sitophilus zeamais. The assessment was carried out on the fifth and tenth day by counting and discarding the dead insects. Leaf extracts of G. elegans showed an insecticidal effect ranging from 27% to 60% by the fifth day, whereas the effect of the remaining extracts tested (if active at all) did not exceed 20% in the same period. By the tenth day, the most active extracts were those of A. phalerata (hexanic, 36.5%) and all those of G. elegans (5280.5%), whereas the effect of the other extracts did not exceed 30%.<br>No presente trabalho foi avaliada a atividade inseticida de extratos de limbos foliares de Tapirira guianensis Aubl. (Anacardiaceae), Attalea phalerata (Mart. ex Spreng.) Burret (Arecaceae), Eugenia uniflora L. (Myrtaceae) e Gomphrena elegans Mart. (Amaranthaceae) e de caules de Myracrodruon urundeuva AllemĂŁo (Anacardiaceae). Foram testados quatro extratos e 18 fraçÔes, com diferentes polaridades. Dez gramas de grĂŁos de trigo foram pulverizados com 1 mL de cada extrato a 10% (p/v). ApĂłs a evaporação do solvente a 38 ÂșC, os grĂŁos foram acondicionados em recipientes juntamente com 20 indivĂduos adultos de Sitophilus zeamais nĂŁo sexados, com 10 a 20 dias de idade. As avaliaçÔes foram feitas no quinto e no dĂ©cimo dia, contando-se o nĂșmero de insetos mortos e descartando-os. Os extratos foliares de G. elegans ocasionaram mortalidade de 27% a 60% atĂ© o quinto dia, enquanto os demais extratos testados, quando ativos, nĂŁo ultrapassaram a faixa de 20% de mortalidade no mesmo perĂodo. No dĂ©cimo dia, os extratos mais ativos foram o proveniente de A. phalerata (hexĂąnico, 36,5%) e todos os de G. elegans (52% a 80,5%), enquanto os demais extratos causaram atĂ© 30% de mortalidade