Impacts of land cover and management change on top-of-canopy and below-canopy temperatures in Southeastern Kenya

Temesgen Abera; Janne Heiskanen; Eduardo Maeda; Vincent Odongo; Petri Pellikka

doi:10.1016/j.scitotenv.2023.162560

Impacts of land cover and management change on top-of-canopy and below-canopy temperatures in Southeastern Kenya

Sci Total Environ. 2023 May 20:874:162560. doi: 10.1016/j.scitotenv.2023.162560. Epub 2023 Mar 3.

Authors

Temesgen Abera¹, Janne Heiskanen², Eduardo Maeda³, Vincent Odongo⁴, Petri Pellikka⁵

Affiliations

¹ Department of Geosciences and Geography, P.O. Box 68, FI-00014, University of Helsinki, Finland; Institute for Atmospheric and Earth System Research, Faculty of Science, University of Helsinki, Finland. Electronic address: temesgen.abera@helsinki.fi.
² Department of Geosciences and Geography, P.O. Box 68, FI-00014, University of Helsinki, Finland.
³ Department of Geosciences and Geography, P.O. Box 68, FI-00014, University of Helsinki, Finland; Area of Ecology and Biodiversity, Faculty of Science, The University of Hong Kong, Hong Kong.
⁴ International Livestock Research Institute, Mazingira Centre, P.O. Box 30709-00100, Nairobi, Kenya.
⁵ Department of Geosciences and Geography, P.O. Box 68, FI-00014, University of Helsinki, Finland; Institute for Atmospheric and Earth System Research, Faculty of Science, University of Helsinki, Finland; State Key Laboratory for Information Engineering in Surveying, Mapping and Remote Sensing, Wuhan University, Wuhan 430079, China.

PMID: 36870488
DOI: 10.1016/j.scitotenv.2023.162560

Abstract

Impacts of land cover conversion have been studied well from the top-of-canopy level using satellite observations. Yet, the warming or cooling impacts of land cover and management change (LCMC) from below-canopy level remain less explored. Here, we studied the below-canopy temperature change from field to landscape level across multiple LCMC in southeastern Kenya. To study this, in situ microclimate sensors, satellite observations, and high-resolution below-canopy temperature modelling approaches were used. Our results show that from field to landscape scale, forest to cropland conversion, followed by thicket to cropland change, generate higher surface temperature warming than other conversion types. At field scale, tree loss increases the mean soil temperature (measured at 6 cm below ground) more than the mean below-canopy surface temperature but its impact on the diurnal temperature range was higher on surface temperature than soil temperature in both forest to cropland and thicket to cropland/grassland conversions. At landscape scale, compared with top-of-canopy land surface temperature warming, which was estimated at Landsat overpass time (∼10:30 a.m.), forest to cropland conversion generates ∼3 °C higher below-canopy surface temperature warming. Land management change, through fencing of wildlife conservation areas and limiting mobility of mega browsers, can have an impact on woody cover and induce more below-canopy surface temperature warming than top-of-canopy in comparison with non-conservancy areas. These results indicate that human induced land changes can generate more below-canopy warming than inferred from top-of-canopy satellite observations. Together, the results highlight the importance of considering the climatic impacts of LCMC from both top-of-canopy and below-canopy level for effective mitigation of anthropogenic warming from land surface changes.

Keywords: Below-canopy temperature; Land cover change; Land management change; Microclimate measurement; Satellite observation; Top-of-canopy temperature.