TY - JOUR
T1 - Heat-Induced alterations in water repellency of tropical and temperate Soils
T2 - A laboratory experiment using Ultisols and Andosols
AU - Perera, H. T.M.
AU - Leelamanie, D. A.L.
AU - Mori, Yasushi
AU - Maeda, Morihiro
N1 - Publisher Copyright:
© 2024 Elsevier B.V.
PY - 2024/8
Y1 - 2024/8
N2 - Water repellency (WR) is commonly reported in soils covered with several plant species that are rich in waxes/resins, including Pinus caribaea (PIN) and Cryptomeria japonica (CED). Due to waxy and resinous litter, these forests are highly prone to wildfires. The heat produced during wildfires alters soil WR, and these alterations may vary between tropical and temperate soils and between soil separates (SS; soil particles ≤ 2 mm) and aggregates (AG; naturally available aggregates; d = 3–5 mm). This study aims to investigate the heat-induced changes in WR of SS and AG in tropical and temperate soils. The SS and AG obtained from four different depths (0–5, 5–10, 10–15, 15–20 cm) in a PIN forest in Sri Lanka (tropical) (PINSS, PINAG) and a CED forest in Japan (temperate) (CEDSS, CEDAG) were heated to 7 heating temperatures (TH) (50, 100, 150, 200, 250, 300, 350 °C) with 2 exposure durations (DE) (1 h, 2 h). The WR were measured using the molarity of an ethanol droplet test and water drop penetration time test. The WR in PINSS and PINAG increased with increasing TH up to 100–150 °C and decreased to be non-repellent with further heating, while that of CEDSS and CEDAG progressively decreased to be non-repellent with heating. Both soil types were non-repellent at higher TH levels (≥250 °C), and 0–5 and 5–10 cm layers became non-repellent at 150–250 °C, while 10–15 and 15–20 cm layers became non-repellent at 50–150 °C. Compared to TH, DE did not significantly alter WR. The WR in two soils showed different responses to heat, especially at lower TH levels. In AG and SS, the degree of WR altered with heating similarly, while persistence (how long soil remains water-repellent) altered differently in both soil types. Research on organic matter composition and soil mineralogy may provide future insights into heat-induced alterations in WR of tested soils.
AB - Water repellency (WR) is commonly reported in soils covered with several plant species that are rich in waxes/resins, including Pinus caribaea (PIN) and Cryptomeria japonica (CED). Due to waxy and resinous litter, these forests are highly prone to wildfires. The heat produced during wildfires alters soil WR, and these alterations may vary between tropical and temperate soils and between soil separates (SS; soil particles ≤ 2 mm) and aggregates (AG; naturally available aggregates; d = 3–5 mm). This study aims to investigate the heat-induced changes in WR of SS and AG in tropical and temperate soils. The SS and AG obtained from four different depths (0–5, 5–10, 10–15, 15–20 cm) in a PIN forest in Sri Lanka (tropical) (PINSS, PINAG) and a CED forest in Japan (temperate) (CEDSS, CEDAG) were heated to 7 heating temperatures (TH) (50, 100, 150, 200, 250, 300, 350 °C) with 2 exposure durations (DE) (1 h, 2 h). The WR were measured using the molarity of an ethanol droplet test and water drop penetration time test. The WR in PINSS and PINAG increased with increasing TH up to 100–150 °C and decreased to be non-repellent with further heating, while that of CEDSS and CEDAG progressively decreased to be non-repellent with heating. Both soil types were non-repellent at higher TH levels (≥250 °C), and 0–5 and 5–10 cm layers became non-repellent at 150–250 °C, while 10–15 and 15–20 cm layers became non-repellent at 50–150 °C. Compared to TH, DE did not significantly alter WR. The WR in two soils showed different responses to heat, especially at lower TH levels. In AG and SS, the degree of WR altered with heating similarly, while persistence (how long soil remains water-repellent) altered differently in both soil types. Research on organic matter composition and soil mineralogy may provide future insights into heat-induced alterations in WR of tested soils.
KW - Soil water repellency
KW - Temperate soil
KW - Tropical soil
KW - Wildfires
UR - http://www.scopus.com/inward/record.url?scp=85197467293&partnerID=8YFLogxK
U2 - 10.1016/j.catena.2024.108230
DO - 10.1016/j.catena.2024.108230
M3 - Journal article
AN - SCOPUS:85197467293
SN - 0341-8162
VL - 243
JO - Catena
JF - Catena
M1 - 108230
ER -