Land Degradation and Development, Journal Year: 2024, Volume and Issue: unknown

Published: Dec. 24, 2024

ABSTRACT Intensified slash‐and‐burn cultivation and forest clearing have caused severe land degradation in the Khasi Hills (Meghalaya plateau, NE India). Despite very high annual rainfall, region faces water scarcity during dry season. Local initiatives aim to restore forests through assisted natural regeneration (ANR) this hydrologically poorly known area. As a first step towards assessing potential hydrological impact of regrowth ANR, we measured infiltrability at sites representing Imperata ‐dominated grassland ( n = 2, degraded baseline); < 20‐year‐old fallows with ANR 3); semi‐mature old‐growth 4, near‐natural bench‐terraced Cryptomeria plantation. Group‐median was highest (425 mm h −1 ), followed by young grasslands (145 68 , respectively), terraced plantation (50 ). Infiltrability increased age an average rate 3.0 y . Dye infiltration experiments were used identify dominant percolation pathways per main land‐cover type. Infiltration least‐disturbed dominated flow along roots, stones other preferential pathways, while matrix grassland; site showed intermediate behaviour (macropore interaction). Comparing median infiltrabilities (maximum) hourly rainfall intensities suggested infiltration‐excess overland may occur occasionally grasslands. improved (with or without ANR), extreme monsoon often shallow stony soils pose serious limitations rebuilding soil storage capacity favour frequent saturation‐excess flow.

Language: Английский