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Research article - Peer-reviewed, 2023

Towards effectively restoring agricultural landscapes in East African drylands: Linking plant functional traits with soil hydrology

Mens, Lotte Patty; Bargues Tobella, Aida; Sterck, Frank; Vågen, Tor-Gunnar; Winowiecki, Leigh Ann; Lohbeck, Madelon

Abstract

Land degradation is a major threat to food security in Sub Saharan Africa. Low infiltration rates in degraded soils increase the risk of surface runoff and decrease soil and groundwater recharge, resulting in further loss of soil fertility, water scarcity and crop failure. Increasing woody vegetation typically enhances soil infiltrability but little is known about how species may have differential effects on the soil hydrological properties. The aim of this study is to understand how woody vegetation and its functional properties affect soil fertility and infiltrability. We measured field-saturated soil hydraulic conductivity (K-fs) and soil organic carbon (SOC) in 38 plots across agricultural landscapes in Muminji, Kenya. Woody vegetation and land use inventories took place and species functional traits were measured on the 63 most abundant species. We systematically tested the effects of vegetation quantity (aboveground woody biomass and vegetation cover) and quality (functional properties and diversity) on soil health (K-fs as a proxy for soil infiltrability and SOC for soil fertility). We found that both vegetation quantity and quality affected soil health. Aboveground woody biomass increased the K-fs and we found a nearly significant positive effect of vegetation cover on SOC. Woody plants with a low leaf thickness positively affected K-fs and a nearly significant negative effect of wood moisture content on SOC was found. Synthesis and applications. This study demonstrates that the systematic assessment of vegetation can lead to evidence-based recommendations to guide land restoration. We found that avoiding bare soil and promoting woody plants, while favouring species with thin leaves and avoiding species with a very low wood density and water storage strategy, is beneficial for soil health across agricultural landscapes in East African drylands.

Keywords

agricultural landscapes; degradation; East Africa; functional traits; Kenya; restoration; soil infiltration; soil organic carbon

Published in

Journal of Applied Ecology
2023, Volume: 60, number: 1, pages: 91-100
Publisher: WILEY

    Sustainable Development Goals

    SDG6 Clean water and sanitation
    SDG15 Life on land
    SDG2 Zero hunger

    UKÄ Subject classification

    Oceanography, Hydrology, Water Resources
    Soil Science
    Ecology

    Publication identifier

    DOI: https://doi.org/10.1111/1365-2664.14311

    Permanent link to this page (URI)

    https://res.slu.se/id/publ/119513