Spatial analysis of fine root distribution on a recently constructed ecosystem in a water-limited environment

Authors

Willis Gwenzi, University of Western Australia
Erik Veneklaas, University of Western Australia
Karen Holmes, Department of Primary Industries and Regional DevelopmentFollow
Timothy M. Bleby, University of Western Australia
Ian R. Phillips, Alcoa World Alumina Australia
Christoph Hinz, University of Western Australia

Document Type

Article

Publication Date

7-30-2011

Journal Title

Plant and Soil

ISSN

Print: 0032-079X Electronic: 1573-5036

Keywords

Global root distribution model, Vegetated engineered cover, Root biomass density, Root diameter distribution, Root length density

Disciplines

Agronomy and Crop Sciences | Natural Resources and Conservation

Abstract

Aims:

(1) to investigate the spatial distribution of fine roots and its correlation with selected soil properties on an artificial ecosystem dominated by woody vegetation species, and (2) to compare the root distribution to that predicted using a global model for natural ecosystems.

Methods:

Root diameter distribution (≤ 5 mm), root biomass density (RBD), root length density (RLD), soil pH, soil electrical conductivity and dry soil bulk density were measured on soil core samples (217) collected from a trench wall using a 20 × 20-cm grid sampling.

Results:

Approximately 90% of the RBD (mean ± standard error: 0.27 ± 0.027 kg m⁻³) and RLD (1.57 ± 0.023 cm cm⁻³) occurred in the top 40 cm, decreasing exponentially to a maximum rooting depth of 150 cm. RBD exhibited a vertical spatial structure associated with soil pH (p < 0.05; r² = 0.48), and a random lateral distribution. Coefficients of variation (CV) of RBD were high irrespective of orientation (vertical: 79–200%, lateral: 50–236%). The root extinction parameter β (0.944) for the global model was lower (p < 0.05) than that of woodlands (β = 0.964–0.976), indicating a shallow root distribution resembling that of grasslands (β = 0.943).

Conclusions:

The superficial root distribution indicated subsoil chemical constraints to root growth, while high lateral variability was attributed to sparse vegetation. The findings stress the need to account for both vertical and lateral variability of roots for accurate modelling of water use and productivity on certain artificial ecosystems with sparse vegetation.

Recommended Citation

Gwenzi, W., Veneklaas, E.J., Holmes, K.W. et al. Spatial analysis of fine root distribution on a recently constructed ecosystem in a water-limited environment. Plant Soil 348, 471–489 (2011). https://doi.org/10.1007/s11104-011-0886-8