Relating plant morphological traits to uprooting resistance in erosion control: A case study in Nguzu-Edda, Ebonyi State
Date
2016-01
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Federal University of Technology,Owerri.
Abstract
The strength with which a plant resists uprooting in form of erosion is influenced by a number of morphological traits such as root form, the proportion of fine lateral roots, the stem basal diameter and the root biomass. However, it is unknown exactly what characteristics best promote plant stability. Few works have been done in this regard. This study relates plant morphological traits with resistance to uprooting by erosion. The case study selected for this research is the eroded land of Nguzu Edda in Ebonyi State, South Eastern-Nigeria where soils are subjected to harsh water erosion resulting in concentrated flows uprooting small plants. Several lateral uprooting tests were carried out to determine the uprooting forces for twelve plant species. In addition, measurements of above ground / underground traits of juvenile plants growing in the case study area were also carried out. Statistical analytical methods such as Analysis of Variance, Discriminant Analysis, Multiple range tests, multiple regressions were employed in the investigation. From results of analysis, plant maximum uprooting force ,FMAX, was found to have a linear positive relationship with stem basal diameter, D, for all the species. The twelve (12) species studied were classified into two resistance groups based on their resistance to uprooting. The resistance group consisting of plant species such as Oxytenthera abyssinica(bamboo), Vernonia amygdalina (bitter leaf), Milicia excelsa(African Teak) associated with high values of root slenderness ratio (21.43, 71.5,72.0), relative root volume {0.62,0.5,0.22}cm3 /cm, relative root dry weight {0.36,0.28,0.11} g/cm, percentage tap root dry weight{0.15,0.50,0.88}, root density{0.58,0.56,0.50}g/cm3 ;low values of specific root length {3.38, 3.59 ,3.04}cm/g and low values of percentage fine root{45.5,36.0,42.0}% were most suitable as they yielded high resistance to uprooting. The relationship between plant resistance to uprooting and morphological traits were found to be non linear in nature for both resistance groups irrespective of growth form. Hence, it is recommended that those plant species with high resistance to uprooting are suitable for use in erosion mitigation, flood control and land reclamation. Also hybrids and clones of plants with desirable traits of high values of root slenderness ratio, relative root dry weight, percentage tap root dry weight, root density and low values of specific root length and percentage fine roots are suitable for breeding as vegetation to mitigate erosion, control flood and reclaim land. The findings of this research will be beneficial to those using vegetation to mitigate erosion and control flood.
Description
This thesis is for the award of Master of Engineering(M.ENG) in Water Resources Engineering
Keywords
Plant traits, lateral uprooting, uprooting resistance, erosion, statistical analysis, Department of Civil Engineering
Citation
Nwite, S. A.(2016). Relating plant morphological traits to uprooting resistance in erosion control: A case study in Nguzu-Edda, Ebonyi State (Unpublished Master's Thesis). Federal University of Technology, Owerri, Nigeria