Dynamics of plant ecology and soil conservation: Implications for cut-slope protection

Slope cuts caused by road construction, influence vegetation and soil properties which lead to ecological degradation and soil erosion. Cut-slope soils are infertile, creating unfavourable conditions for plant growth and a reduction of plant species. We investigated plant communities and species regeneration at a cut-slope area in Malaysia whilst examining the relationship between species diversity and soil erosion. Experimental plots were set at three different vegetation coverage intensities; 0% (A), 10% (B), and 50% (C). Treatment C recorded the highest plant coverage, plant density, species richness, plant diversity, and evenness index over time. In contrast, as there was no vegetation at the start of the experiment, succession rate was the highest in treatment A (bare plot) followed by B and C. The succession rate was lower in C due to high competition between the existing plant communities for space, nutrients, sunlight and water. The plot with the highest vegetation coverage (C) showed improved slope stability for it recorded a significant reduction in soil saturation level and erosion rate whilst increasing the shear strength. Dicranopteris linearis, a fern species was the most dominant species in all treatments for it is a pioneer species that thrives in harsh environment. High plant diversity was effective in enhancing soil properties thus, improving soil shear strength as plant coverage increased. Hence, treatment A consistently displayed the highest soil shear strength followed by treatments B and C.