FRACTAL ANALYSIS OF RHIZOME GROWTH PATTERNS OF SCIRPUS GROSSUS L. ON PEAT AND PADDY SOILS

A. Majrashi, A. Nasrulhaq Boyce, B. Bin Bakar, S. V. Muniandy, M. Moneruzzaman Khandaker

Abstract: This study describes the use of fractal analysis to describe root system in rhizomatous plant, Scirpus grossus L. Root network spread and filling factor of rhizomatous roots are compared with fertilizer applications under different soil types. Fractal analysis allows the structural complexity of such associations to be compared between plant communities, with regard to their potentials for soil resource acquisition and utilization. The NPK fertilizer application at 100:30:30 ha-1 resulted in more robust aerial plant growth with ca. 253.5 ramets m-2 (mean dry aerial bio mass of 23.2 g plant-1) compared with 235.6 ramets m-2 (16.3 g plant-1) in unfertilized peat soils 24 weeks after planting of the mother plant. The parallel figures for plants growing on paddy soils of the Jawa series were ca. 97.08 ramets m-1 (12.19 g plant-1) (fertilized paddy soils) and 83.67 ramets m-1 (10.89 g plant-1) (unfertilized paddy soils) 24 weeks after planting of the mother plant. Mean ramets mortality was significantly higher in unfertilized paddy soils at 121.3 ramets m-2, while in the fertilized paddy soils this was only 34.7 ramets m-2, resulting respective net populations of ca. 218.8 ramets m -2 and 114.3 ramets m -2 in fertilized and unfertilized plots. In paddy soils mean ramets mortality in unfertilized paddy soils was ca. 8.58 ramets m-2, while this was only ca. 5.67 ramets m-2, leading to the respective resultant net populations of 91.41m-2 and 75.09 ramets m-2. Flowering set in earlier among ramets in fertilized peat soils with 103.2 ramets m-2vis-a-vis 77.5 ramets m-2, 24 weeks after transplanting of the mother plant in unfertilized soil. This method allows the structural complexity of such associations to be compared between plant communities, with regard to their potentials for soil resource acquisition and utilization. In peat soil, distinct and partly not significant differences are found (fractal dimension between 1.52 ± 0.53 and 1.50 ± 0.59) in unfertilized and fertilized plots and in paddy soil, fractal dimension between 1.53 ± 0.55 and 1.52 ± 0.49) in unfertilized and fertilized plots. We found distinct and partly not significant differences be compared between plant in peat and paddy soils when analysing many small units of a complex root system association. In larger plant communities, a broad variety of below-ground structures is recorded in its entirety, integrating the specific features of single sub-structures. In that way, extreme fractal dimensions are lost and the diversity decreases. Therefore, the analysis of larger units of root system associations provides a general knowledge of the complexity of root system structures for heterogeneous plant communities.

Keywords: fertilizer application; fractal dimension; modular growth; Scirpus grossus

Date published: 2019-01-17