Analysis of plant responses to the aftermath of fire outbreak in Muhabura Volcanoe, Rwanda.

Abstract

The structure of the community, composition of species and ecological processes at any given site are responses to various aspects of disturbance such as flooding, drought and fire (Alho & Silva, 2012). The majority of plant regeneration modes after fire, are based on resprouting, seed storage, dispersal, and germination. The objectives of this study were to assess plant regeneration in the burnt habitat, comparing the plant communities in unburned areas of the same altitude along the Muhabura volcano of the altitude slope in Volcanoes National Park (VNP), after one year. The study was conducted in the eastern part of the Muhabura volcano which was burned in 2009. Sixty plots in total, thirty in each habitat (burned and unburned), were surveyed using the Braun-Blanquet method. The stratified sampling technique was used in different vegetation types: herbaceous (2X2m), shrubs (5X5m) and forest (10X10m). Square plots were established every 25 m of altitude covering a total of 900m of elevation. The results showed a slight difference in plant diversity of burned area, in which 77 plant species were identified, against 74 plant species identified in unburned area. Five plant communities (two in the burned and three in the unburned habitats) were identified using the Detrended Correspondence Analysis. The coverage of annual plants, Therophytes (indicators of disturbed areas) was high in the burned habitats the unburned habitats were dominated by perennial plants, phanerophytes (indicators of undisturbed areas). The regeneration mechanism showed a great number of woody sprouters, which had an influence on the rapid recovery of the vegetation after fire, and played a positive role in preventing soil erosion and nutrient losses. Erica arborea woody plants did not show any signs of regeneration.