Abstract Detail

Ecology

Bulu, Yetunde [1], Kekere, Otitoloju [2].

Seedling recruitment characteristics of Tithonia rotundifolia invaded fallow land and its competitive relationship with Chromolaena odorata.

Chromolaena odorata (L.) R. M. King & H. Rob and Tithonia rotundifolia (Mill.) S. F. Blake, are exotic invasive weeds in Nigeria. In recent times, a gradual decrease in the population of C. odorata with rapid invasion of T. rotundifolia is observed within the country. Therefore, this study investigated the adaptive features of each weed in competition, with a further determination of the effect of T. rotundifolia on seedling recruitment from the soil seed bank of its invaded and uninvaded plots. The Direct Germination Method was used to assess the readily germinable seed species composition, from soil samples collected from the plots. Sorensen Index of Similarity between the seed bank and their above ground vegetation was estimated. The seedlings of the two plants were subjected to Competition Series Experiment. Forty-four plant species distributed into six and fifteen families occurred on the above-ground of the invaded and non-invaded plots, respectively. Seedlings belonging to 14 families were recruited from soil seed bank at 0-15 cm depth on invaded and non-invaded plots while at 15-30 cm depth, 13 families were recruited. Mariscus alternifolius (227) and Oldenlandia corymbosa (358) were the most abundant species in the seed bank while T. rotundifolia recruited 25 individuals. Low similarity index existed between the seed bank and the standing vegetation of the invaded and uninvaded plots. T. rotundifolia in heteroculture with C. odorata led to improved growth in the former with increased density of the latter compared to when in monoculture and a corresponding reduction in growth yield of C. odorata in the presence of T. rotundifolia compared to when in monoculture. T. rotundifolia was discovered to have some adaptations for competitive advantage over C. odorata and other plant species in the study area.

1 - Adekunle Ajasin University, Plant Science And Biotechnology, Akungba Akoko, Akungba, ON, 342111, Nigeria
2 - Adekunle Ajasin University, Plant Science and Biotechnology, Akungba-Akoko, Ondo State, Nigeria

Keywords:
Chromolaena odorata
Tithonia rotundifolia
Soil seed bank
Seedling recruitment
Competitive interaction.

Presentation Type: Oral Paper
Number: EC12007
Abstract ID:117
Candidate for Awards:Ecological Section Best Graduate Student Paper