Phenology, biomass and reproductive characteristics of Calotropis procera (Aiton) WT Aiton in South Cairo, Egypt

Phenology is a major trait structuring life history strategies and its role in shaping plant invasions that has increasing attention. The present study aimed to examine the role of phenology, reproductive, and morphological attributes of Calotropis procera in colonizing urban areas, besides assessing its biomass and developing allometric regression equation for prediction of its biomass. Sixty-three permanent quadrats were selected to represent the distribution of C. procera in urban habitats at South Cairo Province, Egypt. The present study revealed significant positive correlation between fruiting phase of the species and temperature, as well as the vegetative phase and precipitation. C. procera is characterized by continuous flowering for 8 months, with a peak in April and May, which help in reproductive success of the species. It had its highest biomass in November (439 kg ha(-1)), but the lowest in March (343 kg ha(-1)), with an annual mean of 388 kg ha(-1). The linear regression based on plant volume as an independent variable was found to be the best fit for biomass prediction, with the highest coefficient of determination (R (2) = 0.81). The above-ground biomass of this plant encourages its potential use as a renewable energy source. Our study suggests that C. procera has efficient plastic phenological and functional attributes that may enable it to dominate many ecosystems in the future. Efficient management plans are needed to mitigate the risk of this plant on other ecosystems and conserve other native species.