he present study aims to determine the distribution of Trianthema
portulacastrum L. in Nile Delta, to assess the factors that affect its invasion to the study area, and to determine the associated species and plant communities. It aims also at assessing its germination capacity and morphological plasticity through studying several morphological traits. One hundred and thirty stands (each of about 50 m2) were sampled during summer 2009 – 2010 to represent its population in 4 habitats in Nile Delta (orchards, fields of summer crops, irrigation canals and waste lands). The total number of associated species was 63 species, belonged to 56 genera and 22 families. TWINSPAN classification was applied to the floristic composition of 130 stands and led to identify of 18 vegetation groups. Soil of orchards have the highest sand (39.1 %) and organic matter (9.3 %), while the fields of summer crops have the highest EC (440 μScm-1) and phosphorus (6.9 %). In addition, irrigation canals have the highest silt (28.4 %), clay (58.6 %), pH (8.1), nitrogen (0.22 %) and CaCO3 (8.1 %), while the waste lands have the highest potassium (40.3 mg/L). The most effective elements according to CCA were determined. The dispersal type of Trianthema belongs to the anemochores, flowering time extend from February to September, while fruiting time extends from June to September. Seed characteristics were studied. The germination percentage of Trianthema portulacastrum seeds was the highest in waste lands (74 %); while it attained the lowest value in corn fields (50 %). |
