Abstract
The present study was conducted to evaluate the ecology and nutritive potential of the wild herbal weed Sisymbrium irio in the Nile Delta region. Vegetation and soil were sampled in 50 stands distributed in different habitats in the Nile Delta region of Egypt where Sisymbrium irio was recorded. The present study was investigated in cultivated lands, road-sides, wastelands, orchards and canal banks in five Governorates of the Nile Delta: El-Sharkia, El-Gharbia, El-Behira, Kafr El-Sheikh and El-Dakhlia. The total number of the recorded plant species was 104, belonging to 88 genera and related to 31 families. Floristic analysis revealed that the recorded species were classified into three major functional groups according to their duration (life-span) as follows: 72 annuals, 3 biennials and 29 perennials. Therophytes exhibited the maximum number of species (72.13%). Seven vegetation groups (VG) were identified by the application of TWINSPAN and DECORANA as classification and ordination techniques, respectively. Each of these groups inhabited one or more distinct type of habitats. S. irio was recognized as dominant species for most of these groups and as an important species in group E certain species may show a local dominance/co-dominance, or may be distinctly the most important in a group of stands. The correlation between vegetation and soil characteristics is indicated on the ordination diagram produced by the Canonical Correspondence Analysis (CCA). Sand, silt, clay, pH, calcium carbonate, organic carbon, and water- holding capacity were the most significant soil factors controlling the abundance and distribution of the vegetation groups. The community of S. irio (dominant species in Groups B, F, and G) was affected by, calcium carbonate, water holding- capacity, Mg, Ca, and K. Evaluation of the nutritive status of S. irio shoots showed that sodium, potassium, calcium, magnesium, iron, zinc, and phosphorous were detected in adequate amounts, while copper, manganese, and nickel were below the maintenance level. The present study evaluated the nutritive status of S. irio as good forage.

Key words: Chorotypes, classification, ordination, soil, vegetation, nutrients