EVALUATION OF THE RANGE PLANTS ALONG THE WATER COURSES IN THE NILE DELTA

Abstract

The present study aims at determining the phenological behaviour, standing-crop phytomass, primary production, organic and inorganic contents of II dominant species along the water courses in the Nile Delta in order to evaluate their nutritive values as fodder plants. These species are 4 terrestarials (Cynodon dacty/on, Desmostachya bipinnata, lmperata cy/indrica, and Panicum repens), 3 emergen ts (Echinoch/oa stagnina, Persicaria sa/icifo/ia and Phragmites australis), 2 free floatings (Azo/la jiliculoides and Eichhornia crassipes) and 2 submergents (Ceratophyl/um demersum and Potamogeton cri.5pus). Each season, over 400 quadrates (each of I m 2 ) were rdndomly sampled to represent the distribution of these species along IS canals and lfl drains in S localities within study area.

The above - ground parts of each of the II species that found in each quadrdte were harvested seasonally, and separated into living and dead parts and weighted as a fresh material. The oven dry weights at 105 °C were also estimated. The annual net community production of each species was estimated as the difference between the highest and lowest standing-crop phytomass. The productivity ratio was calculated after dividing the primary production by the lowest value of standing crop. Seasonal samples of the fresh above-ground parts of each species (12 - 83

samples per each species) were collected, separated into living and dead parts, rinsed several times with lap water, twice with distilled water, twice with deionized water and oven dried at 60°C to constant weights. All samples were powdered and kept in small paper bags ready for estimating the organic and inorganic contents.