Vegetation-environment relationships in south Nile Delta

Document Type : Original Article

Authors

1 Department of Botany, Faculty of Science, Tanta University

2 Department of Botany and Microbiology, Faculty of Science, Helwan University

Abstract

The present study aimed at identifying and analysing the plant communities of
the different habitats in south Nile Delta. Two hundred and seventy one stands
were selected to represent the variation in seven major types of habitat
recognized in the study area (terraces, slopes, water edges, open water, gardens
and nurseries, croplands and ditches, fallow and flooded lands. One hundred and
forty four species belonging to 110 genera, 43 families and 23 orders were
recorded. Species-rich families were Gramineae followed by Compositae,
Cyperaceae, Euphorbiaceae, Leguminosa, Polygonaceae and Amaranthaceae.
Thirteen vegetation groups were recognized after the application of
TWINSPAN. Their ordination using DECORANA indicated moisture and
human impact gradients. The moisture gradient starts with the xerophytes or
drought-tolerant plants that inhabited the dry terraces and slopes of the water
courses and ruderal habitats (e.g. Alhagi graecorum, Imperata cylindrica,
Phragmites australis and Pluchea dioscorides groups). Then, passing through
the mesophytes that inhabited the ditches, gardens and croplands (e.g.
Chenopodium ficifolium, Cynodon dactylon-Paspalum dilatatum and Cyperus
rotundus-Cynodon dactylon groups), and the species that inhabited the water
edges (e.g. Phragmites australis, Pluchea dioscorides, Sorghum bicolor and
Cyperus articulatus-Cynodon dactylon groups).The pure aquatic communities
that inhabited the open water (e.g. Eichhornia crassipes-Myriophyllum
spicatum, Vossia cuspidata and Vossia cuspidata-Eichhornia crassipes groups)
represented the other extreme end. The correlations between the soil and water
variables on one hand, and the distribution of common species in the study area
on the other hand were assessed.

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