STUDIES OF PLANT LIFE IN THE NORTHWEST OF THE DELTA, EGYPT
Creators: name: Mahgoub, Alaa M.M.A.
Publisher: name: figshare
Year: 2023
Subjects: Community ecology (excl. invasive species ecology)

description: The present study is an ecological survey of plant life in the northwest of the Delta, Egypt and their adjoining territories. It aims to study the likely relationships between crops (units of farmed ecosystems) and the weed assemblages associated with them and to investigate the affinities of the available flora. It comprises five parts. <strong>1-</strong> <strong>Chapter I.</strong> <strong>Introduction</strong><strong>, </strong>gives a general description of the surveyed area: location, history, geology and soil types, climate and agriculture and land use. <strong>2-</strong> <strong>Chapter II. </strong><strong>Seasonal aspects and general distribution of weeds</strong><strong>,</strong> describes plant life in 14 sites (districts) representing the surveyed area. The survey depends on monthly records of plants in 5 localities of each site. These records of plants and their phonological performance allowed for: (a) their classification into: winter, summer and all-the-year plants, (b) an assessment of their ecological ranges as indicated by their distribution in the sites. <strong>3-</strong> <strong>Chapter III.</strong> <strong>Sociological assemblages</strong><strong> , </strong>describes the weed assemblages in the various crops monitored : eight winter crops ( clover , broad bean , wheat , flax , potato , artichoke , winter tomato and winter vegetables) ; eight summer crops ( cotton , maize , rice , summer tomato , pea-nut , water-melon , sweet-melon and summer vegetables); two perennial crops (taro and sugar cane) and seven orchard crops (citrus, guava, pear, banana, mango, date palm and grapes). Phenological performance and ecological success of species within fields of each crop were monitored throughout 1986 – 1988. These records allow comparison of performance in various years as related to variability of ecological conditions. The distinction between winter weeds and summer weeds is fairly clear; the all-the-year weeds are either perennial species or annuals that regenerate in both seasons. <strong>4-</strong> <strong>Chapter IV. </strong><strong>Discussion</strong><strong>, </strong>summarizes the records of species included in chapter III and examines their sociological ranges. This shows that: 19 species in all 25 assemblages, 7 species in 24 assemblages, 11 species in 23 assemblages, 11 species in 22 assemblages, 12 species in 21 assemblages, 8 species in 20 assemblages, 8 species in 19 assemblages, 10 species in 18 assemblages, 10 species in 17 assemblages, 9 species in 16 assemblages, 17 species in 15 assemblages, 10 species in 14 assemblages, 12 species in 13 assemblages, 15 species in 12 assemblages, 8 species in 11 assemblages, 13 species in 10 assemblages, 14 species in 9 assemblages, 18 species in 8 assemblages, 21 species in 7 assemblages, 23 species in 6 assemblages, 28 species in 5 assemblages, 24 species in 4 assemblages, 40 species in 3 assemblages, 59 species in 2 assemblages, 134 species in one assemblage. This pattern includes that weed species vary in their sociological ranges and their seasonal performance. Sociological range and ecological success seem linked; most of these species in the first category (present in all assemblages) are also species with higher presence estimate values. Performance of weed (its ecological success) will depend on its inherent attributes (ecological amplitude) in relation to the ecological set up in the field; the latter is related to the growth form of the crop, that is, the dominant plant within the community that includes the weeds and to the farming practices (watering, manuring, weeding, etc.). Although a total of 541 species were recorded in the 25 assemblages monitored, but the species that form the weed population are 476 species. An attempt is made to examine the Syntaxonomy (quotient of similarity and presence index coefficient of similarity) of these species. This analysis deals with the sociological affinities between various types of crops. It shows that the index is influenced by the number of species recorded in these assemblages. But we may note closer affinities within the assemblages of winter crops, summer crops, perennial crops and orchards. <strong>5-</strong> <strong>Chapter V. </strong><strong>Floristic features</strong><strong>. </strong>The flora of the surveyed area seems to originate from several adjacent areas, namely: Nile Delta, the Western Desert, the Mediterranean region and the Nile Valley. The recorded 476 species belong to 63 families (51 Dicotyledonous, 10 Monocotyledonous, one Pteridophyta and one Gymnosperm). <em><strong>Gramineae</strong></em> (84 species), <em><strong>Compositae</strong></em> (61 species), <em><strong>Chenopodiaceae</strong></em> (38 species), <em><strong>Leguminosae</strong></em> (36 species), <em><strong>Cruciferae</strong></em> (26 species) and <em><strong>Caryophyllaceae</strong></em> (23 species) have a total of 268 species representing about 56.3 % of the recorded species. New records to the study area include 102 species among which <em><strong>Brassica juncea</strong></em> and <em><strong>Leptochloa panicea</strong></em> are now records to the flora of Egypt. Chorology (floristic category), distribution as well as records (relative abundance) in various crops are given. The chorological analyses revealed that: (a) the flora of the surveyed area shows clearly that it is the meeting point of several phytogeographical elements: Mediterranean (282 species), Sudano-Zambezian (21 species), Irano-Turanian (18 species) and Saharo-Sindian element (2 species). Widely spread taxa include 67 Palaeotropical species, 55 Cosmopolitan species and 28 Pantropical species. Three species are Endemic viz. <em><strong>Sonchus macrocarpus</strong></em>, <em><strong>Echinops</strong></em> <em><strong>tackholmianus</strong></em><em> and</em> <em><strong>Eragrostis aegyptiaca</strong></em>. (b) Winter species are mainly Mediterranean taxa, summer species include higher percentage of Palaeotropicals while about half of the all-the-year species are Cosmopolitan. <br>