Phytosociological Study and Phytoecologique of Psammophytes of the Coastline of The Region of Tlemcen (Oranie-Algeria)

This study is devoted to the analysis of psammophile of coastal dunes of the region of Tlemcen. The interpretation by the factor analysis of matches (A. F. C.) has allowed us to individualize classes’ phytosociologique different. The colonize psammophile, par excellence, the embryonic dunes. Some species colonize the dunes vivid. Finally, other occupies the dunes the most advanced and laid down. Using the data and phytosociologique phytodynamiques, we were able to understand the evolution of this vegetation, and its diversity.


Introduction
The vegetation, the region of Tlemcen, presents a good example of study of plant diversity; and especially an interesting synthesis on the natural dynamics of ecosystems from the shoreline up to the steppe. This study has been launched by several authors. These include mainly: Zeraïa (1981), Dahmani-Megrouche (1997), Quezel (2000), and Bouazza and Benabadji (1998).
The ecosystems Mediterranean coastlines are characterized by climatic constraints and strong soil, salinity, wind, drought and shallow soils or mobile.
The work that we are presenting here concerns the evolution of psammophiles the coastline of the region of Tlemcen. The latter is linked to a high percentage of sand, always higher than 60 %. Although they are located in the northern part; in the South, these formations are well represented and are essentially related to the importance of deposits of sand and the presence of gypsum and salts. This study has been carried out on the basis of the readings phytosociologiques to determine the narrow affinities of different plant groups. In the second place, the knowledge of this floristic richness allows you to make proposals leading to the preservation and improvement of these fragile environments, to limit the degradation and to promote their development in a rational way.

Materials and Methods
The study covers the analysis of the distribution of species in the the coastal region of Tlemcen: study sites were chosen. From the beach Beni Saf up Marsat Ben M'hidi.
For this we chose two areas repartees as follows: • Representive areas them live dunes and dune embryonic (from the beach Beni-Saf up to Marsat Ben M'hidi).
The study area is characterized by a high floristic diversity which is related to the combination of ecological factors that are also very varied (variation bioclimatic, Action anthropozoogéne).
This study has been carried out on the basis of the readings phytosociologique to determine the narrow affinities of different plant groups. In the second place, the knowledge of this floristic richness allows you to make proposals leading to the preservation and improvement of these fragile environments, to limit the degradation and to promote their development in a rational way.
For this study it was selected 10 stations to study locating in the western part of the North West Algeria Figure.1. These are located between 1°27' and 1°51' west longitude and 34Â°27' and 35°18' north latitude. They are geographically limited: to the North by the Mediterranean sea to the south by the wilaya of Na'imah to the west by the moroccan-algerian border to the east by the wilaya of Temouchent to the south-east by the wilaya of Sidi Bel Abbes

Béni Saf
Those lands are limestone lithothamniées rich in fossil shells lumachellique of type post-tablecloths Miocene. rest on these limestones intercalations clays to sandstone Tortonian age (Miocene). The limestones constitute a plateau called "Sidi Safi plateau" from which is calcium carbonate noted for cement plant Beni Saf These limestones are covered with places by volcanic formations of type basaltic, Guardia (1975).

Rachgoune
The station is located at the mouth of Tafna. These are the dune deposits at "El Guedim" and, on the right bank of the Oued, in these dunes appear basalt flows black color inter stratified with the volcanic tuffs, Guardia (1975).

Genesis of Sea Dunes
Under the effect of erosion, sand particles are going to move grace to winds to feed the dune ridge of coastline.

Dunes
The wind pushes the sand which will hang on waste brought by the sea. This forms a hump get bigger and bigger.This is the birth of a dune where embryonic going to develop a ephemeral vegetation based on: Medicago marina; Cakile maritima; Euphorbia paralias. According to Favennec (2002), dune is a deposition of sand edified by the wind into coming up against various obstacles such as vegetation and asperities terrain encountered between the beach and the mainland. The bioclimatic study for two periods  and .  Examination of factorial maps showing the plans of 2/1 and 3/1 projections shows the existence of 04 contrasting sets we will thus attempt to specify what will be the major ecological factors in the diversification of the sward. The positive side of this axis lie in particular species characterizing locations silica, and the negative side revealing a less silica than the first pole.

Plan 2/1:
It seems that this group of species in their vast majority is plants that are most commonly seen in the matorral on siliceous substrate to Cisto-Lavanduletea.
In the center of the axis lie in particular a lot of species of Cakile maritima, Ammophila arenaria, Calystegia soldanella, Echinophora spinosa Medicago minima, Medicago marina These species of psammophytes quintessential (purely psammophilous) that grow on the dunes a strong accumulation Sandy periods of respite from erosion marine; This is a group that is found on the beach of Rechgoune and Marsat Ben M'hidi at an elevation of 0 m on a low slope of zero and with a very low rate of recovery.
The behavior of species diversity and vegetation stresses the importance of the stability of the substrate for vegetation and already show that the coast is highly structured depending on the distance to the sea. The before dune and dune pioneer are influenced by a strong dynamic of sand and have a low plant collection, as well as a monotonous flora. Greater stability of the sand allows the species to cover larger areas and encourages, Furthermore, the coexistence of most abundant species.
It appears therefore that A.F.C was able to reveal the classic data of the littoral vegetation as described in 1923 by Kuhnholtz-Lordat. In phytosociological terms, maritime dunes belonging to the Ammophilion alliance, characterized by Cakile maritima, Eryngium maritimum et Calystegia soldanella.
Vegetation there forms a complex of plant associations arranged parallel to the shore ( Figure 3) and richly described by Molinier and Tallon (1965).
The Agropyretum-mediterraneum is the typical association forming the belt at the base of the dunes (zone 1). Its characteristic species are all observed in (zone 1), we have: Agropyrum junceum, Polygonum maritimum et Cyperus aegyptiacus.
The indications of the analysis of vegetation carried out in this study support this vision, but should not consider these associations and their characteristic species too strictly. Indeed, the analyses presented here also highlight the ongoing nature of the changes in vegetation.
Nude beach (zone 0) there is no vegetation. This area is in fact continually swept by waves that do allow no plant to set. The sand is so naked up to the larger amplitude wave zone. Furthermore, as the present low amplitude tides Mediterranean, this portion of the beach is never covered by water and does not allow a particular fauna to settle. Apart from his recent tourist interest and the fact that it represents the pulling of the constitutive sand dunes area, this portion of the Mediterranean beach is low biological interest.

Results and Discussion (of the Species of the Coast)
It is a set of 57 phytosociological surveys and 223 species on the sandy coast of Sid Safi station; Rechgoune and Ghazaouet.
On the coast, the majority of the species belonging to the class of the Therobrachypodietea This advanced considered grouping formed the coastal juniperais. On the site map, it is aimed at altitudes of 100 m to 400 m, on slopes ranging from 5 to 25% and forming a collection of 70-90%; It is noted from the wet to the semi-arid.
The presence of this group of species is explained by its spatial heterogeneity and has his adaptation (R strategies). This plasticity confirms it a wider environmental spectrum, and colonization of the dunes by producing many seed species (Pinus halepensis; Juniperus phoenicea).

Conclusion
The analysis of the A.F.C highlighted 03 vegetal groups that organise themselves on the map 2/1 and 3/1 according to a schema corresponding to the analysis of adaptive strategies (MAC-ARTHUR 1957) in Chaabane (1993). This segregation is a variation of soil moisture and textural and structural elements. Furthermore, Therophytiques nitrophilous species endowed with a strong potential biotic and reciprocal growth settled more easily, there will be designated the R selection, the form's own selection.
The three groupings sets are represented by: Groups psammophilous by excellence:
In moving away from the beach, a very diverse vegetation moved to attach these dunes giving birth to more or less fixed bright dunes. This vegetation is related to the Therobrachypodietea class www.ccsenet.org/ijb International Journal of Biology Vol. 7, No. 2;2015 The interaction of different natural factors has the mosaics of biotopes and vegetation structure. But this arrangement, linked to the variability of the physicochemical characteristics of the substrates, is particularly disturbed by the actions of origins anthropozoogenic.
This pressure results in depletion of the most advanced sets, a loss of 'natural' biodiversity of specific groups of the coast; it caused great difficulty in the individualization says beaches (Cakiletea maritimae) or even of dunes fixed sets.
Finally, we say that the future is worrying about maintaining this national heritage. It is important that effective, even drastic measures be taken rapidly to alleviate this pressure of anthropozoic origin. Admittedly, this is not unique to the Algerian coast since it occurs in all countries of the Maghreb and on almost all of the territories, but the reduction of vested coastal areas to natural ecosystems is an aggravating factor.
It is with this concern to reduce the pressure, or even to improve the forest of the spit, that we brought the attention on Ammophila arenaria.