Algerian Journal of Research and Technology [email protected] http://www.univ-usto.dz/AJRT/ ISSN : 2543-3954 A.J.R.T Volume 1 (N° 1) (2017) 9-17 Study of the Floristic Diversity in Bissa Forest, Chlef, Algeria F. Senoucia*, A. Ababoub, M. chouiebc, N. Amrousb, N.H. Boukeffoussa Ghoulb a Department of Biology, Faculty of Natural and Life Sciences, University of Mostaganem- Abd El Hamid Ibn Badis, Algeria. b Department of Biology, Faculty of Natural and Life Sciences, University of Chlef-Hassiba Ben Bouali, , Algeria. c Department of Agronomy, Faculty of Natural and Life Sciences University of Mostaganem- Abd El Hamid Ibn Badis, Algeria. *Corresponding author. [email protected] Abstract. The exceptional biological richness of Mediterranean ecosystems was highlighted by many researchers. As part of the Mediterranean basin, northern Algeria is characterized by a high plant biodiversity, estimated to almost 3139 species. In this context, this study focused on the floristic diversity in the Bissa forest, a cork oak forest in the Northwest of Algeria. Throughout the seven cantons of Bissa forest, 122 plant species belonging to 43 families were identified and listed in a local floristic database. The most dominant families in terms of species percentage were the Asteraceae and Fabaceae. The highest biodiversity was shown respectively by the cantons of Ain Lemcen, Oued Rihane and Tizerouine, while the lowest biodiversity was observed in the cantons of Yahia Bouzekri and Sidi M'hamed Aberkane. Through the phytosociological analysis, three major vegetation units with different numbers of diagnostic species with fidelity thresholds ranging from 0.17 to 1 were distinguished. Furthermore, many differential species with a wide ecological spectrum were observed. Finally five species have been identified as generalists present in all cantons and adapting to all conditions of this forest. Keywords. Biodiversity, Phytosociology, Diversity indices, Phi coefficient, Similarity, Bissa forest. INTRODUCTION In ecology, ecosystems are often described by their floristic composition, which form under suitable environmental conditions the vegetal associations (McIntosh 1985). In this context, the vegetal association is a plant community characterized by definite floristic and sociological features (Braun-Blanquet 1932) and growing under a uniform habitat conditions (Flahault and Schroter, 1910), each plant community is recognized by a certain number of diagnostic species as defined by Westhoff and Van der Maarel (1978). According to Curtis (1959), the term 9 diagnostic species is an important concept in vegetation classification; it is a plant of high fidelity to a particular community, whose presence serves as a criterion of recognition of that community. The relative constancy or abundance of these diagnostic species distinguishes one association from another (Whittaker 1962). By their presence, abundance or potency, these species are considered to indicate certain site conditions (Gabriel and Talbot 1984). Patterns of vegetal association are assessed using floristic readings including a list of plants registered in a relatively uniform habitat (Mueller-Dombois and Ellenberg 1974); the floristic composition characterizing any habitat can be expressed by species richness (Fulbright, 2004), percent cover (Gimenez and Diaz, 2001) and fidelity measurements (Bruelheide 2000; Chytrý et al., 2002). North part of Algeria is characterized by a high plant diversity, estimated to almost 3139 species, among which 700 endemic species (Quezel and Santa 1962; 1963), under a constant anthropic and climatic pressure (Molinier 1971). Unfortunately, apart from the great work of Quezel and Santa (1962, 1963), this floristic richness remains poorly known and requires more consideration. The clear and precise knowledge and description of this natural richness is the key element that allows the preservation of this national wealth. In order to contribute to the description and the preservation of the Algerian flora, the aim of this study is the creation of local floristic database with the complete inventory of the flora, the identification of the floristic pattern in Bissa, one of the healthiest cork oak forests in Northwest Algeria. MATERIAL AND METHODS Study area Covering approximately 23 km2, the Bissa Forest is an ecological sanctuary located in a mountainous region 10 km from the Mediterranean and 45 km northeast of Chlef Wilaya, daira of Zeboudja, this forest belongs to the district of Zeboudja and Beni Haoua and is part of Oued Fodda province, extending between 36°25'30"- 36°28'41" of North latitude and 1°25'34"- 1°30'00" of East longitude (Fig. 1). The area is characterized by a very rugged relief, steep slopes and an average height of 700 meters the highest point stands over 1100 m. it is a typical Mediterranean area in terms of climate, distinguished by hot, dry summers and relatively rainy winters, with an annual dry period of 5 months and 74% of the annual precipitations are recorded during winter and autumn. Fig 1. Location of Bissa forest. 10 Vegetation sampling The floristic surveys were carried out over the spring between 2014 and 2016 all around the 7 cantons of Bissa forest (Hab Melouk, Ain Lemcen, Ain Laaouad, Oued Rihane, Tizerouine, Yahia Bouzekri and Sidi M'hamed Aberkane) and over a minimum area of 10×10m, using the presence/absence method. Species identification was done based on Quezel and Santa (1962, 1963). Study of Biodiversity Shannon Index (H) To characterize the species diversity at the cantons level the Shannon (Shannon and Weaver, 1948) Index (H) was used. It’s calculated as follows: H = p ln p (1) Where: psi is the proportion (n/N) of individuals of one particular species found (n) divided by i i the total− ∑ numberi=1 of individuals found (N), ln is the natural log, Σ is the sum of the calculations, s is the number of species. Phytosociology - Sokal and Sneath similarity index and UPGMA algorithm In order to classify the floristic surveys we combined the Sokal and Sneath binary index (Sokal and Sneath, 1963) to create a similarity matrix and the unweighted pair-group method with arithmetic mean (UPGMA) as agglomerative method based on the similarity matrix. The Sokal and Sneath index ranges between 0 and 1 and is defined as follows: S = a/(a + 2(b + c) ) (2) Where: a is the number of species common to the two quadrats, b is the number of species unique to the first quadrat, c is the number of species unique to the second quadrat. - The Φ coefficient of association To extract the main vegetation’s units from the floristic surveys classification, the ϕ-coefficient of association is a statistical measure of association ranging between 0 and 100%, that can be used as a measure of fidelity; it’s calculated as follows (Bruelheide 2000; Ababou et al., 2009; 2010; 2015): . Φ = (3) . N.(np−n).Np Where:�n Np isN −then � Ntotal−Np �number of floristic surveys, Np is the number of floristic surveys in a particular group of sites obtained through Sokal and Sneath-UPGMA classification; n is the number of occurrences of the species in the all sites; np is the number of occurrences of the species in a particular group of sites. RESULTS AND DISCUSSION Biodiversity analysis 122 species distributed over 43 families were recorded throughout the 7 cantons of Bissa forest. Among the 43 families, the 8 most commonly represented were the Asteraceae, Fabaceae, Poaceae, Caryophyllaceae, Lamiaceae, Rosaceae, Geraniaceae and Rubiaceae. Indeed 54% of the total numbers of species belong to these families, while just the Asteraceae and Fabaceae alone accounted for 25% of the total number of the 122 species (Fig. 2). According to Shannon diversity index, the highest biodiversities were registered successively in the cantons Ain Lemcen, Oued Rihane and Tizerouine, while the lowest biodiversities were observed respectively in Yehia Bouzekri and Si M'hamed Aberkane cantons (Fig. 3). 11 The highest Eveness (EH) values of almost 1 confirmed that all inventoried species were equally distributed throughout the 7 cantons with no dominant species (Fig. 3). 0.82 2.46 0.82 0.82 2.46 0.82 0.82 0.82 Fagaceae Smilacaceae 0.82 0.82 Adoxaceae Amaranthaceae 0.82 0.82 9.02 Anacardiaceae Apiaceae 2.46 2.46 Apocynaceae Araceae 1.64 Arecaceae Asparagaceae Asteraceae Boraginaceae 1.64 Brassicaceae Caprifoliaceae 0.82 6.56 Caryophyllaceae Cistaceae 15.57 Clusiaceae Convolvulaceae Crassulaceae Cupressaceae Dioscoreaceae Ericaceae 2.46 Euphorbiaceae Fabaceae 0.82 Geraniaceae Iridaceae Lamiaceae Liliaceae 0.82 0.82 3.28 Linaceae Malvaceae 1.64 0.82 4.92 Myrtaceae Oleaceae 4.92 Orchidaceae Pinaceae 0.82 Plantaginaceae Poaceae 4.10 3.28 Primulaceae Ranunculaceae 1.64 0.82 6.56 3.28 0.82 Rhamnaceae Rosaceae 0.82 0.82 Thymelaeaceae Urticaceae 1.64 0.82 0.82 Fig 2. Percentage of families recorded in Bissa forest. 30 Hab Melouk Oued Rihane Ain Lemcen Aberkane 25 Tizerouine Ain Laaouad Yehia Bouzekri 20 15 10 5 0 Shannon Evenness Margalef Fig 3. Biodiversity indices in the different cantons of Bissa. In terms of specific richness (Margalef Index), the cantons of Ain Lemcen and Oued Rihane showed the highest specific richness, while the lowest specific richness was recorded in the cantons of Ain Laaouad, Si M'hamed Aberkane, and Yehia Bouzekri (Fig. 3). T-test revealed that the differences between the floristic diversities of the 7 cantons vary between non-significant to highly significant. The highest differences (P < 0.001, and P < 0.01) were observed between Yehia Bouzekri canton and all the remaining cantons and also between Si M'hamed Aberkane and Hab Melouk, Oued Rihane, Ain Lemcen, Tizerouine and Ain Laaouad cantons. Whereas, the remaining combinations were not significantly different (P> 0.05) such as those observed between Tizerouine canton and Hab Melouk, Oued Rihane, Ain Lemcen and Ain Laaouad cantons (Table 1). 12 Table 1. Shannon index and comparison between the biodiversity in the seven cantons of Bissa using the t-test.