Frequent Life Form Research Articles

Floristic diversity and vegetation analysis of Wadi Arar: a typical desert Wadi of the Northern Region of Saudi Arabia

W adi Arar in the northern region of Saudi Arabia is one of the mostimportant Wadis of the Kingdom. The present study provides an analysisof vegetation types, life forms, as well as floristic categories and speciesdistribution. A total of 194 species representing 30 families of vascularplants were recorded. Compositae, Gramineae and Leguminosae were themost common recorded families. Therophytes and Chamaephytes are themost frequent life forms, indicating typical desert spectrum vegetation.The distribution of species in the different sectors of the Wadi as well asthe phytochoria for the recorded species is provided. Eighty nine species(45.88%) are typically bi-regional. Furthermore, about 105 species(53.5%) are mono- and pluriregional taxa. The highest number of species(135 or 69.59%) was recorded for annual plants, while the lowest numberof species (59 or 30.41%) was recorded for perennial, short perennial orannual to biennial species.

A Study on Floristic Composition, Chorology and Ecological Structure: A case Study from a Small-scale Forest Reserve, Talesh, Iran

This study, carried out on vegetation of the Gisoum forest reserve with 171 hectares area located 14 km to Resvanshar city, Guilan province, was to examine the structure and composition of the forest vegetation. A first topographic map of the area with the scale of 1:10000 was prepared and the study area was delimited. Transect- quadrate method of sampling was used to record the floristic and phytosociological data necessary for the analysis in about 44 quadrates of 400 m2. Some vegetation parameters viz. density and diameter at breast height (DBH) for trees (over story vegetation) as well as cover-abundance for under story vegetation were recorded, respectively. The life form spectrum of Raunkiaer, the dominant vegetation type of the area, is based on importance value and vegetation structure based on frequency classes, also their chorology caring a central importance in vegetation description were determined. The study of the floristic list showed that 76 species belonging to 66 genera and 45 families existed in the area.The largest families were Asteraceae and Rosaceae with 5 species. Investigation of the geographical distribution of plant species indicated that 44 % belonged to the Europe – Siberian zone. Plant life forms by Raunkiaer method showed that phanerophytes with 35.5 % and hemicryptophytes with 27.6 % were the most frequent life forms. Dominant vegetation type based on importance value index was Buxus hyrcanus-Parrotia persica. Also the evaluation of vegetation structure based on frequency class revealed that abundance-distribution was irregular in under story and regular in upper story vegetation.

A contribution to the ecology and floristic markers of plant associations in different habitats of Sinai Peninsula, Egypt

Sinai Peninsula in Egypt is of special ecological interest because of its variable environment, landscape, distinctive flora. In the present study, 75 species were recorded, belonging to 65 genera and 29 families, and 90.7 % of these species are perennials. The most frequent life form was the chamaephytes (49.4 %) and the Saharo-Sindian taxa were the best represented ones (73.3 %). The classification of the 31 stands gave four communities: Nitraria retusa, Atriplex halimus, Cornulaca monacantha, and Retama raetam. According to the two-way indicator species analysis (TWINSPAN) classification, the ordination of stands showed that the groups A and B are markedly distinguishable, while the groups C and D are superimposed. Chlorides, sulfates, Na, Ca, Mg, K, calcium carbonate, and electrical conductivity are the community distribution controlling parameters. Results of this study demonstrated that the distribution of the plant communities and their composition over a small geographic area in desert ecosystems is related to heterogeneous topography and landform pattern. The heterogeneity of local topography, edaphic factors, and microclimatic conditions leads to variation of the distributional behavior of the plant associations of the study area.

Floristic diversity and vegetation analysis of Wadi Arar: A typical desert Wadi of the Northern Border region of Saudi Arabia

Wadi Arar in the Northern border region of Saudi Arabia is one of the most important Wadis of the Kingdom. The present study provides an analysis of vegetation types, life forms, as well as floristic categories and species distribution. A total of 196 species representing 31 families of vascular plants were recorded. Compositae, Gramineae and Leguminosae were the most common families. Therophytes and chamaephytes are the most frequent life forms, indicating typical desert spectrum vegetation. The distribution of these species in the different sectors of the Wadi as well as the phytochoria for the recorded species is provided. Ninety-one species (46.5%) are typical bi-regional. Furthermore, about 105 species (53.5%) are mono- or pluriregional taxa. The highest number of species (136 or 69.5%) was recorded for annual plants, while the lowest number of species (60% or 30.5%) was recorded for perennial, short perennial or annual to biennial species.

The Lowland Meadow Vegetation of the Central Black Sea Region of Turkey

The vegetation of the lowland meadows in the central Black Sea region of Turkey was analyzed according to the Braun-Blanquet method with the help of TWINSPAN clustering, CCA, and DECORANA ordination methods. Three plant associations were discovered and described in the study area as new. The most abundant and frequent life form in the associations is hemicryptophytes. The Shannon Diversity Index and Evenness was also used for calculations of the associations. The syntaxonomical status of the described associations was ordered as follows: Molinio-Arrhenatheretea Tuxen 1937 Holoschoenetalia vulgaris Br.-Bl. ex Tchou 1948 Gaudinio-Hordeion bulbosi Galan, Deil, Haug and Vicente 1997

Exploration of wild plants wealth with economic importance tolerant to difficult conditions in Khulais Governorate, Saudi Arabia

The present work studied the flora of Khulais region, west Saudi Arabia, with reference to its potential use. Results revealed that the region considers a hot-spot in the Kingdom in term of plant diversity and more diverse region compared with other well studied regions in Saudi Arabia and neighboring countries. A total of 251 plant species belonging to 160 genera and 50 families were identified. The major plant families that contributed in the formation of vegetation of the area in question were Poaceae (42 species) followed by Papilonaceae (20 species), Euphorbiacea and Asteraceae (18 and 15 species, respectively), while eighteen families each was represented by only one species. Therophytes exhibited the maximum number of species (41.2%), followed by Chaemophytes (31.4%), Hemicryptophytes (13.7%) and Phanerophytes (10%), while the least frequent life form class was Geophytes. Floristic list of the studied area showed 96 species with economical importance, 66 species used as fodder, 24 as medical and 6 edible species. The study Shed light on the region and showed that the area has remained botanically virgin and not explored extensively and intensively even though rich in vegetation, providing floristic checklist and strongly recommending further detail study. Key words: Biodiversity, Khulais, Saudi, flora, hot-spot.

Iberian Baetic Endemic Flora and the Implications for a Conservation Policy

The Baetic ranges in the Iberian Peninsula are extremely rich and outstanding in biological terms. Based on the existing literature, herbarium sheets and our own field research, we provide a checklist of the endemic flora growing in the Baetic chorological province. The checklist includes 418 taxa belonging to 43 families, with the species pool concentrated within large families. The highest number of endemic species is recorded in the altitudinal range of 1300–1500 m a.s.l. Hemicryptophytes represent the most frequent life form (45.5%). Conservation priorities should concentrate on non-woody life forms (particularly on hemicryptophytes), and on high mountain areas. Most of the taxa can be ascribed to serial shrublands (36.87%), or rock- or scree-dwelling formations (26.25%), with climactic forest formations playing a minor role (3.24%). This successional position has important implications for conservation programmes. Therefore, a clear distinction should be made between serial or plagioclimactic formations (e.g. dolomite thyme-scrub communities) and degraded communities of little interest for the preservation of biodiversity (e.g. synanthropic vegetation). Astragalus nevadensis subsp. andresmolinae (Díez-Garretas & Asensi) Mota & F.J. Pérez-García is proposed as a new combination.

LA FLORA ALTOANDINA DE LOS SECTORES ESTE Y OESTE DEL PARQUE NACIONAL NAHUEL HUAPI, ARGENTINA

The floristic composition and species richness of the western (moister) and eastern (dryer) areas of the high Andean region of Nahuel Huapi National Park (Argentina) were compared. Species lists were compiled for the two sectors from collections in the alpine area of 20 mountains of the Park (10 from each sector) from 1993 to 1997. A total of 232 species, 111 genera and 48 families were recorded. Asteraceae (with 70 species), Poaceae (17), Apiaceae (12), Fabaceae (11) and Scrophulariaceae (11) are the predominant families in the area, and Senecio (with 22 species), Nassauvia (12), Acaena (7), and Perezia (7) are the best represented genera. There are six endemic species in this protected area. The most frequent life forms are perennial herbs and subshrubs, followed by shrubs, and annual species are nearly inexistent. Species richness was found to increase in relation to the precipitation decrease from west to east: 149 species were found in the moister westem sector and 220 in the dryer eastern sector. Some families and genera are more represented or appear exclusively in one of the two sectors. We discuss current ecological and past historical factor s that could explain this variation in spedes diversity and composition.

Habitat and Plant Communities in the Nile Delta of Egypt II. Irrigation and Drainage Canal Bank Habitat

The present study provides quantitative analysis of the vegetation and spatial variations of environmental factors controlling the abundance and distribution of vegetation in canal and drain banks in the Nile Delta region of Egypt. Five vegetation groups have been recognized: group A codominated by Arundo donax and Polygonum equisetiforme, group B codominated by Rumex dentatus and Polypogon monspeliensis, group C dominated by Eichhornia crassipes, group D codominated by Phragmites australis and Echinochloa stagnina and group E dominated by Typha domingensis. The total number of weeds recorded in the study area is 113 species belonging to 36 families. Therophytes (48.67%) and geophytes (14.16%) are the most frequent life-forms. The major chorotypes in the study area are Mediterranean (42.48%), Cosmpolitan (19.47%), Pantropical (13.27%) and Palaeotropical (12.39%). The relationships between the vegetation gradients and edaphic factors showed that, potassium and sodium cations, potassium adsorption ratio, chlorides, sodium cation adsorption ratio, pH value and water-holding capacity are the main controlling edaphic factors.

Macrophyte community structure and species occurrence in relation to environmental determinants in the ephemeral aquatic habitats of Gavdos, Greece

The aims of this study were to explore the environmental factors that determine the distribution of plant communities in temporary rock pools and provide a quantitative analysis of vegetation–environment relationships for five study sites on the island of Gavdos, southwest of Crete, Greece. Data from 99 rock pools were collected and analysed using Two-Way Indicator Species Analysis (TWINSPAN), Detrended Correspondence Analysis (DCA) and Canonical Correspondence Analysis (CCA) to identify the principal communities and environmental gradients that are linked to community distribution. A total of 46 species belonging to 21 families were recorded within the study area. The dominant families were Labiatae, Gramineae and Compositae while therophytes and chamaephytes were the most frequent life forms. The samples were classified into six community types using TWINSPAN, which were also corroborated by CCA analysis. The principal gradients for vegetation distribution, identified by CCA, were associated with water storage and water retention ability, as expressed by pool perimeter and water depth. Generalised Additive Models (GAMs) were employed to identify responses of four dominant rock pool species to water depth. The resulting species response curves showed niche differentiation in the cases of Callitriche pulchra and Tillaea vaillantii and revealed competition between Zannichellia pedunculata and Chara vulgaris. The use of classification in combination with ordination techniques resulted in a good discrimination between plant communities. Generalised Additive Models are a powerful tool in investigating species response curves to environmental gradients. The methodology adopted can be employed for improving baseline information on plant community ecology and distribution in Mediterranean ephemeral pools.

Land degradation and vegetation distribution in Chott El Beida wetland, Algeria

The aim of this study is to explore the environmental factors that determine plant community distribution in northeast Algeria. This paper provides a quantitative analysis of the vegetation–environment relationships for a study site in the Chott El Beida wetland, a RAMSAR site in Setif, Algeria. Sixty vegetation plots were sampled and analysed using TWINSPAN and Detrended Correspondence Analysis (DCA) in order to identify the principal vegetation communities and determine the environmental gradients associated with these. 127 species belonging to 41 families and 114 genera were recorded. Six of the recorded species were endemic representing 4.7% of the total species. The richest families were Compositae, Gramineae, Cruciferae and Chenopodiaceae. Therophytes and hemicryptophytes were the most frequent life forms. The Mediterranean floristic element is dominant and is represented by 39 species. The samples were classified into four main community types. The principal DCA axes represent gradients of soil salinity, moisture and anthropogenic pressure. The use of classification in combination with ordination techniques resulted in a good discrimination between plant communities and a greater understanding of controlling environmental factors. The methodology adopted can be employed for improving baseline information on plant community ecology and distribution in often critically endangered Mediterranean wetland areas.

Plant Diversity in Miankaleh Biosphere Reserve (Mazandaran Province) in North of Iran

Miankaleh Biosphere Reserve is located in north of Iran, it covers an area about 68800 ha. In this survey the plant specimens were collected from different parts of area during two growing seasons. The aim of this research was identify the plant species, introducing the Flora and determination of life forms. In Miankaleh area 261 species recognized, that belong to 60 families and 177 genera. Among these families represented in area Asteracea, Poaceae, Papilionaceae, Cyperaceae and Brassicaeae had the highest number of species 34, 34, 26, 10 and 10, respectively. Fifty four species (20.68%) were endemics of Irano-Turanian region, the following species of them were endemics for Iran: Lindelofia kandavanensis, Papaver tenuifolium, P. chelidonifolium, Scorzonera tortusissima, Scrophularia gaubae, Crepis gaubae and Crepis papposissima. Therophytes and hemicryptophytes with 137 species (52.5%) and 76 species (29%) were respectively the most frequent life forms of the Biosphere Reserve.

Understory vegetation indicators of anthropogenic disturbance in longleaf pine forests at Fort Benning, Georgia, USA

Environmental indicators for longleaf pine ( Pinus palustris ) ecosystems need to include some measure of understory vegetation because of its responsiveness to disturbance and management practices. To examine the characteristics of understory species that distinguish between disturbances induced by military traffic, we randomly established transects in four training intensity categories (reference, light, moderate, and heavy) and in an area that had been remediated following intense disturbance at Fort Benning, GA. A total of 134 plant species occurred in these transects with the highest diversity (95 species) in light training areas and the lowest (16 species) in heavily disturbed plots. Forty-seven species were observed in only one of the five disturbance categories. The variability in understory vegetation cover among disturbance types was trimodal ranging from less than 5% cover for heavily disturbed areas to 67% cover for reference, light, and remediated areas. High variability in species diversity and lack of difference in understory cover led us to consider life-form and plant families as indicators of military disturbance. Life-form successfully distinguished between plots based on military disturbances. Species that are Phanerophytes (trees and shrubs) were the most frequent life-form encountered in sites that experienced light infantry training. Therophytes (annuals) were the least common life-form in reference and light training areas. Chamaephytes (plants with their buds slightly above ground) were the least frequent life-form in moderate and remediation sites. Heavy training sites supported no Chamaephytes or Hemicryptophytes (plants with dormant buds at ground level). The heavy, moderate, remediated, and reference sites were all dominated by Cryptophytes (plants with underground buds) possibly because of their ability to withstand both military disturbance and ground fires (the natural disturbance of longleaf pine forests). Analysis of soils collected from each transect revealed that depth of the A layer of soil was significantly higher in reference and light training areas which may explain the life-form distributions. In addition, the diversity of plant families and, in particular, the presence of grasses and composites were indicative of training and remediation history. These results are supported by prior analysis of life-form distribution subsequent to other disturbances and demonstrate the ability of life-form and plant families to distinguish between military disturbances in longleaf pine forests.

Vegetation-soil relationships in Tihamah coastal plains of Jazan region, Saudi Arabia

The present study provides quantitative estimates of the vegetation structure and distribution of the plant communities in Tihamah coastal plains of Jazan region in relation to the soil properties. The factors affecting the species distribution and correlation between the vegetational gradients and the edaphic variables are discussed. Eight major community types constitute the major part of the natural vegetation of the study area and are dominated by nine perennials: Ziziphus spina-christi, Calotropis procera, Leptadenia pyrotechnica, Suaeda monoica, Panicum turgidum, Salvadora persica, Acacia tortilis, Tamarix mannifera and Cyperus conglomeratus. The results of this study confirm that the study area is a tropical desert and belongs floristically to the Sudan territory and also that therophytes are the most frequent life-form in the communities. Analysis of the correlation between the vegetational gradients and the edaphic factors show that soil pH, moisture, electric conductivity, organic carbon, calcium carbonate, bicarbonate, soil cations: sodium, potassium, calcium, and the sodium adsorption ratio are the main operating edaphic factors in the area.

Distribution of the plant communities in Tihamah coastal plains of Jazan region, Saudi Arabia

The present study provides quantitative estimates of the vegetation structure and distribution of the plant communities in Tihamah coastal plains of Jazan region. The factors affecting the species distribution and the correlations between the vegetational gradients and the edaphic variables were discussed. Eight major community types constitute the major part of the natural vegetation of the study area and are dominated by nine perennials: Ziziphus spina-christi (L.) Willd, Calotropis procera (Wild) R. Br., Leptadenia pyrotechnica (Forssk.) Decne., Suaeda monoica Forssk., Panicum turgidum Forssk., Salvadora persica L., Acacia tortilis (Forssk) Hayne, Tamarix aphylla (L.) Karst. and Cyperus conglomeratus Rottb. The results of this study confirm that the study area is a subtropical desert and belongs floristically to the Sudanian territory and also that therophytes are the most frequent life-form in this region. Analysis of the correlation between the vegetational gradients and the edaphic factors showed that soil pH, moisture, electrical conductivity, organic carbon, calcium carbonate, bicarbonate, soil cations: sodium, potassium, calcium, and the sodium adsorption ratio are the main operating edaphic factors in the area.