Phytogeographical Analysis Research Articles

Phytogeographical analysis of vascular flora of Ravni Srem flood forests (Vojvodina, Serbia)

The aim of phytogeographical analysis was to determine the plant species origin, genesis and migrations. The study results contribute to the knowledge of phytogeographical classification of the particular regions. The flora structure and composition was determined based on the effects of different chorions. The aim of the floristic research of flood forests of Ravni Srem was to identify the diversity of flora in the region, i.e., in a wider sense, the diversity of flora in Serbia. The phytogeographical analysis was based on floristic research. The identified plant species were classified into the corresponding floral elements, area groups, and area types. The data on their diversity and the degree of representation in the flora of Ravni Srem flood forests were obtained based on the percentage of each area type. It was concluded that the character of the flora of Ravni Srem flood forests was transitional, mostly Eurasian-Central European.

Anthropogenic indicators in pollen diagrams in eastern France: a critical review

The focus of palaeoenvironmental sciences on past human activities and their impact on the environment necessitates a precise understanding of the history and functioning of past and present anthropogenic ecosystems. A process is outlined which uses palaeoenvironmental and historical documentation as well as present-day observations of vegetational changes from two different plant communities, which are characterised by a very specific anthropogenic flora: arable weeds and ruderals. This study is coupled with modern pollen deposition data to deduce a set of pollen types characteristic of the range of human activities practised in eastern France, a region rich in pollen data. First, phytogeographical analysis of the evolution of these plant communities since the Neolithic enables the comparison to be validated. By distinguishing between native plants and aliens introduced long ago (archaeophytes), or more recently (neophytes), and by refining their ecological characteristics, the method also enables identification of species that are strong indicators of human activities. Next, local pollen deposition in these vegetation types is examined with a number of statistical analyses (PCIA, Davis indices), confirming the relationships between a given vegetation community, its theoretical pollen rain and its actual pollen rain, thus distinguishing local and regional pollen indicators. Lastly, comparison of the results obtained by these two approaches leads to a critical synthesis of the traditional anthropogenic pollen indicators (Behre’s “indicator species”) in the study area and to the establishment of more specific local pollen indicators.

Floristic and Phytogeographical analysis of Kudiraimozhi Theri in Tuticorin District, Southern India

A detailed floristic and phytogeographical study of Kudiraimozhi theri was done during 2004- 2007. Among the 510 taxa distributed under 94 families studied from this region. Poaceae is the largest family with 50 species.

Species distribution modelling: Does one size fit all? A phytogeographic analysis of Salix in Ontario

Empirical models for predicting the distribution of organisms from environmental data have often focused on principles of ecological niche theory. However, even at large scales, there is little agreement over how to represent the dimensions of a species’ niche. The performance of such models is greatly affected by the nature of species distributional and environmental data. Regional scale distribution models were developed for 30 willow species in Ontario to examine (i) the predictive ability of logistic regression analysis, and (ii) the effects of using different distributional and environmental data sets. Two original measures of model accuracy and over-prediction were employed and evaluated using independent data. Models based on unique combinations of monthly climate data predicted distributions most accurately for all species. Models based on a fixed set of variables, while generating the highest average probabilities of occurrence for certain species with limited ranges, resulted in the greatest under- and over-estimates of willow distributions. Comparisons of models demonstrated climatic patterns among willows of differing habit and habitat. The distribution of dwarf willow species, present only in the Ontario arctic, followed gradients of summer maximum temperatures. The distribution of the tree species in the southerly portions of the province followed gradients of fall and winter minimum temperatures. Regardless of distributional and environmental data input, no algorithm maximized model performance for all species. Individual species models require individual approaches; i.e., the variable selection technique, the set of environmental factors used as predictors, and the nature of species distributional data must be carefully matched to the intended application. An understanding of evolutionary processes enhances the meaningful interpretation of individual species models. Unless sampling bias and species prevalence can be accounted for, models based on collection point data are best used to guide field surveys. While inferred range data may be better suited to determine potential ecological niches, overestimation of species prevalence and environmental tolerance must be recognized. A combination of available distributional data types is recommended to best determine species niches, an important step in developing conservation strategies.

Osmundo–Alnion woods in Tuscany (Italy): A phytogeographical analysis from a west European perspective

Riparian woods with Alnus glutinosa and Osmunda regalis in Tuscany (central Italy) were studied, whilst western European riparian alderwoods were analysed from a phytogeographical perspective, with particular reference to Osmundo–Alnion and its suballiances. Two associations were identified through the phytosociological analysis of the Tuscan coenoses: Carici pallescentis–Osmundetum regalis ass. nova for mainland Tuscany and Carici microcarpae–Alnetum glutinosae for the Tuscan islands. A phytogeographical analysis for western Europe (47 phytocoenoses, 567 relevés) was performed using floristic classification and chorology‐based discriminant analysis. These allowed us to identify phytocoenoses: (1) attributed to Alnion incanae, correlated with the Eurasian and Boreal chorotypes; and (2) attributed to Osmundo–Alnion, correlated with the west Mediterranean, wide‐distribution and Atlantic chorotypes. The floristic and ecological differences allowed us to divide Osmundo–Alnion into two suballiances: (1) phytocoenoses distributed on the Iberian peninsula, correlated with the Atlantic and endemic Iberian chorotypes, attributable to Osmundo–Alnenion; and (2) phytocoenoses distributed in Algeria, Corsica, Sardinia, Sicily and Tyrrhenian Italy, correlated with the Mediterranean, endemic Sardinian–Corsican and endemic Italian chorotypes, attributable to Hyperico hircini–Alnenion glutinosae.

Diversidade de Leguminosae em uma área de savana do estado de Roraima, Brasil

Leguminosae é considerada a família mais diversa nas savanas de Roraima, que são as maiores áreas de savana da Amazônia brasileira. Este trabalho tem como objetivos fornecer uma listagem florística e analisar os padrões de distribuição geográfica dos táxons de Leguminosae encontrados em uma área de savana em Boa Vista, Roraima (02º52´07´´N; 60º43´03´´W). Foram registrados 80 táxons distribuídos em 38 gêneros. Seis táxons são novos registros para a flora de Roraima. Os gêneros que apresentaram o maior número de espécies foram Aeschynomene e Chamaecrista, cada um com sete espécies. Leguminosae-Papilionoideae foi a subfamília mais diversa em número de gêneros (24) e de táxons infragenéricos (53). A análise da distribuição geográfica revelou a predominância de táxons com padrão neotropical. A área estudada representa um sítio diverso em táxons de Leguminosae, pois concentra cerca de 87% da diversidade citada para a família nas savanas de Roraima.

A note on Phytogeographical analysis of the flora of Parasnath Hill, Jharkhand

Paper deals with the phytogeographical analysis of the flora and shows that the native flora is composed of 12 various phytogeographical elements and predominant elements are Indian wides, tropical and subtropical and Indian.

Distribution patterns, history, and dynamics of peatland vascular plants in Pomerania (NW Poland)

Distribution patterns, history, and dynamics of peatland vascular plants in Pomerania (NW Poland) Pomerania is rich in various peatlands (fens, transitional bogs, raised bogs, spring-water mires, etc.), which support many rare and threatened plant species. This study was aimed: (1) to determine the phytogeographic diversity of Pomeranian peatland vascular plants associated with the classes Oxycocco-Sphagnetea and Scheuchzerio-Caricetea nigrae; (2) to attempt a reconstruction of the history of their postglacial migrations; and (3) to assess the dynamic trends of selected species. A database of records of 83 Pomeranian peatland plants was created, and cartograms of their distribution in Pomerania were made. Each taxon was briefly described, considering its distribution, phytocoenotic spectrum, and biological properties (e.g. pollination mode, diaspores dispersal). The phytogeographic analysis took into account geographic and directional elements, as well as mountain species found in Pomeranian peatlands. The plants' potential for colonization of new sites was assessed on the basis of Raunkiaer's life forms, modes of pollination and seed dispersal, and types of life strategies. As a result of numerical analysis and visual comparison of cartograms, 5 regional distributional types were distinguished: western, northern, eastern, all-Pomeranian, and disjunct. Within the eastern and all-Pomeranian types, which showed internal variation, several subtypes were distinguished. Most of the considered climatic variables (growing season length, temperature, and precipitation variables) were found to affect significantly the floristic variation of Pomeranian peatlands. The available palaeobotanical, palaeoclimatic, palaeoecological, and phytogeographic data, as well as original field research on the distribution of the taxa, allowed the formulation of hypotheses on the time and directions of their migration into Pomerania. Moreover, dynamic trends of selected species are analysed, and the decline of many peatland plant species in Pomerania is discussed.

Vegetation of eastern Unalaska Island, Aleutian Islands, AlaskaThis paper is one of a selection of papers published as part of the special Schofield Gedenkschrift.

Plant communities of Unalaska Island in the eastern Aleutian Islands of western Alaska, and their relationship to environmental variables, were studied using a combined Braun-Blanquet and multivariate approach. Seventy relevés represented the range of structural and compositional variation in the matrix of vegetation and landform zonation. Eleven major community types were distinguished within six physiognomic–ecological groups: I. Dry coastal meadows: Honckenya peploides beach meadow, Leymus mollis dune meadow. II. Mesic meadows: Athyrium filix-femina – Aconitum maximum meadow, Athyrium filix-femina – Calamagrostis nutkaensis meadow, Erigeron peregrinus – Thelypteris quelpaertensis meadow. III. Wet snowbed meadow: Carex nigricans snowbed meadow. IV. Heath: Linnaea borealis – Empetrum nigrum heath, Phyllodoce aleutica heath, Vaccinium uliginosum – Thamnolia vermicularis fellfield. V. Mire: Carex pluriflora – Plantago macrocarpa mire. VI. Deciduous shrub thicket: Salix barclayi – Athyrium filix-femina thicket. These were interpreted as a complex gradient primarily influenced by soil moisture, elevation, and pH. Phytogeographical and syntaxonomical analysis of the plant communities indicated that the dry coastal meadows, most of the heaths, and the mire vegetation belonged, respectively, to the widespread classes Honckenyo–Elymetea, Loiseleurio–Vaccinietea, and Scheuchzerio–Caricetea, characterized by their circumpolar and widespread species. Amphi-Beringian species were likely diagnostic of amphi-Beringian syntaxa, many of these yet to be described.

Contribution à l'inventaire et à l'analyse de la flore ligneuse du plateau des Cataractes (Congo—Brazzaville)

Before this study, the ligneous flora of the Cataracts plate was known only very partially. It was limited to the savannah species of the shrubby layer and an unpublished floristic statement (1950) of about thirty forest species. As for the principal wood (14 species) interested by the forest industry, data are available since the year 2005, within the framework of the inventory of the forest unit of installation Loamba which integrates the forests of our zone of investigation. With the present stage of knowledge, it is inventoried 153 woody species being distributed in 42 families whose floristic diversity varies from 0.65 to 13.07%. As in the African tropical forests, the families best represented are Fabaceae, Euphorbiaceae, Malvaceae and Rubiaceae. In spite owing to the fact that the Cataracts plate evolve in the Guineo-Congolese—Zambezienne transition zone, the phytogeographical analysis shows that the element base is dominated by the guinéo-Congolese species (59.86%). The floristic composition and the phytogeographical behaviour of this flora seem to mark its affinities with the Mayombian and Chaillu flora.

Phytogeography, endemism and affinities of the flora of new Amarambalam Reserve Forests in the Western Ghats of India

Floristic analysis of New Amarambalam Reserve Forests, situated in the Western Ghats of India and forming part of Nilgiri Biosphere Reserve, based on surveys conducted during 1997-2000, has been presented in the paper. The forest area extents to about 265 km2, at an altitudinal range of 40-2600 m above msl. The area is the abode of almost all the forest types of the Indian Peninsula, preserved in an almost pristine state. Intensive floristic survey of the area recorded of a total of 1135 taxa of angiosperms, which belonged to 136 families and 644 genera. The flora is composed of 78 per cent dicotyledons and 22 per cent monocotyledons. Phytogeographical analysis of the flora revealed very high endemism, and almost 21 per cent of the total flowering plants recorded from there were those endemics to Western Ghats of India. Among them, 12.5 per cent were species restricted to Southern part of the Western Ghats. Peninsular Indo-Sri Lankan elements represented 15 per cent of the total flora, which demonstrates the affinity of the region with that of the adjacent ocean Island. Regarding the pattern of distribution of various species outside India, 66 per cent of them were of Indo-Malayan and South and South-East Asian range and 30 per cent of the total flora were composed of pluri-regional species or wides. There were only four per cent taxa in the flora, which are either exotic weeds or escapes from cultivation, showing the less disturbed status of the vegetation.

Floristic characteristics of Visnjicka kosa near Belgrade, Serbia

As a result of floristic investigations of Visnjicka Kosa, 568 plant taxa belonging to 304 genera and 74 plant families were recorded. Phytogeographical analysis showed that this flora can be characterized as being of the Holarctic chorological type (53.00%). Ecological analysis indicated that the flora of the investigated area is of the hemicryptophyte type. Analysis of floristic changes in the last few decades in the investigated area showed declining diversity and strong qualitative changes.

Phytogeography of Asturian (Westphalian D) lycophytes throughout the Euramerican belt of coalfields

A summary is given of the lycophyte species as distributed in fifteen Euramerican coalfields during Asturian (Westphalian D) times. The datasets from the coalfields are analysed using unweighted pair group cluster analyses of Jaccard's Coefficients. Separate analyses were done on the full dataset (the full list of morphospecies) and on a more restricted dataset (only the morphospecies of vegetative organs). Three groupings of coalfields were resolved in the analyses. The two most clearly defined groupings represented the intramontane basin coalfields, and the coalfields of the lowland basins on the Variscan foreland where the lycophyte floras are well documented. The third grouping included those basins with less well-studied lycophyte floras, where the apparently low species diversity has undoubtedly affected the results. More work is needed on these poorly documented floras to produce a more rigorous phytogeographical analysis.

Diversity, geographic variation and conservationof the serpentine flora of Tuscany (Italy)

The specialised flora of serpentine outcrops in Tuscany (Italy) is analysed in terms of species richness and geographic variation, in order to identify main centres of diversity and provide a basis for conservation programmes. Five edaphic groups are distinguished, among which obligate endemics, serpentine-preferential taxa, facultative basiphilous and facultative calcifuge serpentinophytes. Relatively low diversity (87 taxa) and high taxonomic distinctiveness (28.7% of endemics plus preferentials) underscore the insular condition of the ophiolitic outcrops. Hemicryptophytes and chamaephytes are the dominat life-forms, in line with the mainly continental character revealed by the phytogeographical analysis. Presence/absence of the taxa in 10 serpentine island systems was assessed using literature and original field data. Number of species and surface of the areas are significantly correlated. Cluster analysis identifies five groups of areas, while ordination indicates the species which are more effective in determining the floristic differences among the areas. Cecina valley, Monte Ferrato, Murlo hills and upper Tiber valley are the main centres of endemism and taxonomic diversity. However, the positive relationship between floristic and geographic distances and the remarkable proportion of species with frequency < 50% highlights a considerable among-area variation. To ‘catch’ such variation, a network of distant protected sites appears more effective than to search for single areas with high diversity. At least one site in each of the five clusters should be included in a ‘Important Plant Area’ network which would ensure the conservation of such a peculiar component of the Italian vascular flora.

Phytogeography of Late Silurian macrofloras

Cluster analysis and correspondence analysis of Late Silurian (Ludlovian and Pridolian) land-plant macrofossil genera and morphological traits yielded four phytogeographic units: 1) a North Laurussian unit (Bathurst Island), which lay near the palaeoequator; 2) a South Laurussian–Northwest Gondwanan unit (Great Britain, Podolia, and Bolivia), which stretched from 18° S palaeolatitude to 60–75° S palaeolatitude; 3) a Kazakhstanian unit, which probably lay north of the palaeoequator; and 4) a Northeast Gondwanan (Australian) unit, at 10° S palaeolatitude. Phytogeographic analyses based on both genera and morphological traits yielded the same phytogeographic units, suggesting that the observed differentiation does not result from regional taxonomic usage. A data set composed of Pridolian assemblages and ‘range-through’ assemblages (i.e. assemblages composed of taxa that crossed the Siluro-Devonian boundary in each region lacking unequivocal Pridolian [late Late Silurian] assemblages) yielded the same four phytogeographic units, as did a data set composed of range-through assemblages from all six regions having Late Silurian land-plant macrofossils. Thus, the observed phytogeographic differentiation does not result from regional differences in the age of floral assemblages. Zosterophylls ( Zosterophyllum, Distichophytum and Bathurstia) characterize assemblages from the equatorial North Laurussian unit. The near-equatorial East Gondwanan (Australian) unit contains Zosterophyllum, an undescribed endemic zosterophyll genus, Hedeia, the lycopsid Baragwanathia and one additional undescribed endemic genus, which is probably a lycopsid [Tims, J.D.J., 1980. The Early Land Flora of Victoria. PhD Thesis, University of Melbourne, Melbourne, Australia.]. Thus, in the Late Silurian, zosterophylls and large lycopsids were most common in equatorial assemblages. The endemic genera Jugumella (a possible zosterophyll) and Cooksonella (a possible rhyniophyte) characterize the Kazakhstanian unit. Rhyniophytes and rhyniophytoids ( Steganotheca, Pertonella, and the form genus, Tarrantia) characterize the wide-ranging South Laurussian–Northwest Gondwanan unit. This unit may reflect the ecological constraints of Late Silurian land plants. If many Late Silurian land plants belonged to ruderal species with wide dispersal capability that flourished only during the growing season, plants growing in seasonally dry and seasonally cold regions may have been quite similar. However, the morphological simplicity of Late Silurian land plants could cause assemblages from seasonally dry and seasonally cold regions to appear similar, even though they shared few biological genera.

A phytogeographical analysis of the N Moroccan flora

Abstract Valdes, B., Montserrat, J. M. & Font, X.: A phytogeographical analysis of the N Moroccan flora. — Willdenowia 36 (Special Issue): 397-408. - ISSN 0511-9618; © 2006 BGBM Berlin-Dahlem. doi:10.3372/wi.36.36136 (available via http://dx.doi.org/) A numerical analysis is presented of the species composition of 20 assumed natural areas of N Morocco, using a similarity matrix of the distribution of 3113 taxa and a k-means partitive cluster analysis. The results largely support the phytogeographical divisions of N Morocco proposed by Sauvage & Vindt and by Dobignard.

Ecological and species diversity of arid Mediterranean grazing land vegetation

This study was conducted in the arid Mediterranean Reserve located in northern Jordan, representing a continuous grazed arid rangeland ecosystem. Quantitative analyses on species diversity in addition to phytogeographical analysis were conducted. Some ecological parameters such as, life forms, growth forms, species density and frequency were investigated. A total of 93 vascular plant taxa belonging to 78 genera and 26 families were reported. This constitutes about 4.3% of the total flora of Jordan. Reported taxa include 13 species of grasses, 69 forbs and 10 shrubs and semi-shrubs. The botanical survey pointed to the presence of four rare species in Jordan. Plant species were classified into 28 functional groups. Pairwise correlation analyses among the most abundant species, showed that neutral associations dominated (75%) those communities, followed by positive associations (19%), while only (6%) showed negative association. Positive association may be attributed to direct facultative mutualism, or to physical environmental heterogeneity. Such a positive cooperation in the plant community can significantly maintain species diversity in adverse environments. The relationship between primary productivity and species richness showed a humpbacked pattern. Maximum richness corresponded to a biomass level of 300–400 g m −2. However, a sinusoidal curve-fitting model explained the relationship between graminoids biomass and species richness. These findings pointed to the adaptation of plant taxa to livestock grazing and to the small-scale spatial and environmental heterogeneity in arid Middle Eastern Mediterranean rangelands. Results suggest that optimal biodiversity conservation for the arid Middle Eastern grazing lands should consider their high level of spatial heterogeneity. Rangeland managers should adopt grazing plans that apply a range of grazing pressure across the area so as to maintain diversity at local and regional scales.

The vegetation of alpine belt karst-tectonic basins in the central Apennines (Italy)

The vegetation communities of the karst-tectonic basins of the Majella massif alpine belt were studied using the phytosociological methods, and analysed from coenological, synchorological and syntaxonomical viewpoints. During the field-work, 115 relevés were performed using the phytosociological approach of Braun-Blanquet, and these relevés were further subjected to multivariate analyses. Eight clusters of relevés resulted from the numerical classification. The plant communities identified in the study area were ascribed to the following five associations, two sub-associations and one community type: Leontopodio – Seslerietum juncifoliae (ass. nova); Helianthemo – Festucetum italicae (ass. nova); Gnaphalio – Plantaginetum atratae; Taraxaco – Trifolietum thalii gnaphalietosum magellensis (subass. nova); Luzulo italicae – Nardetum, Carici – Salicetum retusae; Saxifrago – Papaveretum julici, Saxifrago – Papaveretum androsacetosum (subass. nova), Plantago atrata and Leontodon montanus community. The distribution of these communities within the karst basins was found to be related to variations in topographic and geomorphological parameters, such as altitude, slope, soil availability and stoniness. All the new associations proposed in this paper belong to the suballiance Leontopodio – Elynenion and to the alliance Seslerion apenninae, both of which are endemic to the central Apennines. In order to compare the plant community types identified within the Majella massif to similar associations found in the rest of the Apennine chain, synoptic tables were constructed. Finally, a comparative phytogeographical analysis of the alpine belt vegetation of the Apennines, Dinarides, southern Balkans and eastern Alps is presented.

On the persistence of Tropical Paleofloras in central Chile during the Early Eocene

Mixed paleofloras first appeared during the Early Eocene of southern South America. These floras were a blend of cold and warm taxa with Austral-Antarctic and Neotropical affinities. Despite the onset of mixed floras, Neotropical floras persisted in central Chile during the Early Eocene. In this study, we analyze the reasons for this persistence and also show that a relationship exists between this persistence and regional paleoclimate. We established the taxonomical composition, associated paleoclimate and phytogeographic affinities of an Early Eocene flora at Caleta Cocholgüe, coastal central Chile. Our results indicate that tropical and subtropical taxa prevailed at Caleta Cocholgüe. These were chiefly Lauraceae, today associated with a humid-warm climate. Physiognomic analyses indicate Mean Annual Temperature and Mean Annual Precipitation above 19 °C and 260 cm, respectively. Moreover, a phytogeographic analysis demonstrates that the Caleta Cocholgüe is closely related to other tropical floras, and poorly linked to contemporary mixed floras. These results strongly suggest that tropical floras persisted in central Chile during the Early Eocene and formed a belt across current subtropical latitudes from southern South America, between 25°S and 37°S. This persistence might be related to the Early Eocene Climatic Optimum and to a shrinking tropical belt, compared to its former Paleocene/Eocene extension.

Ecological and Phytogeographic Characteristics of the Weed Flora of Mirijevo

A total of 228 species of vascular plants from 159 genera and 44 families were found in various types of weed flora of Mirijevo (NE Belgrade). The results represent analysis from floristic, ecological and phytogeographical aspects. An analysis of life forms in the weed flora of Mirijevo showed that hemicryptophytes were dominant (47.81%), with summer-blooming, mostly tall and scapose hemicryptophytes and biannual and caespitose forms prevailing. Among therophytes, which accounted for 34.21%, a significant increase in the number of spring species and lower categories of growth was observed, which may be interpreted as a result of their annual character, i.e. a need to complete their life cycle (seed-to-seed) within a single vegetation season. The phytogeographical analysis of the weed flora of Mirijevo revealed the presence of 135 different floristic elements grouped into 7 main area types. The largest group includes 131 species of the Holarctic area type (57.46%), with a domination of European-West Asian and Eurasian species, which is similar to the phytogeographic structure of the ruderal flora of Belgrade and Serbia.