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Background: Evidence strongly suggests that Beringia was a refugium for tundra taxa throughout the Quaternary (the last 2 million years). However, the genetic consequences of the repeated formation and flooding of the Bering Land Bridge remain uncertain. Aims: The goal of this paper was to determine the role that the unique environmental history of Beringia played in the diversification of tundra flora. Methods: I adopted a comparative coalescent approach to test models of divergence for arctic flora within Beringia. The literature was surveyed for phylogeographic studies that sampled broadly across the region and incorporated molecular markers appropriate for coalescent analyses. Of the 13 possible taxa, only two fit these criteria: Saxifraga oppositifolia (Saxifragaceae) and Vaccinium uliginosum (Ericaceae). Observed gene trees were compared with a distribution of trees simulated under neutral coalescence to test models of population divergence. Population models fell within two major categories reflecting the importance of either the Bering Land Bridge or the Bering Sea dispersal barrier on the distribution of genetic diversity in the species. Results: Both species fit 'bridge' models, but S. oppositifolia supported a model of eastward migration while V. uliginosum fits a unified Beringia refugium model. The evolutionary implications of these findings are discussed. Conclusions: The limited number of studies emphasises the need for more sequence-based research in the region. This will help resolve the history of the Beringia tundra ecosystem, which has important implications for the diversification of tundra flora, the history of Beringia, and the potential consequences of climate change on the distribution of biological diversity. [ABSTRACT FROM AUTHOR]

Asexual organisms usually have larger, and in the Northern Hemisphere, more northern distributions than their sexual relatives. This phenomenon, called geographical parthenogenesis, has been attributed to predispositions in certain taxa, advantages of polyploidy and/or hybrid origin, advantages of uniparental reproduction, introgression of apomixis into sexuals, niche differentiation of clones, and biotic interactions. Here we focus on the role of uniparental reproduction in colonisation, and the importance of different developmental pathways, i.e. autonomous apomixis which does not require pollination and fertilisation of endosperm nuclei for successful seed set, and pseudogamous apomixis which does. A literature survey suggests that geographical parthenogenesis occurs frequently in species with autonomous apomixis, while the correlation with pseudogamy is poorly documented. However, taxonomic patterns (e.g. predominance of Asteraceae) and also methodological bias may influence estimates of frequencies of geographical parthenogenesis. We demonstrate that a flow cytometric seed screen (FCSS) is a powerful method for assessing pseudogamous vs. autonomous apomixis. We show that population genetic studies provide insights into the genetic diversity of apomicts, but do not give strong support for uniparental reproduction being the only explanation of geographical parthenogenesis. Molecular studies help elucidate the evolutionary and biogeographical history of apomictic complexes, and we conclude that multidisciplinary studies are needed to understand fully the phenomenon of geographical parthenogenesis. [ABSTRACT FROM AUTHOR]

Thermophilous deciduous forest is widespread in northern mainland Greece and extends in patches further south to Peloponnisos and the bigger islands. In this paper, we provide a phytosociological survey of the plant communities of deciduous oak and mixed forest throughout Greece, based on about 370 releves from the literature and more than 300 personal unpublished ones. Assocation names of the thermophilous deciduous forest are re-evaluated, and syntaxonomic conclusions added. The releves are classified, and 13 associations and several additional subtypes described and presented in synoptic constancy tables. The following associations were recognized, and characterized by species composition, ecology and distribution: 1. Phillyreo-Carpinetum orientalis, 2. Dryopterido pallidae-Ostryetum carpinifoliae, 3. Tilio tomentosae-Castanetum; 4. Genisto carinalis-Quercetum petraeae, 5. Querco frainetto-Castanetum, 6. Cytiso villosi-Castanetum; 7. Lathyro laxiflori-Castanetum; 8. Symphyto ottomani-Quercetum frainetto, 9. Verbasco glabrati-Quercetum frainetto; 10. Huetio cynapioidis-Quercetum frainetto; 11. Digitali viridiflorae-Quercetum frainetto; 12. Geranio asphodeloidis-Quercetum frainetto; 13. Oenantho pimpinelloidis-Quercetum frainetto. Associations 1-2 are assigned to the alliance Fraxino orni-Ostryion, 4-6 and 8-13 to the Quercion frainetto (both Quercetalia pubescentis), 3 interim to the Tilio-Acerion, and 7 to the Quercetalia ilicis. The two Quercetalia pubescentis alliances co-occur in northern Greece; their habitats differ chiefly in terms of soil conditions, bedrock and topography, rather than in overall climatic character. [ABSTRACT FROM AUTHOR]

Correlations between environmental variables and species distributions can make an important contribution to the formulation of hypotheses of cause-and-effect relationships. At a resolution of 2×2 km, presence/absence data for bryophytes have been collected recently for an area of 4553 km2 in north-west England. The aim of the present paper is to make use of these data in order to investigate the relationship between bryophyte distributions and environment at the landscape level. Analysing the north and south of the study area separately, the major distributional variation of bryophytes was identified using Detrended Correspondence Analysis (DCA) and a comprehensive set of environmental variables was fitted onto the ordination spaces of the first two DCA axes. Altitude (an indirect environmental variable) was most strongly associated with changes in bryophyte distributions in both the north and south, and was coupled with important changes in habitats. Direct and resource variables associated with the altitudinal gradient seem in particular to be related to water supply, nutrient limitation and substrate pH. Alkalinity of the solid geology has an important secondary influence in the north where large exposures of limestone exist, but the scarcity of this rock on the surface of the south results in no major influence on bryophyte distributions. Results are discussed in relation to other comparable studies, which show some clear similarities with the present outcomes, and the major direct and resource gradients that appear to be present at large scales. [ABSTRACT FROM AUTHOR]

The calculation of visibility patterns associated with past monuments and sites is an important element in modern landscape archaeology. These types of investigations have been limited by the inability of current viewshed routines to incorporate vegetation information. The following paper presents a new viewshed algorithm aimed at calculating the probability of locations being visible in the presence of vegetation. To this day, little work has been done to address this limitation, a notable exception is Dean's Permeability Index Model (1997). A review of Dean's model is provided here in the light of the new proposed algorithm. The new algorithm is based on mathematical principles found in Beer-Lambert's Attenuation Law, a physics law governing the attenuation of light through a medium. In addition to common viewshed parameters, the routine requires a 3D model of a tree/plant and a layer indicating the spatial distribution and density of vegetation on the landscape. The possibility of varying both, the spatial and density distribution of tree/plants, and the three-dimensional model representing vegetation makes the model well suited to investigate the impact that vegetation may have on visibility patterns. [ABSTRACT FROM AUTHOR]

Mating tests were used to identify 282 basidiocarp specimens of Armillaria collected in 15 Chinese provinces, mostly in northern and southwestern parts of the country. Fourteen intersterile taxa were found, including the species A. borealis, A. gallica, A. mellea s.str., A. ostoyae, A. sinapina and A. tabescens and eight so far unnamed taxa called Chinese Biological Species (CBS) C, F, G, H, J, L, N and O. The CBS F might be A. singula, previously recorded from Japan, but six Chinese groups, C, H, J, L, N and O, are probably new biological species. The sexual system of 13 taxa is tetrapolar heterothallism. Homothallic forms also were found; they show a low degree of sexual compatibility with A. mellea s.str, and tentatively are included in the CBS G, but it is unclear whether this is a homogeneous group. Notes are presented on the distribution and ecology of the identified taxa. [ABSTRACT FROM AUTHOR]

Woodland vegetation in the Ajlun mountains of Northern Jordan was investigated and surveyed to determine the influences of altitude and topography on patterns of vegetation structure. Three tree species (Quercus calliprinos Webb, Q. ithaburensis Decne, and Q. aegilps) and seven shrubs (Styrax officinalis L., Cistus creticus L., Cistus salviifolius L., Atriplex halimus L., Calycotome villosa (Poir.) Link, Retema raetam L., and Sarcopoterium spinosum (L.) Spach) dominate the woody vegetation in the study area. Higher plant densities were found on the lower altitudes of southwest-facing slopes than on the higher altitudes of northeast-facing slopes. Species segregation occurred on the basis of three main investigated factors: (1) Community ecological importance value complex of the species which combines the relative density, the relative coverage, and the relative frequency of the species; (2) altitudes above sea level; and (3) northeast and southwest slopes. Regeneration was negatively affected by consequently continuous reduction in species diversity and tree-size distribution. [ABSTRACT FROM AUTHOR]

Carmichaelia crassicaulis subsp. racemosa (Kirk) Heenan is a new combination for plants originally described as Corallospartium crassicaule var. racemosum Kirk and later treated as Corallospartium racemosum (Kirk) Cockayne & Allan. This subspecies is distinguished from Carmichaelia crassicaulis subsp. crassicaulis by its slender cladodes and its more lax and spreading growth habit. It is known from disjunct populations in West Otago and mid Canterbury. Based on its restricted distribution and small population sizes C. crassicaulis subsp. racemosa has a conservation assessment of Chronically Threatened/Serious Decline using the New Zealand Threat Classification System. [ABSTRACT FROM AUTHOR]

This review provides a summary of the published information on Guizhou liverworts and hornworts. Representing the first checkist of Guizhou for these groups, it includes all published names of taxa and their distribution up to 2004. A total of 246 specific and subspecific names in 67 genera and 32 families are included. Of these, 205 taxa are currently accepted taxa. [ABSTRACT FROM AUTHOR]

Jonesiobryum dumboi is described as a new moss species from Uganda. It differs from its congeners by possessing more broadly obovate leaves and a costa that ends well below the apex. The species is only known from the type locality where it was collected on branches in the canopy. [ABSTRACT FROM AUTHOR]

The fourteenth set of new national and regional bryophyte records is presented. Included are Aloina aloides (Schultz) Kindb., reported from Golestan province, Iran by A. Tavili, May 2004, No. 10.104; Diplophyllum nanum Herzog, and Fissidens rufulus Schimp. Details of contributor and brief phytogeography are provided. Contact details of column editor included for intending contributors.

Point intercept surveys were conducted on Swan Lake and Middle Lake, Minnesota to quantitatively assess aquatic macrophyte distribution and abundance. A sediment particle size analysis was conducted to determine if sediment particle size influenced sago pondweed (Stuckenia pectinata (L.) Böraer) and wild celery ( Vallisneria americana Michx.) distribution. Swan Lake had more macrophyte species than Middle Lake. Sago pondweed distribution was different between 2001 and 2002 in Middle Lake. Wild celery was only found in Swan Lake and its distribution was also different between sample years. The presence of sago pondweed was positively related to percentage of clay in Swan Lake sediments. The presence of wild celery was negatively related to the percentage of clay in the sediment. No relationship was found between sediment particle size and sago pondweed growing in Middle Lake. [ABSTRACT FROM AUTHOR]

Although developmental instability (DI), measured as fluctuating asymmetry (FA), is expected to be positively related to environmental stress and negatively to habitat quality, the pattern found here was the reverse. Developmental instability of leaf traits (leaf width and vein distances within a leaf) was estimated (using two indices of FA: FA 4 and σ i 2 ) and compared between three populations of Plantago major L. (Plantaginaceae) from northern Serbia. Two of the populations are from chronically polluted areas (Karaburma & Zemun), while Crni Lug is from an unpolluted, natural area. Results obtained using both FA indices were the same; higher asymmetry levels in the unpolluted area than in the polluted sites, were found for both traits. Between the two polluted sites, FA values were significantly higher in Karaburma site for vein distances within a leaf. Concerning differences in FA 4 values between samples, in two cases, results are similar to those found for σ i 2 values, for vein distances within leaf. These are the first quantitative data on P. major indicating that (i) plants living in the stressful sites are more symmetrical and (ii) leaf FA for plant species with wide ecological distribution such as P. major should be considered as an ‘index of habitat quality.’ [ABSTRACT FROM AUTHOR]

The aerial parts of 16 individual Artemisia afra plants from four natural populations were hydrodistilled and the essential oil analyzed by GC/MS. The oil composition varied quantitatively and qualitatively within and between natural populations and showed no correlation to the geographical distribution. The antimicrobial activity was demonstrated by means of time-kill methodology using the respiratory pathogens C. neoformans and K. pneumoniae. Antimicrobial activity was most prominent within 10 min at concentration 0.75% for K. pneumoniae and within 60 min at concentration 1% for C. neoformans. Investigation of the four major compounds most abundant in the A. afra oil (artemisia ketone, 1,8-cineole, α- and β-thujone) indicated minimal antimicrobial activity when investigated independently and in various combinations against K. pneumoniae. [ABSTRACT FROM AUTHOR]

The effect of different sediments on growth, Zn uptake, Zn plant distribution, and morphometric variables of Schoenoplectus americanus were investigated under controlled conditions. Two types of sediments were assayed: from a large natural levee (LS) and alluvial sediments (AS), the former with lower organic matter (OM) and nutrients content than AS, without and with added Zn (2500 μg Zn/g air-dry sediment). Zinc partition in sediment was determined. Increases in water conductivity and Zn concentrations in water and sediments were observed in artificially contaminated treatments. Plants showed a lower aboveground growth rate, height, and width of shoots, and a higher Zn concentration in shoots and rhizomes. In the contaminated treatments, AS treatment showed lower Zn concentration in water and higher Zn concentration in sediments (total, exchangeable, and OM fractions) than LS treatment, due to Zn displacement from floodwater to sediments. The presence of a high level of OM and nutrients also increased aboveground biomass growth, whereas it decreased Zn concentration in shoots. Although the translocation factor increased with Zn addition, it was lower in AS treatment. Sediments of AS treatments are a suitable environment for growth of S. americanus , which partially compensates the toxic effects of Zn. Our results provide an encouraging basis for planning larger scale experiments to test the role of OM and nutrients in improving phytoremediation. [ABSTRACT FROM AUTHOR]

Based on field observations of leaf morphology and variation in chloroplast DNA (cpDNA) in Scandinavia, Norway has been suggested as a suture zone for elm ( Ulmus glabra ) from different glacial refugia. The aim of this paper was to study the geographical concordance between the maternally inherited cpDNA markers (16 populations) and the assumed polygenic and biparentally inherited leaf traits, studied in a field trial (five populations). Two cpDNA haplotypes were detected, but without geographical structure. Leaf traits showed a gradient from typical ssp. montana traits (relatively long, long tapering, absent acute lobes) in western populations to more ssp. glabra -like traits (relatively broad, short tapering, acute lobes present) in eastern and northern populations. The overall geographical concordance between haplotype distribution and leaf traits was limited, probably owing to different inheritance of cpDNA and leaf traits, but the spatial variation in leaf traits and cpDNA in a subset of common populations ( n =5) was compatible with a dual migration of elm to Scandinavia. Both measures suggest a broad suture zone, covering the entire distribution of elm in Norway. The results are discussed in relation to the use of maternally inherited markers, such as cpDNA, in delimiting suture zones. [ABSTRACT FROM AUTHOR]

Four species of Favolaschia are accepted for New Zealand: F. calocera, F. pustulosa, and two new species F. cyatheae and F. austrocyatheae. Favolaschia cyatheae, F. austrocyatheae, and F. pustulosa are native to New Zealand. Favolaschia calocera, first described from Madagascar, has also been previously reported from New Zealand, Norfolk Island, and Italy. We report a wider geographical distribution for this species. Levels of genetic variation between collections suggest that F. calocera is paleotropical, native to Madagascar, southern China, and Thailand, with recent (probably human-induced) introductions to Norfolk Island, Kenya, Italy, New Zealand, and Réunion Island. ITS sequences show that the tiny monocotyledon-inhabiting F. minima is not a Favolaschia; it is here transferred to Panellus. Taxonomic descriptions, illustrations, distribution maps within New Zealand, and a key to the Favolaschia species known from New Zealand are provided, together with a discussion on past miscitations of the genus Favolaschia and its species. [ABSTRACT FROM AUTHOR]

The aim of this study was to assess the accuracy of basal area distributions of sample plots in coniferous forest derived from small-footprint airborne laser scanner data, and to compare the accuracy of two methods for derivation of such distributions based on: (1) two percentiles of a two-parameter Weibull and parameter recovery, and (2) a system of 10 percentiles defined across the range of observed diameters. The 12 percentiles were derived from the empirical basal area distributions of 141 plots with size 300–400 m 2 . Regression analysis was used to relate the percentiles to various canopy height and canopy density metrics derived from the laser data. On average, the distance between transmitted laser pulses was 0.9 m on the ground. The plots were divided into three strata according to age class and site quality. The stratum-specific regressions explained 7–91% of the variability. Total plot volume predicted from the estimated distributions was used to assess the accuracy of the regressions. Cross-validation of the regressions revealed a bias of -1.2 to 2.1% between predicted and ground-truth values of plot volume. The standard deviations of the differences between predicted and ground-truth values of plot volume were 15.1–16.4%. Neither bias nor standard deviation differed significantly between the two validated methods. [ABSTRACT FROM AUTHOR]

The age and spatial structure of six natural old growth Pinus sylvestris stands in Latvia were investigated, to attempt to identify retrospectively the past features of development. In each stand, one or two plots of size 200–900 m 2 were established. Tree locations were mapped, stem diameter was measured, and tree age was determined from cores or by counting branch whorls. Tree distribution was assessed by Ripley's K function. A clumped spatial pattern was shown for P. sylvestris younger than 100 years. The temporal patterns of establishment could be partly linked to favourable climatic periods. The major disturbance affecting pine stands along the coast was windblown sand, which partly buried some stems and probably affected the patterns of seedling recruitment and mortality. Disturbance caused by fire had a major role in determining the past regimens of mortality and establishment in dry stands located inland. The successful invasion during the last century of spruce in more mesic plots with a pine overstorey may be due to fire suppression. [ABSTRACT FROM AUTHOR]

The impact of distance to tree stems on nitrous oxide (N 2 O) fluxes was examined to determine whether it is possible to improve the accuracy of flux estimates from boreal forest soils. Dark static chambers were placed along transects between pairs of trees within a Norway spruce stand and fluxes of N 2 O and carbon dioxide (CO 2 ) were measured during the period 1999–2003. The groundwater table was measured on every sampling occasion along the transects. In addition, radiation transmission, potential diffusion rate and biomass of forest floor vegetation were measured once at each chamber site along one of the transects and soil samples were collected at three depths, from which pH, denitrification enzyme activity, soil moisture, organic matter, and carbon and nitrogen content were determined. There was a high level of variation in the N 2 O fluxes, both spatially and temporally. However, the spatial variation in the N 2 O fluxes within the transect could not be explained by differences in any of the measured variables. Sometimes, mainly when no major peaks occurred, N 2 O fluxes were significantly correlated with CO 2 release. It is concluded that distance to stems cannot be used to improve the design of sampling schemes or for extrapolating flux levels to larger scales. [ABSTRACT FROM AUTHOR]

A morphological study of dispersed Circumpolles pollen grains from the Upper Triassic of the Southern Alps has been initiated with the genus Duplicisporites . Individual pollen grains were studied by means of scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Seen with SEM the pollen surface is finely verrucate with low verrucae of different sizes. A sub-equatorial continuous rimula is clearly visible. The proximal trilete scar is small and indistinct. TEM images reveal a bi-layered exine. The ectexine is formed by numerous small, closely packed, granulae subdivided by irregularly-spaced cavities. In the region of the subequatorial canal, the ectexine becomes thinner, about 1/3 of the usual thickness. At places, the ectexine is slightly separated from the underlying endexine. The endexine is prominent and significantly darker than the ectexine. It is homogeneous and of constant thickness. On the basis of its older age, with respect to Classopollis , the present ultrastructural dataset provides information on the possible origin of cheirolepidiaceous-type morphology. [ABSTRACT FROM AUTHOR]

Anacolosidites Cookson & Pike, a fossil pollen genus recorded since the Campanian, is peculiar in its morphology – six-porate with three apertures on each hemisphere, located away from the equator, and with the distal and proximal apertures positioned over each other. Representatives of this fossil genus are widely considered to represent extant Olacaceae from tribe Anacoloseae. Olacaceae is an exclusively tropical angiosperm family with a pantropical distribution; consequently the fossils are often used to suggest a tropical climate and in addition are frequently used as a stratigraphic marker. Fossil species assigned to Anacolosidites are quite variable and may not all represent Olacaceae, in which case they may not indicate tropical climate. The present study is a morphological survey of fossil pollen assigned to Anacolosidites ; it identifies the published reports of the fossil species that probably represent positive occurrences of Olacaceae pollen in the fossil record. Within Olacaceae, Anacolosidites -type pollen is usually compared with pollen of genera in tribe Anacoloseae, in particular: Cathedra , Anacolosa and Phanerodiscus , but never with the pollen of Ptychopetalum , a genus from tribe Olaceae with closely similar pollen to the other three genera, but with a reticulate tectum and very small circular apertures located near the equator. Nevertheless, the records of reticulate Anacolosidites species which have been excluded from the emended diagnosis are unlikely to be related to Ptychopetalum . The earliest accepted record of Anacolosidites is from the Late Cretaceous (Maastrichtian) of Germany. However, most Late Cretaceous records, and later Russian and Chinese occurrences referred to Anacolosidites , consist mainly of Normapolles-type pollen, whereas many of the Cenozoic records assigned to Anacolosidites have a much clearer affinity with the pollen of Anacolosa , Cathedra and Phanerodiscus (tribe Anacoloseae). The newly emended genus Anacolosidites may be used as a stratigraphic marker for tropical or megathermal climatic conditions. [ABSTRACT FROM AUTHOR]

Stellate pore ornamentation is an unusual feature of angiosperm pollen, so far it is known in only ten genera of Amaranthaceae. The pollen grains of these plants have apertures with large hook-shaped ektexinous bodies that are stellately arranged. Previous studies interpreted this character complex as a synapomorphy in consideration of its strong specialization. By reconstructing the evolution of stellate pore ornamentation based on phylogenetic trees of Amaranthaceae obtained by parsimony, likelihood, and Bayesian analysis of chloroplast trnK/matK DNA sequences, clear evidence is provided for several independent origins and reversals to less specialized aperture types. In addition to the gomphrenoid genus Pseudoplantago , stellate pore ornamentation evolved several times among achyranthoid genera, which have an African distribution. The most derived apertures, with 5 – 6 large protruding hooks, appear independently in Centemopsis on the one hand, and in Psilotrichum sericeum on the other. In an effort to break down the complex character syndrome of stellate pore ornamentation, we delimited a set of six pollen morphological characters that could be independently traced on the phylogeny. It appears that stellate pore ornamentation was independently derived from apertures with equally spread ektexinous bodies that became hook-shaped, reduced in number, and symmetrically arranged. Likewise the symmetrically arranged, rectangular ektexinous bodies in Marcelliopsis represent an independent specialization. In view of this pattern of morphological changes, functional significance in the context of specialized insect pollination syndromes and positive selection for stellate pore ornamentation is hypothesized. Stellate pore ornamentation provides an example of a specialized pollen character complex with adaptive significance, and underlines the need for a dense taxon sampling for analyses of character evolution. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

A syntaxonomic and phytogeographic delimitation of the calcareous open sedge swards in the alpine belt of the Alps ( Caricion firmae ) and subalpine and alpine tussock grasslands in wind-exposed habitats ( Seslerion juncifoliae ) in the area of the south-eastern Alps and of the Dinaric mountains was performed. Analyses based on hierarchical classification, ordination and chorology clearly showed the distinction between the syntaxa: stands from the Liburnian karst (Mt Snežnik – SW. Slovenia, Mts Risnjak and Snježnik – NW. Croatia), Lička Plješivica and the Velebit mountains belong to the Dinaric alliance Seslerion juncifoliae , whereas stands from the Trnovski gozd plateau (W. Slovenia, north-westernmost part of the Dinaric mountains), although somewhat transitional between the two alliances, and stands from the Alps, were classified in the alliance Caricion firmae . The alliance Seslerion juncifoliae of the Dinaric mountains vicariates Caricion firmae of the Alps. [ABSTRACT FROM AUTHOR]

We examined the distribution of trees and shrubs on 14 mid-channel islands in the Swan River, northwest Montana. We observed the general trend that plants were distributed in a linear sequence of send stages. Pioneer successional phase plants dominated the downstream ends of islands, mid-successional vegetation dominated the middle of the islands, and late successional vegetation and the oldest trees were largely restricted to the upstream portions of the largest islands. The observed pattern was most distinct on islands farthest upstream in the river channel (i.e., smallest catchment area) and least distinct on islands farthest downstream in the catchment basin. We conclude the consistent pattern of semi organization and the influence of catchment size would be unlikely if the development of mid-channel river islands were controlled by site-specific factors influencing individual islands independently. We suggest that all islands are responding similarly to the shared influence of fluvial dynamics (i.e., timing, duration, and magnitude of rise and fall of river discharge), but smaller scale variability in plant distribution among individual islands suggests site-specific variables and/or random events modify the action of fluvial dynamics. [ABSTRACT FROM AUTHOR]

Abstract Short essential notions of dynamic-catenal phytosociology are defined as the basis of landscape vegetation science. The most important units  –  vegetation series, geoseries, permaseries and geopermaseries (sigmetum, geosigmetum, permasigmetum and permageosigmetum)  –  are discussed and synthesized in several figures. [ABSTRACT FROM AUTHOR]

We examined trends in vegetation activity at the global scale from 1982 to 1998 using a recently developed satellite-based vegetation index in conjunction with a gridded global climate dataset. Vegetation greening trends were observed in the northern high latitudes, the northern middle latitudes, and parts of the tropics and subtropics. Temperature, and in particular spring warming, was the primary climatic factor associated with greening in the northern high latitudes and western Europe. Temperature trends also explained greening in the US Pacific Northwest, tropical and subtropical Africa, and eastern China. Precipitation was a strong correlate of greening in fragmented regions only. Decreases in greenness in southern South America, southern Africa, and central Australia were strongly correlated to both increases in temperature and decreases in precipitation. Over vast areas globally, strong positive trends in greenness exhibited no correlation with trends in either temperature or precipitation. These areas include the eastern United States, the African tropics and subtropics, most of the Indian subcontinent, and south-east Asia. Thus, for large areas of land that are undergoing greening, there appears to be no climatic correlate. Globally, greening trends are a function of both climatic and non-climatic factors, such as forest regrowth, CO2 enrichment, woody plant proliferation, and trends in agricultural practices. [ABSTRACT FROM AUTHOR]

Multi-annual time series of remote sensing data acquired over Europe from the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) and Medium Resolution Imaging Spectrometer (MERIS) instruments were analysed to assess the state of health of vegetation in Spring 2004, compared to previous years. These data show (1) the dramatic impact of the 2003 drought on a variety of land cover types in Europe and (2) the recovery of most ecosystems to a normal situation in early 2004. [ABSTRACT FROM AUTHOR]

Landscape took on a new meaning through the new science of plant geography of Alexander von Humboldt (1769-1857). In the seventeenth and eighteenth centuries, "landscape" was foremost a painterly genre. Slowly, painted landscapes came to bear on natural surroundings, but by 1800 it was still not common to designate sites as "landscapes." Humboldt looked at plant vegetation with a painterly gaze. Artists, according to him, could suggest in their work that an abstract unity lay hidden underneath observable phenomena. Humboldt projected painted landscapes on nature and found its ecological unity. By doing so, he ultimately stripped the concept of landscape from its primary visual meaning. [ABSTRACT FROM AUTHOR]

The liverwort Plagiochasma appendiculatum Lehm. & Lindenb. is reported for the first time in Europe from Mallorca (Balearic Islands, Spain). The species is described and illustrated and its distribution and ecology are discussed. Plagiochasma appendiculatum differs from P. rupestre (J. R. Forst. & G. Forst.) Steph., the only species of the genus known at present in Europe, by characters such as the bright green or green-yellowish thallus and the orbicular and obtuse scale appendages which are markedly constricted and folded at the base. [ABSTRACT FROM AUTHOR]

The genus Cistus L., mainly growing in the Mediterranean region, is represented by five species in Turkey: C. creticus L., C. laurifolius L., C. monspeliensis L., C. parviflorus Lam., and C. salviifolius L. In this study, in vitro antimicrobial activity of water, methanol, chloroform, ethyl acetate, and buthanol extracts, prepared from dried and powdered leaves and the fruits of the five Cistus species, were investigated by the disk diffusion method against the following microorganisms: Staphylococcus aureus (ATCC 29213 and ATCC 25923), Streptococcus faecalis (ATCC 29212), Bacillus subtilis (ATCC 6633), Bacillus cereus (RSKK 1122), Pseudomonas aeruginosa (ATCC 27853), Escherichia coli (ATCC 25922), and Candida albicans (ATCC 10231). Chloroform, ethyl acetate, butanol, and the remaining aqueous extracts, obtained from the fractionation of methanol extract, were also tested. All of the extracts showed some activity against B. subtilis and B. cereus . Lyophylized extracts showed the highest activity against Staphylococcus aureus 25923 and 29213. Buthanol extracts of the leaves and fruits of C. creticus showed the highest activity. Extracts of all Cistus species did not show any activity against Pseudomonas aeruginosa and Candida albicans . [ABSTRACT FROM AUTHOR]

In 59 samples of periphyton and phytoplankton collected in 2002 - 2003 from the Nahal Qishon (Qishon River), northern Israel, we found 178 species from seven divisions of algae and cyanoprocaryotes. Diatoms, clorophytes, and cyanoprocaryotes prevail. Nitzschia and Navicula (Bacillariophyta) are the most abundant. Most of the species are cosmopolitan or widespread, except Lagynion janei (Chrysophyta), which is endemic for the Mediterranean Realm. About 17% of species (26) are new for Israel and five of them represent the first recorded genera: Crinalium endophyticum Crow, Actinocyclus normanii (Gregory) Hustedt, Rhizoclonium hieroglyphicum (Agardh) Kütz (Chlorophyta), Lagynion janei Bourelly, and Stylococcus aureus Chodat. Most of them come from a rare riverine assemblage with red alga Audouinella pygmea , as well as from the estuarine assemblage. Alkaliphiles predominate among the indicators of acidity, with few acidophiles confined to the communities under the impact of industrial wastes. Among the indicators of salinity, most numerous are the oligohalobien-indifferents and species adapted to a moderate salinity level. The relative species richness of ecological groups and the indices of saprobity are correlated with changes in conductivity, pH, and N-nitrate concentration. Indicators of organic pollution fall in the range of betameso- to alfamesosaprobic self-purification grades. Our studies show ecological significance of the Nahal Qishon as a model for a strongly disturbed aquatic ecosystem in the coastal zone of eastern Mediterranean. [ABSTRACT FROM AUTHOR]

The yield and the chemical composition of Atlas cedarwood oil produced by two distillation modes and seven sample origins were determined. Steam distillation and hydrodistillation gave approximately the same yield (2.5-2.6 mL/100g). The samples from Adrej, Tounfite, Tamjilt and Ajdir gave the highest oil yields. The major constituents in the essential oil were α-himachalene (7.4-16.4%), γ-himachalene (5.1-8.6%), β-himachalene (23.4-40.4%) and (E)-α-atlantone (5.2-29.5%). [ABSTRACT FROM AUTHOR]

Fissidens ellipticoides Brugg.-Nann. & Kürschner (sp. nov.) is described and illustrated. It is compared with the gametophytically similar species F. macrosporus Dix. and F. ellipticus Besch. Three species, F. bogosicus Müll. Hal., F. flaccidus Mitt. and F. taxifolius Hedw. are reported for the first time from the mainland of the Arabian Peninsula. [ABSTRACT FROM AUTHOR]

Members of the moss family Hylocomiaceae have been hypothesized to belong to more than one major clade. While molecular studies performed so far are inconclusive regarding Hylocomiaceae relationships, morphological data are used here to test this hypothesis, based on species representing all genera of the Hylocomiaceae as well as some genera that possibly belong to this family. The results of the analysis suggest that Hylocomiaceae members belong to two major clades, one including mainly northern temperate species and one mainly tropical to subtropical taxa, with most of the latter species found in S. E. Asia. With the morphological context provided here, the next step in the investigation of this family should include both studies of more taxa outside the family, to correctly infer the phylogenetic relationships in a larger framework, and the addition of data from several molecular markers belonging to more than one genome. [ABSTRACT FROM AUTHOR]

Provides information on the geographic distribution of several bryophytes. Fissidens adianthoides; Hygrohypnum polare; Lophozia opacifolia.

Presents a list articles about bryology. "Bryogeographic Patterns in the Small Islands Surrounding the Italian Peninsula, Sicily and Sardinia," by M. Aleffi, Pedrotti C. Cortini and D. Gafra, published in the 2003 issue of the journal "Bocconea"; "Additions to the Bryoflora of Hawk Mountain Sanctuary, Berks County, Pennsylvania," by S. Bartholomew-Began, published in the 1999 issue of the "Journal of the Pennsylvania Academy of Science"; "The Biodiversity of the Granitic Islands of Seychelles," by J. Gerlach, published in the 2003 issue of the journal "Phalsumia."

The saguaro cactus, an icon of the American southwestern desert, defines the extent of the Sonoran Desert through portions of its range. Saguaros rely upon nurse plants for establishment and survival in the harsh temperature and moisture regime of the desert. Freezing temperatures limit the range of the saguaro to the north in Arizona. However, nurse plants extend the range of saguaros by providing more moderate conditions beneath their canopies. This study focuses on precisely these small, highly localized temperature variations, which, we suggest, are linked to regional-scale patterns of distribution of the species, particularly in marginal, cold-limited locales. We sampled 291 saguaros over thirty populations in Arizona, in the northern portion of their range. Saguaros establish under the south side of their nurse's canopy in the coldest parts of their range more often than expected, while a significant distributional bias is not observed in those in warmer, more moderate plots. To further investigate air temperature as a possible factor in the directional bias of saguaro establishment, we collected microclimate data under the north and south sides of the canopies of two common nurse plants, Cercidium microphyllum (a tree) and Ambrosia deltoidea (a shrub) in Phoenix, Arizona. South sides of nurses have significantly higher minimum temperatures than do the north sides. Survivorship in the coldest areas appears to be greatest under the south side of a nurse's canopy, where warmer wintertime microclimatic conditions occur. We suggest that within-canopy microclimatic variability under a single nurse plant may be reflected in regional distributional and in the survivorship patterns of saguaros throughout Arizona. [ABSTRACT FROM AUTHOR]

The Red Sea Basin occupies an area of ca. 810,000 km², including essentially the Red Sea coastal plains (210,000 km²) and the highlands bordering them on both sides (600,000 km²). The bioclimate of the lowlands is of the Mediterranean desert type to the north and equatorial desert to the south. These lowlands are among and perhaps the hottest large area of the planet, with a mean annual temperature approximating 30°C and extremes above 55°C, perhaps reaching 60°C in the Dallol and Assalé depressions. In the highlands the bioclimate is arid Mediterranean to the north, and semiarid to humid equatorial with a bimodal rainfall pattern to the south. The lowlands vegetation is characterized by desert contracted vegetation with many halophyte communities to the north and tropical Acacia-Commiphora savanna in addition to halophytic communities to the south. The highlands vegetation results from vestigial Podocarpus gracilior and Juniperus procera (J. excelsa subsp. polycarpos) forests. Podocarpus, however, is restricted to the moistest places in Ethiopian highlands. These forests are degraded into various stages of evergreen sclerophyll woodland, bushland, and shrubland, physiognomically reminiscent of, and botanically akin to Mediterranean shrublands (garrigue, maquis, etc.). These in turn may evolve towards montane acacia-grassland (Acacia abyssinica, A. negrii, A. origena, A. pachyceras, A. xiphocarpa, Faidherbia albida, Andropogon spp., Eleusine jaegeri, Hyparrhenia spp., Pennisetum schimperi, P. villosum), succession patterns. These patterns are almost similar in botanical composition and structure on both sides of the Red Sea as mentioned by many authors over a couple of centuries. This leads to the definition o fa phytogeographic entity labeled either as the Eritreo-Arabian Domain or Somalo-Arabian Domain, which is a part of the Somalia-Masaï Province and center of endemism, and thus of the SudanoDeccanian Kingdom. The... [ABSTRACT FROM AUTHOR]

This article contributes to the understanding of the changes in distribution and total area of mangrove forests along the mainland Tanzania coast over the past decade. Mangroves are recognized as critical coastal habitat requiring protection and special attention. The Tanzania coastline forms a suitable habitat for establishment of mangroves forests. Mangrove forests are distributed from Tanga in the north to Mtwara in the south covering approximately 109,593 hectares from 1988-1990 and about 108,138 hectares in 2000. The largest continuous mangrove stands are found in the districts of Rufiji, Kilwa, TangaMuheza, and Mtwara. Comparison of data between these two time periods shows that the geographic coverage of mangroves has no dramatic change in the past decade. The Tanzania Mangrove Management Project and other closely related programs and efforts pertaining to mangrove conservation contribute to direct restoration and natural regeneration of mangroves. This study documents the changes of mangroves and demonstrates that remote sensing and GIS offer important data and tools in the advancement of coastal resource management and ecosystem monitoring. Application of geographic information technologies is critical for improved coastal resources management and decision making for sustainable development in Tanzania. [ABSTRACT FROM AUTHOR]

Biogeography is a natural science that deals with the study of the earth's plant and animal distribution patterns in geographical space, both in terms of the present day and also in the context of their evolution and development over time. it has deep historical roots in the identification of the spatial relationships of organisms, while its fundamental principles embody those of the theory of evolution and the ecosystem concept. More recently, the work of, among others, Robert MacArthur and Edward Wilson, has proved instrumental in developing thinking as to how organisms achieve and maintain their ranges. Over longer, geological, time scales, the key principles of biogeography include the influence of changing global geography, especially through continental drift, on biological distributions. In the context of the present day and more recent past, climate and climatic change are regarded as the most significant factors determining the distributions of organisms. Biogeography is applicable to a wide range of practical environmental problems in South Africa. In particular, the discipline has made important advances in understanding issues such as the establishment and management of conservation areas, the prediction of the impact of global climate change on organisms, and on the management of plant and animal communities, including humans, as integral components of ecosystems. [ABSTRACT FROM AUTHOR]

This study was carried out to evaluate site preference of tomato leaf miner, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), developmental stages on processing tomatoes. Eggs, first- and fourth-instar-caterpillars and pupae, damaging processing tomatoes var. IPA-5, at selected stages (I—before flowering, II—before fruits developed, and III—after fruits developed) were examined. Natural oviposition was studied by releasing 3-day-old T. absoluta moths (ca 20–30) in cages under conditions of darkness. At stage I, the females chose the under-side of the leaf for oviposition in the apical part of the plant canopy. However, the number of eggs laid on the under-side of the leaf surface andpetioles were similar in the three plantparts. At stages II and III, the means of eggs laid on either the upper- or under-side of leaf surfaces was similar between apical and median plant parts. Eggs recorded on leaf petioles were equal for the three parts (apical, median, basal). Higher first- and fourth-instar-caterpillars numbers were observed on the apical and median plant parts for the three developmental stages. However, fourth-instar-caterpillars were distributed equally on the three plantparts in stage III. Higher pupation at stage I was observed onthe apical part, while at stages II andIII it was similar among the three plant parts. For all stages, the pupation was higher on leaves, followed by soil, mainstems and fruit (stage III), respectively. Stage III showed a higher number of pupae on the mainstem compared with stages I and II. [ABSTRACT FROM AUTHOR]

A six-step integrated vegetation mapping approach is described for making a small-scale (1:4 million) map of northern Alaska. The method uses two primary maps: (1) a Phytogeographic subzones and Floristic subprovinces Map (PFM) adjusted to Advanced Very High Resolution Radiometer false colour infrared (AVHRR CIR) imagery, and (2) an Integrated Vegetation-Complex Map (IVCM). The IVCM map-polygon boundaries are guided by information from a variety of remote-sensing data (AVHRR imagery, maximum greenness maps and classified images) and hard-copy source maps (surficial geology, bedrock geology, soils, percentage water cover). The map-polygon boundaries are integrated so that they conform to terrain features that are interpretable on the AVHRR CIR. The PFM and IVCM are overlaid in a geographic information system (GIS), and a series of derived maps is created through the use of look-up tables. Northern Alaska is a prototype area for the Circumpolar Arctic Vegetation Mapping (CAVM) project, which has a goal of producing a new vegetation map of the region north of the arctic tree line by the year 2001. The method could be modified and adapted to any region of the Arctic based on locally available information. [ABSTRACT FROM AUTHOR]

Addresses the relationship of meso-scale and micro-scale distributions of two chaparral shrub species in Southern California. Physical proximity of the congeners with mixed ecological communities; Theoretical significance of considering local rarity of a species; Fine-scale patterning through competition.

This paper uses graphic and geographic migration models to examine the relationship between present dominance patterns and presumed source areas for six important native grass species in the Midcontinent Plains. The study has five parts: (1) describing the theoretical migration patterns of grasses as they spread out from a source area: (2) determining the dominant grasses on medium-textured, well-drained, upland range sites in a large sample of counties: (3) fitting trend surfaces to these dominance patterns in order to evaluate the degree to which the distributions are spatially systematic: (4) comparing these trend surfaces with climatic boundaries that are presumed to be significant in limiting the distributions of grasses: and (5) evaluating the relative importance of climatic limits and migration patterns in “explaining” the present distributions of the grasses. The geographic patterns summarized by the trend surface maps appear to favor a migrating-wave hypothesis of grass species dominance: they do not support the idea that grass species distributions are controlled primarily by climatic factors. [ABSTRACT FROM AUTHOR]

The Fairfax line, surveyed in 1746 starts at the southern tip of western Maryland and extends 76.5 miles (123km), bearing S 46° E, to the headwaters of the Conway River in Madison County, Virginia. The forests of the Fairfax line can be divided into five map units, based on the presence or absence of ‘key’ species, which have significantly different woody floras. The forest units show a pattern of alternations with topography and underlying rock type which can be best explained by differences m substrate moisture. Although the common woody species appear in recurring groups, each species responds more or less independently to variation in topographic form, rock type, and direction of exposure. The surveyor's journal documents a large blowdown in the presettlement forests of the Appalachian Plateau, and witness tree data suggest that distribution patterns of the common woody species have changed little m more than two hundred years. [ABSTRACT FROM AUTHOR]

The ‘high plain’ shown on many early maps of Michigan was not a fanciful creation, but reality as perceived by early travelers. Their perception of a high plain was as much the result of a change in vegetation as of an actual change in landforms. [ABSTRACT FROM AUTHOR]

The article focuses on the new flora specie, the Pireella cymbifolia (Sull.), found in Bermuda Island. It also comments on the sea level and other factors influencing the phytogeography of the said island. The existence of Pireella cymbifolia is of more than local interest as it constitutes the northernmost occurrence of the genus Pireella and the northernmost outpost of the Pterobryaceae in the Western hemisphere. It notes that the factors that have effected the persistence of such tropical specie in temperate Bermuda are human agency, birds, current wind and the isostatic changes in sea level.

The article discusses the late glacial and holocene vegetation development of the raised bog Fláje-Kiefern, which lies in the Krušné Hory Mountains in Czech Republic. The phytogeographic region of the mountains is described as a region of mountain flora and vegetation, with thermophilus species largely missing. Conifers prevail in the natural forests. The mountains' bedrock is Precambrian crystallinicum.