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Clustering methods based on environmental variables are useful in the planning of conservation strategies for species and ecosystems. However, there is a lack of work on the regionalization of the vast space of North Africa and the distribution of plant species. The current lists of endemic plants are focused mostly on an occurrence at the country level and not on regions with different conditions. The aim of this work was to lay out an environmental scheme for northwest Africa and to collect data about the occurrence of endemic plants in this area. Clustering with 12 of 33 tested environmental rasters was performed to divide the Maghreb into environmental clusters. Then, a list of 1618 endemic plant taxa (1243 species and 375 subspecies) was prepared and their distribution in estimated environmental clusters was examined. Eleven clusters with different conditions were estimated. The main drivers of regionalization were temperature amplitude, precipitation seasonality, and precipitation of the warmest quarter. According to the occurrence of endemic plants, northwest Africa may be divided into three zones: Atlas, Mediterranean (two environmental clusters), and southern zone (eight environmental clusters). The presented results provide a good basis for understanding the spatial patterns of the Maghreb, including its environment and species diversity. A designed list of endemic plant species together with environmental data may facilitate the planning of future research in north Africa and arranging methods of biodiversity protection. [ABSTRACT FROM AUTHOR]

The origin and evolution of angiosperms can be unravelled by using fossil records to determine first occurrences and phytogeographic histories of plant families and genera. Many angiosperm families, for example the Onagraceae, have a poor macrofossil record, but are more common in palynological records. Modern Onagraceae produce pollen clearly distinct from that of other angiosperms. Combined morphological features obtained by use of light and scanning electron microscopy have enabled assignment of fossil Onagraceae pollen to extant genera, and therefore tracing of the origin and past distributions of extant Onagraceae lineages. We studied a Miocene palynoflora from the Daotaiqiao Formation of north-east China. Using the single-grain technique, we examined individual Onagraceae pollen/tetrads using both light and scanning electron microscopy. Fossil Onagraceae pollen is more frequent than macrofossil remains, but is still rare, and usually represented by a single taxon in palynological samples. Remarkably, samples from the Miocene of north-east China contain five different species: two of Circaea, one of Epilobium, and two of Ludwigia. Such a large number of Onagraceae taxa from a single palynoflora is unknown elsewhere. Whereas Ludwigia pollen is known from Cenozoic sediments of the northern hemisphere, the Circaea pollen is the first fossil pollen assignable to this extant genus. This is also the first fossil record of Epilobium from China. Although the young geological age of this sample does not enable consideration of time of origin for the genera encountered, the co-occurrence of Circaea, Epilobium, and Ludwigia in the mid to late-Miocene of East Asia sheds some light on their phytogeographic histories. [ABSTRACT FROM AUTHOR]

The factors responsible for the patterns of niche differentiation and narrow endemism have rarely been investigated in annual Mediterranean plants. This topic was addressed here by performing comparative studies on realized niches, regional occupancy, global biogeographical distribution and seed traits of a set of Arenaria (Caryophyllaceae) species inhabiting southern Provence (SE France), focusing in particular on Arenaria provincialis, a narrow endemic restricted to the hills and modest calcareous mountains around the city of Marseille. Field studies were carried out from 2008 to 2009 at 624 sites in the limestone mountains where Arenaria species are likely to occur. The Arenaria species occurring in southern Provence vary greatly in their patterns of regional occupancy and their biogeographical distribution. Multivariate analysis of the realized niche showed that they have some similar limiting environmental factors in common, but they do not all occupy the same habitats. Studies on the fruits and seeds showed that the endemic A. provincialis has a larger seed than its congeners and a capsule that remains closed and falls from the plant at maturity. This well-differentiated diaspore specific to A. provincialis may be responsible for the limited dispersal capacity of this species. Phylogenetic analyses showed that A. provincialis is not closely related to the other taxa inhabiting southern Provence, but rather to Arenaria occurring in highland areas in the south of France. The restricted pattern of distribution of A. provincialis is probably due to the past isolation event from which it originated and to its limited dispersal capacity, rather than resulting from its ecological niche range. [ABSTRACT FROM AUTHOR]

The Daisies, Bellis and Bellium, form a monophyletic complex within the core Astereae (Asteraceae). Although most early diverging lineages show an African distribution, the core Astereae is today widespread on five continents with the Bellis/Bellium complex as the only representative in the Mediterranean basin. Molecular clock estimates placed the divergence of Astereae from its sister tribe Anthemideae in the Oligocene. Using a combination of three plastid genes, we estimated divergence times for different lineages of the tribe Astereae. This, together with temporal and biogeographical reconstructions using the nrITS region, allows placing and timing of the major lineages of the Bellis/Bellium complex. The age reconstruction places the divergence of the tribe Astereae in the late Miocene (18-19 million years ago), followed by an out-of-Africa dispersal into Asia where the worldwide expansion may have started. Our results suggest that the colonization of the Mediterranean basin by the Astereae started from Eurasia some 10 million years ago. A Messinian early divergence of the Bellis/Bellium complex in the Mediterranean was estimated. However, a parallel 4-million-year delay for the within-genera diversification was inferred, probably related to the establishment of the sclerophyllous Mediterranean forest. Despite a similar time frame for the within-genera diversification, today's species numbers differ considerably between Bellis (15 spp.) and Bellium (five spp.). [ABSTRACT FROM AUTHOR]

What we consider 'nature' is always historical and relational, shaped in contingent configurations of representational and social practices. In the early twentieth century, the English ecologist A.G. Tansley lamented the pervasive problem of international misunderstandings concerning the nature of 'nature.' In order to create some consensus on the concepts and language of ecological plant geography, Tansley founded the International Phytogeographical Excursion, which brought together leading plant geographers and botanists from North America and Europe. The first IPE in August 1911 started with the Norfolk Broads. It was led by Marietta Pallis, Tansley's former student at Cambridge. This trip and the work of Pallis, neglected in other accounts of this early period of the history of ecology, influenced the relations between Tansley and important American ecologists H.C. Cowles and F.E. Clements. Understanding 'place' as a network of relations, our regional focus shows how taking international dialogue, travel and interchange into account enriches understanding of ecological practice. [ABSTRACT FROM AUTHOR]

Biebersteiniaceae comprise a single genus with four species of perennial herbs occurring from central Asia to Greece. A previous molecular phylogenetic study placed one of the species in an isolated position in Sapindales, while morphological studies had placed Biebersteinia in or near Geraniaceae, albeit doubtfully. We tested the monophyly and placement of the family with data from the chloroplast genes rbcL and atpB obtained for all four species, other major clades of Sapindales and outgroups for a total of up to 114 taxa. Parsimony, Bayesian, and likelihood analyses place Biebersteinia in Sapindales, possibly as sister to the other eight families. Strict and relaxed molecular clocks constrained with fossils of Biebersteinia and up to eight other Sapindales suggest that the Biebersteinia crown group diversified in the Oligocene and Miocene, while the stem lineage dates back to the Late Paleocene. Ages for other sapindalean families are earlier than those obtained in more sparsely sampled analyses, although estimates for Burseraceae agree surprisingly well. Ancestral area analyses suggest that Biebersteinia expanded from the eastern part of its range (i.e. Tibet and Inner Mongolia) to the west, although analyses are hampered by the unclear sister group relationships. [ABSTRACT FROM AUTHOR]

In this study of the Pacific coast of North America, from Baja California to Alaska, we evaluated the hypothesis that the floristic composition of azonal vegetation determines areas and distribution limits similar to those of the corresponding zonobiomes (ZB), and does so in response to the same macroclimatic changes occurring on the continental scale. To this end, 686 vascular plants of the different habitats found in 279 sites along this coastal strip were recorded. Using an objective classification system (Average Linkage Clustering) and factorial analysis, floristic data acquired in fieldwork were classified into groups, which were in turn related to regional macroclimates. Our main finding was that the azonal coastal vegetation follows a distribution model that is closely linked to the corresponding macroclimate. The four ZB of the northern Pacific coast show a flora and azonal vegetation characteristic to each zonobiome; the latitudinal limits of the azonal vegetation practically coinciding with those already established for the zonal vegetation. The Boreal and Temperate ZB show high percentages of broadly distributed elements. The floristically richest zonobiome in terms of endemic taxa is the Mediterranean zonobiome, whereas the flora of Baja California is characterized by a high number of taxa related to Neotropical flora, especially to those showing links with South America. Data on the geographical distribution and habitats of the 247 most significant coastal species are also provided. [ABSTRACT FROM AUTHOR]

The measurement of plant dispersal is vital for understanding plant distribution and abundance at different scales. However, dispersal is difficult to measure and there is a lack of guidance for researchers new to the subject. In this paper we provide advice on methods for measuring dispersal in the field and approaches to experimental design. First, we encourage clear exposition of the aims of the dispersal study and the ultimate use to which the data will be put (e.g. local dynamics, invasion processes, etc). We outline the types of dispersal exhibited by plants and emphasise that many species are dispersed by multiple processes, which are not necessarily related to putative adaptations. Few studies properly address the full range of processes by which a species is dispersed. We review methods for measuring plant dispersal, summarising the type of dispersal measured and problems with each method. We then outline the major questions about effort to be considered in sampling protocols and present an optimisation algorithm for designing dispersal studies given a suite of options, and biological and resource constraints. We propose and demonstrate a simulation modelling approach to comparing the data quality obtained by alternative experimental designs. Integrating simulation models with pilot studies offers a rapid route to improved estimation methods. We then discuss functions commonly fit to dispersal data and recommend caution as none is a priori the best description of the dispersal process. Finally, we call for a better description and understanding of dispersal kernels by: a more rigorous approach to designing dispersal measurement; better targeting of dispersal studies to particular questions; and achieving a deeper understanding of the mechanisms underlying dispersal, so that we can move from descriptions of pattern to a grasp of process. [ABSTRACT FROM AUTHOR]

The central-marginal model assumes unfavourable and more variable environmental conditions at the periphery of a species’ distribution range to negatively affect demographic transition rates, finally resulting in reduced population sizes and densities. Previous studies on density-dependence as a crucial factor regulating plant population growth have mainly focussed on fecundity and survival. Our objective is to analyse density-dependence in combination with the effect of inter-annual variation and range position on all life stages of an annual plant species, Hornungia petraea, including germination and seed incorporation into the seed bank. As previous studies on H. petraea had revealed a pattern opposite to existing theory with lower population densities at the distribution centre in Italy than at the periphery in Germany, we hypothesised that (1) demographic transition rates are lower, (2) the inter-annual variation in demographic transition rates is higher and (3) the intensity of density-dependence is weaker in Italy than in Germany. To analyse demographic transition rates, we used an autoregressive covariance strategy for repeated measures including density and inter-annual variation. All the three hypotheses were confirmed, but the impact of range position, density-dependence and inter-annual variation differed among the transition steps. All transition rates except fecundity were higher in the German populations than in the Italian populations. Germination rate and incorporation rate into the seed bank were strongly density-dependent. Central populations showed a larger inter-annual variation in fecundity and winter survival rate. Winter survival rate was the only transition step with a stronger density-dependence in peripheral populations. In most cases, these differences between distribution centre and periphery would not have emerged without taking density-dependence and inter-annual variation into account. We conclude that including range position, inter-annual variation and density-dependence in one single statistical model is an important tool for the interpretation of demographic patterns regarding the central-marginal model. [ABSTRACT FROM AUTHOR]

Beach communities of eastern North America are commonly dominated by the native perennial grass Ammophila breviligulata. It typically co-occurs with a variety of annual grasses and herbs in the pioneer zone. To determine the potential significance of this vigorous clonal species to the annual community, density, spatial distribution, seed production and potential seed rain were quantified for three focus species ( Triplasis purpurea, Cenchrus tribuloides, and Heterotheca subaxillaris) in a 45×40 m section of coastal beach on Staten Island, New York, USA. During autumn 2000, five 40 m transects (10 m apart) were established perpendicular to shore; ramet density for Ammophila, and densities and per capita seed production for the three species, were estimated in 150 contiguous quadrats (35 cm × 30 cm) per transect. Both Triplasis and Cenchrus were more likely to occur in quadrats without Ammophila. Per capita seed production of Cenchrus and Heterotheca showed a curvilinear decrease with increasing numbers of Ammophila ramets. Mean seed rain per m2 was significantly reduced in the presence of Ammophila for all three focus annuals. In this beach community, Ammophila acts as an ecosystem engineer, but has a mostly negative influence on the distribution, density, and reproduction of the co-occurring annuals. Results suggest that continual, deliberate planting of A. breviligulata could be detrimental to the abundance and diversity of native annual herbs on the eastern coasts of North America. [ABSTRACT FROM AUTHOR]

The origin and natural range of the Stone pine (Pinus pinea L.) has been questioned for more than a century. In this work, we focus the investigation on one of the most important and controversial regions, viz., the Iberian Peninsula and, specifically, the Huelva and Cadiz populations in Andalusia, one of the most representative population cores. Although some authors maintain that it is an autochthonous Iberian species, most of them consider it to he exotic. From this idea, many works have been done and a sintaxonomic scheme has been created, which is accepted by the majority of the scientific community, not including Pinus pinea, nor its formations, since they are considered as man-induced forest crops. However, Stone has been present for several thousand years in the Iberian Peninsula and in the territory studied, as several paleobotanic and historical data show, proving that Pinus pinea is an autochthonous species of this region. This is a clear consequence to the field of geobotany, since — at least — the Stone pine woodlands from the Iberian Southeast must he considered as communities predominated by an autochthonous species that must he included in the sintaxonomichal schemes. [ABSTRACT FROM AUTHOR]

The distribution and taxonomic composition of Rotifera in Southeast Asia is reviewed. For some countries, records are poor: Brunei, Cambodia and Laos are almost terra incognita for rotifers (<10 taxa recorded), while the Thai rotifer fauna is the best documented (ca. 310 taxa on record). However, analysis of the available data is impeded by fuzzy taxonomy and the questionable reliability of many records. Most studies focus on the pelagic or littoral of freshwater habitats. Other habitats are largely ignored. Similarly, few studies deal comprehensively with illoricate Monogononta, sessile Flosculariacea and Collothecacea and, especially, Bdelloidea. The genera Lecane, Brachionus and Trichocerca are the best represented, with littoral taxa predominant. Fisheries-related studies dealing with highly productive pelagic environments tend to over report the contribution of Brachionus. Most taxa are thermophilic character, exemplified by the dominance of tropic-centred Lecane and Brachionus. Some cold-water taxa have been recorded, but the relative climatological homogeneity of the region and low number of studies on high-altitude environments prevent the discrimination of clear latitudinal or altitudinal variation in the distribution of rotifers within Southeast Asia. The majority of Southeast Asian rotifers are widely distributed, including true cosmopolites and thermophilic taxa. There are several local or Oriental endemic Rotifera, mostly Lecane. The American Brachionus havanaensis and Keratella americana appear to have been introduced to the region. The taxonomy of some Rotifera described from the region is commented upon; Brachionus murphyi Sudzuki is recognised as senior synonym of B. niwati Sanoamuang et al. (syn. nov.). Some cases of geographical and/or ecological vicariant species-pairs are suggested. The Southeast Asian rotiferfauna contains a sizeable fraction of taxa occurring in the tropicalregions of the Old World, most of which also occur in tropical Austral [ABSTRACT FROM AUTHOR]

The Rotifera from four peat-swamps in the provinces Suratthanee (Kra-Jood and Kun-Thu-Lee peat-swamps), Nakhonsri-thammarat (Khuan-Kreng peat-swamp) and Yala (Lan-Kway peat-swamp) in southern Thailand were examined by the study of qualitative samples collected on three occasions during July, October and November, 1998. A total of 96 species was identified, seventeen of which are new to the Thai rotifer fauna. The most diverse genera were Lecane (40.6%), followed by Lepadella (8.3%) and Trichocerca (7.3%). The most diverse rotifer fauna was foundin Kra-Jood peat-swamp (61 species), followed by Kun-Thu-Lee (57 species), Lan-Kway (41 species) and Khuan-Kreng (24 species) peat-swamps, respectively. [ABSTRACT FROM AUTHOR]

The species composition of the rotifer fauna of Lake Kud-Thing, NongKhai Province, northeast Thailand was investigated in a monthly sampling program from January to December 1998. A remarkably rich rotifercommunity consisting of 183 taxa was recorded, including 32 new records to the Thai fauna. The most diverse genera were Lecane (23.5%), followed by Trichocerca (16.9%) and Lepadella (11.5%). Lecane isanensis n. sp. is described and figured. Thirteen species (Aspelta circinator, Collotheca tenuilobata, Lecane nelsoni, Lepadella benjamini, Lepadella eurysterna, Sinantherina ariprepes, Testudinella cf. insinuata,Trichocerca abilioi, Trichocerca inermis, Trichocerca montana, Trichocerca orca, Trichocerca rosea and Trichocerca simonei) are new to the Oriental region. Notably, the record of Trichocerca orca is the first since its discovery in New Zealand in 1913. The rotifers can be classified into three groups based on duration of appearance; (1) common, perennial; (2) uncommon, perennial; and (3) uncommon, sporadic species. The high species richness of rotifers, particularly members of the genera Lecane and Trichocerca, but low diversity of Brachionus together suggest that the lake is probably not eutrophicated. [ABSTRACT FROM AUTHOR]

We studied the distribution of Lepadellidae (Rotifera) in freshwaterhabitats in the floodplain of the River Rusizi in northwest Burundi.Twenty-three species belonging to Colurella Bory de St. Vincent, 1824 (3 species), Lepadella Bory de St. Vincent, 1826 (18 species) and Squatinella Bory de St. Vincent, 1826 (2 species) are recorded, 22 of them are new to Burundi. One of the taxa encountered probably represents an unnamed species. Lepadella arabica Segers & Dumont, 1993 is recognised as junior subjective synonym of Lepadella eurysterna Myers, 1942 (syn. nov.). Most of the taxa recorded are cosmopolitan or tropicopolitan, two are restricted to the tropical regions of the Old World and Australia, and one, Squatinella lunata Segers, 1993 is an Ethiopian endemic. [ABSTRACT FROM AUTHOR]

Knowledge of rotifers from Greenland is poor. Those from marine and other saline waters have especially been poorly investigated. The authors have studied meiofauna from different saline localities at DiskoIsland, West Greenland on several occasions from 1990 to 1999. Samples from the intertidal zone, rock pools and a saline, radioactive spring contained 16 rotifer species. Six of these are new to Greenland. The radioactive salt spring has previously been suggested to contain marine relicts dating back to a warmer period with a higher sea level. The samples from the spring, however, did not yield any marine rotifers. It did contain the euryhaline Cephalodella gracilis. A description of its trophi adds to the known variability of this species. The trophi of Notholca striata and N. psammarina are studied in detail using light and scanning electron microscopy for the first time, and aspects of their taxonomy are discussed. [ABSTRACT FROM AUTHOR]

Using a polyclonal antibody against the mate recognition pheromone (MRP) of Brachionus rotundiformis Koshiki strain, we investigated the behavioral reproductive isolation and the similarity of MRP among geographically and temporally isolated B. rotundiformis strains. Males of the Koshiki strain did not discriminate in mating attempts among females of the Koshiki strain and those of conspecific allopatric strains from Hamana, Fiji, Thailand and Spain. Likewise, Koshiki males attempted mating with statistically indistinguishable frequency with Koshiki females and B. plicatilis strains. However, copulation was not consummated between Koshiki males and B. plicatilis females. The amount of anti-MRP binding to three allopatric B. rotundiformis strains was similar to that of the Koshiki strain, but binding to Hamana and the B. plicatilis strain was significantly lower. Four temporally separated B. rotundiformis populations were hatched from resting eggs collected from 0, 5, 10 and 15 cm depth in the sediment of Kai-ike pond in Koshiki island, Japan. Sediment age was determined using the 210Pb method, allowing us to estimate that resting eggs from 15 cm depth were produced 65 years ago. Results of mating assays and anti-MRP binding showed that no behavioral reproductive isolation existsamong the four temporally isolated Koshiki strains. B. rotundiformisappears to be reproductively isolated from B. plicatilis, but heterospecific matings are still attempted between B. plicatilis and B. rotundiformis, suggesting that the MRP remains sufficiently similar to elicit circling behavior. [ABSTRACT FROM AUTHOR]

During the austral summer 1997/98, a survey was made of a series of freshwater bodies on the Kerguelen Islands, Subantarctica (49 deg. S-69 deg. E), in the area of Port-aux- Francais and Val Studer. The rotifer fauna from plankton of 17 lentic freshwaters is listed and commented upon. Species richness (39 taxa) and species diversity are fairly low. Only 6 taxa are euplanktic, the others are facultative plankters or littoral/benthic species. Three of the true plankters found are restricted to the Southern Hemisphere, whereas the rest of the rotifers (apart from two unidentified monogononts) shows a wide-spread or cosmopolitan distribution. Thirty-three taxa are new to the Kerguelen archipelago. A comparison is made with the rotifer assemblages observed on other Subantarctic islands. Taxonomic notes on little known species are added. The validity of Cephalodella gibba microdactyla asseparate subspecies is rejected, and Filinia terminalis kergueleniensis is recognized as junior synonym of F. pejleri. [ABSTRACT FROM AUTHOR]

One hundred and sixteen species of Rotifera are recorded from seven floodplain lakes of the Brahmaputra basin (northeastern India), the highest rotifer biodiversity recorded from these biotopes in the Indian subcontinent to date. The Australasian Brachionus dichotomus reductus and Lecane batillifer; the Oriental Keratella edmondsoni, Lecane blachei and L. acanthinula; the Palaeotropical Lecane braumi, L. lateralis, L. unguitata, Trichocerca tropis, Testudinella greeni and T. brevicaudata; the Pantropical Brachionus donneri and a rather widely distributed Horaella brehmi represent taxa of biogeographical interest.Three species are new additions to the Indian rotifer fauna and eight are new to the N.E. region. Lecanidae > Brachionidae = Colurellidae> Trichocercidae > Testudinellidae comprise the largest fraction (68.0%) of the examined fauna. Comments are made on the general nature and composition of the rotifer taxocoenosis as well as on acidophilic elements, ecology of various taxa and on the species richness of different lakes. [ABSTRACT FROM AUTHOR]

Invertebrates at 20 sites on 19 Campbell Island streams were sampledover the Austral summer of 1996/97. Twelve of the 16 benthic invertebrate taxa known from the island were collected. The most abundant group was the Crustacea, which included an isopod (Notidotea lacustris)and two amphipods, one belonging to the family Eusiridae and one to the suborder Gammaridea. Five species of Diptera were found (three chironomids; Orthocladiinae sp., Chironominae sp. and Maoridiamesa insularis, as well as an empidid and a simuliid Austrosimulium campbellense). One trichopteran, the hydroptilid caddis Oxyethira albiceps and two plecopteran species Rungaperla campbelli and R. longicauda and unidentified Oligochaetes were also collected. In general, Campbell Island streams are stable, deeply incised, have unusually high salinity from wind-blown sea spray and a unique benthic invertebrate fauna. With the exception of high altitude streams with large boulders which had invertebrate communities dominated by Crustacea and the endemic stonefly of the genus Rungaperla, none of the measured environmental variables or geographic location could explain the distinctive communities found. The species-poor stream fauna and the absence of many invertebrate families commonly found on mainland New Zealand appears to be related to the extreme isolation and geological history of the island. [ABSTRACT FROM AUTHOR]

Twenty-five samples from 18 terrestrial and/or freshwater habitats in the eastern part of Korea yielded 38 new records of bdelloid rotifers, 22 of which are new to the Asian fauna. Among these Korean new records, Dissotrocha aculeata reversa Berzins and Habrotrocha plana Milne were recorded outside their type localities for the first time, and Macrotrachela bullata (Murray) was reported only from two countriesafter its description. Bradyscela granulosa de Koning, Habrotrocha gracilis gracilis Montet, Macrotrachela latior Donner, Philodina duplicalcar (de Koning) and P. rugosa coriacea Bryce are recorded outside Europe for the first time. The taxonomy and distribution of these rare species are discussed. [ABSTRACT FROM AUTHOR]

The three most abundant and species-rich genera of erpobdellid leeches - Erpobdella, Dina and Trocheta - have traditionally been distinguished by their annulation pattern. Erpobdella has five unsubdivided annuli per somite, in Dina the last annulus is widened and subdivided once, and in Trocheta, the last and often also the first annulus is further subdivided. The last two genera are often referred to as the subfamily Trochetinae. The presented molecular phylogenetic analysis, based on mitochondrial 12S rDNA sequences and nuclear ITS2 sequences,has revealed a sister relationship between Trocheta and Erpobdella rather than between Trocheta and Dina. Furthermore, the annulation pattern has proved to be inappropriate for the diagnosis of Dina and Trocheta. The taxon Trocheta bykowskii krasense has been classified on the basis of its Trocheta-like annulation; however, according to the molecular phylogeny, it belongs to the Dina clade. A pair of diagnostic PCR primers were developed to identify unambiguously individuals with intermediate annulation. In summary, (1) the traditional genus diagnosis of Dina and Trocheta is no longer tenable, and the genera are not always morphologically distinguishable by traditional characters;(2) T. b. krasense Sket, 1968, should be re-classified as Dina krasensis; (3) the subfamily Trochetinae should be annulled because it does not represent a monophyletic assemblage. [ABSTRACT FROM AUTHOR]

During an annual cycle, flux rates of oxygen, nitrate, nitrite, ammonium, phosphate and silicate were measured in light and dark bell jars at three sites in Ria Formosa (Algarve, Portugal) enclosing either a natural macrophytic community (macroalgae on sand or mud, a seagrass bed of Zostera noltii) or bare sediments. The results are compared with a preceeding study in which the same bell jar technique has beenapplied in the Sylt-Romo Bay of the northern Wadden Sea. Nitrate flux was mainly directed from the water column to the benthic communities in Ria Formosa, as well as in the Sylt-Romo Bay. However, nitrate uptake was higher in the northern, more eutrophic study area. In Ria Formosa, nutrient concentrations were lower than in the Sylt-Romo Bay possibly due to strong water exchange with Atlantic waters. High temperatures and strong insolation had a greater impact on nitrate fluxesin Ria Formosa than in the Sylt-Romo Bay. Bioturbating macrofauna increased ammonium efflux in the Sylt- Romo Bay while this effect was not as pronounced in the Ria Formosa study sites. Benthic phosphate uptake dominated in the Ria Formosa and was correlated to initial phosphate concentrations in incoming waters. At both study sites, oxygen and nutrient fluxes were correlated with temperature. Additionally, flux rates were strongly influenced by biotic components and levels of eutrophication. A literature survey showed that mainly in temperate regions, material fluxes increase with temperature, whereas in warmer areas, ammonium and phosphate fluxes between sediment and water were generally lower. [ABSTRACT FROM AUTHOR]

The community composition of benthic macroinvertebrates from 870 estuarine sites was examined in order to either confirm or challenge established boundaries of biogeographical provinces along the Gulf of Mexico and western Atlantic coasts of the United States. The objective was two-fold: (1) to demarcate boundaries that separate dissimilar fauna in the Gulf of Mexico, and (2) to compare the Gulf of Mexico biogeographically with other well-known provinces. We segmented the coastline into grid cells with dimensions of 1 deg. latitude and 2-4 deg. longitude. Using the descriptive techniques of cluster analysis andnonmetric multidimensional scaling, we determined the similarities in benthic community composition between sites within grid cells in the Gulf of Mexico and compared the biotic ordinations to natural habitat characteristics such as salinity, sediment type, and depth. We then evaluated the overall community composition within each grid cell in the Gulf of Mexico and established whether or not similarities existed between adjacent grid cells. In this manner, we confirmed that aneast-west gradient existed in estuarine benthic community composition along the Gulf of Mexico coast. This information was combined with our previous work in the western Atlantic coast to discern biogeographical provinces. Based on cluster analyses and an analysis of endemicbenthic species the following provinces are proposed: (1) the Virginian province, from Cape Cod, Massachusetts to Wilmington, North Carolina, (2) the Gulf of Mexico, from Rio Grande, Texas to Cape Romano, Florida, and (3) south Florida, south of latitude 26 deg. N. The region encompassing South Carolina, Georgia and northern Florida represents a transitional area between temperate and tropical provinces. [ABSTRACT FROM AUTHOR]

Nitrogen is often a limiting factor to net primary productivity (NPP) and other processes in terrestrial ecosystems. In most temperate freshwater ecosystems, when nitrogen becomes limiting to NPP, populations of N-fixing cyanobacteria experience a competitive advantage, and begin to grow and fix nitrogen until the next most limiting resource is encountered; typically phosphorus or light. Why is it that N-fixing plants do not generally function to overcome N limitation in terrestrial ecosystems in the same way that cyanobacteria function in aquatic ecosystems? To address this question in a particular ecosystem, one must first know whether the flora includes a potential set of nitrogen fixers. I suggest that the presence or absence of N-fixing plant symbioses is foremost an evolutionary consideration, determined to a large extent by constraints on the geographical radiation of woody members of the family Fabaceae. Ecological factors such as competition,nutrient deficiencies, grazing and fire are useful to explain the success of N-fixing plants only when considered against the geographical distribution of potential N-fixers. [ABSTRACT FROM AUTHOR]

We investigated the relationship between plant nitrogen limitation and water availability in dryland ecosystems. We tested the hypothesisthat at lower levels of annual precipitation, aboveground net primary productivity (ANPP) is limited primarily by water whereas at higherlevels of precipitation, it is limited primarily by nitrogen. Using a literature survey of fertilization experiments in arid, semi-arid, and subhumid ecosystems, we investigated the response of ANPP to nitrogen addition as a function of variation in precipitation across geographic gradients, as well as across year-to-year variation in precipitation within sites. We used four different indices to assess the degree of N limitation: (1) Absolute Increase of plant production in response to fertilization (the slope of ANPP vs. amount of added N at different levels of annual precipitation); (2) Relative Response (the percent increase in fertilized over control ANPP at different levels of N addition); (3) Fertilizer Use Efficiency (FUE, the absolute gain in productivity per amount of fertilizer N), and (4) Maximum Response(the greatest absolute increase in ANPP at saturating levels of N addition). Relative Response to fertilization did not significantly increase with increasing precipitation either across the geographic gradient or across year-to-year variation within sites. Nor did the Maximum Response to fertilization increase with increasing precipitation across the geographic gradient. On the other hand, there was a significant increase in the Absolute Increase and FUE indices with both geographical and temporal variation in precipitation. Together, these results indicate that there is not necessarily a shift of primary limitation from water to N across the geographic water availability gradient. Instead, our results support the hypothesis of co-limitation. The apparently contradictory results from the four indices of N limitation can best be explained by an integration of plant ecophysiological, com [ABSTRACT FROM AUTHOR]

We summarize the results of a circumarctic study on biogeographic patterns in genetic diversity within asexual clones of the water flea, the Daphnia pulex complex (a freshwater crustacean). The complex is shown to consist of several thousands of distinct clones, whichcan be grouped into 2 major lineage groups based on molecular markers. The main groups and their component subgroups differ markedly in their distributions, and hybrids are common in 2 zones of overlap (Northern Europe and Canada). Clonal diversity is at least as high in theArctic as in the temperate zone. Moreover, the genetic structure of all the subgroups is extremely fragmented, implying that clonal composition in the Arctic differs conspicuously among regions. This extraordinary diversity with its spatial structure on local to continental geographic scales defies the general notion of the Arctic tundra as a homogenous biome of low biodiversity. [ABSTRACT FROM AUTHOR]

A hypothesis of phylogenetic relationships inferred from analysis ofplastid-encoded rbcL sequences is presented for members of the Solieriaceae, an economically important family containing carrageenan-typephycocolloids. Previous studies established that the Solieriaceae sensu lato forms a terminal clade in the Solieriaceae complex, a cluster of families sister to the Gigartinaceae complex (Gigartinaceae and Phyllophoraceae). The family Solieriaceae (including the Areschougiaceae) presently contains about 20 genera that are widely distributed in warm-temperate and tropical waters throughout the world. Molecular rbcL and published morphological evidence are consistent with an Australasian origin for the family and a Tethyan distribution for its tropical representatives from west to east as far as the Pacific coast of North and South America. The austral lineages (Callophycus, Rhabdonia, Areschougia and Erythroclonium) are resolved at the base of the tree. The remaining genera , comprising the tropical and subtropical cluster, form a robust terminal clade (100% bootstrap support). This assemblage can be divided into seven groups, most of which receive strong bootstrap support: (1) Sarconema, (2) a Eucheuma group, (3) an Atlantic Solieria group, (4) an Indo-Pacific Solieria robusta group, (5) a Meristiella/Meristotheca group, (6) Agardhiella and (7) a Sarcodiotheca group that includes 'Eucheuma' uncinatum from the Gulf of California. Four clusters of species are recognized in the Eucheuma groupthat correspond to the sections: Eucheuma, Gelatiformia (= Betaphycus), Anaxiferae, and Cottoniformia (= Kappaphycus) proposed by MaxwellDoty. No decision is reached regarding the taxonomic rank appropriate to the eucheumoid taxa. [ABSTRACT FROM AUTHOR]

The red alga Polysiphonia setacea Hollenberg (=Womersleyella setacea(Hollenberg) R. Norris), described originally from the Hawaiian Islands and later reported for other tropical localities, has recently become widespread in the Mediterranean. In several localities it forms a dense, almost monospecific turf but, despite its abundance, it appears to reproduce only vegetatively; neither sporangia nor sexual reproductive structures have thus far been found. In order to elucidate its life history, plants were cultured in a variety of conditions of temperature, daylength and photon irradiance, and the upper thermal limit was also determined. Isolates of P. setacea grew well in culture,but were more tufted and branched than wild plants. No reproduction by spores or gametes was observed and only an unusual form of vegetative regeneration was found. Some pericentral cells became darker and larger than the others and produced proliferations from which new plants arose. Plants grew best at 15 and 20 deg. C, and relatively poor growth was observed at 10 and 25 deg. C. At 20 deg. C growth was better in long days than in short days. The upper thermal limit was 28deg. C, and plants were able to tolerate a temperature as low as 5 deg. C for 4 weeks without any damage. These observations show that P. setacea is well adapted to the environmental conditions of the western Mediterranean, and there is good agreement with the phenology of the species in the wild. Although this entity has been treated as an introduction from a tropical area, our results suggest that the Mediterranean entity would not be able to survive or grow in surface waters of tropical areas whence this species has been reported. However, the occurrence of thermal ecotypes in P. setacea is a possibility and further studies, based perhaps on molecular data, are necessary to assess the origin of the Mediterranean populations. [ABSTRACT FROM AUTHOR]

The marine benthic algae from North East Herald Cay, Coral Sea, South Pacific, are listed with taxonomic, bibliographic and biogeographicdetails. The checklist includes 66 species of which 23 are green, 2 are brown, and 41 are red algal species. The almost complete absence of brown algae from what is seemingly a typical tropical reef environment on which a true coral cay has developed is noteworthy. All samples were from the lagoon, which forms the concave side of a crescent-shaped reef and which ranges in depth from 0-30 m. The endemic Caribbean green alga Chamaedoris peniculum is recorded for the Pacific for the first time, and a possibly undescribed species of the genus Rhipiliopsis was also discovered. Although only preliminary, the survey shows that the marine flora is seemingly typical of coral cays for the general region of the Great Barrier Reef. [ABSTRACT FROM AUTHOR]

Partial 18S rDNA sequences, including a 102 base pair insertion, were used to infer a phylogeny among 48 samples across all sections in Halimeda Lamouroux, 1812. The phylogeny reveals a separation of the monophyletic section Rhipsalis into a western Atlantic and a western Pacific clade. Consequently, morphologically similar species within this section such as H. monile (Ellis & Solander) Lamouroux (western Atlantic), and H. cylindracea Decaisne (western Pacific), are not sistertaxa. Vicariant events that separated the tropical regions of the Atlantic and Indo-Pacific Oceans can explain the observed biogeographical pattern in section Rhipsalis. [ABSTRACT FROM AUTHOR]

The zoogeographical distribution of branchiobdellidans (Annelida) and temnocephalidans (Platyhelminthes), ectosymbiotic on freshwater crustaceans, is reviewed and revised. In the areas where the Holarctic branchiobdellidans and Gondwanian temnocephalidans overlap, distributions of species and their respective hosts are reviewed in detail. Specimens of the branchiobdellid, Branchiobdella astaci, and the scutariellid temnocephalidan, Bubalocerus pretneri, were allowed to meet in vitro on the dorsal carapace of a crayfish, Austropotamobius pallipes. This usually resulted in the scutariellid being ingested by a branchiobdellid. Specimens of B. astaci were placed in contact with the host of B. pretneri, Troglocaris sp., a cave-dwelling shrimp and the branchiobdellid immediately moved away from the shrimp. [ABSTRACT FROM AUTHOR]

To increase the overall faunistic knowledge of Swedish Clitellata, asurvey was performed in Nationalstadsparken, a mosaic of fresh and brackish waters, parklands alternating with remnants of natural biota,and areas of urban development, within the cities of Stockholm and Solna on the Baltic coast of Sweden (59 deg. N, 18 deg. E). One hundred and twenty-one species (113 Oligochaeta, 8 Hirudinea) were collected at 31 aquatic and 27 terrestrial or littoral localities; 49 species of Oligochaeta were found at the aquatic localities, 70 species atthe terrestrial/littoral sites. Twenty-four species are new records for Sweden, and this urban national park thus features 64% of all non-marine clitellates known from the country. The result is consistent with a view that diversity is enhanced when human activities increasehabitat complexity, even in areas in direct contact with a large city. [ABSTRACT FROM AUTHOR]

Zonation patterns of gorgonians from 15 sites on reefs south of the main island of Singapore reveal discontinuities in terms of both generic richness and total abundance. This establishes the crest, slope, and bottom as ecologically distinct environments of the reef, as interpreted by these gorgonian population parameters. Only members of thefamily Melithaeidae are able to colonise all three zones. Other genera are restricted to the slope and bottom; in particular, Aconthogorgia and Echinoinuricea are only found at the bottom zone. [ABSTRACT FROM AUTHOR]

A taxonomic revision of the Euglenophyta found exclusively in South America is presented. The taxonomy, geographical distribution and critical analysis of the synonyms are given. More than two hundred species and infraspecific entities from South America are described, many of them recorded several times in different regions. The genus Trachelomonas comprises the highest number of new taxa, reaching more than 100 entities. It is followed by Phacus (48 taxa), Strombomonas (33 taxa), Euglena (15 taxa) Lepocinclis (14 taxa), and Distigma, Entosiphon and Sphenomonas with one new taxon each. [ABSTRACT FROM AUTHOR]

The distribution of four calanoid copepod species of Boeckella in New Zealand are mapped and described. An explanation of their distribution patterns based on panbiogeographic methods is compared to an explanation based on dispersalist concepts. The panbiogeographic explanation is simpler, and is consistent with explanation of distribution patterns among other genera of plants, invertebrates, amphibians and birds. [ABSTRACT FROM AUTHOR]

The genus Eodiaptomus Kiefer contains six species, five of which aredistributed in Asia, and one in Australia and New Guinea. A seventh species, E. sanuamuangae n.sp., is now added from Thailand. It has hitherto been misidentified as E. sinensis (Burckhardt), but can be recognized by various morphologic criteria. In the female, both spines on either wing of the fifth pediger are laterally placed. The third endopodite-segment of P2-P4 has seven, instead of six, setae. The sensory seta on the basis of P5 is extraordinarily long. On the male rightantennule, the spine on segment 8 is much reduced, whereas that on segment 15 is relatively strong; the spinous process on the antepenultimate segment is slender, straight, with a hooked tip and as long as the next segment. Morphologically and geographically, E. sanuamuangaen.sp. links the Asian to the Australian forms. The Australian E. lumholtzi (Sars) is redescribed. A detailed morphological comparison is made of all Eodiaptomus spp. Their taxonomic characters, interspeciesrelationship, and biogeography are discussed. [ABSTRACT FROM AUTHOR]

Six species in two genera of Darwinulidae are here reported from Europe; two of these are known from fossils only. Microdarwinula zimmeri(Menzel) is, in Europe, an interstitial species. Darwinula stevensoni (Brady & Robertson), the type species of the genus, is also the most common darwinulid. Although it abounds in the shallow littoral of lakes, it can also occur in rivers, bogs and springs, both in fresh and saline waters. Darwinula boteai Danielopol is found in interstitialhabitats in Rumania. Darwinula pagliolii Pinto & Kotzian, originallydescribed from Recent South American populations, is reported from fossil, German localities. Darwinula brasiliensis Pinto & Kotzian, originally described as D. africana brasiliensis, also from South America, is here elevated to specific rank. It has been found extant in a bog in southern France and is reported from a museum collection from aScottish lake. The latter species is here reported from Europe for the first time. Finally, Darwinula danielopoli n.sp. is also describedfrom German Holocene (Subrecent) fossils. This species represents the first nominal taxon of a distinctly separate lineage within Darwinula s.1. Global and European distribution, history, ecological tolerance ranges, brooding and clonal taxonomy in this group are discussed. [ABSTRACT FROM AUTHOR]

Thirty-five species of the family Lecanidae are examined from Tripura state in North-Eastern India. Of these, Lecane levistyla and L. scutata are interesting cold-water forms; L. batillifer is an Australasian element; L. acanthinula and L. sinuata are Oriental endemics and L. braumi, L. lateralis and L. simonneae are palaeotropical species. The lecanid fauna also includes the pantropical L. thienemanni and L. sola while the remainder are cosmopolitan and tropicopolitan elements. [ABSTRACT FROM AUTHOR]

Algae collected from an oligotrophic crater lake were identified andcompared with similar regional information. A total of 50 genera and105 infrageneric taxa were identified, mostly Chlorophyta (66%), Cyanophyta (20%) and Bacillariophyta (7 genera: one central and six pennates). Relatively few Chlorococcales were found in this oligotrophic lake. The families most frequently found were Oedogoniaceae (18 species), Desmidiaceae (17), Zygnemataceae (13), Oscillatoriaceae (11), and Chaetophoraceae (9). Two genera of Cyanophyta, seven of Chlorophytaand 59 species are first records for Mexico. [ABSTRACT FROM AUTHOR]

The taxonomy of some Neotropical representatives of the genus Floscularia Cuvier, 1798 (Rotifera: Monogononta) is discussed, based on SEMstudies of trophi and external morphology. Floscularia armata n.sp. and F. bifida n. sp. are described, and F. conifera (Hudson, 1886) isrestored at full species rank. A hypothesis on the functional relevance of differences in trophi morphology for niche segregation is formulated. [ABSTRACT FROM AUTHOR]

The flora of Prespa National Park is composed of 1326 plant species.Among them are 17 Pteridophytes and 1309 Spermatophytes, representedby 11 Gymnosperms, 1057 Dicotyledons and 241 Monocotyledons. The flora is evaluated and categorised into species which can be considered as new for the Greek flora, species under international protection, and rare local species threatened with extinction. Plant species are also categorised according to their ecological requirements, with special reference to the endemic species and their centres of origin in respect to their total percentage (15.4%). [ABSTRACT FROM AUTHOR]

Literature and original information reveals that lakes at any latitude may be expected to lodge +50 spp. of cladocerans, against +150 spp. of rotifers in the temperate, and +210 spp. in the tropical zone. Collector's curves can be used to estimate the number of species present at any point in time in a lake. Hyperbolic regression and Chao's non-parametric estimator were used to extrapolate from species numbersobserved to true numbers present. Estimates for rotifers were better(had lower variances) than for cladocerans, and both were better in the temperate than in the tropical zone, where more species co-exist than in the temperate zone but where many more species are rare. Approximate numbers of samples required to approach true instantaneous species richness were calculated. However, a test in a (sub)tropical lake in Brasil where such an 'asymptotic' number of samples was collected and examined failed to reduce the variance, while recording a number of species higher than predicted. We conclude that seasonal succession was still significant here, and that more research is needed to determine the minimum number of sampling repeats needed for a full census. Lakes with an ATBI (All Taxa Biological Inventory) for rotifersand cladocerans were compared by a complementarity index. This revealed geographic gradients between lakes, strong for cladocerans, but less so for rotifers. It is argued that this mainly reflects a difference in the state of taxonomic advancement between these two groups, and that the theory of cosmopolitanism must be abandoned for both. [ABSTRACT FROM AUTHOR]