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Recognition of species richness spatial patterns is important for nature conservation and theoretical studies. Inventorying species richness, especially at a larger spatial extent is challenging, thus different data sources are joined and harmonized to obtain a comprehensive data set. Here we present a new data set showing vascular plant species richness in Poland based on a grid of 10 × 10 km squares. The data set was created using data from two sources: the Atlas of Distribution of Vascular Plants in Poland and the Polish Vegetation Database. Using this data set, we analysed 2,160 species with taxonomical nomenclature according to the Euro + Med PlantBase checklist in 3,283 squares covering the entire territory of Poland (ca. 312,000 km2). The species were divided into groups according to their status and frequency of distribution, and the statistics for each square were obtained. For purposes of analysis, sampling bias was assessed. The data set promotes theoretical analysis on species richness and reinforces the planning of nature conservations. [ABSTRACT FROM AUTHOR]

Serious concerns exist about potentially reinforcing negative effects of climate change and land conversion on biodiversity. Here, we investigate the tandem and interacting roles of climate warming and land-use change as predictors of shifts in the regional distributions of 1701 plant species in Sweden over 60 years. We show that species associated with warmer climates have increased, while grassland specialists have declined. Our results also support the hypothesis that climate warming and vegetation densification through grazing abandonment have synergistic effects on species distribution change. Local extinctions were related to high levels of warming but were reduced by grassland retention. In contrast, colonisations occurred more often in areas experiencing high levels of both climate and land-use change. Strong temperature increases were experienced by species across their ranges, indicating time lags in expected warming-related local extinctions. Our results highlight that the conservation of threatened species relies on both reduced greenhouse gas emissions and the retention and restoration of valuable habitat. Land use change has been the dominant anthropogenic driver of plant distribution change, but climate change has also become a major factor. This analysis of long-term data shows that warming likely reinforced the impact of grassland abandonment on plant species distribution change in Sweden. [ABSTRACT FROM AUTHOR]

In the era of anthropocene, global warming tends to alter the distribution range of the plant species. Highly fragile to such changes are the species that are endemic, inhabit higher elevations and show narrow distribution ranges. Predicting and plotting the appropriate suitable habitats and keeping knowledge of how climate change will affect future distribution become imperative for designing effective conservation strategies. In the current study we have used BIOMOD ensemble forecasting to study the current and predict the future potential distribution of Dactylorhiza hatagirea and Rheum webbianum and describe their niche dynamics in Himalayan biodiversity hotspots under climate change scenarios using ecospat R package. Results reveal sufficient internal evaluation metrics with area under curve (AUC) and true skill statistic (TSS) values greater than 0.8 i.e. 0.93 and 0.98 and 0.82 and 0.90 for D. hatageria and R. webbianum respectively, which signifies robustness of the model. Among different bioclimatic variables, bio_1, bio_3, bio_8, bio_14 and bio_15 were the most influential, showing greater impact on the potential distribution of these plant species. Range change analysis showed that both the studied species will show significant contraction of their suitable habitats under future climatic scenarios. Representative Concentration Pathway (RCP) 8.5 for the year 2070, indicate that the suitable habitats could be reduced by about 51.41% and 70.57% for D. hatagirea and R. webbianum respectively. The results of the niche comparisons between the current and future climatic scenarios showed moderate level of niche overlap for all the pairs with D. hatageria showing 61% overlap for current vs. RCP4.5 2050 and R. webbianum reflects 68% overlap for current vs. RCP4.5 2050. Furthermore, the PCA analysis revealed that climatic conditions for both the species vary significantly between current and future scenarios. The similarity and equivalence test showed that the niche between present and future climate change scenarios is comparable but not identical. From the current study we concluded that the influence of climate change on the habitat distribution of these plant species in the Himalayan biodiversity hotspots can be considered very severe. Drastic reduction in overall habitat suitability poses a high risk of species extinction and thereby threatens to alter the functions and services of these fragile ecosystems. Present results can be used by conservationists for mitigating the biodiversity decline and exploring undocumented populations on one hand and by policymakers in implementing the policy of conservation of species by launching species recovery programmes in future on the other. The outcomes of this study can contribute substantially to understand the consequences of climate change in the Himalayan biodiversity hotspots. [ABSTRACT FROM AUTHOR]

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]

Information obtained from the analysis of dust, particularly biological particles such as pollen, plant parts, and fungal spores, has great utility in forensic geolocation. As an alternative to manual microscopic analysis of dust components, we developed a pipeline that utilizes the airborne plant environmental DNA (eDNA) in settled dust to estimate geographic origin. Metabarcoding of settled airborne eDNA was used to identify plant species whose geographic distributions were then derived from occurrence records in the USGS Biodiversity in Service of Our Nation (BISON) database. The distributions for all plant species identified in a sample were used to generate a probabilistic estimate of the sample source. With settled dust collected at four U.S. sites over a 15-month period, we demonstrated positive regional geolocation (within 600 km2 of the collection point) with 47.6% (20 of 42) of the samples analyzed. Attribution accuracy and resolution was dependent on the number of plant species identified in a dust sample, which was greatly affected by the season of collection. In dust samples that yielded a minimum of 20 identified plant species, positive regional attribution was achieved with 66.7% (16 of 24 samples). For broader demonstration, citizen-collected dust samples collected from 31 diverse U.S. sites were analyzed, and trace plant eDNA provided relevant regional attribution information on provenance in 32.2% of samples. This showed that analysis of airborne plant eDNA in settled dust can provide an accurate estimate regional provenance within the U.S., and relevant forensic information, for a substantial fraction of samples analyzed. [ABSTRACT FROM AUTHOR]

The current research was carried out in Wadi Elkor, one of the Sarawat Mountains regions, which is a special location from an environmental standpoint and one of the only places in Saudi Arabia where a range of Palaearctic flora co-exists with Afrotropical species. The study aimed to determine the floristic composition as well as the effects of slope aspect and elevation on species, life forms, and phytogeographical elements distribution. The study area is located in Wadi Elkor, a valley in the Sarawat Mountains that cuts off the Al-Hada escarpment, 47 km southeast of Makkah City, Saudi Arabia. We conducted the research at three different locations, each with a different elevation and slope aspect. Based on floristic composition, Ward classification moreover Jaccard comparisons were performed. A total of 189 species was discovered, divided into 131 genera and 43 families. The current study identified Argyrolobium rarum Dumme as a new vascular plant in Saudi Arabia's terrestrial flora. In the current study, the Gramineae, Leguminosae, and Compositae families contributed 29% of the total plant species, whereas 14 families were represented by one species each. Solanum was the most numerous genus, with seven species, followed by Acacia and Pulicaria, each with six species, while Commicarpos and Euphorbia, each with four species. At an elevation of 1060 m above sea level, the north facing slope had the most plants, genera, and families. Therophytes had the most species, accounting for 44%, followed by Chamaephytes, which accounted for 26%. Hemicryptophytes accounted for 12% of the total, while phanerophytes accounted for 10%. In the studied area, the bioregional Saharo-Sindian and Sudano-Zambesian groups were the most well-represented (41%). The floristic composition, as well as the distribution of life forms and phytogeographical components, were found to be significantly affected by the elevation and slope aspects. The study showed that slope aspect and elevation both affected the distribution of plant species, with elevation being the most influential of the two variables. [ABSTRACT FROM AUTHOR]

Background: Little is known about the single-tree influence of Tectona grandis Linn. f. on plant distribution and soil characteristics in Benin City, Nigeria. We investigated the possible single-tree effect of T. grandis on understory plants in an 8-year-old teak plantation at the Moist Forest Research Station. An area of 36.57 m by 60.96 m was marked out and divided into 15 equal-sized subplots containing 10 trees per subplot. Marked distances from the base of a randomly selected tree per subplot were made (0–0.5 m, 0.5–1.0 m and 1.0–1.5 m). Results: Single-tree influence of T. grandis was observed in the soil total organic carbon, total nitrogen and soluble phosphorus, where concentrations were higher with 1.5-m radius from the tree than beyond. Moreover, the pH of the topsoil within 1.5 m from the base of the tree was lower (pH 4.4) than beyond 1.5 m from the base of the tree (pH 5.4). Species-specific single-tree effect was also observed on the understory plant distribution likely due to diverse ecophysiological interactions. Within 1.5 m from the tree, plant species abundance, especially of Sida garckeana, Reisantia indica, Momordica charantia and Tridax procumbens were negatively affected. However, the distribution of Eleusine indica around the tree was not negatively influenced. Plant abundance was generally suppressed in Cynodon dactylon, Axonopus compressus, Andropogon gayanus, Commelina diffusa and Euphorbia hirta. Generally, there were more plant species beyond the canopy fringes than within the canopy, indicating inhibitory single-tree effects. Conclusion: Not all plant species in close proximity to T. grandis are affected. This is important considering that plant-plant associations affect the quality of forest soils. Generally, more plant species were recorded outside the 1.5-m demarcation than within, an increase in soil organic matter may further enhance such plant species abundance. The impact of T. grandis in forest soil quality is possibly a factor of the outcome of its association with neighbouring plant species. Diverse mechanisms at play may be responsible for the observed effects on soil chemistry. However, a reduction in the soil organic matter and variations in other environmental factors also contributed to observed single-tree effect. [ABSTRACT FROM AUTHOR]

Effective monitoring of the current status of species distributions and predicting future distributions are very important for conservation practices at the ecosystem and species levels. The human population, land use, and climate are important factors that influence the distributions of species. Even though future simulations have many uncertainties, such studies can provide a means of obtaining species distributions, range shifts, and food production and help mitigation and adaptation planning. Here, we simulate the population, land use/land cover and species distributions in the Eastern Ghats, India. A MaxEnt species distribution model was used to simulate the potential habitats of a group of endemic (28 species found in this region) and rare, endangered, and threatened (RET) (22 species found in this region) plant species on the basis of IPCC AR5 scenarios developed for 2050 and 2070. Simulations of populations in 2050 indicate that they will increase at a rate of 1.12% relative to the base year, 2011. These increases in population create a demand for more land for settlement and food productions. Land use land cover (LULC) simulations show an increase in built-up land from 3665.00 km2 in 2015 to 3989.56 km2 by 2050. There is a minor increase of 0.04% in the area under agriculture in 2050 compared with 2015. On the other hand, the habitat simulations show that the combined effects of climate and land use change have a greater influence on the decline of potential distributions of species. Climate change and the prevailing rate of LULC change will reduce the extents of the habitats of endemic and RET species (~ 60% and ~ 40%, respectively). The Eastern Ghats have become extensively fragmented due to human activities and have become a hotspot of endemic and RET species loss. Climate and LULC change will enhance the species loss and ecosystem services. [ABSTRACT FROM AUTHOR]

Background: Floristic compositions of non-endemic plants of continental islands were related to the neighboring continents because non-endemic plant species had historically migrated to continental islands from source areas. This study attempts to identify source areas of a continental island by means of floristic analysis and to assess possible migration routes on the basis of geographical distribution ranges of plants. Large quantities of angiosperm data records were downloaded from the Global Biodiversity Information Facility (GBIF). Similarity index and cluster analysis were used to identify the floristic similarities among 22 geographical localities of Taiwan (GLTs) and 34 terrestrial ecoregions in Asia. Geographical distribution ranges of non-endemic angiosperm species in Taiwan (NEASTs) were evaluated to mirror the possible migration routes from different source areas to Taiwan. Results: There are 3275 angiosperm species in Taiwan derived from the dataset of GBIF. Among them, 847 are endemic and 2428 are NEASTs. Geographical distribution ranges of the 2428 NEASTs were categorized into 7 distribution groups. They were widely distribution from equator to Siberia (27 species), tropical ecoregions (345 species), tropical and subtropical ecoregions (663 species), tropical to temperate ecoregions (591 species), subtropical ecoregions (265 species), subtropical to temperate ecoregions (387 species), and temperate ecoregions (150 species). Results of similarity indices and cluster analysis demonstrated that high floristic similarities were observed among GLTs at lowland and southern Taiwan and tropical and subtropical ecoregions in Asia. GLTs at high mountains were assumed to have floristic similarity with temperate ecoregions in Asia, whereas the assumption was not supported by our analysis. It is partly because of that angiosperms with tropical and subtropical distributions extend their ranges from low to high elevations in Taiwan. Conclusions: Subtropical ecoregions at southern China and tropical ecoregions at Indochina were more important than temperate ecoregions on playing source areas of NEASTs. Geographical distribution ranges of NEASTs implied that most of the NEASTs were probably migrated from topical or subtropical ecoregions of Asian continent to Taiwan. [ABSTRACT FROM AUTHOR]

The degree to which tree species will shift in response to climate change is uncertain yet critical to understand for assessing ecosystem vulnerability. We analyze results from recent studies that model potential tree species habitat across the eastern United States during the coming century. Our goals were to quantify and spatially analyze habitat projections and their congruence under multiple climate scenarios and to assess the implications of habitat change for forest vulnerability and adaptation to climate change in and around protected areas. We assessed habitat projections of species habitat extent and forest composition for 35 tree species under climate change from 2000 to 2100 within National Park Service management units in the Appalachian Landscape Conservation Cooperative (ALCC), spanning an approximately 1,500 km latitudinal gradient. Our results show that forest composition and species ranges could change substantially under all greenhouse gas emissions scenarios and that model correspondence was stronger for projections of habitat declines than increases. Model correspondence generally increased at finer spatial scales, but varied by tree species and focal area. In the ALCC, forest composition was projected to change the most in protected area centered ecosystems (PACEs). Northeastern PACEs were projected to be suitable for tree species currently in southeastern PACEs, suggesting that intermediate suitable habitat regions could promote tree species persistence and mitigate the impacts of climate change on eastern forests. These results suggest that climate-specific management of eastern U.S. forest ecosystems will be critical but challenging, requiring integrated assessment and management of PACEs and protected areas as well as higher-resolution monitoring and modeling to inform spatially explicit management decisions within eastern U.S. parks. [ABSTRACT FROM AUTHOR]

Levins's asymmetrical α index quantifies between species overlap over resources more realistically than similar-purpose single-value indices. The associated community-wide $$\bar \alpha$$ index expresses the degree of 'species packing'. Both indices were formulated upon competing animal (i.e., mobile) organisms and are independent of population densities. However, overlap over resources for nonmobile organisms such as plants may have an impact even below carrying capacity. The proposed $$\hat \alpha$$ index, based on Levins's α index, quantifies spatial overlap for plants integrating information on species spatial distribution and crowding conditions. The $$\hat \alpha$$ index is specifically designed for plant distribution data collected in discrete plots with density expressed as percent coverage (%cover) of substratum. We also propose a community-wide $${\hat \alpha_{\text{c}}}$$ index, conceptually analogous to $$\bar \alpha$$ , but furnished with a measure of dispersion ( se $${\hat \alpha_{\text{c}}}$$ ). Species importance within the community is inferred from comparisons of pairwise $$\hat \alpha$$ 's with $${\hat \alpha_{\text{c}}}$$ . The $$\hat \alpha$$ and $${\hat \alpha_{\text{c}}}$$ indices correlate closely and exponentially with plant density, and correct apparent over- and underestimations of interaction intensity at low and very high crowding by Levins's α and $$\bar \alpha$$ , respectively. Index application to aquatic plant communities gave results consistent with within-community and general ecological patterns, suggesting a high potential of the proposed $$\hat \alpha$$ and $${\hat \alpha_{\text{c}}}$$ indices in basic and applied macrophyte ecological studies and management. [ABSTRACT FROM AUTHOR]

Sedum plumbizincicola X.H. Guo et S.B. Zhou ex L.H. Wu (Crassulaceae), a new species restricted to lead-zinc mining areas in Zhejiang Province, China, is described and illustrated. This taxon belongs to sect. Sedum (H. Ohba) S.H. Fu based on the adaxially gibbous carpels and follicles. It superficially resembles S. alfredii Hance and three other Sedum species found in the same area, but differs from these other taxa in bearing 4-merous flowers. Differences in geographical distribution, growth habit, phenology, macromorphology, leaf and stem anatomy, as well as seed micromorphology among S. plumbizincicola, S. alfredii and other related taxa in the genus Sedum are also reported. nrDNA internal transcribed spacers (ITS) sequences from seven populations of S. plumbizincicola support the recognition of this as a taxonomic entity distinct from S. alfredii. [ABSTRACT FROM AUTHOR]

Macrofossils of Carpinus have been widely reported from the Cenozoic of the Northern Hemisphere. However, the leaf cuticules of the genus have rarely been described. A new species, named Carpinus tengchongensis Dai et B.N. Sun, sp. nov., is identified based on 13 leaf fossils, collected from the late Pliocene Mangbang Formation, Tengchong County of Yunnan Province, China. The important characters of the fossil are its oblong-ovate leaf shape, obliquely cordate base, doubly serrulate margin, straight and moderately thick primary vein, pinnate secondary veins, percurrent tertiary veins, orthogonally reticulate areoles, absence of veinlets, anomocytic stomata with double-layered stomatal rim, well-formed T-pieces and trichome bases, which indicates an affinity within the genus Carpinus section Carpinus subsection Monbeigianae, especially with C. tsaiana. Carpinus fossils were present from the Eocene to Pliocene with disjunctive distribution in the North Temperate Zone, which broadly reflected the present distribution pattern and probably demonstrates the tolerance of Carpinus to environmental change. [ABSTRACT FROM AUTHOR]

The main aim of the present study was testing the value of the morphological and anatomical characteristics of the needles in distinguishing Cedrus atlantica, C. libani and C. brevifolia. Nine populations were sampled in their natural habit and 25 characters were used to describe the variation of the brachyblast needles and to analyze the differences between species. The results indicated that morphological and anatomical needle characters provide valuable tools in discrimination of the taxa. The scored differences were statistically significant, as revealed in the Tukey's t test, discrimination analysis and hierarchical analysis of variation. The results support treating C. libani, C. atlantica and C. brevifolia as independent species. [ABSTRACT FROM AUTHOR]

Despite their genetic homogeneity, many taxonomic species are described as European dogroses ( Rosa L. section Caninae (DC.) Ser.) with consistent morphological variability. Here we report a morphometric study of 27 hip and leaf characters of proximate dogrose populations that include Rosa agrestis, a member of the subsection Rubigineae, in Flanders. In principal components analysis one R. agrestis population in Kanne had intermediate morphology between R. canina and R. corymbifera, on the one hand, and three other R. agrestis populations, on the other, suggesting hybridogenic origin. Half-sib R. agrestis seedlings were grown under controlled conditions and their leaf characters were studied. A tendency toward deviating morphology in seedlings from the Kanne population, analogous to the mother plants in the field, and a correlation for specific leaf characters between mother plants and their corresponding seedlings reinforce a genetic basis for the observed divergence in the Kanne population. The assumed hybridogenic mother plants did not produce fewer seeds per hip than the others of the pure populations. In addition, for all sampled dogroses, which included six species, the diameter of the discus was correlated with the number of seeds per hip, whereas the diameter of the orifice was not correlated with this character. This implies that only the diameter of the orifice and not the diameter of the discus might be decisive for species identification among European dogroses. [ABSTRACT FROM AUTHOR]

Clematis s.l. (including Archiclematis and Naravelia) is a genus of approximately 300 species with cosmopolitan distribution. The diversity of its pollen was surveyed in 162 taxa belonging to all infrageneric groups of Clematis s.l. Pollen morphology was investigated by use of scanning electron microscopy to identify useful characters, test taxonomic and systematic hypotheses, and elucidate pollen character evolution on the basis of the molecular phylogeny. Clematis pollen is small to medium (14.8-32.1 μm × 14.2-28.7 μm), oblate to prolate ( P/ E = 0.9-1.4) in shape. The apertures may be tricolpate and pantoporate sometimes with 4-zonocolpate and pantocolpate pollen grains as transitional forms. The tricolpate pollen grains are predominant and occur in all the sections of the genus, whereas pantoporate pollen grains can be found in sect. Tubulosae, sect. Viorna, sect. Viticella, and Naravelia only. Phylogenetic mapping of aperture types reveals that the pantoporate pollen type may be the apomorphy in the genus and evolved several times. The surface ornamentation in all taxa studied is similar and characterized by microechinae evenly distributed on the microperforate tectum. The size and density of spinules on the tectum vary greatly but successive in the whole genus. According to the character syndromes of the ornamentation, separating sect. Brachiata from sect. Meclatis is supported. Though pollen morphology may contribute to investigation of problematic taxa, the taxonomic value of pollen morphology is limited at the species level. [ABSTRACT FROM AUTHOR]

Molecular characterization of Tulipa L. species can elucidate the relationships among the species and provide more information about the taxonomy of this valuable genus. In this study, the genetic relationship among 39 Tulipa accessions from Khorassan and Yazd Provinces, located in east and northeast Iran, were analyzed using inter-simple sequence repeat (ISSR) primers. Ten selected ISSR primers from 20 screened primers generated a total of 97 polymorphic DNA bands. Unweighted pair-group method of cluster analysis based on Dice similarity values separated the accessions into nine groups. Seven species were recognized within these groups, and T. micheliana Hoog was the most frequently encountered species. The subgroups formed within both T. micheliana and T. lehmanniana Merckl. revealed a low level of diversity within these species. T. biebersteiniana Schultes & Schultes fil. and T. biflora Pallas accessions made a separate clusters. The grouping of accessions was generally consistent with principal coordinate analysis (PCA) and clearly showed the position of species in the subgenera and sections of Tulipa. These results clearly showed the usefulness of DNA fingerprinting for identification of Tulipa accessions, and it is imperative to collect and characterize more genetic variability from the other distribution areas of this genus. [ABSTRACT FROM AUTHOR]

Nuclear genome size was determined to investigate the relationships between all 19 species of Araucaria de Jussieu. Species from the two other genera of Araucariaceae, Wollemia and Agathis, were also studied. The genome size of 17 out of the 19 species of Araucaria are reported here for the first time. All Araucariaceae have the same chromosome number 2 n = 26. However, the nuclear DNA contents (2C value) for Araucaria range from 31.3 to 45.4 pg. There is a good correlation between genome size and division in sections, and geographical distribution. The two species from South America have 44.7 and 45.4 pg, the two species from Australia have 35.7 and 44.4 pg and the two species from New Guinea 34.7 and 40.4 pg. All 13 species of New Caledonia and the one from Norfolk Island have a similar, if not identical, amount of nuclear DNA of, on average, 31.9 pg. This corroborates the identical DNA rbcL sequences found for the New Caledonian araucarias. It suggests that the species from New Caledonia diversified more recently and it questions their status as separate species . Compared with this 31.9 pg a strong increase seems to have occurred in the genome size of the 'mainland' araucarias. Genome sizes are evaluated and compared with available taxonomic treatments and extant geographic spreading. The nuclear DNA contents found within the sections are close, making it possible to assign an unknown plant to a section. A difference of 1 pg, which amounts to a difference of 978 Mbp, far exceeds a single character. Nuclear DNA content, as measured by flow cytometry, may conveniently be used to produce systematic data . It is applicable even with young plants or seeds for monitoring the trade in endangered species. [ABSTRACT FROM AUTHOR]

Calypogeia sphagnicola is one of nine species of the genus Calypogeia known in Europe. Occurrence of the species is closely connected with peat bogs. Nowadays, two forms of this species are distinguished- C. sphagnicola f. sphagnicola and C. sphagnicola f. paludosa. The results of the present study, based on two classes of markers-isozymes and sequences of chloroplast genom ( trnH- psbA, rpoC1)-unanimously support the genetic differentiation within the taxon and show that the present-day forms represent genetically distinct species. Phylogenetic analysis resolved two lineages that correspond with the present-day forms with high bootstrap support, which differ in ploidy level: C. sphagnicola f. sphagnicola is haploid, whereas C. sphagnicola f. paludosa is a diploid form. Allopolyploid origin of the diploid form was revealed by the isozyme pattern. Nei's genetic distance between the two present-day forms of C. sphagnicola was 0.472. The forms in Poland have an allopatric pattern of geographic distribution: C. sphagnicola f. sphagnicola occurs exclusively in the lowlands of the northern part of the country on raised peat bogs, whereas C. sphagnicola f. paludosa is found only in the mountains of southern Poland, mainly in the subalpine zone, where it grows on Sphagnum- Polytrichum hummocks on the upper part of north-facing slopes. Plants regarded in this study as C. sphagnicola f. sphagnicola morphologically correspond to the syntype specimen of C. sphagnicola. [ABSTRACT FROM AUTHOR]

Cuscuta (dodder, Convolvulaceae) is a genus of about 200 species of obligate stem parasites with subcosmopolitan distribution. The diversity of pollen and ovule production was surveyed in 128 species and ten varieties. Taxa were assigned to Cruden's mating system categories based on their pollen-ovule ratios. Variation and correlations among floral characters were analyzed using regression and ANOVA, while the mating system categories were subjected to a linear discriminant and canonical variates analysis to assess their cohesiveness. Our data strongly suggest that most Cuscuta species possess a wide range of mixed-mating systems. Whereas four ovules develop in each flower, pollen production varies over three orders of magnitude. Several Cuscuta taxa are highly outcrossing, but no species could be identified that are exclusively selfing. The transition from the one-style flowers of subg. Monogynella to the two-style flowers of subgenera Cuscuta and Grammica, and from simultaneous to sequential maturation of the two stigmas in the latter subgenus, has decreased the role of herkogamy as a facilitator of outcrossing. These evolutionary changes are associated with an increase of species richness in subgenus Cuscuta, and especially in subgenus Grammica. Morphological features were not individually found to have a strong correlation to the mating system, but in general, larger corollas and stigmas were associated with greater pollen-ovule ratios. Cuscuta presents some puzzling results when considered in light of the sex allocation theory, as only some infrageneric lineages demonstrate the predicted pollen size-number tradeoff, while Cuscuta gracillima complex (in subgenus Grammica) displays an unexpected negative relationship between pollen size and style length. The relationship between host range and mating system is discussed, prompting further research into the co-evolution of pollination systems and life history traits between parasites and their host species. [ABSTRACT FROM AUTHOR]

The tribe Stipeae with an estimated number of ca. 600 species is part of the grass subfamily Pooideae and has near worldwide distribution. Its species are often dominant constituents of steppe vegetation and other grasslands, especially in Eurasia, the Americas and Australia. The taxonomy of Old World Stipeae has been studied to date primarily on the basis of morphology and anatomy, while existing molecular phylogenetic investigations have mainly dealt with New World or Australian taxa. We studied 109 new ingroup taxa with a focus on Old World Stipeae (in addition with an extensive outgroup sampling) using chloroplast and nuclear ribosomal DNA sequences (3′ trnK region, ITS1-5.8S gene-ITS2), and discuss taxonomic key characters. Five highly supported monophyletic lineages were identified, some of which were rather unexpected: (a) the narrowly defined Stipa core clade, which is primarily Eurasian but extends into Africa north of the Sahara Desert, (b) the majority of Old World Piptatherum, (c) a 'Transcontinental Stipeae Clade' encompassing Eurasian, African, American and Australian lineages, (d) a Himalayan to E Asian clade and (e) the single species Achnatherum splendens. The large 'Transcontinental Stipeae Clade' contained several lineages of Eurasian Stipeae different from the Stipa core (a), i.e., genera Aristella, Celtica, Oloptum gen. nov., Stipella stat. et. gen. nov., species of Achnatherum, and the species-rich lineages of Nassella/ Jarava in America and of Austrostipa in Australia. In our circumscription Ptilagrostis was nested in (d), a clade (which included some species of Achnatherum and poorly studied Himalayan species ascribed to either Stipa or Orthoraphium) and whose internal structure remained unclear. Oloptum, gen. nov., is described, and the following combinations are made: Achnatherum pelliotii, comb. nov., Aristella keniensis, comb. nov., Oloptum miliaceum, comb. nov., Stipella, stat. et. gen. nov., S. capensis, comb. nov., S. nitens, comb. nov., S. parviflora, comb. nov., S. staintonii, comb. nov., and S. tigrensis, comb. nov. [ABSTRACT FROM AUTHOR]

Floristically, Taiwan is a very rich island due to her varied geography, topography and habitats. Through extended historical research involving past and present botanical inventories of the central mountains, particularly of the Hehuanshan area of Taiwan, we are now able to examine the floristic composition of four elevation zones, 2,000-2,500 m, 2,500-3,000 m, 3,000-3,500 m, and 3,500-3,950 m. We selected four study sites, namely Shinjenkan (SJK) at 2,250-2,585 m, Shihmenshan (SMS) at 3,000 m, Hehuan East Peak (HEP) at 3,401 m, and Hehuan Major Peak (HMP) at 3,408 m, and determined their α, β, and Y diversities along with their Simpson's diversity indices. Our results clearly showed that the species richness (α diversity) was significantly high and decreased as the altitude increased. Coincidently, Simpson's diversity index at 2,250 m was significantly high at 0.85, drastically decreased to 0.17 at 3,145 m, and continued to decrease to 0.10 at both sites at 3408 m. On the other hand, by comparing plant distribution data collected over a century for the Hehuanshan, Alishan and Yushan areas, we were able to predict that plants would migrate mostly from a lower to a higher elevation when the global temperature increases. For instance, in the Hehuanshan area, 16 species would move towards higher elevations and seven species would remain in their original zone. In the Alishan area, seven species would migrate and four would remain in their original zone, and in Yushan, 15 species would migrate out of their zone and five would remain. Of all of the species, at least six risk extinction, since their expected migration would take them far beyond the limits of the land available above 3,950 m. It is concluded that the alpine vegetation will be redistributed, many plant species will move towards a higher elevation and, eventually, at least six plant species (Anaphalis morrisonicola, Artemisia morrisonensis, Swertia randaiensis, Hypericum nagasawai, Angelica morrisonicola, and Cirsium arisanensis) will become extinct. [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]

It is expected that plant species with multiple regenerative strategies have a wider ecological amplitude and geographical distribution. However there is still an anxious question why species with multiple regenerative strategies are not more frequent. In the presented work we asked whether short-lived plants with a potential bud bank i) have a wider geographical distribution, ii) occur more frequently in human-made habitats and iii) more frequently possess invasive status in comparison with the short-lived species without this additional regenerative strategy. Results show that short-lived plants with a potential bud bank are i) more widely geographically distributed, ii) under-represented in natural habitats and weakly over-represented in habitats disturbed by human activities and iii) contrary to expectation, less numerous among neophytes than species without a potential bud bank. This suggests that short-lived root-sprouters are more habitat-specialized when compared with such plants without adventitious bud-bank formation, but are more widely geographically distributed. A higher frequency of multiple regeneration strategies seems to be restricted by costs of having this ability in habitats or situations without a disturbance regime. [ABSTRACT FROM AUTHOR]

The study aims at evaluating how land-use modifies the link between the observed distribution of species and the climatic variability and at detecting species involved in that modification. The area studied covers the phytogeographical transition between the South-Sudanian sector and the North-Sudanian sector in western Burkina Faso. It lies along an aridity gradient, of which the aridity index (UNESCO-MAB) ranges from 0.363 to 0.533. The data studied were derived from observations performed on 192 woody species in 603 vegetation survey plots inside and outside protected areas. The species turn-over (β diversity) and the mutual information were assessed along the aridity gradient inside protected areas on one hand and outside protected areas on the other. Our study shows that the statistical links between the geographical distributions of species and the aridity gradient differ according to whether the observations are performed inside or outside the protected areas. Anthropogenic disturbances, mainly agricultural in the region of study, result in a decrease in the β diversity and in the average mutual information between the distribution of all the woody species and the climatic gradient. Moreover, the variation in mutual information differs according to the species: it diversely decreases with agricultural land-use for most of them, but increases for some. Thus, land-use leads to species-specific changes in the realised climatic niches. [ABSTRACT FROM AUTHOR]

China is rich in energy plant resources. In this article, 64 plant species are identified as potential energy plants in China. The energy plant species include 38 oilseed crops, 5 starch-producing crops, 3 sugar-producing crops and 18 species for lignocellulosic biomass. The species were evaluated on the basis of their production capacity and their resistance to salt, drought, and/or low temperature stress. Ten plant species have high production and/or stress resistance and can be potentially developed as the candidate energy plants. Of these, four species could be the primary energy plants in China: Barbados nut ( Jatropha curcas L.), Jerusalem artichoke ( Helianthus tuberosus L.), sweet sorghum ( Sorghum bicolor L.) and Chinese silvergrass ( Miscanthus sinensis Anderss.). We discuss the use of biotechnological techniques such as genome sequencing, molecular markers, and genetic transformation to improve energy plants. These techniques are being used to develop new cultivars and to analyze and manipulate genetic variation to improve attributes of energy plants in China. [ABSTRACT FROM AUTHOR]

In arid and semiarid environments, the presence of woody species generates a series of environmental gradients that increase spatial heterogeneity and modify the pattern of distribution of the other species. We postulate that the temporal and spatial variability in litter input generated by woody species is a relevant factor in the generation of edaphic heterogeneity by redistribution of nutrients and the physical effects of litter. The objective of this study was to determine the temporal and spatial variability in the amount of litter input under the canopy of dominant woody plants ( Prosopis flexuosa and Larrea divaricata) and in exposed areas at the Ñacuñán Reserve, in the central zone of the Monte desert. Litterfall was collected during 2 years from 30-cm-diameter litter traps distributed at three microsites: under P. flexuosa canopy, under L. divaricata canopy, and in exposed areas. Microhabitats beneath Prosopis showed the highest litter input per m2 (between 320 and 527 g/m2), and, consequently, more than 50% of it fell to the soil beneath the canopy of P. flexuosa. Only 10% fell on exposed areas, which exhibited an annual input rate per m2 of a lower order of magnitude than the sites under Prosopis. Litterfall presented a peak in summer as a consequence of convective storms, and a second one in autumn due to phenological shedding. Our results suggest that woody species have a central importance in the dynamics of nutrients in arid lands by both the increase of total productivity and litterfall, and the spatial and temporal regulation of litter input. [ABSTRACT FROM AUTHOR]

From 2003 through 2005, tidal marsh plant species diversity and abundance on historically surveyed vegetation transects along the salinity gradient of the San Francisco Estuary were investigated to establish empirical relationships between plant distributions and environmental conditions, and furthermore to examine and predict past and future plant distribution changes. This study suggests that for most species, salinity is the primary control on plant distribution. Thus, ongoing changes in estuarine conditions (increasing sea level and salinity) are resulting in a complex mix of plant distribution changes. On the low marsh, where sediment salinity is similar to that of ambient water, halophytic species are replacing salt-intolerant taxa. However, on marsh plains, where increased tidal flooding is moderating high salinity (concentrated by evaporation), halophytic “high marsh” species are being replaced by salt-intolerant “low marsh” taxa. Thus, future changes in plant distributions will hinge on whether marsh sediment accumulation keeps pace with sea level rise. [ABSTRACT FROM AUTHOR]

Abstract  We present an overview of archaeobotanical Carthamus spp. finds from Neolithic to medieval sites in the Near East and adjacent areas. A particular focus is put on the cultivated form of the genus. Safflower appears first in a number of early Bronze Age (3000 b.c.) sites in northern and central Syria. From there it apparently spread to Egypt, the Aegean and south-eastern Europe. The Near Eastern Bronze Age evidence shows a striking exclusiveness in the distribution patterns of safflower and flax, with flax being restricted to Levantine and Iranian sites. This may reflect the contrasting ecological requirements of the two crops, with safflower being well adapted to drought and salinity and thus to arid conditions. At the same time the geographically complementary evidence may indicate a similar use of the two crops and most probably suggests that the safflower was also used for oil almost from the beginning of its cultivation. [ABSTRACT FROM AUTHOR]

Abstract: Tribe Pogonieae (Orchidaceae), as currently known, comprises five genera distributed from South to North America and Eastern Asia. Phylogenetic inferences within Cleistes and among genera of tribe Pogonieae were made based on nrDNA (ITS) and cpDNA (trnL-F, rps16, rbcL, and psaB) sequence data and maximum parsimony. Eighteen species of Cleistes, members of all other genera of Pogonieae, and outgroups were sampled. Analyses based on individual DNA regions provided similar topologies. All evidence indicates that Cleistes is paraphyletic. The North American C. divaricata and C. bifaria are more closely related to the temperate genera Isotria and Pogonia than to their Central and South American congeners, the latter constituting a monophyletic group characterized by the production of nectar as reward, tuberous roots, and their distribution in Central and South America. The Amazonian Duckeella is sister to the remainder of Pogonieae. Taxonomic and biogeographic implications are discussed, and morphological synapomorphies are given for clades obtained in the inferred molecular phylogeny. [Copyright &y& Elsevier]

A molecular study of the wetland pleurocarpous moss Hamatocaulis vernicosus (Mitt.) Hedenäs, based on the ITS region, the trnL- trnF region, and rpl16 revealed two cryptic species. One of these is widespread in Europe, and was also sampled from several localities in Minnesota (United States). The other cryptic species occurs only south of the boreal zone in Europe, and was in addition sampled from single localities in Peru and northernmost Asiatic Russian Federation. Although it seems likely that the southern species colonized parts of Europe from southern refugia after the last glaciation, its wide distribution outside Europe indicates that the speciation event is unrelated to the European glacial history. No correlations could be found between variation in habitat preferences (pH and electric conductivity) and molecular variation. [ABSTRACT FROM AUTHOR]

Floral isolation has been considered to be an important reproductive mechanism governing the species diversification in many genera. In a classic example Aquilegia, sympatric species from North America with diverse floral traits are generally associated with specialized pollinators that prohibit interspecific hybridization. It remains unclear whether species diversification in the genus from Eurasia is also maintained by floral isolation. We investigated floral phenology, floral characteristics and pollinators in three sympatric Aquilegia species ( A. ecalcarata, A. incurvata and A. yabeana) in the Qinling Mountains, Shanxi Province, China from 2001 to 2005. The spurless A. ecalcarata flowers earlier than the other two species with nectar spurs but their floral phenology overlaps. Major pollinators of A. ecalcarata are syrphid flies while bumblebees are major for A. incurvata and A. yabeana. Therefore our observations confirm that mechanical isolation through differential pollinators could contribute reproductive isolation between spurless and spurred species, as demonstrated by studies from North America. Whether floral isolation plays a major role in the reproductive isolation between two spurred species ( A. incurvata and A. yabeana), however, remains to be seen. Further studies are required to quantify the potential role of geographical isolation because they occupy different habitats. [ABSTRACT FROM AUTHOR]

Turkish representatives of the genus Rhaponticoides Vaill. are examined. A key and distribution map of Rhaponticoides species occurring in Turkey are provided for the first time. R. hierroi Ö. Eren sp. nov., from Bakacak pass in the Western Taurus range, SW Anatolia, allied to R. mykalea (Hub.-Mor.) M. V. Agab. & Greuter is described as a species new to science and illustrated. Its habitat conditions and conservation status are considered. Pollen micrographs of R. hierroi and R. mykalea are presented using scanning electron microscopy. [ABSTRACT FROM AUTHOR]

The aquatic plant communities in two Irish canals were examined between 1990 and 1994 to investigate the factors that influence plant species distribution and community structure. Four main aquatic plant groups were identified by TWINSPAN. Two groups were characterised by bankside vegetation, including Carex sp., Juncus bulbosus and Scirpus lacustris. Large mixed assemblages of emergent, floating leaved, free floating and submerged plant species characterised the third group. The fourth group was species poor and was dominated by Cladophora sp. Canonical Correspondence Analysis identified weed control history, total oxidised nitrogen, water colour, distance from feeder stream and distance from summit as the factors that potentially influenced the distribution of plant species. The results indicated that ongoing management practices did not significantly alter the overall structure and abundance of the plant communities during the study period. [ABSTRACT FROM AUTHOR]

Three species of Elodea ( Elodea canadensis Michaux, E. nuttallii St John and E. ernstiae St John) have colonized Europe from the American continent. All three arrived in the Alsatian Rhine floodplain (north-eastern France) soon after their arrival in Europe, i.e. in the mid-19th century for E. canadensis, and in the mid-20th century for E. nuttallii and E. ernstiae. The paper investigates the present distribution of Elodea spp. in the floodplain by quantifying the species’ respective occurrences and by describing their habitats. The study further focuses on E. nuttallii which is presently colonizing other parts of Europe. It analyses whether it has continued to expand in the Alsatian Rhine floodplain during recent decades, and it checks whether changes in the abundance of E. nuttallii have had an impact on species richness of water plant communities. E.␣nuttallii has been found to be at present one of the most dominant and most frequent aquatic plant species in the study sector, while E. canadensis and E. ernstiae are less abundant. The species’ distributions differ with regard to water chemistry and water temperature: E. canadensis occurs in oligo-mesotrophic, rather stenothermic habitats, whereas E. nuttallii and E. ernstiae can be encountered in meso- to eutrophic sites with little or no arrival of stenothermic ground water. By comparing successive vegetation relevés from the same sites the study revealed further that the distribution of E. nuttallii has been stable in recent decades, despite local fluctuations in abundance. No relationship could be established between those fluctuations and changes in species richness or type of local plant communities. The sum of the results suggests that the expansion of E. nuttallii in the Alsatian Rhine floodplain had been completed prior to the study period. The species’ present distribution in the study sector as well as its position in local plant communities might therefore be considered a model for what can be expected to happen in areas where E.␣ nuttallii has only recently arrived. [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]

In order to analyze the extent to which allelopathic action of Cistus ladanifer may influence the successional progression towards Mediterranean sub-climacic shrublands and the geographical distribution of other species, the inhibitory effect of Cistus ladanifer extracts on the germination of 20 Mediterranean species was analyzed. Five of the species tested were characteristic of maquis sub-climacic shrublands: Arbutus unedo, Adenocarpus argyrophyllus, Phillyrea angustifolia, Phillyrea latifolia, and Rhamnus alaternus. Tests were also carried out on 6 Cistaceae species in order to evaluate the auto-toxicity rate of allelopathic extracts: Halimium umbellatum subsp. viscosum, Halimium ocymoides, Cistus ladanifer, Cistus salvifolius, Cistus monspeliensis, and Cistus populifolius. Nine herbaceous species sharing the natural habitat with C. ladanifer were also examined. Results confirmed a clear inhibitory and delaying effect of aqueous C. ladanifer-leaf extracts on the germination of P. angustifolia, P. latifolia, R. alaternus, H. ocymoides, C. populifolius, Erysimum lagascae, Brassica barrelieri, Silene tridentata, and Moricandia moricandioides. Assays with soil collected below the canopy of the C. ladanifer community showed more pronounced inhibitory effect on sub-climacic shrub species than the aqueous extracts. In contrast, the opposite pattern was detected when analyzing the allelopathic effect of natural soil on Cistaceae and herbaceous species. Allelopathic compounds produced by C. ladanifer showed little auto-toxicity. The inhibitory effect of phytotoxic compounds accumulated in the jaral soil upon germination of A. unedo, B.␣barrelieri, and M. moricandioides was eliminated by heating soil at 150 °C for 10 min. Phenolic compounds (i.e. ferulic, p-hydroxybenzoic, vanillic, p-coumaric, and caffeic acids) and terpenes (i.e. α and β-pinene) with allelopathic documented effect were detected in the aqueous extracts and soil samples used in the analyses. We suggest that the allelopathic effect of C. ladanifer may influence the composition and structure of Mediterranean communities where the species is present, since it hinders the establishment of some sub-climacic species and may reduce the area occupied by numerous herbaceous species. [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]

The composition of plant species in grassland communities is determined in part by negative and positive interactions among neighbouring plants; such interactions could be dispersal or – in the case of legumes – symbiotic N2 fixation or resource acquisition. We hypothesised that small scale distribution of plant species may be in part affected by (i) the plant's narrow dispersal in the close neighbourhood, (ii) by the N input into the soil through symbiotic N2 fixation by legumes, and (iii) by small scale heterogeneity of N availability in the soil. To address these hypotheses, in four species-rich semi-natural and natural grasslands along an altitudinal gradient from 900 to 2100 m a.s.l., the association of species that grew within a radius of 5 cm of selected plant species (central plant, CP) was studied. The distribution of the plant species within the plant community was not random and the species composition that grew within a radius of 5 cm of a CP varied with altitude. The strength of the association between a CP and its neighbouring species decreased with increasing altitude. The 5 cm radius was most dominated by individuals of the same species as the CP, suggesting that narrow dispersal (either through seeds or through vegetative propagates) may be most important for the species composition within the sward. δ15N values of non leguminous species growing near legumes compared to non leguminous species that grew far from legumes indicate that N from symbiotic N2 fixation may be another factor influencing the association of plant species. Effects of small scale heterogeneity in apparent N availability in the soil were detected to be the least important for the species composition. [ABSTRACT FROM AUTHOR]

The major environmental gradients underlying plant species distribution were outlined in two climatically and bio-geographically contrasting mires: a Swedish bog in the boreo-nemoral zone, and an Italian bog in the south-eastern Alps. Data on mire morphology, surface hydrology, floristic composition, peat chemistry and pore-water chemistry were collected along transects from the mire margin (i.e., the outer portion of the mire in contact with the surrounding mineral soil) towards the mire expanse (i.e., the inner portion of the mire). The delimitation and the extent of the minerotrophic mire margin were related to the steepness of the lateral mire slope which, in turns, controls the direction of surface water flow. The mineral soil water limit was mirrored in geochemical variables such as pH, alkalinity, Ca2+, Mg2+, Al3+, Mn2+, and SiO2 concentrations in pore-water, as well as Ca, Al, Fe, N and P contents in surface peat. Depending on regional requirements of plant species, different species were useful as fen limit indicators at the two sites. The main environmental factors affecting distribution of habitat types and plant species in the two mires were the acidity-alkalinity gradient, and the gradient in depth to the water table. The mire margin – mire expanse gradient corresponds to a complex gradient mainly reflected in a differentiation of vegetation structure in relation to the aeration of the peat substrate. [ABSTRACT FROM AUTHOR]

Offers information on tea-beverage plant Cleyera japonica Thunb. var wallichiana (DC.) Sealy (Theaceae). Characteristics of the plant; Distribution of the plant in the Himalayas of Nepal; Analysis of the leaf samples of the plant.

Six native Rhododendron species grow in the degraded, fire-prone landscape of Hong Kong: R. simsii and R. farrerae are common and widespread, R. moulmainense is relatively restricted, and R. championiae, R. hongkongense, and R. simiarum are rare. For all species except the rare R. simiarum, there was direct or indirect evidence of regrowth after fire, but only the two smallest and commonest species grow in sites which are frequently burned. Both flowered within 18 months of a fire. Most populations of all species, except R. simiarum, had a deficiency of individuals in the smaller basal circumference classes. Seedlings were found only in three out of four plots of R. simiarum, and one of R. farrerae. A few seedlings of the other rare species were seen in open, litter-free microsites outside the study plots, but no seedlings of the most common species, R. simsii, were seen anywhere. In logistic regression models, one or more measures of plant size were significant positive predictors of flowering at least once in the three year study period for all species, while percentage cover by surrounding vegetation had a significant negative impact on all except R. simsii and R. farrerae, for which no populations are strongly-shaded. Although the absence of current recruitment is not necessarily a cause for concern in long-lived species that can resprout after fire, we recommend that active vegetation management should be tried to enhance the survival and reproduction of R. moulmainense, R. championiae and R. hongkongense, and that new populations of these species and R. simiarum should be created. [ABSTRACT FROM AUTHOR]

Diospyros species distributed widely in Thailand were classified into four ecotypes, according to their habitat; constantly humid area, alternately dry and wet area, mountainous cool area and all area. Some of them inhabit near dwelling areas or in the paddy field in the village. The young fruit is covered with dense pubescence in most species. The size, shape, and color of mature fruit greatly vary greatly with the species. In most species, the mature fruit has a soft pulp and hard skin. The fruit of six species has been used for dying. Four species produce edible fruits, with color and flavor favorable for breeding of edible Diospyros species. The fruit of some species contains some chemicals useful as fish poisoning or of medicines, although the active components have not yet been identified. The edible fruit contained many tannin cells, but the fruit used as fish poisoning and medicines had only a few. [ABSTRACT FROM AUTHOR]

The article deals with the problem of plant species distribution modeling in terms of climate variables including temperatures and rainfall. It proposes the use of autologistic regression model for the modelling of spatial binary data. It describes estimation methods which include coding method (COD), maximum pseudo-likelihood estimation (MPL) and Markov chain Monte Carlo (MCMC). It compares the methods via simulation and proposes the methodology distributions of plant species in Florida.

Climate warming is expected to cause a poleward spread of species, resulting in increased richness at mid to high latitudes and weakening the latitudinal diversity gradient. We used pollen data to test if such a change in the latitudinal diversity gradient occurred during the last major poleward shift of plant species in Europe following the end of the last glacial period. In contrast to expectations, the slope of the gradient strengthened during the Holocene. The increase in temperatures around 10 ka ago reduced diversity at mid to high latitude sites due to the gradual closure of forests. Deforestation and the introduction of agriculture during the last 5 ky had a greater impact on richness in central Europe than the earlier climate warming. These results do not support the current view that global warming alone will lead to a loss in biodiversity, and demonstrate that non-climatic human impacts on the latitudinal diversity gradient is of a greater magnitude than climate change. Climate-induced poleward shifts in plant distributions could flatten latitudinal diversity gradients. However, here the authors show that the spread of forests after the last ice age reduced diversity in central and northern Europe, and that human land-use over the past 5000 years strengthened the latitudinal gradient in plant diversity. [ABSTRACT FROM AUTHOR]

Vegetation impacts on ecosystem functioning are mediated by mycorrhizas, plant–fungal associations formed by most plant species. Ecosystems dominated by distinct mycorrhizal types differ strongly in their biogeochemistry. Quantitative analyses of mycorrhizal impacts on ecosystem functioning are hindered by the scarcity of information on mycorrhizal distributions. Here we present global, high-resolution maps of vegetation biomass distribution by dominant mycorrhizal associations. Arbuscular, ectomycorrhizal, and ericoid mycorrhizal vegetation store, respectively, 241 ± 15, 100 ± 17, and 7 ± 1.8 GT carbon in aboveground biomass, whereas non-mycorrhizal vegetation stores 29 ± 5.5 GT carbon. Soil carbon stocks in both topsoil and subsoil are positively related to the community-level biomass fraction of ectomycorrhizal plants, though the strength of this relationship varies across biomes. We show that human-induced transformations of Earth's ecosystems have reduced ectomycorrhizal vegetation, with potential ramifications to terrestrial carbon stocks. Our work provides a benchmark for spatially explicit and globally quantitative assessments of mycorrhizal impacts on ecosystem functioning and biogeochemical cycling. Mycorrhizas—mutualistic relationships formed between fungi and most plant species—are functionally linked to soil carbon stocks. Here the authors map the global distribution of mycorrhizal plants and quantify links between mycorrhizal vegetation patterns and terrestrial carbon stocks. [ABSTRACT FROM AUTHOR]

The FLOTROP dataset contains numerous plant observations (around 340,000 occurrences) in northern tropical Africa (from the 5th to 25th parallel north) in open ecosystems (savannah and steppe). They were collected by multiple collectors between 1920 and 2012 and were managed by Philippe Daget. These observations are probably the most important and unique source of plant distribution over the Sahel area. The data are now available in the Global Biodiversity Information Facility, Tela Botanica website, and as maps in the African Plant Database. For the overall area involved, this dataset has increased by 40% the data available in the GBIF. For some countries between the 15th and 21st parallel north, the FLOTROP dataset has increased available occurrences 10-fold compared to the data existing in the GBIF. Design Type(s) data integration objective • biodiversity assessment objective • data collection and processing objective Measurement Type(s) Plants Technology Type(s) digital curation Factor Type(s) species • geographic location • temporal_interval Sample Characteristic(s) Viridiplantae • North Africa Machine-accessible metadata file describing the reported data (ISA-Tab format) [ABSTRACT FROM AUTHOR]