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1.
The secondary metabolites of 150 specimens belonging to 29 species of Teloschistes were analysed with HPLC. Seven anthraquinones were detected of which parietin dominated with minor proportions of emodin, teloschistin, fallacinal and parietinic acid. The depsidones vicanicin, caloploicin, and isofulgidin occurred together with some compounds of unknown identity in varying proportions in T. flavicans, T. peruensis, T. stellatus, and one unnamed taxon. Nine chemosyndromes were found in the genus. Most species had only one chemosyndrome, but T. flavicans s. lat. had six syndromes. The geographical distribution patterns of these chemosyndromes in T. flavicans are discussed as well as the applicability of chemical characters for species delimitation in Teloschistes. 相似文献
2.
Ove Almborn 《Nordic Journal of Botany》1992,12(3):361-364
Three species are discussed: Teloschistes hosseusianus Gyelnik, formerly known only from the type locality in Argentina is shown to have a wider distribution in South America. T. stellatus (Mey. & Flot.) Mull. Arg. known only from the type locality in Peru is reported from other localities in Peru and Chile. T. velifer F. Wils. previously known from Australia and New Zealand is reported from six localities in Chile. One of these is T. hollermayeri Ras. which is a synonym of T. velifer. A key is given to the 11 species of Teloschistes so far known from South America. 相似文献
3.
Disjunct species distributions may result from a combination of geologic events and long-distance dispersal. The foliose lichen species complex Leptogium furfuraceum-L. pseudofurfuraceum has an intercontinental disjunction pattern. Populations of this species complex are found in western North America, southern South America, Africa, and southern Europe. We conducted a phylogenetic study to reconstruct the biogeographic history of this species complex using two ribosomal genes (ITS and LSU) and a protein-coding gene (partial RPB2). Results indicated that the complex comprises four geographically restricted genetic lineages. A sister relationship was found between populations from the same hemispheres, incongruent with previous data derived from morphological characteristics and geographical classification schemes. Incorporating Bayesian ancestral area reconstruction and Bayesian divergence time estimation, we proposed an evolutionary hypothesis for the species complex. The results suggested that processes of biotic expansion via transoceanic dispersal were responsible for the species divergence and distribution patterns observed today. This study also expands the view that cryptic speciation is not a rare phenomenon among fungi and lichens. 相似文献
4.
Ove Almborn 《Nordic Journal of Botany》1989,8(5):521-538
Nine species of Teloschisies are recorded from the area and details of their morphology (including considerable ecotypic variation) and distribution are given. All species are illustrated. All relevant type specimens were examined. Four species ( T. chry-sophthalmus, T. exilis, T. flavicans and T. hypoglaucus ) are common in this part of Africa and are also widely distributed elsewhere. T. perrugosus , whose taxonomy has been revised, seems to be endemic to central and southern Africa. T. capensis and T. puber are well-defined endemics of the Atlantic coast in South Africa and Namibia, whereas T. chrysocarpoides occurs in Namibia only. T. pulvinaris , now established as a distinct species, is known only from the type locality in Cape Province. 相似文献
5.
Lucie Zemanová Volodymyr Trotsiuk Robert C. Morrissey Radek Bače Martin Mikoláš Miroslav Svoboda 《Biodiversity and Conservation》2017,26(8):1943-1958
Habitat loss and fragmentation can negatively impact the persistence of dispersal-limited lichen species with narrow niches. Rapid change in microclimate due to canopy dieback exposes species to additional stressors that may limit their capacity to survive and colonize. We studied the importance of old trees as micro-refuges and microclimate stability in maintaining lichen survival and diversity. The study was situated in mountain Norway spruce (Picea abies) forests of the Gorgany Mountains of the Ukrainian Carpathian mountain belt. Lichens were collected on 13 circular study plots (1000 m2). Dendrochronological methods were used to reconstruct age structure and maximum disturbance event history. A linear mixed effects model and general additive models were used to explain patterns and variability of lichens based on stand age and disturbance history for each plot. Tree age was the strongest variable influencing lichen diversity and composition. Recent (<80 years ago) severely disturbed plots were colonized only by the most common species, however, old trees (>200 years old) that survived the disturbances served as microrefuges for the habitat-specialized and/or dispersal limited species, thus epiphytic lichen biodiversity was markedly higher on those plots in comparison to plots without any old trees. Most species were able to survive microclimatic change after disturbances, or recolonize disturbed patches from surrounding old-growth forests. We concluded that the survival of old trees after disturbances could maintain and/or recover large portions of epiphytic lichen biodiversity even in altered microclimates. 相似文献
6.
The riparian vegetation of a basin in the NW Spain was studied to establish its spatial variation pattern and to relate floristic and structural differences in the community to environmental factors. Eighty-seven sampling units in 43 sampling stations were used. Samples were classified in 5 groups using Two Way Indicator Species Analysis (TWINSPAN). Three groups represented reaches with riparian wood along their banks: Mediterranean alderwoods and shrubby willow woods. The remaining two corresponded to floodplains with vegetation colonizing moderately eutrophicated deposits of gravel. Structural characteristics of richness and diversity differentiated the alder woods. In these, the shaded environment created by the woody species limited herbaceous vegetation development. This was dominated by Carex acuta subsp. broteriana. Classification and CCA ordination results were compared. The TWINSPAN groups could be recognized in the CCA graph. The ordination was related to a pollution gradient associated with altitude. This pollution gradient involved bank ruderalization, incorporation of nitrophilous species and a decrease in the vegetation quality. The influence of the lithological features on vegetation was also evident. 相似文献
7.
Species distribution models (SDMs) that employ climatic variables are widely used to predict potential distribution of invasive species. However, climatic variables derived from climate datasets do not account for anthropogenic influences on microclimate. Irrigation is a major anthropogenic activity that influences microclimate conditions and alters the distribution of species in anthropogenic landuses. SDM-based studies appear to ignore the effects of irrigation on microclimatic conditions. This study incorporated irrigation as a correction to precipitation data, to improve the predictive capacity of SDM. As a case study, we examined a SDM of Wasmannia auropunctata, an invasive species that originates in South and Central America, which has invaded tropical and subtropical regions around the world. The potential distribution of W. auropunctata was predicted using Maxent. The model was built based on climatic variables and species records from non-irrigated sites in the native range and then projected on a global scale. Invasive species records were used to evaluate the performance of the model. Precipitation-related variables were modified to approximate actual water input in irrigated areas. Precipitation correction relied on an estimate of irrigation inputs. The model with irrigation correction performed better than the corresponding model without correction, on a global scale and when it was examined in five different geographical regions of the model. These results demonstrate the importance of irrigation correction for assessing the distribution of W. auropunctata in various geographical regions. Accounting for irrigation is expected to improve SDMs for a variety of species. 相似文献
8.
Modeling the spatial distribution and fruiting pattern of a key tree species in a neotropical forest: methodology and potential applications 总被引:1,自引:0,他引:1
Caillaud D Crofoot MC Scarpino SV Jansen PA Garzon-Lopez CX Winkelhagen AJ Bohlman SA Walsh PD 《PloS one》2010,5(11):e15002
Background
The movement patterns of wild animals depend crucially on the spatial and temporal availability of resources in their habitat. To date, most attempts to model this relationship were forced to rely on simplified assumptions about the spatiotemporal distribution of food resources. Here we demonstrate how advances in statistics permit the combination of sparse ground sampling with remote sensing imagery to generate biological relevant, spatially and temporally explicit distributions of food resources. We illustrate our procedure by creating a detailed simulation model of fruit production patterns for Dipteryx oleifera, a keystone tree species, on Barro Colorado Island (BCI), Panama.Methodology and Principal Findings
Aerial photographs providing GPS positions for large, canopy trees, the complete census of a 50-ha and 25-ha area, diameter at breast height data from haphazardly sampled trees and long-term phenology data from six trees were used to fit 1) a point process model of tree spatial distribution and 2) a generalized linear mixed-effect model of temporal variation of fruit production. The fitted parameters from these models are then used to create a stochastic simulation model which incorporates spatio-temporal variations of D. oleifera fruit availability on BCI.Conclusions and Significance
We present a framework that can provide a statistical characterization of the habitat that can be included in agent-based models of animal movements. When environmental heterogeneity cannot be exhaustively mapped, this approach can be a powerful alternative. The results of our model on the spatio-temporal variation in D. oleifera fruit availability will be used to understand behavioral and movement patterns of several species on BCI. 相似文献9.
10.
Lecidea atrofulva [= Miriquidica atrofulva comb, nov.] has been recognized as an obligatorily rusty coloured representative of the genus Miriquidica. M. garovaglii and Lecidea plumbeoatra [= M. plumbeoatra comb, nov.] have been found to develop facultatively rusty coloured thalli. Miriquidica lapponica sp. nov. is described as new to science. 相似文献
11.
F. Conand 《Journal of fish biology》1993,42(6):851-863
The abundance, the seasonal variation and the life history of the silverside, Atherinomorus lacunosus , are studied from fish caught in the lagoons around New Caledonia. About 270 nights of fishing were carried out between 1980 and 1983. The silverside is present in most of the fishing hauls but seldom in large quantities. Fish reproduce from September to December at 1 year of age. At this time their size is about 10 cm. Mortality is high and a few individuals can survive a second year and reach 13 cm. Results from other studies indicate that in a less seasonally contrasted environment than the lagoons of New Caledonia, A. lacunosus has several spawning periods during the year. This species is thus able to adjust its phenology to the environmental conditions. 相似文献
12.
Cladonia (sect. Cocciferae , subsect. Ochroleucae) norvegica T0nsb. & Holien sp. nov., is closely related to C. bacilliformis (Nyl.) DT. & Sarnth. but is morphologically, chemically, and ecologically distinct. Superficially it may resemble C. (sect. Cladonia) coniocraea auct., which is often growing with it. C. norvegica is known from Norway only. 相似文献
13.
The leaf nitrogen contents of beech growing in the Sierra de la Demanda are studied, relating the contents with other structural population characteristics. For this, different experiments were conducted: (a) To analyze of nitrogen levels in shed leaves, in leaf biomass and in leaves decomposing on a test plot in the Tres Aguas beech forest. (b) To study leaf nitrogen contents over a vegetative cycle in the above beech forest. (c) To study the leaf nitrogen contents of thirty beech stands in the Sierra de la Demanda located at different altitudes and corresponding to three beech budding isophenes. Annual nitrogen accumulation in leaf biomass was 79.4 kg ha-1yr-1, of which 22.9 kg ha-1yr-1 return to the soil substrate through shedding and 2.1 kg ha-1yr-1 are actually incorporated into the soil. Nitrogen cannot be a limiting factor for the development of the beech stands studied because all of them surpassed the leaf deficiency threshold. Only other factors such as those of the soil or silvicultural treatment have a decisive effect on the production of the stands studied. Study of the correlations for leaf nitrogen contents and the structural population characteristics explored reveals that leaf nitrogen was only slightly correlated with the mean height of the trees at the plot. 相似文献
14.
G. Y. Chen A. J. Conner Jian Wang A. G. Fautrier R. J. Field 《Molecular biotechnology》1998,10(3):209-216
Energy dissipation (ε) during electroporation was theoretically determined to be ε=0.5CV
0
2 for the various combinations of capacitance (C) and initial voltage (V
0). Experiments on asparagus protoplasts established that electroporation efficiency (EE) and survival rate were directly proportional
to energy dissipation during electroporation. A positive linear relationship exists between energy dissipation per unit volume
and EE, whereas energy dissipation per unit volume and survival rate of protoplasts are related in a negative linear manner.
At the same energy level, longer time constants were more effective at increasing EE. This suggest that energy dissipation
approximating rectangular waveforms is more important than that dissipated as sharply decaying exponential waveforms. With
energy as the key parameter, the optimization of electrical parameters for efficient electroporation is greatly simplified,
is not machine-dependent, and generally applies to all species. 相似文献
15.
Different species of the lichen-forming ascomycete fungus Teloschistes were found to contain group IB introns at position S1506 in the small subunit ribosomal RNA gene. We have characterized the structural organization and phylogeny of the Teloschistes introns Tco.S1506, Tla.S1506, and Tvi.S1506. Common features to all the introns are a small size, a compact RNA structure, and an atypical catalytic ribozyme core sequence motif. Variations in intron sizes, due to sequence extensions in the P1 and P8 loop segments, were observed in different species and isolates. Phylogenetic analyses based on the ITS1-5.8S-ITS2 region as well as the introns show that the Teloschistes S1506 introns represent a distinct evolutionary isolated cluster among the nuclear group I introns. Furthermore, introns from different lineages of Teloschistes villosus appear not strictly vertically inherited probably due to horizontal transfer in one of the lineages. 相似文献
16.
Studies on the genus Acervus from China are reviewed briefly. Six of the seven known species of the genus are currently recorded in this country. Acervus beijingense and A. changchunense are described as new based on morphological features and molecular data, and A. flavidus with minor emendation is added to the Chinese fungus flora. Phylogenetic relationships among four of the seven species of the genus are investigated based on the 28S rDNA sequence analysis. Species of the genus formed a single clade with high bootstrap support. The sequences of A. epispartius forma epispartius and that of A. flavidus obtained from materials in different geographical regions together formed a group with 100% bootstrap support. Ascospore size and shape are important criteria in the taxonomy of the genus and are phylogenetically informative. A dichotomous key to all described species of the genus is provided. 相似文献
17.
Arana L Gangoiti P Ouro A Rivera IG Ordoñez M Trueba M Lankalapalli RS Bittman R Gomez-Muñoz A 《Experimental cell research》2012,318(4):350-360
We previously demonstrated that ceramide 1-phosphate (C1P) is mitogenic for fibroblasts and macrophages. However, the mechanisms involved in this action were only partially described. Here, we demonstrate that C1P stimulates reactive oxygen species (ROS) formation in primary bone marrow-derived macrophages, and that ROS are required for the mitogenic effect of C1P. ROS production was dependent upon prior activation of NADPH oxidase by C1P, which was determined by measuring phosphorylation of the p40phox subunit and translocation of p47phox from the cytosol to the plasma membrane. In addition, C1P activated cytosolic calcium-dependent phospholipase A(2) and protein kinase C-α, and NADPH oxidase activation was blocked by selective inhibitors of these enzymes. These inhibitors, and inhibitors of ROS production, blocked the mitogenic effect of C1P. By using BHNB-C1P (a photolabile caged-C1P analog), we demonstrate that all of these C1P actions are caused by intracellular C1P. It can be concluded that the enzyme responsible for C1P-stimulated ROS generation in bone marrow-derived macrophages is NADPH oxidase, and that this enzyme is downstream of PKC-α and cPLA(2)-α in this pathway. 相似文献
18.
Catapyrenium pyrenaicum is described as new from northern Spain and adjacent France, and the new combinationCatapyrenium velebiticum is made. The new species differs fromC. velebiticum mainly in its laminal pycnidia. Remarks on taxonomy, ecology, and distribution of the species are given. 相似文献
19.
The ionic composition of 38 mineral springs in the province of Granada (Spain), and the distribution of 45 species of nematodes belonging to orders Monhysterida, Araeolaimida, Chromadorida and Enoplida were examined. Water chemistry is used to make two diagrams representing anionic and cationic composition. Diagrams for anionic composition (given the greater variance seen in the springs considered) are used to illustrate the distribution of individual species. The results obtained from species distribution and the correlation between species made it possible to group species which could be associated with springs where each of the anions considered predominated. A greater number of species groups was found to inhabit springs in which chloride concentrations was less than 50% of the total concentration of anions. 相似文献
20.
Fuster V 《Journal of biosocial science》2003,35(1):83-93
The present paper is based on information on marital patterns and reproductive performance (reconstituted families) in the rural community of Los Nogales, Galicia, Spain. Biodemographic data were used to analyse temporal changes and structure of consanguinity in the population, as well as consanguinity versus reproductive success. Of 2347 marriages celebrated between 1871 and 1977, 5.15% were between relatives (up to third degree). The population's inbreeding coefficient was above the Spanish average after 1890, and levels were high during the first part of the 20th century. A possible underestimation of inbreeding coefficients is attributed to the elevated frequency of extramarital births occurring in the Los Nogales population (13.47%). The structures of consanguineous matings, expressed as C22/C33 and C33/C44, turned out to be 0.86 and 0.82 respectively. Regarding migration, before 1920 consanguinity increased, but net migration was negative. In the period 1920-1929 consanguinity began to decrease, prior to maximum emigration. As for reproductive success, information from 1503 reconstituted families shows that complete fertility was slightly higher among consanguineous families despite a greater infant mortality. Lower infertility in consanguineous matings, as well as lower age at marriage and first maternity, could explain the above results. 相似文献