Search results for "Systematics"
showing 10 items of 6702 documents
Long-term dynamics of Collembola in a pine forest ecosystemProceedings of the Xth international Colloquium on Apterygota, České Budějovice 2000: Apte…
2002
Summary Biomonitoring data on soil Collembola collected over a six year period (1992-1997) in Scots pine ( Pinus sylvestris L.) forest in the Northern Vidzeme Biosphere Reserve, northern Latvia, are analysed. Monitoring was conducted in three plots: young (30-40 years), middle-aged (50—70 years), and old (150—200 years) pine stands. Sampling was performed once a year, in late August or early September, according to a systematic sampling scheme. One hundred soil cores (5 cm 2 × 10 cm) were taken within each plot every year, Collembola were extracted from the cores by using a modified high gradient extractor. During the monitoring period, there was a tendency of climate warming between 1992 a…
Why are wasps so intimidating: field experiments on hunting dragonflies (Odonata: Aeshna grandis)
2003
Abstract The mechanisms of aposematism (unprofitability of prey combined with a conspicuous signal) have mainly been studied with reference to vertebrate predators, especially birds. We investigated whether dragonflies, Aeshna grandis, avoid attacking wasps, Vespula norwegica, which are an unprofitable group of prey for most predators. As a control we used flies that were painted either black or with yellow and black stripes. The dragonflies showed greater aversion to wasps than to flies. Black-and-yellow-striped flies were avoided more than black ones, suggesting that aposematic coloration on a harmless fly provides a selective advantage against invertebrate predators. There was no signifi…
Allium therinanthum (Amaryllidaceae), a new species from Israel
2014
Allium therinanthum, a new species of A. sect. Codonoprasum, is described and illustrated from southern Mt. Hermon (Israel). It is a late-flowering diploid species (2n = 16), growing on calcareous substrates of the mountain belt. It is a narrowly distributed geophyte, showing morphological relationships mainly with A. tardiflorum, a typical autumnal species also occurring in Israel within the pinewoods of Mt. Carmel. The morphology, karyology, leaf anatomy, ecology, conservation status and taxonomical relations are examined for both species. A taxonomic comparison with the most allied late flowering species of the sect. Codonoprasum is provided.
Types of names of Orobanche taxa described from North Africa
2013
In the framework of the revision of the genus Orobanche (including Phelipaea) in the Mediterranean area, the original material for 31 names of new taxa described from North Africa by Ball, Battandier, Forsska°l, Maire (partly with Emberger and Jahandiez), Persoon, Poiret and Pomel has been analysed. Typification is discussed, and where necessary types are designated. Accepted names and synonyms of the recognized taxa are given. Three species are illustrated, and one new combination (O. inexspectata) is proposed.
Calongea prieguensis (Pezizaceae), a rare hypogeous ascomycetes in Europe
2019
Calongea prieguensis is a rare hypogeous ascomycetes with fragmented distribution in Europe. The taxonomy, ecology and distribution of this species are reported in this short note. The new locality from northen Sicily widens the area of distribution of C. prieguensis in Europe.
Isoëtes todaroana (Isoëtaceae, Lycopodiophyta), a New Species from Sicily (Italy)
2009
Isoetes todaroana, a new species from western Sicily (Italy), is described. Morpholog- ical, anatomical and ecological characters are given. The main differential characters are the presence of only two leaf air chambers, rather than four as in all other known species of the genus, and the shape of the scales, which have two lateral rounded lobes and one central spine-like lobe, together with its peculiar calcophilic habitat. So far, the species is known from a single locality.
A new synonym and a new combination in Stipa aliena Keng (Poaceae: Stipa sect. Regelia)
2015
Stipa section Regelia comprises three species occurring in mountainous areas of Central Asia. One of them, S. smithii , was described by Martinovský in 1970, but the taxon has been overlooked in later taxonomical studies. The species was described with two varieties, var. smithii and var. macrocarpa . As a result of our taxonomical studies, we find the typical variety of the taxon to be conspecific with Stipa aliena , and propose that the second one be recognized as Stipa aliena var. macrocarpa comb. nov. Remarks on species belonging to section Regelia and micromorphological patterns of their lemma morphologies are discussed. A key to species close to S. aliena is provided.
Restrictive mate choice criteria cause age-specific inbreeding in female black grouse, Tetrao tetrix
2012
Inbreeding is generally rare in large, natural populations yet mate choice often appears to be random with respect to kinship. This suggests that the risks of inbreeding may be small because passive mechanisms of inbreeding avoidance, for example dispersal, are effective at lowering inbreeding risk. Previous theoretical and empirical studies have assumed that the risks of inbreeding are constant over an individual’s life span, but in the lek-breeding black grouse, inbreeding increases with female age. To determine whether inbreeding avoidance mechanisms are also age dependent, we generated four null models of random mate choice ranging from complete randomness to more biologically realistic…
Myxosporea parasites in roach, Rutilus rutilus (Linnaeus), from four lakes in central Finland
1991
Ten myxosporean species belonging to three families were found in roach, Rutilus rutilus (Linnaeus), obtained in 1985 and 1986 from four lakes in central Finland which are connected to each other, but differ in water quality. One of the lakes is polluted by paper and pulp mill effluent, two are eutrophic and one is oligotrophic and still in its natural state. Eight species were found in all the lakes. The most common species were Myxidium rhodei Leger, 1905, Myxobolus muelleri Butschli, 1882 and Myxobolus pseudodispar Gorbunova, 1936 with prevalences varying between 66–80, 16–31 and 32–59%, respectively, in the four lakes. The largest difference in myxosporean prevalence between lakes was f…
Body size and mating strategies in the simultaneous hermaphrodite Oxynoe olivacea (Mollusca, Opisthobranchia, Sacoglossa).
2004
Summary 1To better understand the role and importance of body size in hermaphroditic mating system theory, the mating behaviour of the shelled sacoglossan Oxynoe olivacea was studied. This simultaneous hermaphrodite exhibits bilateral and unilateral sperm transfer and thus it is particularly suitable for studies on hermaphrodite sexual conflict. 2In this study three hypotheses on body size were tested: that O. olivacea partner size has an effect on (i) mating mode choice, (ii) duration of mating modes, and (iii) choice of sexual role. Furthermore, we tested Charnov's hypothesis that in O. olivacea, like many simultaneous hermaphrodites, a sexual conflict exists and the male role is preferre…