Search results for "Systematics"
showing 10 items of 6702 documents
Distribution of graminoids in open habitats in Tajikistan and Kyrgyzstan
2022
Aims: Landscapes of Middle Asia are exposed to human influence due to long-lasting pastoral tradition, and now are largely dominated by non-forest vegetation. Graminoids perform key ecosystem functions, and constitute an important feed source for livestock. We studied the distribution patterns of graminoids cover under climatic and grazing pressure gradients in different open vegetation types. Study area: Tajikistan, Kyrgyzstan. Methods: 1,525 vegetation plots representing five open vegetation types (mires, salt marshes, tall-forb communities, pseudosteppes and steppes) were extracted from the Vegetation of Middle Asia Database. We assessed the relative cover of graminoid species in each ve…
Early Palaeozoic palaeobiogeography and palaeoecology of stylophoran echinoderms
2007
44 pages; International audience; Stylophorans (cornutes, mitrates) represent one of the most diverse classes of Cambro-Ordovician echinoderms. They were freeliving, benthic, non-radiate forms, closely related to asterozoans and crinoids. Taphonomic, sedimentological, and palaeosynecological data provide useful information on key aspects of stylophoran palaeoecology. Such a combined approach suggests that the rarity of stylophorans in proximal environments (above storm-wave base) was probably original and does not exclusively result from the possession of a loosely articulated polyplated calcitic test. Conversely, stylophorans were relatively abundant in deeper settings (below storm-wave ba…
The hyo-laryngeal complex of Tarsius bancanus (Mammalia, Primates): a developmental and phylogenetic aspect
2008
The present approach reconstructed the hyo-laryngeal complex of fetal Tarsius bancanus by using the AMIRA 3.1.1 software. Our work fills a gap of ontogenetic research as this region has only been superficially described for an adult specimen representing the same genus. Furthermore, based on 51 characters we conducted several cladistic analyses considering the "Prosimii"/Haplorrhini-debate. Some anatomical information has been taken from the literature. Macclade© 4.06 was used in order to measure TL-, CI-, and RC-values of these two competing hypotheses, however, resulting in equal support. A PAUP© 4.02b parsimony analysis based on the Haplorrhini-hypothesis showed a significant bootstrap-v…
Epidemiology of tattoo skin disease in bottlenose dolphins Tursiops truncatus from the Sado estuary, Portugal
2003
We report on the epidemiology of tattoo disease in a community of bottlenose dolphins Tursiops truncatus from the Sado estuary, Portugal. The presence of tattoos (T++) and tattoo-like (T+) lesions was examined in 586 photographic records of 35 dolphins taken from 1994 to 1997. Images were rated into 3 categories: good (GI), average (AI) and poor (PI). Dolphins positive for T++ lesions were observed in 19 GI. Dolphins with T+ lesions were seen in 39 GI, 23 AI and 6 PI. For statistical analysis the dolphins were divided into 2 age classes (immature and adult) and the data grouped into 2 periods (1994-1995 and 1996-1997). Minimum prevalence of T++ lesions in 32 dolphins was 21.9% in 1994-1995 …
Airborne birch pollen in Poland and Latvia in the light of data obtained from aerobiological monitoring and tauber traps in relation to mean air temp…
2012
Birch pollen contains allergens belonging to those with the strongest allergenic properties. In order to trace pollen season patterns of this taxon and pollen annual sums at a wider regional scale, cooperation was established with the University of Latvia in Riga (Latvia). A comparison of the results obtained in the years 2003-2008 in Lublin and in Riga, using volumetric samplers, shows that there was a similar trend in the abundance of birch pollen. The highest sums were noted at both sites in 2003. In all the study years, more birch pollen grains were recorded in Lublin than in Riga, on the average by 7110. The birch pollen seasons started earlier in Lublin than in Riga, on the average by…
A new species of Agrostis (Gramineae) in the A. alpina complex
2000
Abstract A new species of Agrostis L. ( A. barceloi ) is described from the northern mountains of Mallorca (Balearic Islands). The new taxon belongs to sect. Agrostis and is mainly related to A. alpina Scop. and A. schleicheri Jord. & Verl. on morphological grounds. However, A. barceloi differs from A. alpina by its narrowly-lanceolate inflorescence, with panicle branches erect during and after anthesis, non-scabrid leaves, and by smaller lemmas and others. The new species is distinguished from A. schleicheri by the smaller spikelets, lemma, palea, and anthers. In addition, A. barceloi is tetraploid (2 n =28), and differs cytologically from the diploid A. alpina (2 n =14) and the hexaploid …
<p><strong>Typification of the name <em>Eryngium siculum </em>(Apiaceae)</strong></p>
2020
As part of an ongoing study on the names of vascular plants described from Sicily (e.g., Di Gristina et al. 2012, Domina et al. 2014, 2016, Di Gristina et al. 2017, Domina et al. 2017a, 2017b, Scafidi & Domina 2019, Di Gristina et al. 2020), a nomenclature study of the name Eryngium siculum Lojacono-Pojero (1906: 294) (Apiaceae Lindl.), which appears to be yet untypified (see Domina et al. 2014, Peruzzi et al. 2015), is here presented. The present study, which deals with the untypified name Eryngium siculum Lojacono-Pojero (1906: 294), falls within the researches promoted by the Italian Botanical Society aimed to recognize and typify all the taxa described from Italy, in order to increa…
Chemosystematic study on leaf volatile compounds of Saxifraga L. series Ceratophyllae (Saxifragaceae)
1999
Extracts from 65 samples corresponding to 13 species and 18 taxa of Saxifraga series Ceratophyllae s. l. were analysed by GC and GC/MS. This paper provides the first chemosystematic information on volatile composition of a seemingly natural group in the Saxifragaceae. Diterpenoids and n-alkanes appear to be the most important constituents and some of them are associated to different species and taxonomic series. The application of multivariate analysis techniques to GC and GC/MS data has allowed the classification of samples into two groups, corresponding approximately to the series Ceratophyllae s. str. and Pentadactyles, previously proposed on the basis of morphological and cytotaxonomica…
Three new Spanish species of Biscutella L. (Brassicaceae) and remarks on B. valentina (L.) Heywood
2000
Abstract Three new species are described in Biscutella sect. Biscutella from the central-eastern mountains of the Iberian Peninsula B. bilbilitana Mateo & M.B. Crespo, B. segurae Mateo & M.B. Crespo, and B. conquensis Mateo & M.B. Crespo. They are characterized morphologically, ecologically and chorologically. Data separating them from B. valentina (L.) Heywood, a taxon to which they sometimes have been referred, are also reported.
Cost-Efficiency of Decaying Wood as a Surrogate for Overall Species Richness in Boreal Forests
2006
Decaying wood is one of the most important elements for species richness in boreal forests. We tested how well reserve selection based on the amount and quality of decaying wood results in a representation of four ecologically different taxa (beetles, birds, wood-inhabiting fungi, and vascular plants). We also compared the cost-efficiency of the use of dead-wood indicators with comprehensive species inventory. Our database included 32 seminatural old-forest stands located in northern Finland. Decaying wood was a relatively good indicator of saproxylic species but not overall species richness. Even though dead wood did not reflect accurately overall species richness, our results indicated th…