Shedding light on typical species: implications for habitat monitoring

Habitat monitoring in Europe is regulated by Article 17 of the Habitats Directive, which suggests the use of typical species to habitat conservation status. Yet, the Directive uses the term “typical” species but does not provide a definition, either for its use in reporting or for its use in impact assessments. To address the issue, an online workshop was organized by the Italian Society for Vegetation Science (SISV) to shed light on the diversity of perspectives regarding the different concepts of typical species, and to discuss the possible implications for habitat monitoring. To this aim, we inquired 73 people with a very different degree of expertise in the field of vegetation science by means of a tailored survey composed of six questions. We analysed the data using Pearson's Chi-squared test to verify that the answers diverged from a random distribution and checked the effect of the degree of experience of the surveyees on the results. We found that most of the surveyees agreed on the use of the phytosociological method for habitat monitoring and of the diagnostic and characteristic species to evaluate the structural and functional conservation status of habitats. With this contribution, we shed light on the meaning of “typical” species in the context of habitat monitoring.

Syntaxonomical analysis of sandy grassland vegetation dominated by Festuca vaginata and F. pseudovaginata in the Pannonian basin

Festucetum vaginatae Rapaics ex Soó 1929 em. Borhidi 1996 is a characteristic association of the calcareous sandy areas of the Pannonian basin; its dominant grass species is Festuca vaginata. Another typical species of these sandy areas is the newly discovered F. pseudovaginata. The question is whether F. pseudovaginata forms an independent coenotaxa? Our study proved that F. vaginata and F. pseudovaginata populations grow separately and compose different associations. Stands dominated by F. pseudovaginata had a higher species richness and harboured twice as many Festuco-Brometea species compared to the Festucetum vaginatae stands. Diagnostic species of the Festucetum pseudovaginatae association are Festuca pseudovaginata, Colchicum arenarium, Ephedra distachya, Koeleria majoriflora, and Astragalus onobrychis. The number of species, the density of the individuals, and the variability and diversity of the vegetation separated it from the Festucetum vaginatae association; thus, it can be considered an independent endemic association. Festucetum pseudovaginatae has its own differentiating and dominant species: Carex stenophylla, Cynodon dactylon, Eryngium campestre, Kochia laniflora.

Contributions to the Knowledge of Sexual Dimorphism in Liolaemus darwinii (Squamata, Liolaemi-dae) in the Monte Desert of Argentina

The lizard Liolaemus darwinii (Liolaemidae) is a typical species with wide distribution in Monte environments of Argentina. The objective of this study is contribute to knowledge of sexual dimorphism in a population of L. darwinii (Bell, 1843). We evaluated sexual shape variation of the cephalic region through procustes analyses with geometric morphometry. We predict that the heads in males will have differences in shape with respect to females. The results showed significant sexual differences in shape, mainly in the region around the eyes. There were no significant differences in sizes. Geometric morphometry analyses are a useful tool for addressing sexual differences in Monte lizards. This constitutes the first study for the center-west of Argentina in San Juan province that implements these geometric morphometry analyses.

A new pioneer association of detrital substrata of the hilly and low-mountain belts in Central Apennines (Italy)

Plant communities dominated by Petrosedum ser. Rupestria in Italy have always been referred to the Sedo albi-Scleranthetea biennis Br.-Bl. 1955 class. This group of species was also often found more or less abundant in the garrigue and pasture vegetation. Some unusual plant communities dominated by Petrosedum rupestre (L.) P.V.Heath with a conspicuous presence of typical species of scree vegetation were found and sampled in the Abruzzo region, on more or less mobile debris. In order to classify such communities, syntaxonomic, structural, chorological and ecological analyses have been performed. All the Petrosedum ser. Rupestria dominated communities reported in Italy have been compared with the sampled vegetation. A new perennial pioneer association, linked to more or less mobile detrital substrata of the hilly and lower-mountane belts of the calcareous Central Apennines has been here described with the name Linario purpureae-Petrosedetum rupestris. Based on the syntaxonomic analysis, this association has been included in the Linarion purpureae alliance (Scrophulario bicoloris-Helichrysetalia italici order). The Linario-Petrosedetum has been divided into two subassociations: a typical one named petrosedetosum rupestris and a thermophilous one of the lower altitudes named teucrietosum flavi. The study revealed the originality of such communities and their appropriate classification in the Thlaspietea rotundifolii class. This is the first record in Italy of a Petrosedum ser. Rupestria-rich community framed in the scree vegetation class.

Morphology and distribution of Aspergillus niger in the forest soils of Zailiysky Alatau (Kazakhstan)

In the Zailiysky Alatau forests, Aspergillus niger is mosty found in the rhizosphere of Picea schrenkiana,much less – in the rhizosphere of Sorbus tianschanica, Malus sieversii and Juniperus spp. In the rhizosphere ofArmeniaca vulgaris, Crataegus spp. and Populus tremula, the fungus was registered once. The morphological features ofdifferent strains of Aspergillus niger do not vary significantly, however, strains 331b and 346b with a low growth rate arecharacterized by smaller sizes of conidial structures. Aspergillus niger is a typical species in the rhizosphere of spruce inconiferous forests at an altitude of 1700–2100 m above sea level and in the rhizosphere of spruce, rowan and juniper injuniper forests above 2300 m above sea level.

Reaction of micromycetes of leached chernozem on the application of different forms of nitrogen fertilizers

Application of nitrogen fertilizers did not significantly affect the number of micromycetes. The restructuring of the species structure of the mycobiome did not exceed the adaptive zone of “stress” – a change in the frequency of occurrence of typical species. Typical types of leached chernozem micromycetes include deuteromycetes of the genera Aspergillus, Penicillium, Trichoderma, Gliocladium, Humicola, Fusarium, zygomycetes (genus Rhizopus), ascomycetes (genera Thalaromyces, Chaetomium). On average, the density of dominant species of micromycetes increased by 20 %, which indicates the development of the “dominance concentration” of typical species and a decrease in the share of rare and random species of fungi in the mycocomplex. In the experiment variants, the density of Penicillium daleae, P. funiculosum, Fusarium solani, and Aspergillus ustus species increased compared to control. These types of micromycetes are toxigenic and synthesize broad-spectrum mycotoxins (fungicidal, antibiotic, and phytotoxic). As a result, the phytotoxic activity of the soil increased to 7 and 20 % (native soil) and to 19-34 % (initiated microbial community). More pronounced changes were observed in the variant with ammonium sulfate. Thus, nitrogen fertilizers at a dose of N90 cause a “stress” reaction of the mycobiome, an increase in the share of toxigenic species and phytotoxic activity of leached chernozem. With long-term systematic use of nitrogen fertilizers, even in medium doses, it is possible to reduce the potential fertility of chernozems.

Taxonomic notes on the identity of Rungia latior var. anamalayana (Acanthaceae) from Western Ghats, India

Rungia latior Nees var. anamalayana Chandrab. & V. Chandras., examined as part of the revisionary studies on the Acanthaceae of Western Ghats, have shown some taxonomic ambiguity. As the original authors rightly pointed out, the variety ‘does not fit within the circumscription of the typical species’. Based on our recent collections, we also felt that the varietal status is superfluous as the same has got some merits to be recognized as a distinct species. As such the status of the variety has been reassessed; elevated to the specific rank and a new combination has been set, conserving the varietal name as the specific epithet. Accordingly, the species is renamed as Rungia anamalayana (Chandrab. & V. Chandras.) A. Nazarudeen & G. Rajkumar comb. et stat. nov. The distinctive features and alliance of the species is discussed and a full account of the species is presented with illustrations.

Janus dimers from tunable phase separation and reactivity ratios

Janus dimers, as a typical species of anisotropic material, are useful for both theoretical simulations and practical applications.

Population structure and natural diet of Astyanax cf. paranae Eigenmann 1914 a typical species of neotropical headwaters streams

This work describes the habits of individuals of the species Astyanax cf. paranae that inhabit Ribeirão do Ferro, a bedside stream. Overall, 92 specimens were analyzed (53 females and 39 males), and the size ranged from class 4.7-5.7 cm to class 10.7-11.7 cm. The females consisted in the larger portion of the samples, except for classes of 4.7-5.7 and 5.7-6.7 cm. The condition factor between males and females (t = 2.1545; p < 0.05) shows distinguished values, with females having higher averages. Fragments of allochthonous insects and plant matter make up the basis of the species' diet. The study showed that the population of A. cf. paranae is predominantly females and have the highest standard for length and weight, which may favor biological diversity and increased larvae and juveniles, maximizing the chance of individuals reaching adulthood. The species prefers an environment with predominance of rocks and logs, which favors shelters. Its diet comes mostly from the riparian forest, with a high dependence on the allochthonous items, thus, these vegetations are very important for maintaining populations of the species.