Search results for "Specie"
showing 10 items of 4389 documents
Soil properties determine the elevational patterns of base cations and micronutrients in the plant-soil system up to the upper limits of trees and sh…
2018
Abstract. To understand whether base cations and micronutrients in the plant–soil system change with elevation, we investigated the patterns of base cations and micronutrients in both soils and plant tissues along three elevational gradients in three climate zones in China. Base cations (Ca, Mg, and K) and micronutrients (Fe, Mn, and Zn) were determined in soils, trees, and shrubs growing at lower and middle elevations as well as at their upper limits on Balang (subtropical, SW China), Qilian (dry temperate, NW China), and Changbai (wet temperate, NE China) mountains. No consistent elevational patterns were found for base cation and micronutrient concentrations in both soils and plant tissu…
Brown bear behaviour in human-modified landscapes: The case of the endangered Cantabrian population, NW Spain
2018
Large carnivores are recolonizing parts of their historical range in Europe, a heavily modified human landscape. This calls for an improvement of our knowledge on how large carnivores manage to coexist with humans, and on the effects that human activity has on large carnivore behaviour, especially in areas where carnivore populations are still endangered. Brown bears Ursus arctos have been shown to be sensitive to the presence of people and their activities. Thus, bear conservation and management should take into account potential behavioural alterations related to living in human-modified landscapes. We studied the behaviour of brown bears in the Cantabrian Mountains, NW Spain, where an en…
Studies on the genus Capparis L. (Capparaceae) in Lao PDR. V: A new species from limestones of the Luang Prabang Province
2020
A new species of Capparis L., C. lianosa Fici & Souvannakhoummane, is described and illustrated from limestones of the Muang Ngoi District, Luang Prabang Province, in northern Lao PDR. Th e new species, belonging to Capparis sect. Monostichocalyx Radlk., is related to C. zeylanica L., differing in several characters as the shorter stipular thorns, the leaves with apex acuminate, the shorter, glabrous or glabrescent gynophore and the flattened stigma.
Notes on the distribution, ecology and conservation status of two very rare sedges (Carex, Cyperaceae) rediscovered in Sicily (Italy)
2017
New data on the geographical distribution and ecology of two rare taxa of Carex collected in the area of the Nebrodi Mountains (Sicily) are provided; the Sicilian populations of both taxa are at the border of their respective ranges, and their regional distribution is still poorly known. The new population of Carex x boenninghausiana reported here confirms the presence of this hybrid in Sicily, but at the same time it represents the only known population currently occurring in Italy; in fact, the other - so far only - known Italian population is considered extinct. The second report concerns Carex grioletii, recently considered doubtful for the Sicilian flora, whose new population here repo…
Standardization proposal for the mapping of Caulerpa taxifolia expansion in the Mediterranean sea
1999
Fourteen years after the first observation of Caulerpa taxifolia (Valh) C. Agardh in the northwestern Mediterranean Sea, this green alga of tropical origin is now present in five countries (Spain, France, Monaco, Italy and Croatia). By the end of 1997, more than 46 km(2), at depths of between 0 and 50 m, were found to be affected by this expansion. A standardization of the cartographic procedure is proposed here. Such a standardization is necessary to compare maps produced by various organizations from different countries. For a given independent station, it is based on the definition of three levels of colonization:Level I refers to a station where one or several colonies less than 100 m a…
Revision of the Afrotropical genus Leiodontocercus (Orthoptera, Tettigoniidae, Phaneropterinae) with a description of four new species
2020
Specimens belonging to the genus Leiodontocercus are rare or even absent in natural history museum collections; this is likely due to at least two reasons, notably, their relatively small size, and, the sheer difficulty in finding them in dense Afrotropical forests. Until recently, three species from less than fifteen specimens were known from this genus, whose identification relied on a singular diagnostic character, that is, the shape of the male cerci. The present contribution is based on the examination of thirty specimens collected from various countries, ranging from central to west Africa; apart from the male cerci, a second diagnostic character – the stridulatory file – is used to d…
Taxonomic remarks on Scilla anthericoides Poir. (Asparagaceae, Scilloideae), a neglected species from Algeria
2016
Scilla anthericoides is a neglected name traditionally considered as Urginea maritima var. anthericoides. Based on recent field observations of living plants completed by karyological analyses, we promote again this taxon at species rank, under the genus Charybdis. It differs from other species of Charybdis maritima aggregate by many characters of flowers, fruits, bulbs, leaves and by ploidy level. It is endemic to the regional hotspot Kabylias-Numidia-Kroumiria in north-eastern Algeria. It is a threatened species that has been assessed as vulnerable.
Establishing laboratory cultures and performing ecological and evolutionary experiments with the emerging model speciesChironomus riparius
2019
Chironomus riparius is a well‐established model organism in various fields such as ecotoxicology and ecology, and therefore, environmental preferences, ecological interactions and metabolic traits are well‐studied. With the recent publication of a high‐quality draft genome, as well as different population genetic parameters such as mutation and recombination rate, the species can be used as an alternative to the Drosophila models in experimental population genomics or molecular ecology. To facilitate access to this promising experimental model species for a wider range of researchers, we describe experimental methods to first create and sustain long‐term cultures of C. riparius and then use…
The light-harvesting system of Euglena gracilis during the cell cycle
1989
The apoproteins of the light-harvesting chlorophyll-protein complexes LHCI and CP29 (apparent molecular weights of 27 kDa and 29 kDa, respectively) of Euglena gracilis were identified immunologically. Both complexes are present in the thylakoids of autotrophically cultured Euglena cells during the whole cell cycle. The relative amount of each apoprotein tends to increase towards the end of the cell cycle. The light-harvesting chlorophyll-protein complex of photosystem II, LHCII, of E. gracilis contains chlorophyll a, chlorophyll b, neoxanthin, diadinoxanthin and beta-carotene. Its chlorophyll a/b ratio is about 1.7 during the whole cell cycle. About 9 h after cell division the ratio of diad…
Tamarix arborea var. arborea and Tamarix parviflora: Two species valued for their adaptability to stress conditions.
2016
The choice of stress resistant and highly adaptable species is a fundamental step for landscaping and ornamental purposes in arid and coastal environments such as those in the Mediterranean basin. The genus Tamarix L. includes about 90 species with a high endurance of adversity. We investigated the water relations and photosynthetic response of Tamarix arborea (Sieb. ex Ehrenb.) Bge. var. arborea and T. parviflora DC. growing in an urban environment. Both species showed no evidence of drought or salt stress in summer, and appeared to follow two strategies with T. arborea var. arborea investing in high carbon gain at the beginning of the summer, and then reducing photosynthetic activity at t…