Search results for "RARE"
showing 10 items of 2778 documents
Species richness and food web structure of soil decomposer community as affected by the size of habitat fragment and habitat corridors
2005
While most ecologists agree that the effects of fragmentation on diversity of organisms are predominantly negative and that the scale of fragmentation defines their severity, the role of habitat corridors in mitigating those effects still remains controversial. This ambiguousness rests largely on various difficulties in experimentation, a problem partially solved in the present paper by the use of easily manipulated soil communities. In this 2.5-year-long field experiment, we investigated the responses of soil decomposer organisms (from microbes to mesofaunal predators) to habitat fragment size, in the presence or absence of habitat corridors connecting the fragments. The habitat fragments …
Fourier-transform infrared spectroscopic analyses of cellulose from different bacterial cultivations using microspectroscopy and a high-throughput sc…
2016
Abstract Broad application of bacterial cellulose (BC) has led to search for new commercially interesting producers and consequently also for low-cost screening methods to select BC with particular properties. BC produced by four symbiotic Kombucha associations and fourteen acetic acid bacteria isolated from these Kombucha associations were purified by frequent washing with distilled water and pre-treatment with alkali. The obtained native and mercerized BC pellicles were analysed by two common time-saving FT-IR spectroscopy methods—high-throughput screening (HTS) and microspectroscopy. The FT-IR spectra showed traces of microbial cells and acids entrapped between the microfibrils of BC eve…
A new rare species of Oedipoda Latreille, 1829 (Orthoptera: Acrididae) from South Italy
2019
Oedipoda cynthiae n. sp. (Orthoptera: Acrididae: Oedipodinae) is described from Apulia (South Italy). In the past, the same population here considered had been assigned to O. miniata and later to O. charpentieri. Morphological features, biogeographical considerations, and a preliminary molecular analysis confirm that this population must be assigned to a new species, which is described and illustrated here.
Evaluating the presence of microplastics in striped dolphins (Stenella coeruleoalba) stranded in the Western Mediterranean Sea.
2020
Litter is a well-known problem for marine species; however, we still know little about the extent to which they're affected by microplastics. In this study, we analyse the presence of this type of debris in Western Mediterranean striped dolphins' intestinal contents over three decades. Results indicated that frequency was high, as 90.5% of dolphins contained microplastics. Of these microplastics, 73.6% were fibres, 23.87% were fragments and 2.53% were primary pellets. In spite of the high frequency of occurrence, microplastic amount per dolphin was relatively low and highly variable (mean ± SD = 14.9 ± 22.3; 95% CI: 9.58–23.4). Through FT-IR spectrometry, we found that polyacrylamide, typic…
Cetacean strandings and museum collections: A focus on Sicily island crossroads for mediterranean species
2021
The study examined the extent of the cetacean strandings in Italy, with a particular focus on Sicily Island. The paper aimed to contribute to the description of a pattern that contemplates the “regular and rare” cetacean species passage along the Sicilian coast. The estimate of marine cetacean strandings was extrapolated from the National Strandings Data Bank (BDS—Banca Dati Spiaggiamenti) and evaluated according to a subdivision in three coastal subregions: the Tyrrhenian sub-basin (northern Sicilian coast), the Ionian sub-basin (eastern Sicilian coast), and the Channel of Sicily (southern Sicilian coast). Along the Italian coast, more than 4880 stranding events have been counted in the pe…
Sampling effort and information quality provided by rare and common species in estimating assemblage structure
2020
Made available in DSpace on 2020-12-12T01:06:11Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-03-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Academy of Finland Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Reliable biological assessments are essential to answer ecological and management questions but require well-designed studies and representative sample sizes. However, large sampling effort is rarely possible, because it demands large financial resources and time, restricting the number of sites sampled, the duration of the study and the sampling effort at each site. In…
Xyloglucan endotransglucosylase and cell wall extensibility
2011
Transgenic tomato hypocotyls with altered levels of an XTH gene were used to study how XET activity could affect the hypocotyl growth and cell wall extensibility. Transgenic hypocotyls showed significant over-expression (line 13) or co-suppression (line 33) of the SlXTH1 in comparison with the wild type, with these results being correlated with the results on specific soluble XET activity, suggesting that SlXTH1 translates mainly for a soluble XET isoenzyme. A relationship between XET activity and cell wall extensibility was found, and the highest total extensibility was located in the apical hypocotyl segment of the over-expressing SlXTH1 line, where the XET-specific activity and hypocotyl…
Response of soil mites (Acari, Mesostigmata) to long-term Norway spruce plantation along a mountain stream
2018
During the nineteenth and twentieth centuries, coniferous monocultures were introduced, replacing natural broadleaved forests in Central Europe, mainly for economic benefits. In the mountains, Norway spruce [Picea abies (L.) H. Karst] was introduced in large areas previously covered with beech forests and also in natural riverside habitat corridors such as river valleys, despite its negative impact on the soil environment by e.g. organic matter accumulation, decrease of soil pH and changes in C/N ratio. We aimed to check how long-term Norway spruce plantations affect species richness and diversity of soil mites along a mountain river in former mixed and broadleaved forests. The study, based…
Post-fire beetle succession in a biodiversity hotspot: Białowieża Primeval Forest
2020
Abstract Fires can heavily impact forest ecosystems but fire consequences for animal communities at burned and control sites are rarely investigated in natural forests. Here we present a 10-year study of post-fire beetle succession in natural ecosystem of Bialowieza Primeval Forest, Poland, being a hotspot for beetle fauna. We sampled beetles at burned and unburned (control) sites and compared local alpha and regional gamma diversity between treatments and over time. In total, 27,958 individuals belonging to 630 beetle species were recorded. Average species richness (alpha diversity) and density per sample was higher in burned forest than in control sites, and this difference was especially…
An Enigmatic European Harvestman (Opiliones): New Record and Redescription of Dicranopalpus larvatus (Canestrini, 1874)
2019
Dicranopalpus larvatus is redescribed based on type material. Recent first findings of this rare species on Sardinia enable to provide the essential morphological characters. Original drawings are presented with emphasis on penial and pedipalpal morphology. Dicranopalpus larvatus is a small, short-legged, ground-dwelling species endemic to Italy that matures in autumn and winter and has completed its life cycle in April. Additional information on phenology, life cycle, ecology, distribution and systematic position is given.