Search results for "Rete"
showing 10 items of 3470 documents
Subaerial exposure and drowning processes in a carbonate platform during the Mesozoic Tethyan rifting: The case of the Jurassic succession of Western…
2016
Abstract The Liassic carbonate platform succession outcropping at Monte Maranfusa (central Western Sicily) consists of a shallowing-upward sequence of peritidal carbonates, with Jurassic to Paleogene pelagic limestone and siliciclastic Tertiary covers above. The cyclic sequences of subtidal wackestones/packstones, intertidal microcrystalline carbonates with bird's-eye pores, and supratidal bioclastic grainstones are interbedded with dark layers of the following composition: 1) dark-gray, compact, and well-cemented limestone with blackish clasts, interpreted as calcretes (a type of carbonate soil) and 2) reddish calcite laminae, deformed by elongated cavities, filled with vadose silt, interp…
Do small protected habitat patches within boreal production forests provide value for biodiversity conservation? : A systematic review protocol
2019
Background Forest harvesting is the main driver of habitat degradation and biodiversity loss in forests of the boreal zone. To mitigate harmful effects, small-scale habitats with high biodiversity values have been protected within production forests. These include woodland key habitats, and other small-scale habitat patches protected by voluntary conservation action. This article describes a protocol for a systematic review to synthesize the value of small habitat patches left within production landscapes for biodiversity. The topic for this systematic review arose from a discussion with the Finnish forestry sector and was further defined in a stakeholder workshop. Research question: Do sma…
Floral scent in a sexually deceptive Ophrys orchid: from headspace collections to solvent extractions
2018
Sexually deceptive orchid flowers use visual, tactile and olfactory cues of female insects in order to attract males of one or a few closely related species as pollinators. Ophrys L. is the most species-rich genus of sexually deceptive orchids in the Mediterranean Basin. Despite Ophrys pollinated by Andrena male bees use alkanes and mainly alkenes with specific double-bond positions as key signals that trigger pseudocopulatory behavior, some volatile organic compounds (VOCs) with low molecular weight were found as long-range attractants non-eliciting copulatory behavior. Since floral scents in Ophrys have been extensively studied by solvent extractions here we aimed to understand which flor…
Exploration of the Oxynoticeratidae ornamental morphospace using the discrete cosine transform (DCT) to analyze rib patterns.
2006
The discrete cosine transform (DCT) is a Fourier-related transform widely used in signal processing and well suited to analyzing open outlines such as ammonite ribs. The method is applied here to depict and decipher the ribbing morphospace of a large group of Lower Jurassic ammonites composed of the Oxynoticeratidae and their close ancestors. Because they are clearly associated with buoyancy and/or swimming ability, the usually clearly involute, comparatively smooth and compressed shells of these ammonites may well be misleading taxonomic markers. In this context, quantitative analysis of the ribbing pattern using the DCT may significantly improve our perception of the ornamental patterns e…
Bryophyte Species Richness on Retention Aspens Recovers in Time but Community Structure Does Not
2014
Green-tree retention is a forest management method in which some living trees are left on a logged area. The aim is to offer ‘lifeboats’ to support species immediately after logging and to provide microhabitats during and after forest re-establishment. Several studies have shown immediate decline in bryophyte diversity after retention logging and thus questioned the effectiveness of this method, but longer term studies are lacking. Here we studied the epiphytic bryophytes on European aspen (Populus tremula L.) retention trees along a 30-year chronosequence. We compared the bryophyte flora of 102 ‘retention aspens’ on 14 differently aged retention sites with 102 ‘conservation aspens’ on 14 d…
Combination of the OSA process with thermal treatment at moderate temperature for excess sludge minimization
2019
Abstract This study investigated the chance to couple the conventional Oxic Settling Anaerobic (OSA) process with a thermic treatment at moderate temperature (35 °C). The maximum excess sludge reduction rate (80%) was achieved when the plant was operated under 3 h of hydraulic retention time (HRT). Compared with the conventional OSA system, the thermic treatment enabled a further improvement in excess sludge minimization of 35%. The observed yield coefficient decreased from 0.25 gTSS gCOD−1 to 0.10 gTSS gCOD−1 when the temperature in the anaerobic reactor was increased to 35 °C, despite the lower HRT (3 h vs 6 h). Moreover, the thermic treatment enabled the decrease of filamentous bacteria,…
Application of a new protocol to evaluate the benthic impacts of aquaculture: Colonization of experimental units for monitoring by polychaeta
2019
A range of different protocols and indices have been developed in recent years for the definition of Environmental Quality Standards in aquaculture. However, it can be difficult to compare these protocols or indices between different regions or different habitats due to spatial heterogeneity at different scales. We carried out a field study to estimate the effectiveness of experimental units (sediment-filled trays) as an environmental management tool. The experimental units were filled with two different sediments - sand and mud - and placed underneath two fish farm facilities for one month. Using polychaetes to assess the ecological status, AMBI and multidimensional analysis showed clear r…
Performance of a membrane-coupled high-rate algal pond for urban wastewater treatment at demonstration scale
2020
[EN] The objective of this study was to evaluate the performance of an outdoor membrane-coupled high-rate algal pond equipped with industrial-scale membranes for treating urban wastewater. Decoupling biomass retention time (BRT) and hydraulic retention time (HRT) by membrane filtration resulted in improved process efficiencies, with higher biomass productivities and nutrient removal rates when operating at low HRTs. At 6 days of BRT, biomass productivity increased from 30 to 66 and to 95 g.m(-3).d(-1) when operating at HRTs of 6, 4 and 2.5 days, respectively. The corresponding nitrogen removal rates were 4, 8 and 11 g N.m(-3).d(-1) and the phosphorous removal rates were 0.5, 1.3 and 1.6 g P…
Reciprocal extrapolation of species distribution models between two islands – Specialists perform better than generalists and geological data reduces…
2020
Abstract This study aims to test the extrapolation effects of species distribution models (SDM) using three groups of predictor variables: climate, relief and geology (bedrock type). We highlight potential ecological differences for selected taxa, regarding both generalists and specialists in terms of edaphic conditions. We used distributional data of 12 woody species shared by two large Mediterranean islands (Crete and Sicily) to calibrate Maxent models of their potential distribution. We trained models with data from Crete and extrapolated to Sicily and vice versa. We tested ten proxies for the three variable groups and compared AUC values as a measure of model performance. Extrapolation …
Classification of European and Mediterranean coastal dune vegetation
2018
Aims: Although many phytosociological studies have provided detailed local and regional descriptions of coastal dune vegetation, a unified classification of this vegetation in Europe and the Mediterranean Basin has been missing. Our aim is to produce a formalized classification of this vegetation and to identify the main factors driving its plant species composition at a continental scale. LocationAtlantic and Baltic coasts of Europe, Mediterranean Basin and the Black Sea region. - Methods: We compiled a database of 30,759 plots of coastal vegetation, which were resampled to reduce unbalanced sampling effort, obtaining a data set of 11,769 plots. We classified these plots with TWINSPAN, int…