Search results for "GRAS"
showing 10 items of 727 documents
Classification of steppe vegetation in the eastern Pamir Alai and southwestern Tian-Shan Mountains (Tajikistan, Kyrgyzstan)
2018
Aims: To complete the syntaxonomical scheme for the steppe vegetation of the montane and alpine zones in the Pamir Alai and southwestern Tian-Shan Mountains in Tajikistan and Kyrgyzstan with some remarks on its environmental predictors. Location: Tajikistan and Kyrgyzstan. Methods: A total of 274 relevés were sampled in 2016–2017 using the seven-degree cover-abundance scale of Braun-Blanquet. They were classified with modified TWINSPAN with cut-off levels of 0%, 5%, 10% and 25% and total inertia as a measure of cluster heterogeneity. Diagnostic species were identified using the phi coefficient as a fidelity measure. Detrended correspondence analysis (DCA) and canonical correspondence analys…
Reference growth charts for Posidonia oceanica seagrass: An effective tool for assessing growth performance by age and depth
2016
Abstract Growth performance of rhizomes has become among the most used descriptors for monitoring Posidonia oceanica seagrass dynamics and population status. However, ability to detect any change of growth in space or in time is often confounded by natural age-induced decline. To overcome this problem, we have produced reference growth charts, which in other areas are universally recognized as a very powerful tool for comparing growth of living beings during their ontogeny. Reference growth charts involving different P. oceanica growth performance measures (speed of growth and primary production of rhizomes) have been built using proper statistical frameworks (GLMM, Segmented and Quantile R…
Impacts of arbuscular mycorrhizal fungi on nutrient uptake, N2 fixation, N transfer, and growth in a wheat/faba bean intercropping system
2019
Arbuscular mycorrhizal fungi (AMF) can play a key role in natural and agricultural ecosystems affecting plant nutrition, soil biological activity and modifying the availability of nutrients by plants. This research aimed at expanding the knowledge of the role played by AMF in the uptake of macro- and micronutrients and N transfer (using a 15 N stem-labelling method) in a faba bean/wheat intercropping system. It also investigates the role of AMF in biological N fixation (using the natural isotopic abundance method) in faba bean grown in pure stand and in mixture. Finally, it examines the role of AMF in driving competition and facilitation between faba bean and wheat. Durum wheat and faba bea…
Short-term response of the slow growing seagrass Posidonia oceanica to simulated anchor impact
2007
Experimental evaluations about the impact of anchors of small vessels have previously shown that each anchoring can on average damage up to six shoots of Posidonia oceanica, removing small amount of biomass and, at the same time, interrupting continuity among shoots. The aim of the paper was to investigate the response of P. oceanica to different damage intensity at two levels of substrata compactness. Three treatments were considered: control (no damage); low damage (simulated anchor damage by three strokes of a hoe); and high damage (six strokes). Disturbance was higher where the substratum was highly penetrable and after one year significant variation was observed among treatments for bo…
Taxonomic and Phylogenetic Investigations on Psoralea Acaulis (Psoraleeae: Fabaceae) With the Description of A New Genus Kartalinia
2018
Salmeri, Cristina/0000-0002-5261-590X WOS: 000454161300003 Psoralea acaulis Hoffm. is a very peculiar and taxonomically isolated species of the tribe Psoraleeae, occurring in the Caucasian territories. Currently, this tribe contains 10 distinct genera, well differentiated morphologically. Due to some morphological similarities, P. acaulis was attributed to Bituminaria Heist ex Fabr., a genus with a Mediterranean-Macaronesian distribution. However, as it has many characters, some of which are autapomorphic, it was assigned its own subgenus: Christevenia Barneby ex C. H. Stirt. In light of detailed cladistic and phylogenetic analyses, this arrangement is taxonomically questionable and rather …
Taxonomic investigations on Psoralea palaestina (Fabaceae), a critical species of Mediterranean flora
2016
Psoralea palaestina is a critical and unappreciated species described from Palestinian territories, and currently treated as synonym of P. bituminosa, nowadays known as Bituminaria bituminosa. Nomenclatural investigations allowed to ascertain that it was validly described for the first time by Bassi (1768) and not by Gouan (1773), as previously thought. Extensive taxonomic investigations revealed that this very peculiar legume is morphologically well differentiated from the other allied known species. Therefore, it has to be properly treated at specific level and transferred to the genus Bituminaria, thus proposing a new combination: Bituminaria palaestina. Based on literature, herbarium an…
Grass leaves as potential hominin dietary resources
2018
Discussions about early hominin diets have generally excluded grass leaves as a staple food resource, despite their ubiquity in most early hominin habitats. In particular, stable carbon isotope studies have shown a prevalent C4 component in the diets of most taxa, and grass leaves are the single most abundant C4 resource in African savannas. Grass leaves are typically portrayed as having little nutritional value (e.g., low in protein and high in fiber) for hominins lacking specialized digestive systems. It has also been argued that they present mechanical challenges (i.e., high toughness) for hominins with bunodont dentition. Here, we compare the nutritional and mechanical properties of gra…
Reuse of urban-treated wastewater from a pilot-scale horizontal subsurface flow system in Sicily (Italy) for irrigation of Bermudagrass (Cynodon dact…
2016
Constructed wetlands (CW) are one of the most important biological technology for the treatment and reuse of wastewaters. The aim of this study was to evaluate the reuse of treated wastewater (TWW) from CW for irrigation of Bermudagrass turf (Cynodon dactylon (L.) Pers.) and assess the effects of TWW on the biometric and qualitative parameters of the turfgrass and on chemical–physical soil properties. The research was carried out in Sicily (Italy) in a pilot-scale horizontal subsurface flow system which was fed with urban TWW following secondary treatment from an activate sludge wastewater treatment plant. The pilot-system included three separate parallel units. The outflow TWW flowed downh…
Does an ant-dispersed plant, Viola reichenbachiana, suffer from reduced seed dispersal under inundation disturbances?
2008
Many plant species use ants as seed dispersers. This dispersal mode is considered to be susceptible to disturbances, but the effect of natural, small-scale disturbances is still unknown. We investigated how small-scale disturbances due to inundation affect seed dispersal in Viola reichenbachiana, a dominant myrmecochorous herb in riparian forests. Inundation disturbances were high in depressions and low on hillocks of the forest floor. We found that V reichenbachiana was similarly abundant at highly and less disturbed sites, contrary to other, non ant-dispersed species. We also found that the motivation of ants to disperse seeds was higher at highly disturbed sites. Nevertheless, the number…
Seedling growth of a native ( Ampelodesmos mauritanicus ) and an exotic ( Pennisetum setaceum ) grass
2016
Scarce information is available on the biological reasons why a small subset of introduced species can effectively establish within novel ecosystems. A comparison of early growth traits can help to explain the better performance of alien invasive species versus native co-occurring species. In one year-long experiment, we compared the early life stages of Ampelodesmos mauritanicus (Poir.) Dur. & Schinz (Amp), a native perennial Mediterranean grass, and Pennisetum setaceum (Forssk.) Chiov (Penn), an emerging invader grass in sub-arid and Mediterranean-climate areas. The Penn seedlings grew significantly faster and were approximately 2.5 times taller than the Amp seedlings, reaching a fina…