scholarly journals Η χλωρίδα και η βλάστηση του όρους Σαϊτά (Βόρεια Πελοπόννησος)

2021 ◽  
Author(s):  
Διονύσιος Μέρμυγκας
Keyword(s):  
Bromus Hordeaceus

Βασικός στόχος της διατριβής είναι η καταγραφή της χλωρίδας της και η φυτοκοινωνιολογική μελέτη και καταγραφή των μονάδων βλάστησης του όρους Σαϊτά. Το όρος Σαϊτάς βρίσκεται στη βόρεια Πελοπόννησο και διοικητικά ανήκει στις περιφέρειες Δυτικής Ελλάδας και Πελοποννήσου. Το μεγαλύτερο μέρος του όρους καλύπτεται από ασβεστολιθικούς σχηματισμούς. Στην περιοχή έρευνας του όρους Σαϊτά διακρίνονται δύο γεωτεκτονικές ζώνες ή ενότητες: η ζώνη της Πίνδου και η ζώνη της Τρίπολης. Tο βιοκλίμα στο μεγαλύτερο τμήμα της περιοχής μελέτης έχει ασθενή μέσο-μεσογειακό χαρακτήρα εκτός από το νοτιοανατολικό τμήμα της περιοχής που εμφανίζει έντονο μέσο-μεσογειακό χαρακτήρα. Σύμφωνα με την έρευνά μας, η χλωρίδα του όρους Σαϊτά αποτελείται συνολικά από 800 taxa από τα οποία 774 αναφέρονται για πρώτη φορά από την περιοχή. Από αυτά η Iris hellenica αποτελεί νέο είδος για την επιστήμη, το υποείδος Bromus hordeaceus subsp. hordeaceus είναι νέα αναφορά για την Πελοπόννησο, ενώ η Viola oligyrtia ήταν γνωστή ως τώρα μόνο από το όρος Ολίγυρτος. Από τον προσδιορισμό των βιομορφών προκύπτει πως επικρατούν τα ημικρυπτόφυτα και τα θερόφυτα. Στο όρος επικρατούν τα μεσογειακά γεωστοιχεία. Τα ελληνικά ενδημικά taxa της περιοχής ανέρχονται σε 67. Με βάση τον δείκτη Sørensen για το σύνολο της χλωρίδας ο Σαϊτάς εμφανίζει τη μεγαλύτερη χλωριδική ομοιότητα με τα όρη της Βόρειας Πελοποννήσου, Ερύμανθο, Κυλλήνη και Παναχαϊκό. Αντιστοίχως, με βάση τον υπολογισμό του δείκτη Sørensen για τα ελληνικά ενδημικά, ο Σαϊτάς παρουσιάζει τη μεγαλύτερη χλωριδική ομοιότητα με τα όρη Ερύμανθο, Κυλλήνη και Χελμό. Από το σύνολο της χλωρίδας του Σαϊτά, 53 taxa περιλαμβάνονται σε εθνικούς και διεθνείς καταλόγους και βιβλία σπάνιων και απειλούμενων φυτών. Για τη μελέτη της βλάστησης του όρους Σαϊτά εφαρμόσαμε τη φυτοκοινωνιολογική μέθοδο του Braun-Blanquet. Κατά την αναλυτική φάση μελέτης της βλάστησης πραγματοποιήθηκαν 231 φυτοληψίες. Περιγράφονται 5 φυτοκοινωνίες, 16 κοινότητες και 2 όψεις που ανήκουν σε 10 συνενώσεις, 9 τάξεις και 7 κλάσεις.

Phosphorus-utilisation efficiency and leaf-morphology traits of Rytidosperma species (wallaby grasses) that differ in their growth response to phosphorus fertilisation

2016 ◽  
Vol 64 (1) ◽  
pp. 65 ◽  
Author(s):  
Heidi A. Waddell ◽  
Richard J. Simpson ◽  
Hans Lambers ◽  
Brent Henderson ◽  
Megan H. Ryan ◽  
...  
Keyword(s):  
Leaf Area ◽  
Growth Rates ◽  
Dry Matter ◽  
Perennial Grasses ◽  
Dry Matter Content ◽  
Potential Growth ◽  
Fast Growing ◽  
Bromus Hordeaceus ◽  
P Concentration ◽  
Utilisation Efficiency

Rytidosperma species are perennial grasses found in cool temperate grasslands of Australia. The species differ in their intrinsic growth rates, response to phosphorus (P) fertiliser application and critical external P requirements (P required for 90% maximum growth). The present study examined whether internal P-utilisation efficiency (PUE) by Rytidosperma species influenced these differences. The PUE of nine Rytidosperma species and two grasses of Mediterranean origin, Bromus hordeaceus L. and Lolium perenne L., was assessed using alternative measures of shoot P concentration or its reciprocal. No measure of PUE was correlated with the critical external P requirements of the species. One measure of PUE, shoot dry matter per unit P, when assessed at a common shoot P content was correlated with potential growth rate (P < 0.001; r = 0.93; 4 mg shoot P). However, other measures of PUE were not correlated with potential growth rates. All of the fast-growing species (B. hordeaceus, L. perenne, Rytidosperma duttonianum (Cashmore) Connor & Edgar and Rytidosperma richardsonii (Cashmore) Connor & Edgar) exhibited high PUE, whereas PUE varied substantially among the slower-growing species. The fast-growing Rytidosperma species differed in the contribution that area-based P concentration of leaves and specific leaf area (SLA) made to the achievement of high PUE, and they retained shoot-morphology traits normally associated with slow-growing species such as smaller leaf area, smaller SLA and higher leaf dry matter content.

scholarly journals Evaluation of New Harvesting Methods to Reduce Weeds on Arable Fields and Collect a New Feedstock

Energies ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1688 ◽  
Author(s):  
Christoph Glasner ◽  
Christopher Vieregge ◽  
Josef Robert ◽  
Johanna Fenselau ◽  
Zahra Bitarafan ◽  
...  
Keyword(s):  
Weed Management ◽  
Growing Season ◽  
Integrated Weed Management ◽  
Management Approach ◽  
Weed Seed ◽  
Galium Aparine ◽  
Bromus Hordeaceus ◽  
Weed Seeds ◽  
Arable Fields ◽  
Combine Harvester

During harvesting, grain, straw, and chaff with weed seeds are separated. The chaff is returned to the fields, resulting in weed problems in the subsequent crops. We estimated the fraction of weed seeds a combine harvester could potentially harvest and used various methods to collect the chaff and treat it with heat to kill weed seeds or reduce weed seed germination. Chaff with weed seeds was placed on top of the straw and afterwards baled with the straw as a method to remove weed seeds from the field. We exposed chaff with weed seeds to exhaust gas with various temperatures and durations to study whether this heating method could be used to reduce the input of viable weed seeds to the soil during harvesting. By collecting the shed weed seeds during the growing season, we estimated that a combine harvester could potentially harvest 41%, 11%, and 100% of the seeds produced in the growing season by Bromus hordeaceus, Cirsium arvense, and Galium aparine, respectively. When the chaff was placed on top of the straw, 45% of the weed seeds stayed in the chaff fraction on top of the straw swath after one day, 35% got into the straw swath, and 20% past through the swath to the ground. Therefore, baling straw with chaff placed on the top only had a limited effect on reducing weed seed infestation. The study showed that thermal weed seed control during harvesting could potentially be applicable and incorporated in an integrated weed management approach.

On the origins of the tetraploid Bromus species (section Bromus, Poaceae): insights from internal transcribed spacer sequences of nuclear ribosomal DNA

Genome ◽  
1997 ◽  
Vol 40 (5) ◽  
pp. 730-743 ◽  
Author(s):  
Malika L. Ainouche ◽  
Randall J. Bayer
Keyword(s):  
Ribosomal Dna ◽  
Internal Transcribed Spacer ◽  
Phylogenetic Trees ◽  
Direct Sequencing ◽  
Diploid Species ◽  
Pcr Amplification ◽  
Nuclear Ribosomal Dna ◽  
Species Introduction ◽  
Bromus Hordeaceus ◽  
Allotetraploid Species

The internal transcribed spacer (ITS) region of nuclear ribosomal DNA from 22 diploid and tetraploid annual Bromus species of section Bromus (Poaceae) and three species belonging to other Bromus sections, Bromus catharticus (section Ceratochloa), Bromus anomalus (section Pnigma), and Bromus sterilis (section Genea), were investigated by PCR amplification and direct sequencing. The length of the ITS-1 region varied from 215 to 218 bp, and that of the ITS-2 region from 215 to 216 bp, in the species analyzed. ITS-1 was more variable and provided more informative sites (49) than ITS-2 (32). No variation was encountered within species. In pairwise comparison among species of section Bromus, sequence divergence ranged from 0.0 to 8.0% for the combined ITS-1 and ITS-2 regions. Parsimony analysis using Avena longiglumis and Hordeum vulgare as outgroups resulted in well-resolved phylogenetic trees and showed that section Bromus is monophyletic according to the species analyzed outside of the section. The analysis clarified the phylogenetic relationships among monogenomic (diploid) species. Introduction of the allotetraploid species did not change the general topology of the trees obtained using only the diploid species. Although some tetraploid–diploid species relationships will have to be clarified with faster evolving markers, the ITS sequences are shown to be useful for assessing evolutionary relationships among closely related Bromus species, as well as for clarifying taxonomic problems in previously controversial cases (e.g., Bromus alopecuros and Bromus caroli–henrici). New hypotheses are proposed concerning the origin of several allotetraploid species. For example, it is shown that the tetraploid Bromus hordeaceus diverged earlier than all other species of section Bromus, excluding the diploid B. caroli–henrici, which is found to be basal in this group. The tetraploid Bromus arenarius, which was considered a hybrid between sections Bromus and Genea, and the tetraploid Bromus adoensis are sister taxa within section Bromus; they belong in a weakly differentiated clade with the diploids Bromus brachystachys, Bromus japonicus, Bromus squarrosus, Bromus arvensis, and Bromus intermedius.Key words: Bromus, allopolyploidy, ITS, ribosomal DNA, phylogeny.

Genetic Structure and Allozyme-Microhabitat Associations in Bromus hordeaceus

Oikos ◽  
1993 ◽  
Vol 68 (1) ◽  
pp. 99 ◽  
Author(s):  
Mikael Lönn ◽  
Mikael Lonn
Keyword(s):  
Genetic Structure ◽  
Bromus Hordeaceus

Herbicides and Mowing to Control Barb Goatgrass (Aegilops triuncialis) and Restore Native Plants in Serpentine Grasslands

2011 ◽  
Vol 4 (4) ◽  
pp. 448-457 ◽  
Author(s):  
Paul A. Aigner ◽  
Rhett J. Woerly
Keyword(s):  
Seed Development ◽  
Native Species ◽  
Nonnative Species ◽  
Flower Initiation ◽  
Native Grasses ◽  
Aegilops Triuncialis ◽  
Early Season ◽  
Late Season ◽  
Bromus Hordeaceus ◽  
Early Seed Development

AbstractSerpentine grasslands are relatively free of the invasive species that typify other California grasslands, but recently are threatened by the spread of barb goatgrass, a Eurasian annual that is unique in its tolerance of serpentine soils. We evaluated two graminicides (clethodim and fluazifop), one broad-spectrum herbicide (glyphosate), mowing, and hand pulling for their effectiveness in controlling barb goatgrass and for restoring native species cover and diversity. We also evaluated application timing for the graminicides: before goatgrass flowering (early season), at flower initiation (midseason), and at early seed development (late season). Glyphosate was applied at early seed development. The 10 treatment combinations were applied to 10 blocks of 4-m2 (43-ft2) experimental plots in an inner Coast Range serpentine grassland with high cover of barb goatgrass but few other nonnative species. After 2 yr of treatment, all treatments except glyphosate reduced goatgrass frequency. Hand pulling, fluazifop, and mowing were most effective at controlling goatgrass, reducing frequency by 60, 51, and 48%, respectively (compared to a 30% increase on control plots). Midseason applications of clethodim and fluazifop were more effective than those applied early or late. Hand pulling, fluazifop, and clethodim increased native forb frequency by 31, 46, and 74%, respectively, with the benefit of the graminicides decreasing with later applications. Native grasses were at least partially resistant to the graminicides. Cover of one sided blue grass (Poa secunda), the most widespread native grass, might have been reduced slightly by early-season applications but was increased by late-season applications. Cover of soft brome (Bromus hordeaceus), the only other widespread nonnative species in the study, was reduced by early-season applications of the graminicides. Clethodim and fluazifop show great potential to selectively remove barb goatgrass and other nonnative annual grasses in grasslands that are otherwise dominated by native grasses and forbs. Mowing is a less selective, but viable alternative.

Arbuscular mycorrhizal percent root infection and infection intensity of Bromus hordeaceus grown in elevated atmospheric CO2

Mycologia ◽  
1998 ◽  
Vol 90 (2) ◽  
pp. 199-205 ◽  
Author(s):  
Matthias C. Rillig ◽  
Michael F. Allen ◽  
John N. Klironomos ◽  
Christopher B. Field
Keyword(s):  
Infection Intensity ◽  
Arbuscular Mycorrhizal ◽  
Atmospheric Co2 ◽  
Root Infection ◽  
Elevated Atmospheric Co2 ◽  
Bromus Hordeaceus

Arbuscular Mycorrhizal Percent Root Infection and Infection Intensity of Bromus hordeaceus Grown in Elevated Atmospheric CO2

Mycologia ◽  
1998 ◽  
Vol 90 (2) ◽  
pp. 199 ◽  
Author(s):  
Matthias C. Rillig ◽  
Michael F. Allen ◽  
John N. Klironomos ◽  
Christopher B. Field
Keyword(s):  
Infection Intensity ◽  
Arbuscular Mycorrhizal ◽  
Atmospheric Co2 ◽  
Root Infection ◽  
Elevated Atmospheric Co2 ◽  
Bromus Hordeaceus

scholarly journals Growth and Yield of Cultivated Grape with Native Perennial Grasses Nodding Needlegrass or California Barley as Cover Crops

HortScience ◽  
2010 ◽  
Vol 45 (1) ◽  
pp. 154-156
Author(s):  
Michael J. Costello
Keyword(s):  
Cover Crops ◽  
Cover Crop ◽  
Perennial Grasses ◽  
Growth And Yield ◽  
Native Grasses ◽  
Trunk Diameter ◽  
Bromus Hordeaceus ◽  
Significant Difference ◽  
Cv Barbera ◽  
Neutral Effect

Two California native perennial grasses, nodding needlegrass [Nassella cernua (Stebbins & R.M. Love) Barkworth] and California barley [Hordeum brachyantherum Nevski ssp. californicum (Covas & Stebbins) Bothmer, N. Jacobsen & Seberg], were compared with a conventional grass cover crop, ‘Blando’ brome (Bromus hordeaceus L.), as well as resident (weedy) vegetation and a clean cultivated control for effects on growth and yield of cultivated grape (Vitis vinifera L. cv. Barbera). Statistical analyses did not reveal yield differences between treatments with floor vegetation (the native grasses, ‘Blando’ brome, and resident vegetation) and clean cultivation, the cover crop treatments (the native grasses and ‘Blando brome’) and clean cultivation, nor the native grass treatments versus treatments with non-native floor vegetation (‘Blando’ brome and resident vegetation). However, there was a significant difference between the two native grasses with the average yield of nodding needlegrass 26.2% higher than that of California barley. Treatments did not differ in °Brix, berry weight, or pruning weight. At the end of the study, vine trunk diameter was 7.1% higher under the cover crop treatments than resident vegetation. Given these results, in vineyards where a neutral effect on growth or yield is desired, nodding needlegrass would be suitable as a permanent cover crop, whereas California barley would not.

Sign in / Sign up

Export Citation Format

Share Document