Search results for " evolution."
showing 10 items of 9653 documents
Physiological and Structural Responses to Prolonged Water Deficit in Young Trees of Two Olive Cultivars
2022
This study aimed to characterize the physiological and structural responses of potted one-year-old olive trees belonging to two olive cultivars—‘Nocellara del Belice’ and ‘Cerasuola’—exposed to prolonged drought under greenhouse conditions. Two irrigation treatments based on evapotranspiration (ET) were imposed for 69 days, i.e., well-watered (WW, 100% ET) and drought-stressed (DS, 10–30% ET). Leaf stomatal conductance (gs), stem water potential (Ψstem), transpiration (E), photosynthetic capacity (Amax), water use efficiency (WUE), stem (Kstem) and root (Kroot) hydraulic conductance, trunk diameter variations (TDV), and leaf patch attenuated pre…
VegItaly: The Italian collaborative project for a national vegetation database
2012
Abstract Two years after its official start, the national vegetation database VegItaly, a collaborative project supported by the Italian scientific community and developed by a large group of scientists, is presented. This article offers a concise overview of the content of the database, currently consisting of 31,100 vegetation plot, including published and unpublished data. Some basic statistics are analysed; for example, data distribution in space and time, represented vegetation types expressed as physiognomic categories. Although rather young and still in progress, VegItaly already contains data from all the Italian regions and stands as an optimal candidate for the development of an I…
Typification of five plant names described based on specimens collected by Józef Warszewicz in Central and South America.
2022
Józef Warszewicz (1812–1864) was one of the first Polish naturalists to explore the flora of the tropical New World. During two expeditions to Central and South America (1844–1850 and 1850–1853) he collected and delivered to Europe up to twenty thousand plant specimens. To honour his service and his achievements in plant collections, different taxonomists described more than 100 taxa using the surname Warszewicz, for example in the genus name (Warszewiczia) and the species epithets (warszewiczii, warscewiczii, warszewicziana). Unfortunately, a large part of Warszewicz’s collection of plant species deposited in the Berlin Herbarium (B), including many type specimens was destroyed during Worl…
Wetland Restoration with Hydrophytes: A Review
2021
Restoration cases with hydrophytes (those which develop all their vital functions inside the water or very close to the water surface, e.g., flowering) are less abundant compared to those using emergent plants. Here, I synthesize the latest knowledge in wetland restoration based on revegetation with hydrophytes and stress common challenges and potential solutions. The review mainly focusses on natural wetlands but also includes information about naturalized constructed wetlands, which nowadays are being used not only to improve water quality but also to increase biodiversity. Available publications, peer-reviewed and any public domain, from the last 20 years, were reviewed. Several countrie…
Plasmid Viability Depends on the Ecological Setting of Hosts within a Multiplasmid Community
2022
Plasmids are extrachromosomal genetic elements, some of which disperse horizontally between different strains and species of bacteria. They are a major factor in the dissemination of virulence factors and antibiotic resistance. Understanding the ecology of plasmids has a notable anthropocentric value, and therefore, the interactions between bacterial hosts and individual plasmids have been studied in detail. However, bacterial systems often carry multiple genetically distinct plasmids, but dynamics within these multiplasmid communities have remained unstudied. Here, we set to investigate the survival of 11 mobilizable or conjugative plasmids under five different conditions where the hosts h…
Mind the gap: Treefalls as drivers of parental trade-offs
2015
Abstract Tree‐fall gaps are small‐scale disturbances whose formation, colonization, and role in forest dynamics are well documented, but whose effects on animal ecology are still greatly overlooked, except for studies comparing species richness of gaps 6+ months old to that in the closed canopy. Other factors associated with the invasion of fresh tree‐fall gaps such as animal breeding adaptations have been largely neglected. I studied the immediate (within hours and days) arrival of the poison frog Dendrobates tinctorius in new tree‐fall gaps to examine the dynamics of their invasion in relation to tadpole rearing. I found that rearing sites are occupied sooner and tadpoles deposited at hig…
Orbital angular momentum parton distributions in quark models
1999
At the low energy, {\sl hadronic}, scale we calculate Orbital Angular Momentum (OAM) twist-two parton distributions for the relativistic MIT bag model and for non-relativistic quark models. We reach the scale of the data by leading order evolution in perturbative QCD. We confirm that the contribution of quarks and gluons OAM to the nucleon spin grows with $Q^2$, and it can be relevant at the experimental scale, even if it is negligible at the hadronic scale, irrespective of the model used. The sign and shape of the quark OAM distribution at high $Q^2$ may depend strongly on the relative size of the OAM and spin distributions at the hadronic scale. Sizeable quark OAM distributions at the had…
Are Red Lists really useful for plant conservation? The New Red List of the Italian Flora in the perspective of national conservation policies
2013
La nuova Lista Rossa della flora Italiana comprende tutte le "policy" specie italiane e altre specie di nota conservazione e comprende 400 taxa di cui il 65% sono minacciate di estinzione. La Lista Rossa si basa su un enorme data-set georeferenziato utile per gli scopi di conservazione. - The New Red List of the Italian Flora includes all the Italian policy species and other species of known conservation concerns for a total of 400 taxa, 65% of which are threatened with extinction. The Red List is based on a huge georeferenced data-set useful for conservation purposes. -
Mitochondrial sequence analysis of Salamandra taxa suggests old splits of major lineages and postglacial recolonizations of Central Europe from disti…
2000
Representatives of the genus Salamandra occur in Europe, Northern Africa and the Near East. Many local variants are known but species and subspecies status of these is still a matter of dispute. We have analysed samples from locations covering the whole expansion range of Salamandra by sequence analysis of mitochondrial D-loop regions. In addition, we have calibrated the rate of divergence of the D-loop on the basis of geologically dated splits of the closely related genus Euproctus. Phylogenetic analysis of the sequences suggests that six major monophyletic groups exist (S. salamandra, S. algira, S. infraimmaculata, S. corsica, S. atra and S. lanzai) which have split between 5 and 13 milli…
The effect of inbreeding rate on fitness, inbreeding depression and heterosis over a range of inbreeding coefficients
2014
Understanding the effects of inbreeding and genetic drift within populations and hybridization between genetically differentiated populations is important for many basic and applied questions in ecology and evolutionary biology. The magnitudes and even the directions of these effects can be influenced by various factors, especially by the current and historical population size (i.e. inbreeding rate). Using Drosophila littoralis as a model species, we studied the effect of inbreeding rate over a range of inbreeding levels on (i) mean fitness of a population (relative to that of an outbred control population), (ii) within‐population inbreeding depression (reduction in fitness of offspring fro…