Search results for " Quercus"

Spatio‐temporal patterns of tree growth as related to carbon isotope fractionation in European forests under changing climate

2019

Aim The aim was to decipher Europe‐wide spatio‐temporal patterns of forest growth dynamics and their associations with carbon isotope fractionation processes inferred from tree rings as modulated by climate warming. Location Europe and North Africa (30‒70° N, 10° W‒35° E). Time period 1901‒2003. Major taxa studied Temperate and Euro‐Siberian trees. Methods We characterize changes in the relationship between tree growth and carbon isotope fractionation over the 20th century using a European network consisting of 20 site chronologies. Using indexed tree‐ring widths (TRWi), we assess shifts in the temporal coherence of radial growth across sites (synchrony) for five forest ecosystems (Atlantic…

Description of the sexual generation of Dryocosmus destefanii (Hymenoptera: Cynipidae: Cynipini) and disclosure of its life cycle

2020

The sexual generation of Dryocosmus destefanii Cerasa & Melika, 2018 that emerges from galls on Q. suber L. in Italy is described for the first time, establishing its heterogonic life cycle. We provide observations on its distribution, illustration of adults and galls and information on its biology as supported by morphological and molecular data. An illustrated identification key to Western Palaearctic Dryocosmus species is also given. 

Living and Dead Aboveground Biomass in Mediterranean Forests: Evidence of Old-Growth Traits in a Quercus pubescens Willd. s.l. Stand

2017

For a long time, human impact has deeply simplified most of the forest ecosystems of the Mediterranean Basin. Here, forests have seldom had the chance to naturally develop a complex and multilayered structure, to host large and old trees and rich biological communities, approaching old-growth conditions. Also for this reason, limited information is currently available about Mediterranean old-growth forests, particularly with regard to deadwood. The main aim of this work is to help fill this critical knowledge gap. In Sicily (Italy), we identified a Quercus pubescens forest that seemed to show some typical old-growth features. Total living volume (360 m3 ha−1) and basal area (34 m2 ha−1) wer…

A multivariate morphometric analysis of diagnostic traits in southern Italy and Sicily pubescent oaks

2020

AbstractSpecies identification within the species complex ofQ. pubescensis a well-known taxonomic challenge among European botanists. Some of the specific pubescent oak binomials currently accepted in various European floras and checklists were originally described in Sicily and southern Calabria. As a consequence, several species belonging to the pubescent oaks group (Q. pubescens,Q. amplifolia,Q. congesta,Q. dalechampii,Q. leptobalanaandQ. virgiliana) are reported in the taxonomic and phytosociological literature. To verify whether it was possible to associate a diverse set of morphological characters with each of these different taxa, thirteen natural populations of pubescent oak from Si…

The decline of the cork oak growing in Sicily is accompanied by the loss of the functions proper to agroforestry systems

2021

The cork oak is one of the most important tree species in the Mediterranean basin, where it covers more than 2 million hectares. Among evergreen oaks, Quercus suber stands out for the variety of cultural systems in which it has been successfully employed, including typical agroforestry systems. Accordingly, a wide range of ecosystem services may be associated to cork oak, including the preservation of biodiversity, carbon sequestration and forage production. In the Mediterranean, the cork oak represents a key species for many natural and seminatural landscapes and habitats, as well as playing a prominent role for the economic and social development of local communities. However, there is in…

1200 years of decadal-scale variability of Mediterranean vegetation and climate at Pantelleria Island, Italy.

2013

A new sedimentary sequence from Lago di Venere on Pantelleria Island, located in the Strait of Sicily between Tunisia and Sicily was recovered. The lake is located in the coastal infra-Mediterranean vegetation belt at 2 m a.s.l. Pollen, charcoal and sedimentological analyses are used to explore linkages among vegetation, fire and climate at a decadal scale over the past 1200 years. A dry period from ad 800 to 1000 that corresponds to the 'Medieval Warm Period' (WMP) is inferred from sedimentological analysis. The high content of carbonate recorded in this period suggests a dry phase, when the ratio of evaporation/precipitation was high. During this period the island was dominated by thermop…

Conservation of genetic diversity in artificially regenerated holm oak (Quercus ilex L.) populations

2004

Reforestation with autochtonous species should take into account the preservation of the variability and the geographical structure of genetic diversity in forest species. In order to provide empirical data, genetic composition of an artificial population of holm oak (Quercus ilex L.) and its natural seed-origin population in Andalusia were analysed with six microsatellite loci. The genetic diversity indices applied show a reduction in the artificial stand if compared with the natural one, probably due to an inappropriate forester seed collection strategy limited to a few trees.

Preliminary observations on fungal endophytic community and mycorrhizal status in symptomless Quercus ilex seedlings

2014

Recently, a study on the Quercus ilex L. decay caused by biotic and abiotic agents has hypothesized alterations on endophytic and mycorrhizal fungal populations. Since holm oak is among the most representative Mediterranean species, that occurs widely in both urban and rural areas, in this work we preliminarly report these symbiotic fungal communities in asymptomatic seedlings, in order to compare these populations with those found in seedlings subjected to water and saline stress. Endophytic fungi were isolated from twigs and leaves and identified by morphological and molecular analysis. The ectomycorrhizal status was evaluated on root samples randomly selected to calculate the percentage …

Flora and vegetation of pastures utilized by the Sicilian Black Pig of the Nebrodi Mountains (NE Sicily).

2007

Rediscovery of Cerroneuroterus apenninus (Trotter, 1923) (Hymenoptera: Cynipidae: Cynipini) a valid species from Italy with description and neotype d…

2021

Neuroterus apenninus Trotter, 1923 associated with a Cerris section oak, Quercus cerris L., was rediscovered in Italy in 2017. Alessandro Trotter (1903) described a leaf gall collected on Q. cerris from the Italian Apennines; he did not obtain the gall inductor and ascribed the galls to the genus Neuroterus, based on morphological similarity with other Neuroterus galls. We have found the same gall and obtained the gall inducer. Detailed study of morphological characters of adults revealed that the species belongs to the genus Cerroneuroterus Melika & Pujade-Villar, 2010. The asexual generation of Cerroneuroterus apenninus comb. n. is described for the first time, a neotype is designated…