Search results for "beech"

Changes in the Content of Chlorophyll and Redox Components of the Thylakoid Membrane during Development and Senescence of Beech (Fagus sylvatica) Lea…

1995

Abstract Leaves from 145-year-old and 44-year-old beech trees were harvested during 1991-1993. Chlorophyll (Chl) and redox components of the thylakoid membrane, including P-700, cytochrome f (Cyt f) and D1 protein, were determined with the following results. Chl a + b, P-700 and Cyt f per unit of fresh weight (FW), dry weight (DW) and leaf area (LA) increase significantly during leaf development. This can be attributed to a massive membrane syn­thesis and new thylakoid formation in the cells. The Chl a/Chl b ratio decreases with the synthesis of Chl during the development of beech leaves and is reduced further with Chl breakdown in the stage of senescence. When expressed on the basis of Chl…

Biodiversity within the subfamily Alyssinae (Hymenoptera, Braconidae) in the Natural Park Peñas de Aya (Spain)

2011

Biodiversity within the subfamily Alyssinae (Hymenoptera, Braconidae) in the Natural Park Peñas de Aya (Spain). The study of parasitoid Hymenoptera is of significance for the assessment of diversity in a given area because of their role in the regulation of insects populations. The present work analyses diversity within Alysiinae (Hymenoptera, Braconidae) in the Forested Estate of Artikutza, located in the Natural Park Peñas de Aya, western Pyrenees, Spain. Collection of specimens was spread over two years and was carried out in two different habitats: mixed forest and beech forest. A total of 2,270 specimens, belonging to 22 separate genera, were captured. Subsequently, alpha, beta and gam…

Bryophytes as ecological indicators in the beech woods of sicily

2019

Beech woods, which have in Sicily one of the southernmost places of their distribution area, are localized in the mountain belt of North and North-Eastern Sicily, at an altitude of 1300-1900 m, reaching 900 m on the Peloritani. They are referred to the priority habitat 9210*, according to the Natura 2000 network of the European Union. Beech woods settle on different soils, such as incoherent sandy volcanic (Etna), calcareous or silico-arenaceous (Madonie) and clayey-schistose soils (Nebrodi and Peloritani). Bryophytes are considered important components of forestry ecosystems. Many of these organisms are specific to particular types of microhabitats and sensitive to changes such that specie…

Solar UV-B radiation affects leaf quality and insect herbivory in the southern beech tree Nothofagus antarctica

2004

We examined the effects of solar ultraviolet-B (UV-B) radiation on plant-insect interactions in Tierra del Fuego (55°S), Argentina, an area strongly affected by ozone depletion because of its proximity to Antarctica. Solar UV-B under Nothofagus antarctica branches was manipulated using a polyester plastic film to attenuate UV-B (uvb-) and an Aclar film to provide near-ambient UV-B (uvb+). The plastic films were placed on both north-facing (i.e., high solar radiation in the Southern Hemisphere) and south-facing branches. Insects consumed 40% less leaf area from north- than from south-facing branches, and at least 30% less area from uvb+ branches than from uvb-branches. The reduced herbivory …

Distribution of sulphur forms in soils from beech and spruce forests of Mont Loz�re (France)

1993

From a quantitative inventory of sulphur forms and sulphur budget, the relation between the distribution of the various sulphur forms and the sulphate fluxes in three soil profiles has been addressed. These profiles are located in two forested watersheds at Mont Lozere. One has been sampled in a beech forest and the other two in a spruce forest and in a harvested plot of this spruce forest, respectively. The mean annual input-output budgets showed a sulphur immobilization in the soil cover of the three plots. In the preserved spruce forest plot, because of larger dry depositions, the sulphur immobilization is much greater than in other plots and occurs essentially in the B horizons. In the …

Genomic basis of drought resistance inFagus sylvatica

2020

In the course of global climate change, central Europe is experiencing more frequent and prolonged periods of drought. These drought events have severe and detrimental impacts on the forest ecosystem. The drought years 2018 and 2019 affected European beeches (Fagus sylvatica L.) in noticeably different ways: even in the same local stand, badly drought damaged trees immediately neighboured apparently healthy trees. This led to the hypothesis that the genotype rather than the environment was responsible for this conspicuous pattern. We used this natural experiment to study the genomic basis of drought resistance in a Pool-GWAS approach. Contrasting the extreme phenotypes, we identified 106 si…

Caracterización, Inventariación y aplicación del método de Valoración Biogeográfica de paisajes vegetales (LANBIOEVA) a la comarca de Collsacabra (Gi…

2018

The study presented in this paper takes part of a research project (LANBIOEVA: Landscape Biogeographic Evaluation) carried out for the past 25 years and it is, for now, its last stage. It’s a global landscape valuation method focused on vegetation as a main element of different units that can be evaluated. So far, the use of this method has resulted in numerous works: books, articles, book chapters, communications and presentations, and it has been applied in the study of different temperate and boreal regions of Europe and America. The method has been applied in the study and assessment of diverse vegetation landscapes of the Collsacabra shire (Girona). The objective is to verify its effec…

Author response: Genomic basis for drought resistance in European beech forests threatened by climate change

2021

Climate signals in stable carbon and hydrogen isotopes of lignin methoxy groups from southern German beech trees

2021

Stable hydrogen and carbon isotope ratios of wood lignin methoxy groups (δ13CLM and δ2HLM values) have been shown to be reliable proxies of past temperature variations. Previous studies showed that δ2HLM values even work in temperate environments where classical tree-ring width and maximum latewood density measurements are less successful for climate reconstructions. Here, we analyse the annually resolved δ13CLM values from 1916–2015 of four beech trees (Fagus sylvatica) from a temperate site near Hohenpeißenberg in southern Germany and compare these data with regional- to continental-scale climate observations. Initial δ13CLM values were corrected for the Suess effect (a decrease of δ13C i…

Genetic variation of European beech (Fagus sylvatica L.) along an altitudinal transect at mount Vogelsberg in Hesse, Germany

2000

Allelic and genotypic variation at 13 different enzyme loci of autochthonous European beech (Fagus sylvatica L.) was investigated in six 110-160-year-old stands growing at elevations between 150 and 660 m above sea level on the western slope of mount Vogelsberg in central Germany. The highest elevated population showed the highest number of effective alleles (Ne), the highest total heterozygosity (He) and the highest population differentiation deltaT. Also, the genotype SKD-A2A3 of shikimate dehydrogenase was significantly more frequent at the two highest elevated stands (P = 11%) than at the three lowest elevated stands (P = 1%). Further differences in genotype frequencies between 11 of 15…