Search results for "Tree"
showing 10 items of 1841 documents
Association of Marginal Leaf Scorch with Sodium Accumulation in Salt-stressed Peach
2000
The effect of specific ion toxicity during salt stress was tested in the present study. The experiment was repeated twice, in 1996 and 1998, with `Nemaguard' peach seedlings and rooted cuttings grown in hydroponics under two NaCl concentrations (50 and 30 mm). Foliage was separated in symptomatic and symptomless leaves and the amount of sodium (Na+) and chloride (C1–) was determined. Significantly higher Na+ content was found in symptomatic than in symptomless leaves in both experiments, whereas in only two of the six cases was Cl– content higher in symptomatic than in symptomless leaves. The Na+ threshold for leaf scorch was somewhere between 4 and 6 mg·g–1 dry weight. Results indicated th…
New low-vigour apricot rootstocks compared
2010
About ten years ago nurseries began to test several novel apricot stocks developed either to reduce plant vigour and boost early as well as high cropping or as a more suitable replacement for Myrabolan (Prunus cerasifera) and Apricot seedling in water-logged or chlorotic soils. These stocks were the Italian bred selections of Prunus domestica Penta and Tetra, the P. cerasifera Adara and the Prunus insititia Adesoto® 101, both Spanish-bred seedlings, and Plumina@, a Prunus bessey × P. cerasifera hybrid developed in France. Performance testing was carried out under a national project. The trials were set up in 2001 in plots of pilot orchards at Imola in Bologna Province, Ancona, Caserta, Pale…
Site quality evaluation by classification tree: an application to cork quality in Sardinia
2005
Cork harvesting and stopper production represent a major forest industry in Sardinia (Italy). The target of the present investigation was to evaluate the ‘‘classification tree’’ as a tool to discover possible relationships between microsite characteristics and cork quality. Seven main cork oak (Quercus suber) producing areas have been identified in Sardinia, for a total of more than 122,000 ha. Sixty-three sample trees, distributed among different geographical locations and microsite conditions, were selected. A soil profile near each sample tree was described, soil samples were collected and analysed. After debarking, cork quality of each sample tree was graded by an independent panel of e…
PERTUMBUHAN LINGKARAN POHON JATI PADA DUA SISTEM KULTUR BERBEDA DI JAWA TIMUR
2008
<p><em>Study dendrochronology or tree-ring dating is defined as the study of chronological sequence of annual growth rings in trees. Teak (Tectona grandis) is one of various tree species that has been identified for the use of tree-ring studies in tropical regions. Teak is found to be suitable for dendrochronology as it is long-lived and develops defined annual growth rings. In Java, teak cans growth naturally or intensively in plantation. The two silviculture conditions will give different sensitivity on climate effect. Therefore, the effect of silviculturer will on natural teak and plantation teak in Saradan, Madiun, and East Java. As a part of the study, ten core samples from…
Distribution ofLeprariain Latvia in Relation to Tree Substratum and Deciduous Forest Type
2012
The aim of the study was to evaluate the distribution of Lepraria lichen species in dry deciduous forests, in relation to tree substratum and forest characteristics. In total, 34 localities with 1020 trees (13 tree species) were studied in different parts of Latvia. Lepraria spp. were found on 642 trees: L. eburnea on 8 trees, L. incana on 80 trees, and L. lobificans on 568 trees. Lepraria eburnea was recorded for the first time in Latvia. Tree species, tree bark crevice depth, inclination, pH and forest type were the most important variables explaining the presence of Lepraria species. Lepraria incana was associated with Quercus robur and Tilia cordata, while L. lobificans was associated w…
Boosting for ranking data: an extension to item weighting
2021
Gli alberi decisionali sono una tecnica predittiva di machine learning particolarmente diffusa, utilizzata per prevedere delle variabili discrete (classificazione) o continue (regressione). Gli algoritmi alla base di queste tecniche sono intuitivi e interpretabili, ma anche instabili. Infatti, per rendere la classificazione più affidabile si `e soliti combinare l’output di più alberi. In letteratura, sono stati proposti diversi approcci per classificare ranking data attraverso gli alberi decisionali, ma nessuno di questi tiene conto ne dell’importanza, ne delle somiglianza dei singoli elementi di ogni ranking. L’obiettivo di questo articolo `e di proporre un’estensione ponderata del metodo …
Machine learning for land use change analysis and modelling.
2019
Urban development can take different forms or features, depending on its geographical location and its socioeconomic, political and cultural context. Nevertheless, the overall action relies on one fundamental principle: building construction in order to give people housing. Therefore, the main objective of this research is to determine whether an underlying universal aspect of the urban development process can be distinguished from a specific one, being the reflect of local specificities. Specifically, this research analyzes the land use change on the French-German cross-border area. Indeed, the border context enhances the difference within this territory. Nonetheless, the internal European…
Variabilité de la température entre 1951 et 2014 en Allemagne associée à l’évolution de la floraison des pommiers.
2018
Apple tree bloom onset in Germany has advanced by 2 days/decade in 1951-2014 and by 3 days/decade in 1988-2014, behaving similarly in respect to its evolution since 1951 and its sensitivity to temperature to other species’ phenological spring phases. The evolution however was not linear; by conducting a split moving-window dissimilarity analysis (SMWDA) we were able to detect the “break-period” 1987-1989 which coincides with a breakpoint that has been identified in the phases of the North Atlantic Oscillation (NAO). We observed distinct spatial patterns with apple bloom advancing from southwest to northeast and, most interestingly, a longitudinal gradient in the trend of apple bloom onset r…
The genetic heritage of Alpine local cattle breeds using genomic SNP data
2020
Abstract Background Assessment of genetic diversity and population structure provides important control metrics to avoid genetic erosion, inbreeding depression and crossbreeding between exotic and locally-adapted cattle breeds since these events can have deleterious consequences and eventually lead to extinction. Historically, the Alpine Arc represents an important pocket of cattle biodiversity with a large number of autochthonous breeds that provide a fundamental source of income for the entire regional economy. By using genotype data from medium-density single nucleotide polymorphism (SNP) arrays, we performed a genome-wide comparative study of 23 cattle populations from the Alpine Arc an…
“The tree was there first” – using an everyday ecological dilemma to explore the personal orientations of secondary school students in environmental …
2020
Studies have repeatedly shown that the goals of environmental education are as indispensable as they are difficult to achieve. In particular, the discrepancy between environmental awareness and eve...