scholarly journals Mouvements de masse et dynamique d’un géosystème alpestre : étude dendrogéomorphologique de deux sites de la vallée de Boulc (Diois, France)

2002 ◽  
Vol 52 (2) ◽  
pp. 153-166 ◽  
Author(s):  
Laurent Astrade ◽  
Jean-Paul Bravard ◽  
Norbert Landon

Résumé Les mouvements de versant constituent un risque naturel majeur dans les Alpes du sud où la nature du terrain et le climat sont particulièrement favorables à leur développement. Ils représentent également une source importante de sédiments pour les cours d'eau. L'objectif de cet article est de dater, au moyen de l'analyse dendrochronologique, les mouvements ayant affecté deux versants instables d'un même bassin hydrologique. Les réponses de 41 pins sylvestres ( Pinus sylvestris L.) aux micro-mouvements du versant de Ravel-et-Ferriers montrent que le glissement de terrain de janvier 1994 est le résultat d'une forte instabilité existant depuis la fin des années 1980, mais surtout la conséquence d'une évolution à long terme du versant (huit périodes d'instabilité depuis le début du siècle). L'étude de la mortalité de 35 pins sylvestres et de 47 sapins pectinés ( Abies alba Mill.) partiellement enfouis retrace la chronologie de la formation d'un lac de barrage sous l'influence des différentes coulées boueuses de Bonneval-en-Diois. Les liens étroits entre ces événements et certaines situations pluviométriques exceptionnelles ont été utilisés afin de dater avec exactitude les mouvements récents. L'analyse dendrochronologique a donc permis de déterminer l'appartenance typologique des deux glissements, et de connaître les épisodes actifs de rechargement sédimentaire des cours d'eau associés aux sites. Les processus de fossilisation décrits à Bonneval-en-Diois montrent d'ailleurs des analogies avec les conditions régnant dans les Alpes du sud au début de l'Holocène où une partie des épais remblaiements des vallées creusées dans les formations marneuses serait à attribuer à des mouvements de masse localisés.

2018 ◽  
Vol 69 (9) ◽  
pp. 2338-2342
Author(s):  
Mariana Popescu ◽  
Diana Puiu ◽  
Anca Daniela Raiciu

The study describes the composition of volatile oils obtained by steam distillation of water fir (Abies alba), pine (Pinus sylvestris), juniper (Juniperus communis), rosemary (Rosmarinus officinalis), sage (Salvia officinalis), and coriander (Coriandrum sativum) using the gas chromatography technique coupled with mass spectrometry (GC-MS). Chromatographic profile revealed the presence of specific components for each studied volatile oil. It noted the presence of a and b- pinene in all volatile oils studied at different concentrations. Volatile oils studied, from green sources and rich in a, b-pinene will be used as raw materials for creating products with anti-inflammatory, antiseptic, bronchodilators properties.


Plant Disease ◽  
2005 ◽  
Vol 89 (9) ◽  
pp. 1015-1015
Author(s):  
G. Urek ◽  
S. Širca

Bursaphelenchus mucronatus Mamiya & Enda, a nematode associated with aboveground tissues of pine trees, is very similar morphologically to the pine wood nematode (PWN), B. xylophilus, a devastating pest that has caused widespread losses to pine woods in some parts of Asia since the early 1900s. During 1999, B. xylophilus was identified for the first time in Europe in Portugal (3), leading to concern that pines and other conifers all over Europe might be endangered. To protect forests from PWN and other pests, the European Union and other countries now regulate the importation of all coniferous chips, sawn wood, and logs and also have organized surveys to determine the extend of PWN infestation. Slovenia has approximately 1,227,832 ha of forest that makes up more than 60% of the surface of the country. The percentage of conifers within forests is 47.9% and comprised mainly of Picea, Pinus, Abies, and Larix species (2). During the summers of 2002-2004, approximately 100 ha of conifer forests in Slovenia were surveyed for the presence of PWN. In total, 170 wood samples from dead and dying pine (Pinus sylvestris L., P. nigra Arnold), spruce (Picea abies L.), and fir (Abies alba Miller) were analyzed. B. xylophilus (Steiner & Buhrer) Nickle was not found in the area, but a closely related nematode, B. mucronatus, previously shown to be pathogenic on conifer seedlings (4), was isolated from samples of P. sylvestris. Of 34 P. sylvestris samples analyzed, B. mucronatus was found in three samples. Samples were taken from a conifer forest located in the central part of Slovenia near the international airport of Ljubljana. The species was identified morphologically and also characterized by polymerase chain reaction restriction (PCR)-fragment length polymorphism (RFLP) analysis on the basis of ITS-rDNA fragment patterns. According to RFLP patterns (1), the analyzed species was recognized as the East-Asian type of B. mucronatus. Beside these findings, the specimens of B. homanni (Braasch) and Bursaphelenchus sp. have also been found in Slovenia. The results of the survey show that PWN was not found in Slovenia, but three different species of the Bursaphelenchus genus were present. References: (1) H. Braasch et al. Nachrbl. Dtsch. Pflanzenschutzd. 51:312, 1999. (2) M. Jurc et al. Zb. Gozdarstva in Lesarstva 72:121, 2004. (3) M. M. Mota et al. Nematology 1:727, 1999. (4) J. R. Sutherland. Pine wilt nematode. Pages 19–20 in: Compendium of Conifer Diseases. E. M. Hansen and K. J. Lewis, eds. The American Phytopathological Society, St. Paul, MN. 1997.


2017 ◽  
Vol 59 (2) ◽  
pp. 110-122
Author(s):  
Anna Ilek ◽  
Jarosław Kucza ◽  
Karolina Morkisz

AbstractThe subject of the present research is the water storage capacity of bark of seven forest tree species: Pinus sylvestris L., Larix decidua Mill., Abies alba Mill., Pinus sylvestris L., Quercus robur L., Betula pendula Ehrh. and Fagus sylvatica L. The aim of the research is to demonstrate differences in the formation of bark water storage capacity between species and to identify factors influencing the hydrological properties of bark. The maximum water storage capacity of bark was determined under laboratory conditions by performing a series of experiments simulating rainfall and by immersing bark samples in containers filled with water. After each single experiment, the bark samples were subjected to gravity filtration in a desiccator partially filled with water. The experiments lasted from 1084 to 1389 hours, depending on the bark sample. In all the studied species, bark sampled from the thinnest trees is characterized by the highest water storage capacity expressed in mm H2O · cm-3, while bark sampled from the thickest trees - by the lowest capacity. On the other hand, bark sampled from the thickest trees is characterized by the highest water storage capacity expressed in H2O · cm-2whereas bark from the thinnest trees - by the lowest capacity. In most species tested, as the tree thickness and thus the bark thickness and the coefficient of development of the interception surface of bark increase, the sorption properties of the bark decrease with bark depth, and the main role in water retention is played by the outer bark surface. The bark of European beech is an exception because of the smallest degree of surface development and because the dominant process is the absorption of water. When examining the hydrological properties of bark and calculating its parameters, one needs to take into account the actual surface of the bark of trees. Disregarding the actual bark surface may lead to significant errors in the interpretation of research results.


Forests ◽  
2019 ◽  
Vol 10 (5) ◽  
pp. 403 ◽  
Author(s):  
Jacek Kamczyc ◽  
Marcin K. Dyderski ◽  
Paweł Horodecki ◽  
Andrzej M. Jagodziński

Replacement of native deciduous forests by coniferous stands was a common result of former European afforestation policies and paradigms of forest management and led to considerable ecological consequences. Therefore, the most popular management strategy nowadays in multi-functional forestry is the re-establishment of mixed or broadleaved forests with native species on suitable habitats. However, our knowledge about the effects of tree species introduced into coniferous monocultures on soil mesofauna communities is scarce. We investigated abundance, species richness and diversity of Mesostigmata mite communities in decomposed litter of seven broadleaved (Acer platanoides L., A. pseudoplatanus L., Carpinus betulus L., Fagus sylvatica L., Tilia cordata Mill., Quercus robur L., Q. rubra L.) and four coniferous (Abies alba Mill., Larix decidua Mill., Picea abies [L.] Karst., Pinus sylvestris L.) species. We collected 297 litterbags after 6, 12 and 18 months of exposition in Scots pine (Pinus sylvestris) monocultures in Siemianice Experimental Forest (SW Poland). Generally, species richness and diversity in litter samples were much lower than in the soil mite pool. The highest abundance was found in P. sylvestris and A. alba litter, while the lowest was found in A. platanoides. The most abundant families were Zerconidae, Parasitidae, Veigaiidae, and Trachytidae. Our study revealed that neither species richness nor diversity were affected, but that mite abundance was affected, by the tree species (litter quality). The mite communities were similarly comprised in both high- and low-quality litter and mite abundance decreased during the decomposition process in nutrient-poor Scots pine forests. Moreover, few mite species benefited from the decomposed litter. Additionally, a litter of various tree species was inhabited mainly by eu- and hemiedaphic mite species. Mite assemblages in A. alba, P. sylvestris, and Q. robur litter had higher abundances. Exposition time seems to be an important driver in shaping the mite community during the early stages of litter decomposition.


BioResources ◽  
2015 ◽  
Vol 10 (4) ◽  
Author(s):  
Mohamed Zidan Mohamed Salem ◽  
Ramadan A. Nasser ◽  
Aleš Zeidler ◽  
Hosam O. Elansary ◽  
Ibrahim M. Aref ◽  
...  

BioResources ◽  
2015 ◽  
Vol 10 (4) ◽  
Author(s):  
Mohamed Zidan Mohamed Salem ◽  
Aleš Zeidler ◽  
Martin Böhm ◽  
Mervat E. A. Mohamed ◽  
Hayssam M. Ali

2019 ◽  
Vol 48 (No. 9) ◽  
pp. 377-387 ◽  
Author(s):  
R. Podlaski

The objectives of this study are to determine a trend of the radial growth at breast height (b.h.) and to compare the radial growth of trees of younger and older generations in the XX century for fir (Abies alba Mill.), beech (Fagus sylvatica L.) and pine (Pinus sylvestris L.) in the Świętokrzyski National Park. In the investigated area fir, 41 to 200–300 years of age at breast height, gradually regenerated its radial growth after a very strong decline during 1971–1990, and most likely the process of vitality reduction and death of its stands of various age is slowly coming to an end. Pine showed a systematic decrease in the radial increment during 1885–1994, and there were no distinct symptoms indicating a change of this unfavourable trend. Beech showed no significant decrease in the radial increment during 1885–1994. In the Świętokrzyski National Park the differences in the radial growth between younger and older generations were noticeable only in the case of beech. The radial growth of trees of different ages was very similar in the case of fir and pine.  


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