scholarly journals Density of wood of pine-tree and spruce in the mixed mature forests of the North-West Russia boreal zone

2018 ◽  
Author(s):  
Dmitry Danilov ◽  
Natalia Belyaeva ◽  
Dmitry Zaytcev
Keyword(s):  
2020 ◽  
Vol 10 (2) ◽  
pp. 151-169
Author(s):  
Ekaterina A. Pinaevskaya ◽  
Sergey N. Tarkhanov ◽  
Aleksandr S. Pakhov

Pinus sylvestris L. is the main tree species of forest ecosystems in the European North of Russia, therefore, in-depth studies of the diversity of forms and growth processes of this plant are important. Forms in pine stand out according to morphological and other characteristics. In conditions of prolonged excessive soil moisture, the joint growth of various forms of pine is observed. The aim of the work is to study the growth of various forms of pine according to morphostructural characteristics in the shrub-sphagnum forest type estuary of the Onega River. Investigations of tree growth (according to the form of seed cone scales apophysis and crown habit) were carried out in shrub-sphagnum pine forests of different ages in the north-west of the European part of Russia (northern taiga subzone). Morphometric measurements of the vegetative and generative spheres in the forms of scots pine were made. It is established that the advantage in morphometric characteristics, average values ​​of radial growth, late and early wood has a pine tree with a «convex» apophysis form. The advantage with respect to the morphometric characteristics of the trunk and crown is form with «ordinary» crown habit. The «ordinary» form has larger cones, a larger value of radial growth and macrostructural parameters of wood compared to the «swamp».


Author(s):  
Daryl A. Cornish ◽  
George L. Smit

Oreochromis mossambicus is currently receiving much attention as a candidater species for aquaculture programs within Southern Africa. This has stimulated interest in its breeding cycle as well as the morphological characteristics of the gonads. Limited information is available on SEM and TEM observations of the male gonads. It is known that the testis of O. mossambicus is a paired, intra-abdominal structure of the lobular type, although further details of its characteristics are not known. Current investigations have shown that spermatids reach full maturity some two months after the female becomes gravid. Throughout the year, the testes contain spermatids at various stages of development although spermiogenesis appears to be maximal during November when spawning occurs. This paper describes the morphological and ultrastructural characteristics of the testes and spermatids.Specimens of this fish were collected at Syferkuil Dam, 8 km north- west of the University of the North over a twelve month period, sacrificed and the testes excised.


2014 ◽  
Author(s):  
Roald Amundsen ◽  
Godfred Hansen
Keyword(s):  

2003 ◽  
pp. 136-146
Author(s):  
K. Liuhto

Statistical data on reserves, production and exports of Russian oil are provided in the article. The author pays special attention to the expansion of opportunities of sea oil transportation by construction of new oil terminals in the North-West of the country and first of all the largest terminal in Murmansk. In his opinion, one of the main problems in this sphere is prevention of ecological accidents in the process of oil transportation through the Baltic sea ports.


Author(s):  
Angelina E. Shatalova ◽  
Uriy A. Kublitsky ◽  
Dmitry A. Subetto ◽  
Anna V. Ludikova ◽  
Alar Rosentau ◽  
...  

The study of paleogeography of lakes is an actual and important direction in modern science. As part of the study of lakes in the North-West of the Karelian Isthmus, this analysis will establish the dynamics of salinity of objects, which will allow to reconstruct changes in the level of the Baltic Sea in the Holocene.


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