Biological Systems, Biodiversity, and Stability of Plant Communities

2015 ◽  
Flora ◽  
2010 ◽  
Vol 205 (10) ◽  
pp. 682-694 ◽  
Author(s):  
Corinne Sarthou ◽  
Denis Larpin ◽  
Émile Fonty ◽  
Sandrine Pavoine ◽  
Jean-François Ponge

2021 ◽  
Vol 22 (8) ◽  
Author(s):  
Alevtina Danilova ◽  
Aidar Sumbembayev

Abstract. Danilova AN, Sumbembayev AA. 2021. The status of the Dactylorhiza incarnata populations in the Kalba Altai, Kazakhstan. Biodiversitas 22: 3180-3195. The article provides a botanical description of the current state of populations of threatened species Dactylorhiza incarnata (L.) Soo in the Kalba. The ecological analysis of the flora, the ecological optimum of the species, the vitality of plant communities, and the degree of anthropogenic load are presented in the research. On the basis of field surveys, four main populations were identified in 13 typical plant communities. Flora of plant communities of D. incarnata on the Kalba Ridge includes 117 species belonging to 30 families and 80 genera. The ecological optimum of D. incarnata can be spotted on the southeastern slopes with diffused lighting and moderate wind impact. The plant communities with optimal conditions are Filipendulo-Sanguisorbo-Thalictrosum and Carexoto-Equiseto-Filipendulo-Festucosum characterized by highly humid meadows and forest edges with low density and competition. Self-maintenance and reproduction of the species are fulfilled mainly by seeds, less often by vegetative reproduction of the finger root. Due to analysis of the age composition of populations and the dynamics and stability of plant communities the recovery index is within the optimum. Typical indicator species are Thalictrum simplex L., Salix viminalis L., Filipendula ulmaria (L.) Maxim., Sanguisorba officinalis L., Geranium pratense L., Festuca pratensis Huds.


Author(s):  
Henry S. Slayter

Electron microscopic methods have been applied increasingly during the past fifteen years, to problems in structural molecular biology. Used in conjunction with physical chemical methods and/or Fourier methods of analysis, they constitute powerful tools for determining sizes, shapes and modes of aggregation of biopolymers with molecular weights greater than 50, 000. However, the application of the e.m. to the determination of very fine structure approaching the limit of instrumental resolving power in biological systems has not been productive, due to various difficulties such as the destructive effects of dehydration, damage to the specimen by the electron beam, and lack of adequate and specific contrast. One of the most satisfactory methods for contrasting individual macromolecules involves the deposition of heavy metal vapor upon the specimen. We have investigated this process, and present here what we believe to be the more important considerations for optimizing it. Results of the application of these methods to several biological systems including muscle proteins, fibrinogen, ribosomes and chromatin will be discussed.


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