Geomorphological controls on vegetation changes: a case study of alluvial fans in southwest of Miami City, Northeastern Iran

2021 ◽  
Vol 14 (5) ◽  
Author(s):  
Sepideh Imeni ◽  
Hasan Sadough ◽  
Shahram Bahrami ◽  
Ahmadreza Mehrabian ◽  
Kazem Nosrati
2015 ◽  
Vol 40 (1) ◽  
pp. 77-104
Author(s):  
Tomasz Szygendowski ◽  
Andrzej Brzeg

Abstract In this paper, changes of the non-forest xerothermic vegetation of the “Murawy Dobromierskie” steppe reserve which occurred in the period 1993-2012 are examined. The material comprises 50 relevés, of which 43 date from 2012 and the other 7 - from 1993. Reléves were arranged in 5 analytic tables. A synoptic table was also compiled, and for each syntaxonomical species group distinguished, values of the cover coefficient (C), the collective group share index (G), and the systematic group value (D) were estimated and compared. On the basis of the obtained results, a significant decline in abundancy and/or constancy was observed within the following groups: Ch. Artemisietea vulgaris, Ch. Cirsio-Brachypodion pinnati, Ch. Festuco-Brometea, Ch. Geranion sanguinei, Ch. Koelerio-Corynephoretea, and Ch. Origanetalia and Trifolio-Geranietea sanguinei, whereas for the taxa of the Rhamno-Prunetea, a notable increase in the share of the reserve vegetation was recorded. A sizeable expansion of the moss layer was also observed in this period. The results are discussed with special regard to differences in the methodical background of both field studies.


Ecopersia ◽  
2017 ◽  
Vol 5 (1) ◽  
pp. 1711-1730 ◽  
Author(s):  
Amin Salehpour Jam ◽  
◽  
Mahmoudreza Tabatabaei ◽  
Amir Sarreshtehdari ◽  
◽  
...  

Author(s):  
Gary R. E. Beckstead ◽  
Drum S. Cavers

Pipeline crossings of streams, whether large or small, must consider the ability of the stream channel to scour its bed and erode its banks. Case studies are presented to illustrate the kinds of dynamic environments which must be considered in designing pipeline stream crossings. These characteristics may be determined through the use of comparative historical aerial photography and site photographs and surveys. The case studies presented as examples in this paper include gullies, bedrock-lined channels, entrenched meandering streams, multi-channel wandering streams, degrading channels, alluvial fans, and major channels affected by regulation and man-made structures. Natural hazards such as debris jams and beaver dams are also discussed. For each case study, the characteristics of the channels are described, the design approach discussed and site-specific constraints presented which affected the final design.


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