Effects of altitudinal gradient on species composition of naturally regenerated trees in Larix kaempferi plantations in central Japan

2010 ◽  
Vol 15 (1) ◽  
pp. 65-70 ◽  
Author(s):  
Takuo Nagaike
2007 ◽  
Vol 19 (1) ◽  
pp. 17-24 ◽  
Author(s):  
Niek J.M. Gremmen ◽  
Bart van de Vijver ◽  
Yves Frenot ◽  
Marc Lebouvier

Altitudinal gradients provide excellent opportunities to study relationships between species distribution and climatic variables. We studied the species composition of 39 samples of moss-inhabiting diatoms, collected at 50 m intervals from 100–650 m above sea level. The samples contained a total of 130 diatom species, of which 51 occurred in 10 or more samples. Altitude appeared to be the most important variable explaining variation in species composition. Of the 51 common species, 33 showed a significant relationship with altitude. Although the majority of the latter declined with increasing altitude, for nine species the probability of occurrence first increased with increasing elevation, but decreased again at higher altitudes, and four species increased systematically with elevation. As a result, expected species richness per sample decreased from an estimated 43 at 100 m to 25 species per sample at 650 m. Diatom distribution patterns proved to be suitable predictors of the altitudinal position of sample sites. Cross-validation yielded a strong relationship between predicted and observed altitudes.


2017 ◽  
Vol 3 (01) ◽  
pp. 07-13
Author(s):  
Vertika Shukla ◽  
Rajesh Bajpai ◽  
Manoj Semwal ◽  
D. K. Upreti

In recent years there has been growing interest in the study on lichen diversity with relation to altitudinal gradient and anthropogenic disturbances , as changes in lichen community composition may indicate air quality and microclimatic changes. The altitudinal data of species diversity and its subsequent changes with respect to time and space may provide vital information regarding impact of air pollution and/or climate change at regional or global scales. Chopta-Tungnath and adjoining areas of Garhwal Himalaya provide habitat and ecological variation with range of altitude lying between 300 to 3000 m. Out of the 116 species of lichens known from the studied area, the highest species diversity was observed between altitudes 1800 to 2100 m. Lichen communities occurring between 600–1800 m were dominated by members of Physciaceae, while Parmeliaceae were most common above 1800 m. Altitude beyond 2100 m experiences high precipitation, varying temperature conditions and increased incident UV radiation, which are responsible for controlling the variability in lichen diversity to a great extent in the region. The diversity of secondary metabolites in lichen species and consequent changes in species composition at various altitudes indicate the association of secondary chemicals in conferring the lichens resistance to biotic and abiotic stresses. The correlations of lichen diversity, secondary metabolites and the altitudes at which the lichens are growing, present suggestive role of secondary metabolites in determining species composition and sustainability in different environmental conditions.


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