Spatial Diversity of Bird Communities of the Middle Taiga of the Central Siberian Plateau

2016 ◽  
Vol 23 (1) ◽  
Keyword(s):  
Spatial Diversity ◽  
Bird Communities ◽  
Middle Taiga

The spatial diversity of bird communities in the middle taiga of the Central Siberian Plateau

2016 ◽  
Vol 9 (1) ◽  
pp. 9-17 ◽  
Author(s):  
L. G. Vartapetov ◽  
A. G. Larionov ◽  
N. N. Egorov
Keyword(s):  
Spatial Diversity ◽  
Bird Communities ◽  
Middle Taiga

Functional evenness of bird communities varies along the elevational gradient in Europe: Conservation implications

2019 ◽  
Author(s):  
Federico Morelli ◽  
Yanina
Keyword(s):  
Species Richness ◽  
Elevation Gradient ◽  
Bird Species ◽  
Elevational Gradient ◽  
Negative Association ◽  
Bird Communities ◽  
Breeding Bird ◽  
Bird Species Richness ◽  
Large Spatial Scale ◽  
Functional Evenness

ContextThe negative association between elevation and species richness is a well-recognized pattern in macro-ecology. ObjectivesThe aim of this study was to investigate changes in functional evenness of breeding bird communities along an elevation gradient in Europe. MethodsUsing the bird data from the EBCC Atlas of European Breeding Birds we estimated an index of functional evenness which can be assumed as a measure of the potential resilience of communities.ResultsOur findings confirm the existence of a negative association between elevation and bird species richness in all European eco regions. However, we also explored a novel aspect of this relationship, important for conservation: Our findings provide evidence at large spatial scale of a negative association between the functional evenness (potential community resilience) and elevation, independent of the eco region. We also found that the Natura2000 protected areas covers the territory most in need of protection, those characterized by bird communities with low potential resilience, in hilly and mountainous areas.ConclusionsThese results draw attention to European areas occupied by bird communities characterized by a potential lower capacity to respond to strong ecological changes, and, therefore, potentially more exposed to risks for conservation.

Vegetation structure of tundra and taiga on the map of the natural vegetation of Europe

2007 ◽  
pp. 13-22 ◽  
Author(s):  
T. K. Yurkovskaya
Keyword(s):  
Vegetation Cover ◽  
Abiotic Factors ◽  
Self Regulation ◽  
Space Structure ◽  
Middle Taiga ◽  
Russian Plain ◽  
Forest Communities ◽  
The North ◽  
Tundra Vegetation ◽  
Starting Point

I have focused only on some features of structure in the taiga vegetation cover. In conclusion I would like to tell some words about the causes of complicated space structure of the taiga and tundra vegetation cover. The causes of latitudinal differentiation are climatic undoubtedly, but heterogeneity of vegetation cover within the limits of tundra and taiga subzones is accounted for different factors. In tundra abiogenic factors prevail, first of all the permafrost processes. That is the reason why tundra vegetation cover is so sensible to any disturbances and so hard regenerates after various transformations. In taiga the space structure is mostly the result of self-regulation and self- restoration of biota. The abiotic factors, certainly, play significant role, but they recede to the second plan. So we showed that in the north and middle taiga the structure of vegetation cover, during the Holocene up to present time, is determined in many respects by the increasing role of mires. Suffice it to look at the map of distribution of mires in order to estimate their role in vegetation cover of the easteuropean taiga (Yurkovskaya, 1980). So, the increase of mire area on the Russian Plain in m2/year per 1000 ha varies between 200 and 700, the average increas is ca 300—400 m2/year (Elina et all., 2000). The mires favour peniplenization and unite the separate areas of forest communities into the whole by means of forming the buffer paludificated territories (various hydrophilous variants of forest communities). But if mires, at all their stability, after destroying practically don't restore, the forests even after continuous cuttings restore their structure and composition through the series of successional stages unless an ecotope is damaged completely. Hence the space structure of taiga is the result, first of all, self development and self regulation of its vegetation cover. But, as it is known, at present time the process of destruction of natural biota has gone too far that the question arises not only about supporting its state and structure but also about the survival of the mankind itself. In this regard the vegetation map of Europe is the invaluable basis, which gives the starting point for all conservational, ecological and economical measures. But it is important to learn reading and using the map. And this is one of our actual goals.

MIMO Systems in a Composite Fading and Generalized Noise Scenario: A Review

2020 ◽  
Vol 14 ◽  
Author(s):  
Keerti Tiwari
Keyword(s):  
System Performance ◽  
Performance Enhancement ◽  
Channel Model ◽  
Mimo Systems ◽  
Mimo System ◽  
Spatial Diversity ◽  
Spatial Multiplexing ◽  
Channel Models ◽  
Efficient System ◽  
Composite Channel

: Multiple-input multiple-output (MIMO) systems have been endorsed to enable future wireless communication requirements. The efficient system designing appeals an appropriate channel model, that considers all the dominating effects of wireless environment. Therefore, some complex or less analytically acquiescent composite channel models have been proposed typically for single-input single-output (SISO) systems. These models are explicitly employed for mobile applications, though, we need a specific study of a model for MIMO system which can deal with radar clutters and different indoor/outdoor and mobile communication environments. Subsequently, the performance enhancement of MIMO system is also required in such scenario. The system performance enhancement can be examined by low error rate and high capacity using spatial diversity and spatial multiplexing respectively. Furthermore, for a more feasible and practical system modeling, we require a generalized noise model along with a composite channel model. Thus, all the patents related to MIMO channel models are revised to achieve the near optimal system performance in real world scenario. This review paper offers the methods to improve MIMO system performance in less and severe fading as well as shadowing environment and focused on a composite Weibull-gamma fading model. The development is the collective effects of selecting the appropriate channel models, spatial multiplexing/detection and spatial diversity techniques both at the transmitter and the receivers in the presence of arbitrary noise.

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