• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 1
  • 1
  • Tagged with
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Vliv dřevinné skladby a stáří lesních porostů na složení hnízdních ornitocenóz

Neoralová, Kateřina January 2015 (has links)
This thesis evaluates the influence of selected stand characteristics of deciduous forest on the composition of nesting ornithocenosis. Especially the influence of the composition of forest stand age and structure and abundance of cavity trees. Using the point counting method, composition of nesting birds has been found on 50 census points located systematically in the stands of different ages and with different tree composition (mainly various presence of European beech (Fagus sylvatica L.) and oak (Quercus spp.)). There were 1119 birds in total belonging to 38 species. It turned out that the presence of oak in vegetation affects the numbers of Finches, Great Spotted Woodpeckers, Blue Tits, Blackbirds, Golden Orioles, Cuckoos and Wood Pigeons. Presence of beech in forests affected some bird species with the opposite trend to the presence of oak in most cases. The number of species and individuals and diversity of bird communities at the census points increased with increasing presence of oak and decreased with the presence of beech. Stand age and spatial structure appeared to be an important factor in the occurrence of some bird species. The highest number of species has been recorded in the old stands. Cavity trees appeared primarily in old forests and had an impact on the presence of the Collared Flycatcher, Nuthatch, Chiffchaff and Willow Warbler. Generally, diversity and the number of species and individuals increased with the number of cavity trees. Nesting densities were calculated. Birds with the highest brood densities were Chaffinch, Great Tit, Nuthatch, Blue Tit, Chiffchaff and Great Spotted Woodpecker. Decreased abundance of ornithofauna during the nesting season has also been shown.
2

Bush recession - Dubu Drift, Keiskamma River

Skead, C J (Cuthbert John) January 1962 (has links)
Caption "Lone Scotia species tree left standing when all other bush destroyed above Dubu Drift, on the Keiskamma R. southern King William’s Town district. Even the veld is destroyed. Ca. 1962"

Page generated in 0.0387 seconds