• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 2
  • 1
  • 1
  • Tagged with
  • 5
  • 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

Analýza druhového zloženia vegetácie rastúcej na čiernych skládkach vo vybranom území

Maxianová, Alžbeta January 2017 (has links)
This thesis named Analysis vegetation grown on illegal landfills in selected areas is deal with illegal landfills and vegetation grown on them. For research were used two localities with illegal waste. On this localities were demarcation some fields and during every seasons (spring, summer, autumn) was done phytosociological relevés. One phytosociological relevé was on 16 m2 and contains data of coverage total and coverage of each part, also list of plant species and list of waste. Wastes were classified by catalogue of waste. After that were data from phytosociological releves and plant coverage valuated through programme Canoco.
2

Land use and vegetation change on the Long Mynd

Musgrove, Nicholas James January 2009 (has links)
The plant communities of the Long Mynd plateau are the culmination of over 3000 years of human intervention that largely deforested the uplands, and subsequently maintained the generally treeless heath and grassland communities now extant. The capacity of these communities to respond to directional change is well known, indeed the traditional mode of heathland management, burning, depends on the regenerative capacity of the target species, generally heather (Calluna vulgaris), for its success. However, changes in post WW2 stocking practice; the loss of ponies followed by an increase in the numbers of sheep and a change to them being overwintered on the hill, led to excessive grazing and damage to the heath. This coincided with the spread over the hill by bracken (Pteridium aquilinum) and other changes in the distribution and nature of the vegetation. A sequence of vegetation surveys made by various individuals and organisations over the past 75 years or so has been analysed in an attempt to delineate spatial and temporal changes in the vegetation. This demonstrated the need for a standardised survey methodology to allow consistent monitoring. The analysis showed that bracken had been infiltrating most of the communities from its origins outside the lower limits of the Common as well as from some of the valley sides. Within the last decade, this expansion has apparently been contained in line with the current management plan for control. A survey of 730 quadrats in some 30 stands was made to characterise the variation of the vegetation on the plateau, and to relate it to some of the associated environmental factors. Classification, unconstrained ordination and ordination constrained by the abiotic environmental variables, showed that, a) the strongest trend in the vegetation distinguished water-flushed communities, b) non-wetland communities differentiate between heathland and grassland, c) this trend can be only partly be attributed to the measured abiotic environmental variables, d) the amount of pure Pteridietum [U20] is limited, although much of the heathland and grassland has bracken within it. There are indications that invasion by bracken often correlates with a loss of dominance of Calluna in favour of Deschampsia flexuosa and Vaccinium myrtillus. Difficulties in associating these trends with measured abiotic variables suggests, other factors probably management processes, are critical in driving this trend. Distribution of ‘heathland’ bryophytes was found to be associated more with the structure of their ‘host’ vascular communities rather than with abiotic factors. Finally, this investigation considers the practical implications with regard to the future encouragement of heather and the control of bracken. Cutting rather than burning appears to be the ecologically most suitable method for heather regeneration and bracken control.
3

Stanovení vzorců selektivního chování rybářů ve statistikách českého rekreačního rybolovu / Stanovení vzorců selektivního chování rybářů ve statistikách českého rekreačního rybolovu

Jankovský, Martin January 2011 (has links)
Methods for detecting patterns of angler selective fishing behaviour in the long term recreational fishery statistics are presented in this Ph.D. Thesis. The motivating idea is that mainly different anglers' fishing preferences or attitudes towards particular fish species obstruct applying anglers' catches data for ongoing use in ichthyology research. Better recognising angler selectivity is therefore judged to be the key point from the viewpoint of fish and fishery sciences. Methods affecting angler behaviour can be directly applied by other specialists, e.g. social scientists. The thesis consists of five papers two of which are published (paper 1, 2), other two of which are accepted for publishing (paper 3, 4) and the last of which (paper 5) is in the status of manuscript before submitting. In the first two papers the role of common carp catches is focused. By using multivariate techniques it is studied if the increased exploitation of carp increases also the exploitation of other fish species. Time series of carp catches serve as an explanatory variable, other species catches through the same time are processed as independent variables. According to expectations the positive effect of carp catches on those of the other species was approved at the river section with the highest expected density...
4

Motýli českých maloplošných chráněných území - analýza s ohledem na funkční vlastnosti / Butterflies of Czech protected areas - analysis interpreted by functional traits

BARTOŇOVÁ, Alena January 2013 (has links)
Butterflies (Insecta: Lepidoptera) of 125 Czech national protected areas were counted covering all seasonal aspects. A matrix of several functional traits of each species was used to explain impact of characteristics describing heterogeneity and geometry of the reserves, after removing influence of geography and habitat type.
5

A Diatom Phosphorus Inference Model for 30 Freshwater Lakes in NE Ohio and NW Pennsylvania

Scotese, Kyle C. January 2008 (has links)
No description available.

Page generated in 0.1264 seconds