The thesis aims for relationship between military-caused disturbance intensity and species richness, conservation value and composition of arthropods communities in the Brdy Mts. In the Brdy abandoned military area (MTA), a highly heterogeneous habitat mosaic developed by the long-term influence of military disturbances on two shooting areas of Jordán and Tok. The habitats range from strongly disturbed sites with sparse vegetation, through heterogeneous growths of Erica and Vaccinium in moderately disturbed sites, to sparse woodlands in the least disturbed sites. Based on the shooting areas history reconstruction, 24 study plots of 4 categories of different disturbance intensity were selected in both shooting areas together. Standardized sampling of seven groups of arthropods was performed in summer 2017 by pitfall traps, yellow pan traps, and light traps. More intensive disturbances positively influenced species richness of Aculeates and conservation value of spiders and beetles, but negatively affected species richness of moths. Simultaneously, the intensity of disturbances affected community composition of spiders, moths, beetles, Aculeates and Orthopteroids. Endangered species mostly affiliated to the more intensively disturbed plots. This results should be helpful in understanding of influence...

Abstract not available

The work has consisted of the measurement of processes connected with the normal management of grouse moors in the Glen Clova area of Angus. The problems associated with burning have been summarised together with the remits of previous work. The geology and topography of Glen Clova have been described briefly, and the vegetation of the Rottal area of the glen has been described in detail with respect to the particular parts under consideration. A method of ring counts has been used to define the age of Calluna stands. The methods used for analysis of mineral nutrients have been described. One method, Atomic Absorption Spectroscopy, has required extensive calibration and has been described in more detail. It has been shown that the temperature and duration of heath fires depends upon the age of the vegetation. The temperature and duration of a fire determined the loss of nitrogen in the form of smoke. The temperature of a fire has been shown to affect the solubility of nutrients in ash. Increase in temperature caused a greater release of soluble potassium and calcium, but a decrease in soluble phosphate, The release of mineral nutrients from Calluna leaf litter has been compared with that from ash. Experiments were instigated to measure the effect of grazing upon the yield and mineral content of Calluna, the greatest effect being found 5 - 10 years after burning. The addition of mixed fertiliser to some of the stands was found to increase the yield and nutrient content of the leaven of Calluna. Soil samples from 22 stands of Calluna were analysed in November each year, for three years, and the total content of nitrogen, phosphate, potassium, magnesium, calcium and iron estimated. In the first instance other analyses including pH, conductivity, organic carbon and mechanical analysis were performed in order to distinguish between the two soil types present. Significant changes in the nutrient content of the soils have been discussed. A balance sheet of the losses and gains to the ecosystem was prepared to indicate the changes in mineral nutrients. it has been calculated that the potential losses of individual nutrients by leaching, ignition and grazing could be replaced over a period of 15 years from rainwater, with the exception of phosphate which is only present in small quantities in rainwater. The implications of the results have been discussed.

Heathlands typically experience regimes consisting of frequent and intense fires. These fire regimes play important roles in the lifecycles and population dynamics of all species in these communities. Prescribed fire is commonly applied to heathlands to minimise the risk of wildfires as well as to promote biodiversity. Ignitions in heathlands tend to either be unsustainable, or quickly develop into rapidly spreading intense fires. This presents a major problem for the application of prescribed fire and is the primary focus of this thesis. Heathland ignition has been investigated in three sections; litter ignition; vertical development of fire into the shrub layer; and horizontal spread through the shrub layer. These were studied in laboratory experiments using miniature versions of field fuels. Ignition success in litter layers was related to the dead fuel moisture content. Litter type, ignition source, and presence of wind were found to affect the range of ignitable fuel moisture contents of a litter bed. The effect of litter type was best explained by density. Dense litter beds required drier conditions for ignition than low density litter beds. The vertical development of fire into shrubs was mostly dependent on live fuel moisture content, but crown base height, presence of wind, ignition source, shrub height and the percentage of dead elevated fuel were also important. Horizontal spread of fires through shrub layers was most affected by the presence of a litter layer, with nearly all ignitions successful when there was an underlying litter fire. Fire spread would only occur in shrubs without a litter layer when the shrub layer was dense and dry, or had a substantial dead fuel component. Spread was more likely to be sustained when there was wind. Models predicting the moisture content of dead fuels were tested in heathlands, and as would be expected those that can be calibrated for different fuel types were found to have the best performance. Fuel moisture content and fuel load models were reviewed for heathlands, and a number of recommendations for future research were made.