Three colonies of wood-ants Formica lugubris were taken from native Caledonian pinewoods and re-established in the laboratory. Experiments were conducted during which each of these colonies was provided with two discrete patches at which foragers could drink from filter papers saturated with aqueous solutions of sucrose; these patches were replenished continuously with the solutions. Three series of experiments were conducted in which the hypothesis tested was that the ants would distribute themselves between the patches according to the ideal free distribution. During the first series of experiments, the rate of supply of sucrose was manipulated by changing the concentrations of the solutions while maintaining equal rates of supply. Under each concentration ratio an equilibrium distribution was established. When the concentrations were equal, foragers distributed in a ratio of 1:1. When the concentrations were unequal the proportion of foragers at the richer patch was consistently less than the proportion of sucrose available there; ratios of sucrose of 1:2 and 1:4 were associated with equilibrium distributions of foragers in the ratios of approximately 1:1 and 1:2 respectively. In the second series of experiments, it was shown that these ratios were dependent on the overall rate of regeneration of the solutions; increases in the overall rate of regeneration were associated with increased proportional occupation of the richer patch. Throughout this experiment, the concentrations of the solutions were 7% w/v and 28% w/v and the rates of regeneration of the solutions at both patches were equal. Distributions were established at four different rates of regeneration. At the lowest rate of regeneration (0.2ml.h-1) the proportion of foragers at the richer patch was significantly lower than the ideal free prediction of 0.8. At the three higher rates of regeneration (0.4ml.h-1, 0.6ml.h-1 and 0.8ml.h-1) the proportion of foragers at the richer patch was significantly greater than the proportion of sucrose available there.

In 2001-2004 investigation was made in Rūdiškės forest, which is a part of Trakai Forest Enterprise, Rūdiškės Forestry. 74 bird species were recorded. They belong to 11 orders. Number of local populations, community structure and their dynamics were investigated in breeding, late summer, autumn migration, wintering and spring migration seasons. The local breeding bird community consists of 62 species. Chaffinch (Fringilla coelebs L.) is an absolute dominate. Chiffchaff (Phylloscopus collybita (Vieill.)), Great Tit (Parus major L.) and Tree Pipit (Anthus trivialis (L.)) are dominants. The lowest number of species of the Rūdiškės forest bird community is characteristic for autumn and winter seasons (31 and 24 species respectively). Fluctuations of numbers of the local populations in the some seasons were statistically not significant in 2001-2004. As an exception, population density of Long-tailed Tit (Aegithalos caudatus (L.)) differed considerably in autumn migration season of the 2001-2003. Variation of numbers of the local population of Great Tit (Parus major L.), Chaffinch (Fringilla coelebs L.) and Eurasian (Treecreeper Certhia familiaris L.) was rather high in spring season as well. Most important factors responsible for habitat selection of Mistle Thrush (Turdus viscivorus L.), Stock Dove (Columba oenas L.), Wood Lark (Lullula arborea L.), Common Redstart (Phoenicurus phoenicurus L.), European Nightjar (Caprimulus europaeus (L.)) and Tengmalm’s Owl (Aegolius funereus... [to full text]

Consideration of forest management at the landscape scale is essential if commitments to the conservation of biodiversity are to be upheld. The ecosystem management approach, developed largely in North America, has made use of various landscape modelling tools to assist in planning for biodiversity maintenance and ecological restoration. The roles of habitat suitability models, metapopulation models, spatially explicit population models (SEPMs) and forest landscape dynamics models (FLDMs) in the planning process are discussed and a review of forest dynamics models is presented. Potential is identified for developing landscape models in the UK for both landscape restoration projects and semi-natural woodland management. Glen Affric, in northern Scotland contains a large area of native pine and birch woodland and is the subject of a long-term restoration project. A new model, GALDR (Glen Affric Landscape Dynamics Reconstruction) is introduced and is believed to be the first FLDM developed for British woodland. The theory behind the model is described in detail and preliminary results and sensitivity analyses are presented. Furthermore, GALAM (Glen Affric Lichen Abundance Model), a new SEPM for the rare epiphytic lichen Bryoria furcellata is also described. Results of simulations from the linked GALDR and GALAM models are presented which shed light on the role of landscape heterogeneity in determining the dynamics of lichen habitats and populations. It is concluded that, whilst much work will be required to develop a management-oriented decision support system from the GALDR model, the modelling process may aid researchers in the identification of knowledge gaps in ecological theory relevant to management and restoration.