Termites are important ecosystem engineers in tropical and sub-tropical terrestrial regions where they influence ecosystem processes by altering the physical and chemical structure of the habitat. Termites affect nutrient availability by decomposition and comminution (shredding) of organic matter and act as agents of bioturbation as they re-work substrates during the construction of nests, tunnels and runways. At present we have a relatively good understanding of termite diversity patterns in the tropics through the extensive use of the standardised transect sampling protocol by Eggleton et al. (1995). These diversity data suggest that there is a functional difference in termite assemblage structure, and potentially in termite abundance and biomass, among comparable habitats across continents. However due to the lack of comparable abundance and biomass data from South America this has not previously been confirmed. In this thesis I, therefore, collected extensive data on termite taxonomic and functional assemblage structure in a South American site in Peru. The data were used to compare termite abundance and biomass from two comparable sites in Africa (Cameroon) and south east Asia (Malaysia) in order to gain better understanding of the role termites play in ecosystem processes. I found that there was an intercontinental difference in the abundance and biomass of termite feeding-groups mainly due to the dominance of soil-feeding termites in Cameroon and the absence of fungus-growing termites from Peru. The impact of certain lineages on the intercontinental differences suggests that the differences may be due to biogeographical evolution. Moreover, Eggleton et al. (1998) show that larger-bodied soil-feeding termites in Cameroon process more energy per unit area than predicted by their body size. Due to the need for an examination of the allometric relationships in termite assemblages outside Africa and the development of a more sophisticated feeding-group classification I explore the findings in Eggleton et al. (1998) further using population density - body mass relationships in three termite feeding-groups among the three continental sites in Cameroon, Peru and Malaysia. I found that large-bodied soil-feeding termites in Cameroon and large-bodied wood-feeding termites in Peru had higher population densities than expected by their body masses. As the population density - body mass relationship is inverse to that of the energy - body mass relationship the results suggest that the two feeding-groups also use more energy than expected by their body masses. Further, we have a relatively good understanding of the role termites play as ecosystem engineers e.g. in nutrient cycling and distribution, however, compared with our understanding of wood and litter decomposition in tropical forests quantitative data on the impact of termites in soil processes is poorly understood. In this thesis I conducted, to our knowledge, the first in situ soil macrofauna exclusion experiment using translocated soil in Peru to examine the impact of termites on soil C and N loss. I found that termites promote soil C and N loss which may be linked to the increase in microbial activity due to the passage of soil through the termite gut as well as the affect termites have on bioturbation and nutrient distribution. To conclude, in this thesis I present the first intercontinental comparison of abundance and biomass as well as the first in situ soil macrofauna exclusion experiment to date. The link between termite ecology, biogeography and evolution is discussed as well as the contribution of this thesis to the field of termite ecology.

This thesis describes the shift in vegetation of broadleaf forests in eastern part of the Elbe River Basin between 1958-1968 and 2011-2013. It emphasizes the understorey vegetation. From lowland woodlands in other temperate regions in Europe and North America changes towards eutrophic and mesophytic vegetation are documented, specifically driven by changes in forest management and by atmospheric depositions; in some localities the game impact can be also important. The data were obtained by sampling 190 typological semi-permanent plots, which were precisely located - in 43% the original soil pit was found. The vegetation on study sites shifted towards nutrient-demanding, shade- adapted species, it was partly ruderalized. These changes can be seen on the level of species and communities as well as on phytosociological level. Increase of soil pH and moisture was discovered using Ellenberg indicator values. The number of seedlings and cover of shrubs also increased significantly. Homogenization of sites was significant as well although total number of species and alpha- diversity remained unchanged. These changes are probably caused by changes in forest management and by atmospheric depositions of nitrogen. On subset of plots in game-preserves the vegetation also demonstrated eutrophication but no increase in...

Long-term forest vegetation changes were studied in the Bohemian Forest and its foothills. New vegetation relevés were taken at sites of typological plots established by forest engineers between 1955 and 1980. Data from 158 semi-permanent plots were analysed using modern statistical methods. The data show significant changes and homogenization of the vegetation. Ellenberg indicator values indicate eutrofication. Repeated measurements of soil pH suggest acidification, but the interpretation of these data is complicated by methodological problems. The forests under study exhibit high spatial variability. No main prevailing trend in vegetation changes was found. The changes are considered to be related to sulphur and nitrogen deposition and forest management. The influence of increasing age of forest stands seems to be unimportant. Discussed are not only vegetation changes and their possible causes but also the possibilities and limitations of using such old forestry data in botanical and ecological studies.

No description available.

Because of the scarcity of information for bird communities at the major mainland rivers of southeastern Alaska, the main objective of this study was to provide baseline information including distribution, status, and habitat associations of breeding birds. I conducted a meta-analysis of all known reports (including the current study) conducted at major mainland rivers during the breeding season. I described bird species composition, distribution, abundance estimates, status, habitat associations, and guild membership for all birds recorded at 11 major mainland rivers. Based on incidental observations, 170 species were recorded by all studies. Of these, 134 species were known or suspected to breed, accounting for 50% of all birds known from Alaska and 80% of all birds known from southeastern Alaska. In addition, I provided information on species of management concern as well as management implications and recommendations. I used point counts to survey birds within deciduous riparian vegetation at 6 major mainland rivers during 2000-2002. I compared bird species composition, abundance, richness, and diversity among four main vegetation types of deciduous riparian vegetation: shrubland, young deciduous forest, mature deciduous forest, and mixed deciduous-coniferous forest. Species richness was similar among all habitat types; however, relative abundance and diversity of birds was highest in mixed forest stands. Mature forests had the greatest number of species associated with the Canadian interior. I also used point counts to compare bird species composition, abundance, richness, and diversity among 6 major mainland rivers consisting of three trans-mountain and three coastal rivers. Latitude, connectivity, and availability of mature and mixed forests were the major factors thought to cause differences in bird communities among rivers. Contrary to our predictions, coastal rivers had higher bird species richness, diversity, point abundance , and point richness than trans-mountain rivers. Of the 10 species associated with the Canadian interior recorded during point counts, 8 occurred at both trans-mountain and coastal rivers.

Shallow sheltered Baltic Sea bays are ecologically important habitats that harbour a unique vegetation community and constitute vital reproduction areas for many coastal fish species. Knowledge about the invertebrate community in these bays is, however, limited. This thesis examines the macroinvertebrate community in shallow sheltered Baltic Sea bays and how it is affected by: (1) the natural morphometric isolation of bays from the sea due to post-glacial land uplift; and (2) differences in vegetation types. The invertebrate biomass and number of taxa was found to decrease with increased bay isolation. The taxon composition changed from dominance by bivalves and gastropods in open bays to a community composed of a larger proportion of insects in isolated bays. Stable isotope analysis indicated epiphytes and periphyton as the major energy resources for most of the examined consumers, but the relative importance of these in relation to larger plants decreased for some consumers with increased bay isolation. A comparison of invertebrate abundance between plants revealed a close relationship with morphological complexity of the plants. More complexly structured plants had higher invertebrate abundance than plants with simpler morphology. The results suggest that management of these coastal habitats should be dynamic and take into consideration the natural change in invertebrate community resulting from the slow bay isolation process. In addition, the results imply that changes in the aquatic vegetation due to anthropogenic influences could induce changes in the invertebrate community as the plant habitat structure is altered. A changed invertebrate community may in turn affect higher trophic levels since invertebrates are important food for many fish and waterfowl species. / At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: Submitted. Paper 4: In press.

Darbo objektas – grynų eglynų pomiškis Lietuvos miškuose. Darbo tikslas – ištirti savaiminio žėlimo priklausomybę eglynuose nuo jų erdvinės struktūros. Darbo metodai : miškų inventorizacijos ir laikinų apskaitos aikštelių duomenų analizės, matematinės statistikos metodai. Darbo rezultatai. Remiantis miškų inventorizacijos bei laikinų apskaitos aikštelių duomenimis, išanalizuotas pomiškio kiekis eglynuose priklausomai nuo jų augavietės, amžiaus, skalsumo bei medyne susidariusių aikščių dydžio. Nustatyta, kad tik 20 % vyresnių nei 40 metų eglynų turi pomiškio. Didžiausias kiekis pomiškio rastas Ld ir Nb augavietėse (1,9 tūkst. vnt./ha). 4 – 12 amžiaus klasių eglynuose didėjant amžiui pastebimas nežymus pomiškio kiekio didėjimas. Ištyrus pomiškio kiekio priklausomybę nuo skalsumo nustatyta, kad skalsumui mažėjant, pomiškio kiekis didėja. Pomiškio kiekis priklausomai nuo aikštės dydžio svyruoja nuo 12 iki 17 tūkst. vnt./ha aikštės plotui didėjant nuo 2 iki 10 arų. / Work subject – Undergrowth of spruce stands in Lithuanian forests. Work objective – To estimate forest grows in itself of spatial structure in spruce stand. Work methods: Data analyses of forest inventory and temporary of free space in forest, mathematical statistics methods. Work results. Was made analyses of spruce undergrowth quantity in different forest site type, age, growing stock and free space size in forest. It was established that 20 % of older then 40 years spruce forests has undergrowth. The biggest amount of growth was found in Ld and Nb forest site types. When age is growing in 4 – 12 age class of spruce the undergrowth quantity is growing too. It is ascertain that undergrowth quantity is rise up when growing stock is felling down. Undergrowth quantity variations of 12 to 17 thous.units/ha when free space size in forest variation of 2 to 10 are.

Conservation of wood-decaying fungi requires improved knowledge about the long-term effects of forest management; regarding habitat loss, fragmentation and fire suppression. To better understand such effects, I examined the influence of area, isolation, fire history and forest stand characteristics on communities of wood-decaying fungi. Species richness and composition were studied along a gradient of 22 forested islands varying in size (0.16 to 17.58 ha) and fire history (spanning 5000 years) in a boreal forest archipelago in northern Sweden. A total of 490 records of 41 polypore species were found in 33 circular plots, each 0.1 ha in size. Species richness and the number of red-listed species were analyzed using generalized linear models (GLMs), while species composition was examined using non-metric multidimensional scaling (NMDS) ordination. The species composition was clearly different between recent-fire (< 300 years since last fire) and old-fire (≥ 300 years since last fire) islands, mirroring the shift in tree species composition as pine-associated fungal species were replaced by spruce-associated fungal species. The volume of logs was the only variable influencing the species richness, although the diversity of logs showed a clear trend of also influencing species richness positively. The results demonstrate the importance of having both recent-fire and old-fire forests as landscape-level habitats and species pools, where fire naturally would constitute a key role for maintaining forest biodiversity in the boreal forest landscape. The results also stress the importance of dead wood for species richness at the individual forest stands.

Macrophytes are an integral component of lake littoral zones and play an irreplaceable role in maintaining the ecological balance of wetlands. Recent research has highlighted the role of lake-scale environmental factors (or “filters”) and catchment- and/or landscape-scale processes in explaining variation in macrophyte communities across different scales. In this work, the effects of land-use and connectivity on macrophyte communities were explored at two contrasting spatial scales (i.e. local catchment scale and topographic catchment scale). At the local catchment scale, the results revealed strong scale-dependency. The effects of land use on macrophyte richness were most apparent at fine spatial scales (within 0.5 to 1 km) and significantly outweighed the importance of hydrology. In terms of growth form composition, the effects of hydrological connectivity were stronger than those of land use, with the greatest effect observed at an intermediate distance (~ 5 km) from the lake. The study on the hydrologically-connected lake pairs indicated that environmental filters were more influential in explaining species turnover than lake connectivity. Interestingly, geographical connectivity explained more of the variability in species turnover than hydrological connectivity. Moreover, the relative importance of environmental filters and lake connectivity to species turnover was very sensitive to the degree of human disturbance. The multi-scale interaction analyses indicated the effect of lake alkalinity on macrophyte composition is strongly influenced by catchment scale variables including hydrological features and land use intensity. The turnover in macrophyte composition in response to variability in alkalinity was stronger in catchments with low lake and stream density and weaker in catchments with a more highly developed hydrological network. Lake abiotic variables were found to have more influence on macrophyte composition in lowland catchments with a higher intensity of human disturbance. Moreover, the catchment-scale factors promoting the establishment of different communities were found to vary between catchments depending on lake type, the degree of environmental heterogeneity and hydrological connectivity.

Lichens are the result of an symbiotic interaction between fungus, the mycobiont, and one or more photosynthetic components, the photobionts, which can be a green algae and/or a cyanobacteria. This study aimed to compare the species richness and composition of corticolous crustose lichens in two forest types, Caatinga and Brejo de Altitude, in relation to the influence of biotic and abiotic parameters such as light, bark pH and diameter at breast height (DBH) of the host, and elevation. To collect the lichens two transects of 300 m each were delimited, one per site. Along these transects, sampling points were marked every 10 m, in a total of 30 points per site and 60 points for the whole work. For each of the points, the nearest tree was selected which had a lichen cover at the height of 0.5 m to 1.50 m from the ground on the tree trunk. The species richness and composition for each area were analyzed. Altogether, 576 samples were collected, totaling 96 species of corticolous microlichens. There was no significant difference in species richness between the two areas. With respect to the species composition, the areas were different, but with some common species between them. Comparing the species richness of corticicolous lichens with biotic and abiotic factors, only the diameter at breast height (DBH) of the selected host presented a significant relationship. Relating the composition and biotic and abiotic factors, we had elevation, DBH and vegetation types, canopy openness, influencing the species composition. Thus, the results presented in this study are intended to contribute to the ecological knowledge of lichenized fungi, and enhancing the ecological and lichenological knowledge on Caatinga and Brejo de Altitude. / Os liquens surgem a partir da interação simbiótica entre um fungo, o micobionte, e um ou mais componentes fotossintéticos, fotobiontes, que podem ser algas verdes e, ou cianobactérias. Este trabalho teve como objetivo comparar a riqueza e composição de liquens corticícolas crostosos em duas fitofisionomias, Caatinga e Brejo de Altitude, no semiárido brasileiro, verificando se a riqueza e composição de espécies destes liquens são influenciadas pelos fatores bióticos e abióticos, como luminosidade, pH da casca e diâmetro na altura do peito (DAP) do hospedeiro, e altitude. Para a coleta dos liquens, foram demarcados dois transectos de 300 m, um em cada área de estudo. Ao longo destes transectos foram demarcados pontos a cada 10 m, sendo 30 pontos para cada área, perfazendo um total de 60 pontos. Para cada ponto demarcado, foram adotados como critério de escolha do hospedeiro a maior proximidade do ponto e a presença de talos liquênicos na altura de 0,5 m até 1,50 m em relação ao solo no tronco da árvore. Foram analisadas a riqueza e composição de espécies para cada área. Ao todo, foram coletadas 576 amostras, totalizando 96 espécies de microliquens corticícolas. Não houve uma diferença significativa na riqueza entre as duas áreas. Com relação à composição de espécies, as áreas apresentaram diferença, porém com algumas espécies comuns para as duas áreas. Comparando a riqueza de liquens corticícolas com os fatores bióticos e abióticos, apenas o diâmetro à altura do peito (DAP) do hospedeiro selecionado, apresentou-se de forma significativa em relação à riqueza de espécies de liquens corticícolas. Relacionando a composição de espécies e os fatores bióticos e abióticos, tivemos elevação, DAP e fitofisionomias (local), abertura do dossel, e riqueza influenciando a composição. Desta forma, os resultados apresentados neste estudo visam contribuir para o conhecimento ecológico dos fungos liquenizados, assim como se torna subsídio para outras pesquisas que venham a aprimorar e enriquecer o conhecimento ecológico e liquenológico da Caatinga e Brejos de Altitude.