No description available.

Thesis (M. Sc.)--Carleton University, 2003. / Includes bibliographical references (p. 141-146). Also available in electronic format on the Internet.

Student Number : 0310612G - MSc research report - School of Geography, Archaeology and Environmental Studies - Faculty of Science / Wildfire prediction and management is an issue of safety and security for many rural communities in South Africa. Wildfire prediction and early warning systems can assist in saving lives, infrastructure and valuable resources in these communities. Timely and accurate data are required for accurate wildfire prediction on both weather conditions and the availability of fuels (vegetation) for wildfires. Wildfires take place in large remote areas in which land use practices and alterations to land cover cannot easily be modelled. Remote sensing offers the opportunity to monitor the extent and changes of land use practices and land cover in these areas. In order for effective fire prediction and management, data on the quantity and state of fuels is required. Traditional methods for detecting vegetation rely on the chlorophyll content and moisture of vegetation for vegetation mapping techniques. Fuels that burn in wildfires are however predominantly dry, and by implication are low in chlorophyll and moisture contents. As a result, these fuels cannot be detected using traditional indices. Other model based methods for determining above ground vegetation biomass using satellite data have been devised. These however require ancillary data, which are unavailable in many rural areas in South Africa. A method is therefore required for the detection and quantification of dry fuels that pose a fire risk. ASTER and MAS (MODIS Airborne Simulator) imagery were obtained for a study area within the Lowveld region of the Limpopo Province, South Africa. Two of the ASTER and two of the MAS images were dated towards the end of the dry season (winter) when the quantity of fuel (dry vegetation) is at its highest. The remaining ASTER image was obtained during the middle of the wet season (summer), against which the results could be tested. In situ measurements of above ground biomass were obtained from a large number of collection points within the image footprints. Normalised Difference Vegetation Index and Transformed Vegetation Index vegetation indices were calculated and tested against the above ground biomass for the dry and wet season images. Spectral response signatures of dry vegetation were evaluated to select wavelengths, which may be effective at detecting dry vegetation as opposed to green vegetation. Ratios were calculated using the respective bandwidths of the ASTER and MAS sensors and tested against above ground biomass to detect dry vegetation. The findings of this study are that it is not feasible, using ASTER and MAS remote sensing data, to estimate brown and green vegetation biomass for wildfire prediction purposes using the datasets and research methodology applied in this study. Correlations between traditional vegetation indices and above ground biomass were weak. Visual trends were noted, however no conclusive evidence could be established from this relationship. The dry vegetation ratios indicated a weak correlation between the values. The removal of background noise, in particular soil reflectance, may result in more effective detection of dry vegetation. Time series analysis of the green vegetation indices might prove a more effective predictor of biomass fuel loads. The issues preventing the frequent and quick transmission of the large data sets required are being solved with the improvements in internet connectivity to many remote areas and will probably be a more viable path to solving this problem in the near future.

Thesis (M.SC.) - Carleton University, 2007. / Includes bibliographical references (p. 136-146). Also available in electronic format on the Internet.

No description available.

Tyrimų rezultate buvo nustatyti trako ir gyvosios dirvožemio dangos pokyčiai pušynuose po atvejinių kirtimų I atvejo Na, Nb, Nc, Lb augavietėse bei įvertinti pomiškio gausumo pokyčiai. Įvertinta gyvosios dirvožemio dangos įtaka paprastosios pušies savaiminukų gausumui po I kirtimų atvejo tirtose augavietėse. Įvertintos kirtaviečių ekologinės sąlygos pagal Elenbergo fitoindikacinės skalės indikatorines vertes skirtingose augavietėse. Nustatyta smiltyninio ir miškinio lendrūnų fitometrinių parametrų ir elementinės sudėties pokyčiai po atvejinių kirtimų I atvejo. Atliktais tyrimais nustatyti dirvožemio cheminių savybių pokyčiai. Palyginta plynųjų ir atvejinių kirtimų įtaka dirvožemio temperatūros ir drėgnio, mineralinio azoto, ir kvėpavimo intensyvumo pokyčiams. / Results of the research allowed determining the changes of undergrowth and ground vegetation in pine forest after the first step of shelterwood cuttings in Na, Nb, Nc and Lb sites and to evaluate the alterations of saplings abundance. The influence of ground vegetation on the abundance of Scotch Pine sapling after the first step of shelterwood cuttings in investigated sites was assessed. Ecological conditions of cutting sites in different soil sites were estimated according to Ellenberg’s indicator values for phytoindication. The alterations of morphometric indices and chemical composition of wood small-reed and rough small-reed after the first step of shelterwood cuttings were assessed. The changes of soil chemical characteristics were determined after investigation. The influence of clear cuttings and shelterwood cuttings on the alterations of soil moisture, temperature, mineral nitrogen and respiration intensity was compared.

In Lithuania the energy production from the forest wood comprises up to 90% of the total biomass derived energy. Increasing use of wood fuel increases the removal of the plant essential nutrients from the ecosystem because the branches, tops and needles/leaves contain relatively higher amount of the nutrients than stems. If to compare with the removal of the stems-only, the nutrient losses from the forest ecosystem increase up to 5 times. One way to return nutrients to the ecosystem is to apply forest fuel waste – wood ash - as fertilizers. In this study the effects of the differential wood ash fertilization and ash fertilization in complex with nitrogen on the ground vegetation structure (species composition, abundance), biomass and chemical composition in Pinus sylvestris stands (forest type – Vaccinio-Pinetum) was estimated. For the first time, the long-term impact of nitrogen as well the influence of the high nitrogen doses on ground vegetation structure and abundance in Scots pine stands growing on infertile sandy soils (Haplic Arenosols) were studied in Lithuania. The spreading of the nitrophylous plant species in the ground vegetation in pine stands during 20 years period were detected. The role of the trees competition in the soil rhizosphere zone on ground vegetation was analysed. The following soil and ground vegetation parameters were estimated: soil moisture, pH and chemical composition, also the biomass of vascular plants, coverage, biomass and chemical... [to full text] / Lietuvoje iki 90% energijos gamybai naudojamos biomasės sudaro mediena. Iš miško išvežant visas miško kirtimo atliekas, o ne paliekant natūraliam suirimui, maisto medžiagų nuostoliai miško ekosistemoje padidėja iki 5 kartų. Kompensuojamasis miškų tręšimas medienos kuro pelenais – tai vienas iš būdų grąžinti maisto medžiagas į miško ekosistemą. Darbe įvertintas kompensuojamojo tręšimo medienos kuro pelenais diferencijuotas ir kompleksinis (kartu su azotu) poveikis brukninių pušynų gyvosios dirvožemio dangos struktūrai bei biomasės cheminei sudėčiai. Pirmą kartą Lietuvoje tiriamas ilgalaikio tręšimo azotu bei didelių azoto dozių poveikis brukninių pušynų, augančių nederlinguose smėlžemiuose, gyvosios dirvožemio dangos rūšių sudėčiai bei gausumui. Nustatytas foninių azoto iškritų sąlygotas nitrofilinių augalų rūšių išplitimas brukninių pušynų (Vaccinio-Pinetum) gyvojoje dirvožemio dangoje. Ištirtas miško ekosistemos edifikatorių konkurencinis poveikis rizosferoje: dirvožemio drėgniui, pH bei cheminei sudėčiai, žolių/krūmokšnių padengimui bei biomasei, gyvosios dirvožemio dangos dominanto bruknės (Vaccinium vitis-idea L.) biomasei bei biomasės cheminei sudėčiai. Atlikti tyrimai leidžia daryti išvadas, kad samanų rūšims tiek medienos kuro pelenų, tiek azoto poveikis yra neigiamas, tuo tarpu žolių/krūmokšnių rūšims – teigiamas. Visgi, azoto poveikis žolių/krūmokšnių rūšims priklauso ne tik nuo dozės, bet ir nuo patekimo į miško ekosistemą dažnio. Brukniniuose pušynuose... [toliau žr. visą tekstą]

Lietuvoje iki 90% energijos gamybai naudojamos biomasės sudaro mediena. Iš miško išvežant visas miško kirtimo atliekas, o ne paliekant natūraliam suirimui, maisto medžiagų nuostoliai miško ekosistemoje padidėja iki 5 kartų. Kompensuojamasis miškų tręšimas medienos kuro pelenais – tai vienas iš būdų grąžinti maisto medžiagas į miško ekosistemą. Darbe įvertintas kompensuojamojo tręšimo medienos kuro pelenais diferencijuotas ir kompleksinis (kartu su azotu) poveikis brukninių pušynų gyvosios dirvožemio dangos struktūrai bei biomasės cheminei sudėčiai. Pirmą kartą Lietuvoje tiriamas ilgalaikio tręšimo azotu bei didelių azoto dozių poveikis brukninių pušynų, augančių nederlinguose smėlžemiuose, gyvosios dirvožemio dangos rūšių sudėčiai bei gausumui. Nustatytas foninių azoto iškritų sąlygotas nitrofilinių augalų rūšių išplitimas brukninių pušynų (Vaccinio-Pinetum) gyvojoje dirvožemio dangoje. Ištirtas miško ekosistemos edifikatorių konkurencinis poveikis rizosferoje: dirvožemio drėgniui, pH bei cheminei sudėčiai, žolių/krūmokšnių padengimui bei biomasei, gyvosios dirvožemio dangos dominanto bruknės (Vaccinium vitis-idea L.) biomasei bei biomasės cheminei sudėčiai. Atlikti tyrimai leidžia daryti išvadas, kad samanų rūšims tiek medienos kuro pelenų, tiek azoto poveikis yra neigiamas, tuo tarpu žolių/krūmokšnių rūšims – teigiamas. Visgi, azoto poveikis žolių/krūmokšnių rūšims priklauso ne tik nuo dozės, bet ir nuo patekimo į miško ekosistemą dažnio. Brukniniuose pušynuose... [toliau žr. visą tekstą] / In Lithuania the energy production from the forest wood comprises up to 90% of the total biomass derived energy. Increasing use of wood fuel increases the removal of the plant essential nutrients from the ecosystem because the branches, tops and needles/leaves contain relatively higher amount of the nutrients than stems. If to compare with the removal of the stems-only, the nutrient losses from the forest ecosystem increase up to 5 times. One way to return nutrients to the ecosystem is to apply forest fuel waste – wood ash - as fertilizers. In this study the effects of the differential wood ash fertilization and ash fertilization in complex with nitrogen on the ground vegetation structure (species composition, abundance), biomass and chemical composition in Pinus sylvestris stands (forest type – Vaccinio-Pinetum) was estimated. For the first time, the long-term impact of nitrogen as well the influence of the high nitrogen doses on ground vegetation structure and abundance in Scots pine stands growing on infertile sandy soils (Haplic Arenosols) were studied in Lithuania. The spreading of the nitrophylous plant species in the ground vegetation in pine stands during 20 years period were detected. The role of the trees competition in the soil rhizosphere zone on ground vegetation was analysed. The following soil and ground vegetation parameters were estimated: soil moisture, pH and chemical composition, also the biomass of vascular plants, coverage, biomass and chemical... [to full text]

Le feu est la principale perturbation naturelle dynamisant les écosystèmes du biome boréal. En ce sens, il affecte toutes les composantes de ces écosystèmes, incluant le couvert végétal, les conditions du sol, la faune et les populations humaines. Des effets complexes des changements climatiques sur les feux sont à prévoir, et la compréhension de ces effets est cruciale pour prédire le futur des écosystèmes et leur impact sur les populations locales. Ceci est d’autant plus vrai que les études portant sur l’écologie des feux sont rares pour les zones plus nordiques, comme au Nunatsiavut, la région Inuite du nord du Labrador. De plus, bien que la science occidentale puisse aider à développer cette compréhension, le savoir écologique des populations autochtones qui ont toujours cohabité avec les feux est aussi fondamental. Dans ce contexte, des entrevues semi-dirigées ont été menées dans deux communautés inuites (Nain et Postville, Nunatsiavut) pour documenter le savoir inuit local au sujet de cette perturbation et de ses impacts. Des inventaires écologiques traditionnels ont aussi été menés, complémentant les savoirs inuits. Les populations végétales au sol ont aussi été caractérisées sur le site de trois feux de forêt en régénération pour clarifier comment ces communautés végétales se rétablissent après feu dans la région, et comment certaines variables environnementales et biotiques affectent cette réponse. Comme résultats clefs, cette étude a démontré que les utilisations des sites de feux par les Inuit sont dominées par la récolte de bois brûlés, suivi d’activités généralement réalisées en parallèle comme la chasse. La relation avec le feu varie entre les deux communautés, cette relation étant plus proche à Postville qu’à Nain en lien avec des différences dans la taille et la distance des feux par rapport aux communautés, de même que différents niveaux d’hétérogénéité dans le paysage avant le passage des feux. Cette étude a démontré que le rétablissement des communautés végétales après feux en milieux côtiers au Nunatsiavut suit les patrons généraux observés ailleurs, notamment dans le sud-est et l’ouest du Labrador, tels qu’une transition des communautés muscinales de lichens, avec quelques exceptions notables, telle que des effets négatifs inattendus du feu sur Vaccinium angustifolium, qui devraient faire l’objet de recherches plus approfondies. / Forest fires are the predominant natural disturbance driving ecosystem dynamics in the boreal forest. As such, fire affects all components of these ecosystems, including vegetation cover, soil condition, wildlife and human populations. As ongoing climate change is expected to have complex impacts on forest fires, notably increasing their frequency, intensity and magnitude, understanding these effects is crucial to predicting the future of ecosystems and their impacts on local human communities. This is especially true in areas where studies on forest and fire ecology have been scarce, as in Nunatsiavut, the Inuit region of northern Labrador, Canada, encompassing coastal mountainous zones. Furthermore, while Western science can help develop this understanding, the Indigenous Knowledge of populations that have always coexisted with fire, is also key to understand fire and its impacts. In this context, semi-structured interviews were conducted in two Inuit communities (Nain and Postville, Nunatsiavut) to document local Inuit Knowledge of fire and its impacts. To complement Inuit Knowledge, ecological field studies were also conducted. As part of this thesis three regenerating forest fire sites were studied to clarify how ground vegetation communities regenerate after fire in the region, and how environmental and biotic variables affect the responses. As key outcomes, this study showed that wood harvesting, followed by concomitant activities such as hunting and berry harvesting, dominated Inuit use of previously burnt sites. Inuit use and relationship with forest fires differed in the two studied communities, the more southern community of Postville had a closer relationship with fires than Nain, notably due to differences in the size of fires and their distance from the communities, as well as different levels of pre-fire landscape heterogeneity. This study also showed that the re-establishment patterns of ground vegetation communities after fire in coastal Nunatsiavut mostly follows those observed in southeast and western Labrador, which included community switches in moss species and lichens; however there were unexpected negative impacts of fire on Vaccinium angustifolium, which requires further investigation.

ANNOTATION Hana Beranová University of south Bohemia in České Budějovice {--} Faculty of education {--} department of biology Course: M7504 Teacher for grammar schools Fields of study: Teaching of biology, Teaching of chemistry Floristic research of catchment area of Pozdeň stream and Bílichov stream round Slaný Diploma thesis 2008 The study deals with a description of vegetation of catchment area of Bakov stream and Zlonice stream. In title of study are used the names Pozdeň stream and Bílichov stream, but it{\crq}s only local description. The search had been realised during the vegetation seasons of the years 2006 and 2007. There are characterised geological-petrographical, soil, climatic, hydrographic ratios and basic phytogeographical characteristics of this area in the form of a search. Selected genera of the observed plants are characterised and their incidence is figured in the schematic map of the area. There were found out 299 genera of plants, from which there are 48 stated in the Červený a černý seznam cévnatých rostlin České republiky (stav v roce 2000) (Procházka F. (ed.), 2001). There are described locations of important genera of plants. In discussion of the thesis are described factors, which influence the incidence of some genera of plants. In the annex there are attached schematic maps with places of occurence of the plant genera and photographic documentation. Head of the diploma thesis: Mgr. Rostislav Černý, CSc.