Browsing by Organization "Bio- och miljövetenskaper, Institutionen för"

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Now showing items 1-20 of 308
  • Voigt, H.-R. (Skärgårdsinstitutet vid Åbo Akademi, 2001)
  • Lodenius, M.; Seppänen, A.; Herranen, M. (D. Reidel Publishing Co., 1983)
  • Alcamo, J.; Amann, M; Hettelingh, J.-P.; Holmberg, M.; Hordijk, L.; Kämäri, J.; Kauppi, L.; Kauppi, P.; Kornai, G.; Mäkelä, A. (Royal Swedish Academy of Sciences, 1987)
  • Kauppi, P.E.; Kämäri, J.; Posch, M.; Kauppi, L.; Matzner, E. (Elsevier, 1986)
  • Alcamo, J.; Kauppi, P.E.; Posch, M.; Runca, E. (IIASA, 1984)
  • Donner, K.; Djupsund, K.; Reuter, T.; Väisänen, I. (Elsevier, 1991)
  • Kauppi, P.E.; Hari, P.; Kellomäki, S. (Blackwell, 1978)
  • Myneni, R. B.; Dong, J.; Tucker, C. J.; Kaufmann, R. K.; Kauppi, P. E.; Zhou, L.; Liski, J.; Alexeyev, V.; Hughes, M. K. (National Academy of Sciences, 2001)
    The terrestrial carbon sink, as of yet unidentified, represents 15–30% of annual global emissions of carbon from fossil fuels and industrial activities. Some of the missing carbon is sequestered in vegetation biomass and, under the Kyoto Protocol of the United Nations Framework Convention on Climate Change, industrialized nations can use certain forest biomass sinks to meet their greenhouse gas emissions reduction commitments. Therefore, we analyzed 19 years of data from remote-sensing spacecraft and forest inventories to identify the size and location of such sinks. The results, which cover the years 1981–1999, reveal a picture of biomass carbon gains in Eurasian boreal and North American temperate forests and losses in some Canadian boreal forests. For the 1.42 billion hectares of Northern forests, roughly above the 30th parallel, we estimate the biomass sink to be 0.68 ± 0.34 billion tons carbon per year, of which nearly 70% is in Eurasia, in proportion to its forest area and in disproportion to its biomass carbon pool. The relatively high spatial resolution of these estimates permits direct validation with ground data and contributes to a monitoring program of forest biomass sinks under the Kyoto protocol.
  • Kauppi, P.E.; Selkäinaho, J.; Puttonen, P. (Finnish Zoological and Botanical Publishing Board, 1983)
  • Kikuchi, R. (Elsevier Science B.V., 1999)
    The rapid increase in population and economic growth have led to an increase in energy demand. Coal reserves are distributed worldwide, and coal is now known to be the most stable and available energy source. However, utilization of coal as an energy source involves the generation of a great amount of coal ash, and the recycling rate of the ash is rather low. Coal ash is mainly used in civil construction materials, and there is a limit to the demand for coal ash by construction industries: therefore, the increasing amount of coal ash will be a serious problem in the near future. Different applications should be considered. In this paper, three environmentally-friendly methods for coal ash recycling are described. Firstly, alkali treatment can transform coal ash to zeolite, which is used in deodorant and for wastewater treatment and soil improvement. Secondly, potassium silicate fertilizer is produced from coal ash and has a higher retentivity in the soil than that of conventional fertilizers. Thirdly, emission of sulfur dioxide is controlled by flue gas desulfurization using coal ash. It is considered that environmentally-friendly use of coal ash is important from the viewpoints of energy, economy, and environmental strategy in order to realize the concept of sustainable development.
  • Mukherjee, A.B.; Bhattacharya, P. (NRC Research Press, 2001)
  • Voigt, H.-R. (Yhtyneet Kuvalehdet, 1976)
  • Voigt, H.-R. (Scandinavian Society for Parasitology, 1981)
  • Voigt, H.-R. (Nordenskiöld-samfundet, 1972)
  • Lehvävirta, S.; Rita, H.; Koivula, M. (Elsevier GmbH, 2004)
    In order to maintain indigenous, self-regenerating tree populations in urban woodlands, it is essential to identify factors affecting the survival of tree seedlings and saplings. In densely populated areas, intensive recreational use may cause considerable wear of the vegetation and soil, and decrease the total number of saplings. At the same time trees, high stones and other structural elements in a woodland patch can act as natural barriers and give shelter against wear. Hence, we hypothesised that with an increasing amount of wear, a greater proportion of tree saplings survive, and is thus found, close to these natural barriers. We tested this hypothesis with observational data, and described the microhabitat associations of different sapling species in detail to define the most favourable or unfavourable microhabitats. We recorded the microhabitats of saplings and randomly chosen points in 30 medium-fertile Picea abies dominant woodlands in Helsinki and the surroundings, Finland. The description included location in relation to physical objects (stones, trees, topography, etc.), other saplings, vegetation and canopy. We then compared the sapling microhabitats to those available (the random points). Our results suggest that the microhabitat associations of saplings change with increasing wear: Sorbus aucuparia, Populus tremula, Rhamnus frangula, Picea abies and Acer platanoides saplings grew more often close to natural barriers (obstacles X30 cm high excluding other saplings), the first three showing a statistically significant response to wear in logistic regression models. The saplings were able to grow in a variety of microhabitats, but the species also differed in their microhabitat associations. In general, saplings grew in groups, and in worn sites the grouping was more pronounced. With increasing wear the saplings associated more positively with trees, canopy cover and lush vegetation.
  • Niemelä, J. (Finnish Zoological and Botanical Publishing Board, 2000)
    Biodiversity monitoring provides guidelines for decisions on how to manage biological diversity in terms of production and conservation. Monitoring determines the status of biological diversity at one or more ecological levels and assesses changes over time and space. Monitoring at the global level is needed to compare trends caused by the increasing homogenisation of the world’s landscapes. Bioindicators are routinely used, but each indicator’s potential to determine changes in the overall biodiversity should be rigorously tested. Monitoring is a vital feedback link between human actions and the environment, but incorporation of monitoring results into decision making is hampered by poor communication between ecologists and decision-makers. A global network for assessing biodiversity changes (GLOBENET) is described as an example of an initiative that attempts to address the above issues by using a simple field protocol with the aim to develop tools for assessment and prediction of the ecological effects of human-caused changes in the landscape.