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  • Koivula, M.; Niemelä, J. (Finnish Forest Research Institute (Metla), 2002)
  • Kauppi, P.E.; Posch, M. (American Association for the Advancement of Science, 1989)
  • Voigt, H.-R. (Västnyländska kultursamfundet, 2007)
  • Whiteman, G.; Forbes, B.C.; Niemelä, J.; Chapin, F.S. (Royal Swedish Academy of Sciences, 2004)
    This paper discusses the role of companies in high-latitude regions, which are conceptualized as socially and economically mediated ecosystems, and identifies a number of important social actors within the business environment. We present three examples of corporate activity at high latitudes and discuss a variety of common threads. Notably, we argue that business theory and practice needs to move beyond a narrow social or economic concept of organizational resilience and embrace the ecological resilience of high-latitude regions as a business management goal. We also suggest that regional ecosystem resilience needs to become a meaningful measure of sustainable corporate governance, one that corporate boards of directors can review and commit to. The paper concludes with a call for a detailed research agenda on the role of transnational and national companies within high-latitude regions.
  • Voigt, H.-R. (International Symposium on Trace Elements and Health, 2007)
  • Lodenius, M. (Springer-Verlag New York Inc., 2003)
  • Lodenius, M.; Soltanpour-Gargari, A.; Tulisalo, E. (Springer-Verlag New York Inc., 2002)
  • Lodenius, Martin; Josefsson, Jussi; Heliövaara, Kari; Tulisalo, Esa; Nummelin, Matti (Wiley-Blackwell, 2009)
    Ash fertilization of forests returns nutrients to forest ecosystems and has a positive effect on soil pH, but it also may elevate Cd concentrations of forest biota. Cadmium concentrations of some forest insects (Formica ants, carabids and Coleopteran larvae from decaying wood) were investigated in southern Finland, where two plots were fertilized with wood ash, while two other plots represented unfertilized control plots. In ants, mean Cd concentration was 3.6 ± 1.4 mg/kg, with nest workers having significantly higher concentrations than workers trapped in pitfall traps. Concentrations at fertilized and unfertilized plots were similar. In carabid beetles, the average Cd concentration of Carabus glabratus was 0.44 ± 0.36 mg/kg, with no significant difference between control plots and fertilized plots. In another carabid beetle, Pterostichus niger, mean Cd concentration was higher at fertilized plots compared to control plots. We conclude that the variation of Cd concentrations in the insects studied is more efficiently controlled by species-specific differences than fertilization history of the forest floor.
  • Kauppi, P.E.; Tomppo, E.; Ferm, A. (Kluwer, 1995)
  • Alaruikka, D.; Kotze, D.J.; Matveinen, K.; Niemelä, J. (Kluwer Academic Publishers, 2003)
    To investigate the effects of urbanization on carabid beetles (Carabidae) and ground dwelling spiders (Araneae) a study was completed along a 20 kmurban–rural forest gradient in the Helsinki–Espoo area of southern Finland. To study changes in assemblage structure, abundance and species richness, these taxa were collected in the year 2000 using pitfall traps, which had been placed in four forest sites within each of the urban, suburban and rural zones.We expected to find changes in the abundances and species richnesses in the two taxa across the urban–rural gradient, but did not find any. Our second and third hypotheses, stating that generalist species and small-bodied species should gain dominance along the gradient from rural to urban sites, were partly supported as carabid specialists were more characteristic of suburban and rural environments whereas generalists were more likely to be collected from rural areas compared to suburban or urban sites. Furthermore, medium to large-sized carabid individuals were more likely to be collected in the rural sites compared to urban forests. We found no evidence for significant changes in spider abundance or species richness across the urban–rural gradient in relation to body size or habitat specialization. We suggest that urbanization does not have significant effects on the total abundances and species richnesses in these two taxa. However, individual species responded differently to urbanization, and there were significant differences in the specialization and body sizes of carabids across the gradient.
  • Niemelä, J.; Kotze, J.; Venn, S.; Penev, L.; Stoyanov, I.; Spence, J.; Hartley, D.; Montes de Oca, H. (Kluwer Academic Publishers, 2002)
    We studied communities of carabid beetles in residual forest patches along urban-suburban-rural gradients in three cities (Helsinki, Finland; Sofia, Bulgaria and Edmonton, Canada) to examine their responses to urbanisation. Only Finnish carabids showed a marked division of community structure along the gradient. In Bulgaria and Canada, carabids did not separate into distinct urban, suburban and rural communities. Our results provide some support for the predictions that species richness will decrease, that opportunistic species will gain dominance, and that small-sized species will become more numerous under disturbance such as that provided by urbanisation. The rather weak and varied response of carabids to this disturbance suggests that local factors and their interaction are of primary importance for community composition. Occurrence of reasonably similar carabid communities across the gradient at each of the three levels of urbanisation suggests that habitat changes commonly associated with urbanisation have not affected the ecological integrity of carabid assemblages in residual urban forest patches.
  • Heikkinen, J.E.P; Virtanen, T.; Huttunen, J.T.; Elsakov, V.; Martikainen, P.J. (American Geophysical Union, 2004)
    [1] We studied the carbon dioxide and methane fluxes from early June to mid-September 2001 in the Russian tundra of northeast Europe. Gas fluxes were measured with chamber techniques to determine the seasonal (100 days) carbon gas balance for terrestrial ecosystems representing various vegetation types. Also, the gas balance for aquatic ecosystems in the region was measured. The 2001 fluxes were compared to colder and wetter season fluxes from 1999. The Sphagnum sp. dominated peat plateau fen and Carex sp. and Sphagnum sp. dominated intermediate flarks were carbon sinks of 106 and 110 g C m2, respectively. In addition, methane emissions were highest from these sites. Other terrestrial surfaces lost carbon to the atmosphere (28-118 g C m2). The thermokarst lake and the river had seasonal carbon losses of 15 and 34 g C m2, respectively. For areal integration, the distributions of the various functional surfaces were classified based on Landsat TM satellite image and on-site validation. This data was used to integrate the carbon fluxes for the entire Lek Vorkuta catchment. The upscaling indicated that the catchment (114 km2) lost 4 (±3.5) Gg C to the atmosphere in summer 2001. The results suggest that predicted warming in the tundra region would induce a substantial loss of carbon. In the warm summer of 2001, the carbon gas released from the whole northeast European tundra (area 205,000 km2) was 8 Tg C when calculated from the Lek Vorkuta data.
  • Kauppi, P.E.; Mielikäinen, K.; Kuusela, K. (American Association for the Advancement of Science, 1992)
  • Kauppi, P.E.; Posch, M.; Hänninen, P.; Henttonen, H.M.; Ihalainen, A.; Lappalainen, E.; Starr, M.; Tamminen, P. (Metla, 1997)
  • Lodenius, M.; Kumpulainen, J. (Elsevier Science Publishers B. V., 1983)
  • Donner, K.; Grönholm, M.-L. (Elsevier, 1984)
    We have reexamined the receptive fields of frog retinal ganglion cells focussing on their surround properties. Carefully excluding artifacts due to stimulation of the (Gaussian) RF center, we found that spiking responses can be elicited by step stimulation of any receptor type in the surrounds of all the classes 1–4 Maturana et al. (1960) (J. gen. Physiol. 43, 129–175). The surround responses are antagonized by the responsive center and suppressed by the inhibitory surround, but are seen because of their slower dynamics. The responsive surround differs spectrally from the center: in the latter, cones and green rods compete, in the former, their signals sum.
  • Ishitani, M.; Kotze, D.J.; Niemelä, J. (Blackwell, 2003)
    As part of the international Globenet project, carabid beetles (Coleoptera, Carabidae) were collected using pitfall traps from four urban, four suburban and four rural sites in Hiroshima City, Japan, during the 2001 summer season. In agreement with expectation, carabid abundance and species richness decreased significantly from rural to urban sites. Furthermore, no large, and only few individuals of medium-sized specialist species were collected from the urban environment, while many specimens of medium-sized and some large-sized specialist species were collected from the suburban and rural sites. Hiroshima city was characterised by medium-sized generalist carabids, while the suburbs and the rural environments were characterised by small-sized generalist beetles. These results did not apply at the species level. To summarise, we found a significant effect of urbanisation on the composition of carabid beetle assemblages in Hiroshima City. These changes were similar to those found in previous studies performed in Sofia (Bulgaria), Edmonton (Canada) and Helsinki (Finland). Thus, it appears that urbanisation has some similar and predictable effects on carabid assemblages in various parts of the world.
  • Candolin, Ulrika (Royal Society of London, 2000)
    Fitness costs of signalling are essential in order for reliable sexual signalling to prevail when the interests of the sexes con£ict. This means that signalling can be subjected to a life history trade-o¡ between present and future signalling e¡ort. Here, I show that three-spined stickleback males (Gasterosteus aculeatus), who have a single breeding season during which they breed repeatedly, change their red nuptial coloration over the season depending on their body size at the start of breeding. Large males that completed several breeding cycles increased their red coloration over the season, whereas small males, who completed only a few cycles, did not. The increase in coloration was accompanied by an increase in parental success when males were energy constrained, but not when they had access to an unlimited food supply. Red coloration was thus an honest signal of male parental ability despite changes in signal expression when both signalling and parental care were costly and the investments in them changed simultaneously over the reproductive lifetime. However, the honesty of the signal varied over a lifetime. At the penultimate cycle, bright males cannibalized some of their eggs, probably to increase survival to the last cycle, whereas males cared for their o¡spring independent of coloration at the ultimate cycle.