Browsing by Subject "Pinus sylvestris"

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  • Kuuluvainen, Timo (Suomen metsätieteellinen seura, 1989)
  • Lintunen, Anna; Lindfors, Lauri; Kolari, Pasi; Juurola, Eija; Nikinmaa, Eero; Hölttä, Tuomo (2014)
  • Kellomäki, Seppo; Oker-Blom, Pauline (Suomen metsätieteellinen seura, 1983)
  • Cape, J. N.; Fowler, D. (Suomen metsätieteellinen seura, 1981)
  • Luomajoki, Alpo (The Society of Forestry in Finland - The Finnish Forest Research Institute, 1993)
    Timing of anthesis in 21 Scots pine stands from 14 localities in Finland was studied at the canopy level from 1963 to 1974. Distributions of pollen catches were compared to the normal Gaussian distribution. The basis for the timing studies was the 50 per cent point of the anthesis-fitted normal distribution. Development up to this point was characterized in calendar days, in degree days (>5 °C) and in period units. The count of each unit began on March 19 (included). The period unit was found to be the most accurate delineator of development both in a single year and also in the majority of cases as stand averages over several years. Locally, calendar days were a more accurate parameter for stand average. Anthesis in northern Finland occurred at a later date than in the south as was expected, but at a lower heat sum. The variation in the timing of anthesis and the variation of pollen catches increased northwards. The geographical correlations calculated against distances measured along simulated post-glacial migration routes were stronger than purely latitudinal correlations. Effects of the reinvasion of Scots pine into Finland are thus still visible in pine populations. The proportion of the average annual heat sum needed for anthesis grew rapidly above a latitude of 63° even though the heat sum needed for anthesis decreased towards the timberline. In light of flowering phenology it seems probable that the northern populations of Scots pine in Finland have still not completely adapted to the prevailing cold climate at these latitudes. A moderate warming of the climate would therefore be beneficial for Scots pine.
  • Pukkala, Timo; Kolström, Taneli (Suomen metsätieteellinen seura, 1987)
  • Kuuluvainen, Timo; Aakala, Tuomas; Várkonyi, Gergely (Springer Singapore, 2017)
    Abstract Background After their death, Scots pine trees can remain standing for decades and sometimes up to 200 years, forming long-lasting and ecologically important structures in boreal forest landscapes. Standing dead pines decay very slowly and with time develop into ‘kelo’ trees, which are characterized by hard wood with silvery-colored appearance. These kelo trees represent an ecologically important, long lasting and visually striking element of the structure of natural pine-dominated forests in boreal Fennoscandia that is nowadays virtually absent from managed forest landscapes. Methods We examined and mapped the amount, structural features, site characteristics and spatial distribution of dead standing pine trees over a ten hectare area in an unmanaged boreal forest landscape in the Kalevala National Park in Russian Viena Karelia. Results The mean basal area of dead standing pine trees in the forested part of the landscape was 1.7 m2∙ha−1 and the estimated volume 12.7 m3∙ha−1. From the total number of standing dead pine trees 65% were kelo trees, with a basal area of 1.1 m2∙ha−1 and volume of 8.0 m3∙ha−1, the remainder consisting of standing dead pines along the continuum between a recently dead tree and a kelo tree. Overall, standing dead pines were distributed throughout the study area, but there was a tendency towards spatial clustering up to <100 m distances. Standing dead pines were most commonly situated on flat ground or in the mid slope in the local topography. In addition, standing dead pines contributed to substrate diversity also by commonly having charred wood and broken tops. Based on the presence of dead pine snags in different stage of transition from a recently dead pine to a kelo with silvery surface, it seems evident that the process of kelo recruitment was continuously in action in the studied landscape. Conclusions Kelo trees are an omnipresent feature in natural pine-dominated forest landscapes with important contribution to forest structural and substrate diversity. Because of their longevity and extremely slow turnover dynamics and importance for biodiversity, protection of vulnerable kelo tree populations, and ensuring their continuous recruitment, should be of high priority in forest restoration and sustainable management.
  • Marsman, Floor; Nystuen, Kristin O.; Opedal, Oystein H.; Foest, Jessie J.; Sorensen, Mia Vedel; De Frenne, Pieter; Graae, Bente Jessen; Limpens, Juul (2021)
    Questions Changes in climate and herbivory pressure affect northern alpine ecosystems through woody plant encroachment, altering their composition, structure and functioning. The encroachment often occurs at unequal rates across heterogeneous landscapes, hinting at the importance of habitat-specific drivers that either hamper or facilitate woody plant establishment. Here, we assess: (1) the invasibility of three distinct alpine plant community types (heath, meadow andSalixshrubland) byPinus sylvestris(Scots pine); and (2) the relative importance of biotic (above-ground interactions with current vegetation, herbivory and shrub encroachment) and microclimate-related abiotic (soil temperature, moisture and light availability) drivers of pine seedling establishment success. Location Dovrefjell, Central Norway. Methods We conducted a pine seed sowing experiment, testing how factorial combinations of above-ground removal of co-occurring vegetation, herbivore exclusion and willow transplantation (simulated shrub encroachment) affect pine emergence, survival and performance (new stem growth, stem height and fraction of healthy needles) in three plant communities, characteristic of alpine tundra, over a period of five years. Results Pine seedling emergence and survival were similar across plant community types. Herbivore exclusion and vegetation removal generally increased pine seedling establishment and seedling performance. Within our study, microclimate had minimal effects on pine seedling establishment and performance. These results illustrate the importance of biotic resistance to seedling establishment. Conclusion Pine seedlings can easily establish in alpine tundra, and biotic factors (above-ground plant interactions and herbivory) are more important drivers of pine establishment in alpine tundra than abiotic, microclimate-related, factors. Studies aiming to predict future vegetation changes should thus consider local-scale biotic interactions in addition to abiotic factors.
  • Luo, Fuhe (Suomen metsätieteellinen seura, 1983)
  • Renvall, August (Suomen metsätieteellinen seura, 1913)
    Acta Forestalia Fennica
  • Ding, Yiyang; Leppälammi-Kujansuu, Jaana; Salemaa, Maija; Schiestl-Aalto, Pauliina; Kulmala, Liisa; Ukonmaanaho, Liisa; Nöjd, Pekka; Minkkinen, Kari; Makita, Naoki; Zeleznik, Peter; Merila, Paivi; Helmisaari, Heljä-Sisko (2021)
    Forest ecosystem productivity is strongly linked to site nutrient availability, which is influenced by litter inputs and their decomposition rates. Fine roots and mycelia are key contributors in belowground soil carbon (C) accumulation, but studies have seldom reported how belowground litter C input is related to site types in boreal forests. In this study, three mature and one young Pinus sylvestris forests along a site type gradient in southern Finland were chosen for measurements of fine root biomass, fine root longevity, below- and aboveground growth phenology and annual litter input from tree and understorey vegetation. Site types were distinguished by understorey vegetation composition, which indicated the site fertility. Fine root biomass per tree stand basal area decreased significantly from nutrient-poor to nutrient-rich sites, the nutrient-poor sites with longer fine root longevity resulted in an equal belowground litter input with the nutrient-rich site. Above- and belowground annual litter inputs were 131–236 and 70–91 g m−2 year−1, respectively. Aboveground litter increased with site fertility, resulting into belowground litter having a decreasing trend from 37% to 23% of total litter inputs with increasing site fertility. Ectomycorrhizal mycelia and understory production contributed 8–13% and 18–41% of belowground production, respectively. Contribution of understorey vegetation to the belowground litter C input was lower than that of trees at xeric and sub-xeric sites but equaled to that of trees at the mesic site. Our study showed distinct dimensions of below- and aboveground litter inputs influenced by site types. Moreover, we emphasize that the belowground C inputs from ectomycorrhizal mycelia and the understorey in addition to those of trees should always be considered in C balances and C reporting in boreal conifers.
  • Mõttus, Matti; Aragão, Luiz; Bäck, Jaana; Clemente, Rocío Hernandez; Maeda, Eduardo Eiji; Markiet, Vincent Robert Leon; Nichol, Caroline; Oliveira, Raimundo Cosme; Restrepo-Coupe, Natalia (2019)
    The spectral properties of plant leaves relate to the state of their photosynthetic apparatus and the surrounding environment. An example is the well known photosynthetic downregulation, active on the time scale from minutes to hours, caused by reversible changes in the xanthophyll cycle pigments. These changes affect leaf spectral absorption and are frequently quantified using the photochemical reflectance index (PRI). This index can be used to remotely monitor the photosynthetic status of vegetation, and allows for a global satellite-based measurement of photosynthesis. Such earth observation satellites in near-polar orbits usually cover the same geographical location at the same local solar time at regular intervals. To facilitate the interpretation of these instantaneous remote PRI measurements and upscale them temporally, we measured the daily course of leaf PRI in two evergreen biomes—a European boreal forest and an Amazon rainforest. The daily course of PRI was different for the two locations: At the Amazonian forest, the PRI of Manilkara elata leaves was correlated with the average photosynthetic photon flux density (PPFD) ( R2=0.59 ) of the 40 minutes preceding the leaf measurement. In the boreal location, the variations in Pinus sylvestris needle PRI were only weakly ( R2=0.27) correlated with mean PPFD of the preceding two hours; for Betula pendula, the correlation was insignificant regardless of the averaging period. The measured daily PRI curves were specific to species and/or environmental conditions. Hence, for a proper interpretation of satellite-measured instantaneous photosynthesis, the scaling of PRI measurements should be supported with information on its correlation with PPFD.
  • Zhang, Chao; Atherton, Jon; Penuelas, Josep; Filella, Iolanda; Kolari, Pasi; Aalto, Juho; Ruhanen, Hanna; Back, Jaana; Porcar-Castell, Albert (2019)
    Chlorophyll a fluorescence (ChlF) is closely related to photosynthesis and can be measured remotely using multiple spectral features as solar-induced fluorescence (SIF). In boreal regions, SIF shows particular promise as an indicator of photosynthesis, in part because of the limited variation of seasonal light absorption in these ecosystems. Seasonal spectral changes in ChlF could yield new information on processes such as sustained nonphotochemical quenching (NPQ(S)) but also disrupt the relationship between SIF and photosynthesis. We followed ChlF and functional and biochemical properties of Pinus sylvestris needles during the photosynthetic spring recovery period to answer the following: (a) How ChlF spectra change over seasonal timescales? (b) How pigments, NPQ(S), and total photosynthetically active radiation (PAR) absorption drive changes of ChlF spectra? (c) Do all ChlF wavelengths track photosynthetic seasonality? We found seasonal ChlF variation in the red and far-red wavelengths, which was strongly correlated with NPQ(S), carotenoid content, and photosynthesis (enhanced in the red), but not with PAR absorption. Furthermore, a rapid decrease in red/far-red ChlF ratio occurred in response to a cold spell, potentially relating to the structural reorganization of the photosystems. We conclude that all current SIF retrieval features can track seasonal photosynthetic dynamics in boreal evergreens, but the full SIF spectra provides additional insight.
  • Kuittinen, Helmi (University of Helsinki, 1992)
  • Alakärppä, Emmi; Taulavuori, Erja; Valledor, Luis; Marttila, Toni; Jokipii-Lukkari, Soile; Karppinen, Katja; Nguyen, Nga; Taulavuori, Kari; Häggman, Hely (2019)
    Plants have evolved a suite of photoreceptors to perceive information from the surrounding light conditions. The aim of this study was to examine photomorphogenic effects of light quality on the growth of Scots pine (Pinus sylvestris L.) seedlings representing southern (60 °N) and northern (68 °N) origins in Finland. We measured the growth characteristics and the expression of light-responsive genes from seedlings grown under two LED light spectra: (1) Retarder (blue and red wavelengths in ratio 0.7) inducing compact growth, and (2) Booster (moderate in blue, green and far-red wavelengths, and high intensity of red light) promoting shoot elongation. The results show that root elongation, biomass, and branching were reduced under Retarder spectrum in the seedlings representing both origins, while inhibition in seed germination and shoot elongation was mainly detected in the seedlings of northern origin. The expression of ZTL and HY5 was related to Scots pine growth under both light spectra. Moreover, the expression of PHYN correlated with growth when exposed to Retarder, whereas CRY2 expression was associated with growth under Booster. Our data indicates that blue light and the deficiency of far-red light limit the growth of Scots pine seedlings and that northern populations are more sensitive to blue light than southern populations. Furthermore, the data analyses suggest that ZTL and HY5 broadly participate in the light-mediated growth regulation of Scots pine, whereas PHYN responses to direct sunlight and the role of CRY2 is in shade avoidance. Altogether, our study extends the knowledge of light quality and differential gene expression affecting the early growth of Scots pines representing different latitudinal origins.
  • Kellomäki, Seppo; Hari, Pertti (Suomen metsätieteellinen seura, 1980)