Effects of Climate, Site Conditions, and Seed Quality on Recent Treeline Dynamics in NW Russia: Permafrost and Lack of Reproductive Success Hamper Treeline Advance?
- 623 Downloads
Treeline advance alters albedo and carbon storage and is an important feedback mechanism to the global climate system. Establishment of trees north of the treeline requires favorable climate, suitable microsites, and viable seeds. Here we studied the influence of climate and microsite conditions on tree and seedling growth at four transects from forest through woodland to tundra in NW Russia, and tested the viability of seeds from the region. General growth patterns and establishment periods of the treeline species Picea obovata are similar across the study sites suggesting a regional driver (for example, climate). Individuals established as early as the 1640s, but mainly between 1850 and 1880, and during a major and continental scale establishment wave in the 1950s and 1960s. No establishment occurred after 1982. Older trees mainly showed significant and stable positive relationships to growing year summer temperatures and significant stable negative correlations to previous year summer temperatures in nearly all plots. Trees from the last establishment wave showed more mixed responses, but current year summer temperature positively affected growth. Active layer depth was similar in all plots with trees but decreased sharply in treeless tundra. A major role for the lack of recent establishment seems to be very low seed viability, possibly combined with early strong fall frosts, which might have severely limited successful recruitment in the last decades of the twentieth century. For a successful establishment of P. obovata in tundra areas of NW Russia, permafrost degradation and (generally) warmer winters might be a prerequisite.
Keywordsdendroecology Picea obovata recruitment tree rings seed viability climate warming
This study was supported by a Sofja Kovalevskaja Award from the Alexander von Humboldt Foundation (M. Wilmking), the German National Scholarship Foundation (S. Kenter) and the EU-Project CARBO-North (6th FP, Contract No. 036993).
- ACIA author consortium. 2005. Impacts of a warming arctic–arctic climate impact assessment, Cambridge.Google Scholar
- Bigras FJ, Coursolle C, Margolis HA. 2004. Survival and growth of Picea glauca seedlings as a function of freezing temperatures and exposure times during budbreak and shoot elongation. Scand J For Res 19:206–16.Google Scholar
- Driscoll W, Wiles G, D’Arrigo R, Wilmking M. 2005. Divergent tree growth response to recent climatic warming, Lake Clark National Park and Preserve, Alaska. Geophys Res Lett 32: L20703. doi: 10.1029/2005GL024258.
- French HM. 2007. The periglacial environment. Chichester: Wiley.Google Scholar
- Fritts H. 1976. Tree rings and climate. New York: Academic Press.Google Scholar
- Grissino-Mayer HD. 2001. Evaluating crossdating accuracy: a manual and tutorial for the computer program COFECHA. Tree-Ring Res 57:205–21.Google Scholar
- Gromtsev A. 2002. Natural disturbance dynamics in the boreal forests of European Russia: a review. Silva Fennica 36:41–55.Google Scholar
- Juday GP, Barber V, Rupp S, Zasada J, Wilmking M. 2003. A 200-year perspective of climate variability and the response of white spruce in Interior Alaska. Chap. 12 p. 226–250. In: Greenland D, Goodin D, Smith R, Eds. Climate variability and ecosystem response at long-term ecological research (LTER) sites. Oxford: University Press.Google Scholar
- Kullman L. 2010. One century of treeline change and stability—experiences from the Swedish Scandes. Landsc Online 17:1–31.Google Scholar
- Lopatin E, Kolstrom T, Spiecker H. 2007. Impact of climate change on radial growth of Siberian spruce and Scots pine in North-western Russia. iForest 1: 13–21. (online 2008-02-28). http://www.sisef.it/iforest/show.php?id=447.
- Popov PP. 1980. The sowing qualities of Picea obovata seeds. Lesnoe Khozyaistvo No. 2: p 64–65.Google Scholar
- Sannikov SN. 1970. Survival and growth of seedlings of conifer species in different types of micro-environment on felled areas. Ekologiya No. 1: 60–68.Google Scholar
- Suarez F, Binkley D, Kaye MW. 1999. Expansion of forest stands into tundra in the Noatak National Preserve, northwest Alaska. Ecoscience 6(3):456–70.Google Scholar
- Thomas P. 2000. Trees: their natural history. Cambridge: Cambridge University Press.Google Scholar
- Zoltai SC. 1995. Permafrost distribution in peatlands of west-central Canada during the Holocene warm period 6000 years BP. Geogr Phys Quat 49(1):45–54.Google Scholar