Variation in reproductive potential across a multi-species treeline

References

• Bakuzis, E. V., and H. L. Hansen. 1965. Balsam fir Abies balsamea (Linnaeus) Miller: A monographic review. Minneapolis, MN: U of Minnesota Press.
   Google Scholar
• Beyer, H. L. 2004. Hawth’s analysis tools for ArcGIS. Available at the following web site www.spatialecology.com/htools.
   Google Scholar
• Black, R. A., and L. Bliss. 1980. Reproductive ecology of Picea mariana (Mill.) BSP., at tree line near Inuvik, Northwest Territories, Canada. Ecological Monographs 50 (3):1–15. doi:https://doi.org/10.2307/2937255.
   Web of Science ®Google Scholar
• Broome, A., S. Hendry, and A. Peace. 2007. Annual and spatial variation in coning shown by the Forest Condition Monitoring programme data for Norway spruce, Sitka spruce and Scots pine in Britain. Forestry 80 (1):17–28. doi:https://doi.org/10.1093/forestry/cpl046.
   Web of Science ®Google Scholar
• Brown, C. D., G. Dufour-Tremblay, R. G. Jameson, S. D. Mamet, A. J. Trant, X. J. Walker, S. Boudreau, K. A. Harper, G. H. R. Henry, L. Hermanutz, et al. 2018. Reproduction as a bottleneck to treeline advance across the circumarctic  forest  tundra  ecotone. Ecography. doi:https://doi.org/10.1111/ecog.03733.
   Google Scholar
• Chapin, F. S., and A. M. Starfield. 1997. Time lags and novel ecosystems in response to transient climatic change in arctic Alaska. Climatic Change 35 (4):449–61. doi:https://doi.org/10.1023/A:1005337705025.
   Web of Science ®Google Scholar
• Conover, W. J., and W. Conover. 1980. Practical nonparametric statistics, 1–462. New York, NY: John Wiley.
   Google Scholar
• Cooper, D. J. 1986. White spruce above and beyond treeline in the Arrigetch Peaks Region, Brooks Range, Alaska. Arctic 39 (3):247–52. doi:https://doi.org/10.14430/arctic2081.
   Web of Science ®Google Scholar
• Cooper, W. S. 1911. Reproduction by layering among conifers. Botanical Gazette 52 (5):369–79. doi:https://doi.org/10.1086/330666.
   Google Scholar
• Cranston, B. H., and L. Hermanutz. 2013. Seed-seedling conflict in conifers as a result of plant-plant interactions at the forest-tundra ecotone. Plant Ecology & Diversity 6 (3–4):319–27. doi:https://doi.org/10.1080/17550874.2013.806603.
   Web of Science ®Google Scholar
• Daly, C., and D. Shankman. 1985. Seedling establishment by conifers above tree limit on Niwot Ridge, Front Range, Colorado, USA. Arctic and Alpine Research 17 (4):389–400. doi:https://doi.org/10.2307/1550864.
   Web of Science ®Google Scholar
• Danby, R. K., and D. S. Hik. 2007. Variability, contingency and rapid change in recent subarctic alpine tree line dynamics. Journal of Ecology 95 (2):352–63. doi:https://doi.org/10.1111/jec.2007.95.issue-2.
   Web of Science ®Google Scholar
• Despland, E., and G. Houle. 1997. Climate influences on growth and reproduction of Pinus banksiana (Pinaceae) at the limit of the species distribution in eastern North America. American Journal of Botany 84 (7):928–928.
   Web of Science ®Google Scholar
• Dullinger, S., T. Dirnbock, and G. Grabherr. 2004. Modelling climate change-driven treeline shifts: Relative effects of temperature increase, dispersal and invasibility. Journal of Ecology 92 (2):241–52. doi:https://doi.org/10.1111/jec.2004.92.issue-2.
   Web of Science ®Google Scholar
• Duncan, D. P. 1954. A study of some of the factors affecting the natural regeneration of tamarack (Larix laricina) in Minnesota. Ecology 35 (4):498–521. doi:https://doi.org/10.2307/1931040.
   Web of Science ®Google Scholar
• Elliott, D. L., and S. K. Short. 1979. The northern limit of trees in Labrador: A discussion. Arctic 32 (3):201–06. doi:https://doi.org/10.14430/arctic2620.
   Web of Science ®Google Scholar
• Elliott-Fisk, D. L. 1983. The stability of the northern Canadian tree limit. Annals of the Association of American Geographers 73 (4):560–76. doi:https://doi.org/10.1111/j.1467-8306.1983.tb01859.x.
   Web of Science ®Google Scholar
• Farmer, R. E., Jr. 1996. Seed ecophysiology of temperate and boreal zone forest trees. Delray Beach, FL: St. Lucie Press.
   Google Scholar
• Finnis, J. 2014. Projected impacts of climate change for the province of Newfoundland & Labrador. St. John’s, Newfoundland: Office of Climate Change and Energy Efficiency.
   Google Scholar
• Fortin, M.-J., P. Drapeau, and P. Legendre. 1989. Spatial autocorrelation and sampling design in plant ecology. Vegetatio 83 (1–2):209–22. doi:https://doi.org/10.1007/BF00031693.
   Google Scholar
• Foster, D. R. 1983. The history and pattern of fire in the boreal forest of southeastern Labrador. Canadian Journal of Botany 61 (9):2459–71. doi:https://doi.org/10.1139/b83-269.
   Google Scholar
• Fraser, J. 1976. Viability of black spruce seed in or on a boreal forest seedbed. The Forestry Chronicle 52 (5):229–31. doi:https://doi.org/10.5558/tfc52229-5.
   Web of Science ®Google Scholar
• Gamache, I., and S. Payette. 2004. Height growth response of tree line black spruce to recent climate warming across the forest-tundra of eastern Canada. Journal of Ecology 92 (5):835–45. doi:https://doi.org/10.1111/jec.2004.92.issue-5.
   Web of Science ®Google Scholar
• Gamache, I., and S. Payette. 2005. Latitudinal response of subarctic tree lines to recent climate change in eastern Canada. Journal of Biogeography 32:849–62.
   Web of Science ®Google Scholar
• Grace, J., F. Berginger, and L. Nagy. 2002. Impacts of climate change on the tree line. Annals of Botany 90 (4):537–44.
   Web of Science ®Google Scholar
• Greene, D. F., J. C. Zasada, L. Sirois, D. Kneeshaw, H. Morin, I. Charron, and M. J. Simard. 2007. A review of the regeneration dynamics of North American boreal forest tree species. Canadian Journal of Forest Research 29 (6):824–39. doi:https://doi.org/10.1139/x98-112.
   Google Scholar
• Harsch, M. A., P. E. Hulme, M. S. McGlone, and R. P. Duncan. 2009. Are treelines advancing? A global meta‐analysis of treeline response to climate warming. Ecology Letters 12 (10):1040–49. doi:https://doi.org/10.1111/j.1461-0248.2009.01355.x.
   PubMed Web of Science ®Google Scholar
• Hofgaard, A. 1993. Seed rain quantity and quality, 1984–1992, in a high altitude old‐growth spruce forest, northern Sweden. New Phytologist 125 (3):635–40. doi:https://doi.org/10.1111/nph.1993.125.issue-3.
   Web of Science ®Google Scholar
• Holtmeier, F. K. 2009. Mountain timberlines: Ecology, patchiness, and dynamics. Dordrecht, The Netherlands: Springer Verlag.
   Google Scholar
• Hustich, I. 1953. The boreal limits of conifers. Arctic 6 (2):149–62. doi:https://doi.org/10.14430/arctic3871.
   Google Scholar
• International Seed Testing Association (ISTA). 2009. International rules for seed testing. International Seed Testing Association (ISTA). Bassersdorf, Switzerland.
   Google Scholar
• IPCC. 2014. Climate change 2014: Impacts, adaptation, and vulnerability. Volume I: Global and Sectoral Aspects. Contribution of Working Group II to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change, Cambridge University Press, Cambridge and New York.
   Google Scholar
• Jacobs, J., S. Chan, and E. Sutton. 2014. Climatology of the forest-tundra ecotone at a maritime subarctic-alpine  site, Mealy Mountains, Labrador. Arctic 67 (1). doi:https://doi.org/10.14430/arctic4358.
   Google Scholar
• Jameson, R. G. 2012. Conifer seed production, seed viability and relative potentials for upslope advance at a multispecies treeline, central Labrador, Canada. MSc thesis, Department of Biology, Memorial University of Newfoundland, St John’s, NL, Canada.
   Google Scholar
• Jameson, R. G., A. J. Trant, and L. Hermanutz. 2015. Insects can limit seed productivity at the treeline. Canadian Journal of Forest Research 45 (3):286–96. doi:https://doi.org/10.1139/cjfr-2014-0385.
   Google Scholar
• Kambo, D., and R. K. Danby. 2017. Constraints on treeline advance in a warming climate: A test of the reproduction limitation hypothesis. Journal of Plant Ecology 11 (3):411–22. doi:https://doi.org/10.1093/jpe/rtx009.
   Web of Science ®Google Scholar
• Kantorowicz, W. 2000. Half a century of seed years in major tree species of Poland. Silvae genetica 49 (6):245–48.
   Web of Science ®Google Scholar
• Körner, C., and J. Paulsen. 2004. A world wide study of high altitude treeline temperatures. Journal of Biogeography 31 (5):713–32. doi:https://doi.org/10.1111/j.1365-2699.2003.01043.x.
   Web of Science ®Google Scholar
• Koshkina, N., P. Moiseev, and A. Goryaeva. 2008. Reproduction of the Siberian spruce in the timberline ecotone of the Iremel Massif. Russian Journal of Ecology 39 (2):83–91. doi:https://doi.org/10.1134/S1067413608020021.
   Web of Science ®Google Scholar
• Krasowski, M. J., and D. G. Simpson. 2001. Frost-related problems in the establishment of coniferous forests, Conifer Cold Hardiness, 253–85. Dordrecht, The Netherlands: Springer.
   Google Scholar
• Kroiss, S. J., and J. HilleRisLambers. 2015. Recruitment limitation of long‐lived conifers: Implications for climate change responses. Ecology 96 (5):1286–97.
   Web of Science ®Google Scholar
• Laberge, M.-J., S. Payette, and J. Bousquet. 2000. Life span and biomass allocation of stunted black spruce clones in the subarctic environment. Journal of Ecology 88 (4):584–93. doi:https://doi.org/10.1046/j.1365-2745.2000.00471.x.
   Web of Science ®Google Scholar
• Lamb, H. 1980. Late Quaternary vegetational history of southeastern Labrador. Arctic and Alpine Research 117–35. doi:https://doi.org/10.2307/1550510.
   Google Scholar
• Legendre, P., and M. J. Fortin. 1989. Spatial pattern and ecological analysis. Vegetatio 80 (2):107–38. doi:https://doi.org/10.1007/BF00048036.
   Google Scholar
• Lescop-Sinclair, K., and S. Payette. 1995. Recent advance of the arctic treeline along the eastern coast of Hudson Bay. Journal of Ecology 83 (6):929–39. doi:https://doi.org/10.2307/2261175.
   Web of Science ®Google Scholar
• Lindgren, K., I. Ekberg, and G. Eriksson. 1977. External factors influencing female flowering in Picea abies (L.) Karst. Studia Forestalia Suecica 142:1–53.
   Google Scholar
• Lloyd, A. H., and C. L. Fastie. 2003. Recent changes in treeline forest distribution and structure in interior Alaska. Ecoscience 10 (2):176–85. doi:https://doi.org/10.1080/11956860.2003.11682765.
   Web of Science ®Google Scholar
• Loader, S. 2007. Spatially explicit modelling of topographic and climatic influences on vegetation distribution in Labrador’s Mealy Mountains. MSc thesis, Department of Geography, Memorial University, St. John’s, Canada.
   Google Scholar
• Mamet, S. D., and G. P. Kershaw. 2012. Subarctic and alpine tree line dynamics during the last 400 years in north-western and central Canada. Journal of Biogeography 39 (5):855–68. doi:https://doi.org/10.1111/jbi.2012.39.issue-5.
   Web of Science ®Google Scholar
• Mencuccini, M., P. Piussi, and A. Zanzi Sulli. 1995. Thirty years of seed production in a subalpine Norway spruce forest: Patterns of temporal and spatial variation. Forest Ecology and Management 76 (1):109–25. doi:https://doi.org/10.1016/0378-1127(95)03555-O.
   Web of Science ®Google Scholar
• Messaoud, Y., Y. Bergeron, and H. Asselin. 2007. Reproductive potential of balsam fir (Abies balsamea), white spruce (Picea glauca), and black spruce (P. mariana) at the ecotone between mixedwood and coniferous forests in the boreal zone of western Quebec. American Journal of Botany 94 (5):746–54. doi:https://doi.org/10.3732/ajb.94.5.746.
   Web of Science ®Google Scholar
• Miller, G., and R. Cummins. 1982. Regeneration of Scots pine Pinus sylvestris at a natural tree‐line in the Cairngorm Mountains, Scotland. Ecography 5 (1):27–34. doi:https://doi.org/10.1111/eco.1982.5.issue-1.
   Google Scholar
• Munier, A., L. Hermanutz, J. Jacobs, and K. Lewis. 2010. The interacting effects of temperature, ground disturbance, and herbivory on seedling establishment: Implications for treeline advance with climate warming. Plant Ecology 210 (1):19–30. doi:https://doi.org/10.1007/s11258-010-9724-y.
   Web of Science ®Google Scholar
• Nathan, R., and H. C. Muller-Landau. 2000. Spatial patterns of seed dispersal, their determinants and consequences for recruitment. Trends in Ecology & Evolution 15 (7):278–85. doi:https://doi.org/10.1016/S0169-5347(00)01874-7.
   PubMed Web of Science ®Google Scholar
• Nienstaedt, H. 1985. Inheritance and correlations of frost injury, growth, flowering, and cone characteristics in white spruce, Picea glauca (Moench) Voss. Canadian Journal of Forest Research 15 (3):498–504. doi:https://doi.org/10.1139/x85-082.
   Web of Science ®Google Scholar
• Payette, S. 1993. The range limit of boreal tree species in Québec-Labrador: An ecological and palaeoecological interpretation. Review of Palaeobotany and Palynology 79 (1):7–30. doi:https://doi.org/10.1016/0034-6667(93)90036-T.
   Web of Science ®Google Scholar
• Payette, S., J. Deshaye, and H. Gilbert. 1982. Tree seed populations at the treeline in Rivière aux Feuilles area, northern Quebec, Canada. Arctic and Alpine Research 14 (3):215–21. doi:https://doi.org/10.2307/1551154.
   Web of Science ®Google Scholar
• Payette, S., L. Filion, A. Delwaide, and C. Bégin. 1989. Reconstruction of tree-line vegetation response to long-term climate change. Nature 341 (6241):429–32. doi:https://doi.org/10.1038/341429a0.
   Web of Science ®Google Scholar
• Payette, S., L. Filion, L. Gauthier, and Y. Boutin. 1985. Secular climate change in old-growth tree-line vegetation of northern Quebec. Nature 315 (6015):135–38. doi:https://doi.org/10.1038/315135a0.
   Web of Science ®Google Scholar
• Payette, S., and R. Gagnon. 1979. Tree‐line dynamics in Ungava peninsula, northern Quebec. Ecography 2 (4):239–48. doi:https://doi.org/10.1111/j.1600-0587.1979.tb01295.x.
   Google Scholar
• Pereg, D., and S. Payette. 1998. Development of black spruce growth forms at treeline. Plant Ecology 138 (2):137–47. doi:https://doi.org/10.1023/A:1009756707596.
   Web of Science ®Google Scholar
• Powell, G. 1977. Biennial strobilus production in balsam fir: A review of its morphogenesis and a discussion of its apparent physiological basis. Canadian Journal of Forest Research 7 (4):547–55. doi:https://doi.org/10.1139/x77-072.
   Web of Science ®Google Scholar
• Powell, G. R. 2009. Lives of Conifers: A Comparative Account of the Coniferous Trees. Baltimore, MD: Johns Hopkins University Press.
   Google Scholar
• R Development Core Team. 2016. R: A language and environment for statistical computing, reference index version 3.0. Vienna, Austria: R Foundation for Statistical Computing.
   Google Scholar
• Rangel, T. F., J. A. F. Diniz-Filho, and L. M. Bini. 2010. SAM: A comprehensive application for spatial analysis in macroecology. Ecography 33 (1):46–50. doi:https://doi.org/10.1111/j.1600-0587.2009.06299.x.
   Web of Science ®Google Scholar
• Reiners, W. A., and G. E. Lang. 1979. Vegetational patterns and processes in the balsam fir zone, White Mountains New Hampshire. Ecology 60 (2):403–17. doi:https://doi.org/10.2307/1937668.
   Web of Science ®Google Scholar
• Roberts, B. A., N. P. P. Simons, and K. W. Deering. 2006. The forests and woodlands of Labrador, Canada: Ecology, distribution, and future management. Ecological Research 21:868–80. doi:https://doi.org/10.1007/s11284-006-0051-7.
   Web of Science ®Google Scholar
• Roland, C. A., J. H. Schmidt, and J. F. Johnstone. 2014. Climate sensitivity of reproduction in a mast-seeding boreal conifer across its distributional range from lowland to treeline forests. Oecologia 174 (3):665–77. doi:https://doi.org/10.1007/s00442-013-2821-6.
   Web of Science ®Google Scholar
• Scott, G. 1995. Canada’s vegetation: A world perspective. Montreal, Quebec: McGill-Queen’s Press-MQUP.
   Google Scholar
• Scott, P. A., R. I. Hansell, and W. R. Erickson. 1993. Influences of wind and snow on northern tree-line environments at Churchill, Manitoba, Canada. Arctic 46 (4):316–23.
   Web of Science ®Google Scholar
• Simms, É., and H. Ward. 2013. Multisensor NDVI-based monitoring of the tundra-taiga interface (Mealy Mountains, Labrador, Canada). Remote Sensing 5:1066–90. doi:https://doi.org/10.3390/rs5031066.
   Web of Science ®Google Scholar
• Sirois, L. 1997. Distribution and dynamics of balsam fir (Abies balsamea [L.] Mill.) at its northern limit in the James Bay area. Ecoscience 4 (3):340–52. doi:https://doi.org/10.1080/11956860.1997.11682413.
   Web of Science ®Google Scholar
• Sirois, L. 2000. Spatiotemporal variation in black spruce cone and seed crops along a boreal forest – Tree line transect. Canadian Journal of Forest Research 30 (6):900–09. doi:https://doi.org/10.1139/x00-015.
   Web of Science ®Google Scholar
• Sprugel, D. G. 1976. Dynamic structure of wave-regenerated Abies balsamea forests in the north-eastern United States. The Journal of Ecology 64 (3):889–911. doi:https://doi.org/10.2307/2258815.
   Web of Science ®Google Scholar
• Sutton, E. 2008. Investigation of soil characteristics and climate change in the Mealy Mountains and Torngat Mountains. Honours Thesis, Department of Geography, Department of Geography, Memorial University, St. John’s, NL, Canada.
   Google Scholar
• Sveinbjörnsson, B., A. Hofgaard, and A. Lloyd. 2002. Natural causes of the tundra-taiga boundary. Ambio 1223–29.
   Web of Science ®Google Scholar
• Szeicz, J. M., and G. M. MacDonald. 1995. Recent white spruce dynamics of the subarctic alpine treeline of north-western Canada. Journal of Ecology 83 (5):873–85. doi:https://doi.org/10.2307/2261424.
   Web of Science ®Google Scholar
• Trant, A. J. 2013. Changing treelines: How variability in scale and approach improve our understanding. PhD Thesis, Department of Biology, Memorial University, Memorial University, St. John’s, NL, Canada.
   Google Scholar
• Trant, A. J., and L. Hermanutz. 2014. Advancing towards novel tree lines: A multispecies approach to treeline dynamics in subarctic alpine Labrador. Journal of Biogeography 41 (6):1115–25. doi:https://doi.org/10.1111/jbi.12287.
   Web of Science ®Google Scholar
• Trant, A. J., R. G. Jameson, and L. Hermanutz. 2011. Persistence at the tree line: Old trees as opportunists. Arctic 64 (3):367–70. doi:https://doi.org/10.14430/arctic4126.
   Web of Science ®Google Scholar
• Trant, A. J., K. Lewis, B. H. Cranston, J. A. Wheeler, R. G. Jameson, J. D. Jacobs, L. Hermanutz, and B. M. Starzomski. 2015. Complex changes in plant communities across a Subarctic alpine tree line in Labrador, Canada. Arctic 68 (4):500–12. doi:https://doi.org/10.14430/arctic4528.
   Web of Science ®Google Scholar
• Tremblay, B., E. Lévesque, and S. Boudreau. 2012. Recent expansion of erect shrubs in the Low Arctic: Evidence from Eastern Nunavik. Environmental Research Letters 7 (035501):035501. doi:https://doi.org/10.1088/1748-9326/7/3/035501.
   Google Scholar
• Trindade, M. 2009. On the spatio-temporal radial growth response of four alpine treeline species to climate across central Labrador, Canada. PhD Thesis, Department of Geography, Department of Geography, Memorial University, St John’s, NL, Canada.
   Google Scholar
• Viereck, L. A. 1970. Forest succession and soil development adjacent to the Chena River in interior Alaska1. Arctic and Alpine Research 1–26. doi:https://doi.org/10.2307/1550138.
   Google Scholar
• Wheeler, J. A., L. Hermanutz, and P. M. Marino. 2011. Feathermoss seedbeds facilitate black spruce seedling recruitment in the forest-tundra ecotone (Labrador, Canada). Oikos 120 (8):1263–71. doi:https://doi.org/10.1111/j.1600-0706.2010.18966.x.
   Web of Science ®Google Scholar
• Zasada, J. C., T. L. Sharik, and M. Nygren. 1992. The reproductive process in boreal forest trees. In A systems analysis of the global boreal forest, eds. H. H. Shugart, R. Leemans, and G. B. Bonan, 85–125. Cambridge: Cambridge University Press.
   Google Scholar