The Northern Inland Temperate Rainforest of British Columbia: Old Forests with a Young History?

Abstract The inland temperate rainforest (ITR) in east-central British Columbia is marked by superlative examples of old-growth cedar-hemlock forest. How long has this old-growth forest structure been a major component of this landscape? What is the biological and conservation significance of the history of this forest type? Here we present paleoecological evidence from a study in the Robson Valley of the Upper Fraser River. Sediment cores from Gerry Lake and Redmountain Lake show that western hemlock and western redcedar increased in abundance only within the last 2000 years. Thus, the old-growth forests of the northern ITR may have been present for only a few generations of trees. It is even possible, based on our preliminary evidence, that the oldest western redcedar in these stands may be the first colonizing individuals at these sites. Further paleoecological studies, including a combination of stand-age structure and pollen analysis from small lakes and forest hollows, are needed in order to understand the historical significance of these stands. A recent establishment of the ITR has implications for understanding the assembly of the modern diverse biota of the region as well as how the biota will respond to future climate change.

[1]  M. Pellatt,et al.  Climate change and ecosystem response in the northern Columbia River basin — A paleoenvironmental perspective , 2008 .

[2]  J. Clague,et al.  Western Canadian glaciers advance in concert with climate change circa 4.2 ka , 2008 .

[3]  D. Sprugel,et al.  Millennial-scale changes in local vegetation and fire regimes on Mount Constitution, Orcas Island, Washington, USA, using small hollow sediments , 2008 .

[4]  K. Ritland,et al.  Patterns of post-glacial colonization by western redcedar (Thuja plicata, Cupressaceae) as revealed by microsatellite markers , 2008 .

[5]  D. Gavin,et al.  Midge-inferred Holocene summer temperatures in Southeastern British Columbia, Canada , 2008 .

[6]  R. Hebda.  British Columbia Vegetation and Climate History with Focus on 6 ka BP , 2007 .

[7]  Tongli Wang,et al.  Potential effects of climate change on ecosystem and tree species distribution in British Columbia. , 2006, Ecology.

[8]  D. Gavin,et al.  Spatial variation of climatic and non‐climatic controls on species distribution: the range limit of Tsuga heterophylla , 2006 .

[9]  B. Hawkes,et al.  Soil and sedimentary charcoal evidence for Holocene forest fires in an inland temperate rainforest, east-central British Columbia, Canada , 2006 .

[10]  D. Gavin,et al.  Correspondence of pollen assemblages with forest zones across steep environmental gradients, Olympic Peninsula, Washington, USA , 2005 .

[11]  T. Goward,et al.  Lichenological evidence for the recognition of inland rain forests in western North America , 2005 .

[12]  Y. Huang,et al.  EVIDENCE FOR THE CLOSE CLIMATIC CONTROL OF NEW ENGLAND VEGETATION HISTORY , 2004 .

[13]  D. Vitt,et al.  Patterns of bryophyte diversity in humid coastal and inland cedar- hemlock forests of British Columbia 1 , 2003 .

[14]  I. Walker,et al.  Postglacial spread of hemlock (Tsuga) and vegetation history in Mount Revelstoke National Park, British Columbia, Canada , 2003 .

[15]  M. Pellatt,et al.  Climate Change in Coastal British Columbia — A Paleoenvironmental Perspective , 2003 .

[16]  C. Whitlock,et al.  Spatial variation of modern pollen in Oregon and southern Washington, USA. , 2000, Review of palaeobotany and palynology.

[17]  L. Cwynar.  The abundance of exotic western hemlock pollen at Waterdevil lake, white pass, northern British Columbia: a preliminary analysis , 1993 .

[18]  L. Cwynar,et al.  An inexpensive sieving method for concentrating pollen and spores from fine-grained sediments , 1979 .

[19]  Rexford F. Daubenmire,et al.  Floristic plant geography of eastern Washington and northern Idaho , 1975 .

[20]  Leroy E. Detling.  Historical Background of the Flora of the Pacific Northwest , 1968 .

[21]  K. Faegri,et al.  Textbook of Pollen Analysis , 1965 .

[22]  K. Flessa,et al.  The Geological Record of Ecological Dynamics: Understanding the Biotic Effects of Future Environmental Change , 2005 .

[23]  I. S. Spoonera,et al.  The impact of air mass circulation dynamics on Late Holocene paleoclimate in northwestern North America , 2003 .

[24]  R. Raeside,et al.  The impact of air mass circulation dynamics on Late Holocene paleoclimate in northwestern North America , 2003 .

[25]  André F. Lotter,et al.  Loss on ignition as a method for estimating organic and carbonate content in sediments: reproducibility and comparability of results , 2001 .

[26]  D. Soltis,et al.  Comparative phylogeography of north-western North America : a synthesis , 2001 .

[27]  L. K. Croft,et al.  Interior Columbia Basin ecosystem management project , 1997 .

[28]  P. Marshall,et al.  Age structure of Thuja plicata in the tree layer of old-growth stands near Vancouver, British Columbia , 1995 .

[29]  P. Reimer,et al.  Extended 14C Data Base and Revised CALIB 3.0 14C Age Calibration Program , 1993, Radiocarbon.

[30]  C. Whitlock.  Vegetational and Climatic History of the Pacific Northwest during the Last 20,000 Years: Implications for Understanding Present-day Biodiversity , 1992 .