hlp 2003 10 rpt dendroecologicalanalysisoflwdinriparianzonesoffoothillslandscapesofalbertapilotstudy
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Dendroecological Analysis of Large Woody Debris
in Riparian Zones of Foothills Landscapes of Alberta
- Pilot Study Report -
Submitted by
Dr. Lori D. Daniels and Sonya R.E. Powell Department of Geography
University of British Columbia
Submitted to the Natural Disturbance Program
Foothills Model Forest Hinton Alberta
October 31, 2003
DISCLAIMER The views, statements and conclusions expressed, and the recommendations made in this report are entirely those of the author(s) and should not be construed as statements or conclusions of, or as expressing the opinions of the Foothills Model Forest, or the partners or sponsors of the Foothills Model Forest. The exclusion of certain manufactured products does not necessarily imply disapproval, nor does the mention of other products necessarily imply endorsement by the Foothills Model Forest or any of its partners or sponsors. Foothills Model Forest is one of eleven Model Forests that make up the Canadian Model Forest Network. As such, Foothills Model Forest is a non-profit organization representing a wide array of industrial, academic, government and non-government partners, and is located in Hinton, Alberta. The three principal partners representing the agencies with vested management authority for the lands that comprise the Foothills Model Forest, include Weldwood of Canada Ltd. (Hinton Division), Alberta Sustainable Resource Development and Jasper National Park. These lands encompass a combined area of more than 2.75 million hectares under active resource management. The Canadian Forest Service of Natural Resources Canada is also a principal partner in each of the eleven Model Forest organizations and provides the primary funding and administrative support to Canada’s Model Forest Program. The Foothills Model Forest mission: We are a unique partnership dedicated to providing practical solutions for stewardship and sustainability on Alberta forestlands. What we learn will be:
• reflected in on-the-ground practice throughout Alberta and elsewhere in Canada, where applicable;
• incorporated in forest and environmental policy and changes;
• widely disseminated to and understood by a broad spectrum of society. This will be the result of a solid, credible, recognized program of science, technology, demonstration and outreach.
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ACKNOWLEDGEMENTS This research was possible through the generous support of Weldwood of Canada Ltd. (Hinton Division), Jasper National Park, the Canadian Forest Service, Alberta Newsprint Company, and Alberta Sustainable Resource Development. This project is one of many inter-related research projects of the Foothills Model Forest (FMF) Natural Disturbance (ND) Program. The FMF Natural Disturbance Program is a long-term integrated research and integration program concerned with identifying, quantifying, and communicating the patterns and processes of natural disturbances since 1996. Further information on other FMF ND program initiatives and research can be found in: Andison, D.W. 2003. Foothills Model Forest Natural Disturbance Program long-term research plan. 8th edition. Foothills Model Forest, Hin on, Alberta.
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For more information on the FMF Natural Disturbance Program, or the Foothills Model Forest, please contact the Foothills Model Forest in Hinton, Alberta at (780) 865-8330, or visit their website at: http://www.fmf.ab.ca.
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Executive Summary
Our goal is to understand large woody debris dynamics, including recruitment, decay rates, and residence time of logs in small streams of the Foothills Model Forest, Alberta, Canada. In this pilot study, we used tree-ring analyses to determine the year of tree death of large woody debris. We sampled live, canopy trees and woody debris of white spruce and lodgepole pine in two riparian forests. Age structures and master ring-width series were developed from increment cores from live trees. In the field, we classified the stage of decay of the woody debris according to branch, bark and bole traits. We determined the year of death by statistically crossdating ring-width series from logs with the master series. The oldest white spruce established in 1759. Canopy trees grew slowly and the stand was uneven-aged. There were two episodes of tree death, c. 1900 and in the 1990s. The lodgepole pine stand initiated c.1900 after fire. Initially trees grew quickly, but growth slowed after 1940 and trees died between 1932 and 1997. The stage of decay of large woody debris varied with time since tree death and position of the wood relative to the stream. Large woody debris submerged in water and embedded in stream banks decays slowly and may persist more than 100 years. Thus, to be ecologically sustainable, forest management must account for impacts on the amount and type of woody debris in riparian forests, since it will influence stream morphology, aquatic habitat, and biodiversity for the next century.
Examples of large woody debris in small streams of Foothills Model Forest
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Background Information
In 2001, the Natural Disturbance Program and Fish and Watershed Program at the
Foothills Model Forest joined forces to look at several issues related to the relationship between terrestrial disturbance and riparian zone functions. At that time, the Natural Disturbance Program had examined the patterns of natural disturbance in riparian zones and the Fish and Watershed Program had developed a stream classification system to provide a framework for both management and research. The Foothills Models Forest sponsored a two-day workshop of about 25 participants representing FMA-holders, parks, government, and academic institutions. The objective was to define a strategy based on a common understanding of the problem(s) related to riparian management. The group identified the following two objectives:
1) To gain a better understanding of the biological and physical processes and functions of
disturbance in riparian zones, and, 2) To explore a variety of adaptive management tactics for riparian zones.
Guided by these over-arching goals, the Natural Disturbance Program initiated two
projects to examine the long-term dynamics of large woody debris (LWD). The first study uses aerial photography and ground sampling to determine post-fire recruitment patterns of LWD. The second study is this pilot study. It was specifically designed to identify historical trends in recruitment of in-stream wood. The premise of this study is that the woody material within a stream today may have originated from disturbance events that occurred decades to centuries ago. We lack knowledge of the links between stand dynamic processes, the mechanisms that create woody debris, and recruitment into the riparian zone. Dendrochronological techniques, specifically crossdating of ring-width patterns, will allow us to interpret radial growth histories of individual trees and determine the year of death of wood in the streams (Daniels et al. 1997). Dates of tree death can be compared to the dates of known fires, floods, droughts, or insect disturbances to identify the processes that generate LWD. This will provide a timeframe for the recruitment of LWD into streams and will also allow us to evaluate the so-called “residence time” of LWD in streams (Hyatt and Naiman 2001).
Objectives In this pilot study we developed and tested methods to measure the temporal dynamics of
large woody debris in riparian zones of small streams with the Foothills Model Forest. The specific objectives of this research were:
(1) develop site-specific tree-ring chronologies for lodgepole pine and white spruce, (2) develop efficient and effective methods for preparing large woody debris for
dendroecological analyses, and (3) use crossdating to assign calendar years to the tree-rings of the woody debris,
ultimately to estimate the year in which the trees died.
This information will contribute to understanding of natural disturbances within the riparian zone, the residence time and decay rate of large woody debris in these ecosystems, the temporal impacts of natural disturbance on riparian habitat structures and small stream morphology. The results of this research will contribute to a comprehensive analysis of large wood debris dynamics within the riparian forests of the Foothills Model Forest.
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Methods Study Sites
Site 1 Two sites were selected for this pilot study (Figure 1). Site 1 (#723 of McCleary et al. (2002)) is located in the Erith River watershed and surrounded by lodgepole pine with alder, willow and poplar within the riparian zone. Site 2 (#193 in McCleary et al. (2002)) is located in the Fish River watershed in a white spruce-dominated stand with alder, willow and poplar in the riparian zone. We selected small drainage basins (< 10 km2) to ensure that downed wood is not transported from upstream to downstream locations during peak flow events, thus linking the surrounding forest with woody debris at each site. Since local trees supply downed wood which decays in situ, the results from our analysis of the LWD can be directly linked to the temporal dynamics of the surrounding forest.
e 2
Figure 1. Location of study sites 1 and 2 in the Footh
Tree Ages and Chronology Development
Increment cores were extracted from living canopy-do
1, 20 lodgepole pine were cored; one core was sampled per tresite 2, 20 white spruce were cored twice; the cores were from oapproximately 30 cm above the ground. The cores were dried,surfaced by sanding with 120 to 400 grit sand paper, and visuamicroscope. (Stokes and Smiley 1968). For cores that intercepusing the equation:
5
ill
me ap mllyte
SITE 2 .
s Model
inant tret 1.3 m
posite siounted crossdad the pit
Site 1 1 1 SITE 1 .
s Forest, Alberta.
es at both sites. At site above the ground. At des of the stem and on wood supports, ted using a 40x h, age was calculated
Age core height = 2002 – pith year + 1 For tree cores that did not contain the pith, Duncan’s (1989) method was used to approximate the number of missing rings and estimate the pith-year and tree ages. In this study we did not correct tree age for the number of years for trees to grow to sample height. Since trees were cored at breast height (1.3 m above ground) for lodgepole pine and 30 cm above ground for white spruce, pith years underestimate the actual year of tree establishment and true age.
The ring-width series of each core were measured using a Velmex bench interfaced with a computer and statistically crossdated (Holmes 1983). Accurately dated and highly correlated ring-width series were combined into master ring-width series for each species and site. Standard chronologies were created by (a) normalizing each ring-width series to show growth rate departures from the mean growth rate and (b) standardizing individual ring-width series with a negative exponential curve or sloping line to removing the age-related growth trend (Cook 1985, Cook and Holmes 1986). Determining Year of Death for Large Woody Debris
A total of 35 bridged or in-stream downed wood were sampled (n=20 at Site 1 and n=15
at Site 2), either by extracting increment cores or by cutting cross-sectional disks from the bole (Appendix1 and 2). For each piece of large woody debris, we described its position relative to the stream bed as bridge, collapsed bridge, submerged or partly submerged on the streambed, or embedded in the streambank. These positions represent different functional roles of logs within the stream channel as decay ensues. Stages of decay were modified from Maser et al. (1979). In general, class 1 logs have sound bark and wood, twigs are present; class 2 logs have branches and/or bark is mostly intact; class 3 logs are round, bark is detached or absent; and, class 4 logs are oval and bark is absent. Class 5 logs are too decomposed to allow intact tree-ring samples to be extracted.
Increment cores and disks from large woody debris in decay classes 1 and 2 were air dried then sanded following the protocols described for the increment cores. Wood samples that were at more advanced stages of decayed (classes 3 and 4) were frozen then prepared following one of two methods. Samples with poor structural integrity were saturated with paraffin wax, air dried, then sanded. For samples with moderate structural integrity, we bound the circumference of the disk with duct tape then sanded the samples while they were frozen. After sanding, these disks were air dried.
We measured the ring-width series of the radius with the maximum number of rings. The ring-width series from the woody debris were statistically crossdated with the standard chronologies to determine the calendar year of the outer-most ring of the wood sample and to estimate the year of tree death. This method assumes that the outer-most ring of the wood sample is the last ring that was formed when the tree was alive. As some rings may have been lost due to physical erosion or decay through time, the accuracy of the results is greatest when bark and/or sapwood are included in the sample. Thus, the crossdating results are not absolutely accurate but they provide a precise (repeatable) estimate of the year of tree death. With this limitation in mind, we verified the statistical outcomes by examining the position of narrow marker rings and patterns of suppression and release in each crossdated ring-width series. After statistical crossdating and visual verification, a calendar year was assigned to the outermost ring of each core or basal disk from the large woody debris and it was considered the best estimate of the year of tree death. We rejected two samples, one lodgepole pine and one white spruce, for which an acceptable date for the outer-most ring could not be determined.
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Results and Discussion Lodgepole Pine
The standard chronology for lodgepole pine extended from 1905 to 2002 and included 18 ring-width series with an inter-correlation of 0.54 (Figure 2). Negative marker years, rings that were consistently narrow among sampled trees and may be used for visual crossdating, were 1914, 1916, 1946, 1971, 1982, 1983, 1985, 1996 and 1997. Abrupt suppressions in 1942 to 1948, 1982 to 1985, and 1995 to 1997 may indicate disturbance by insects or pathogens.
Figure 2. Lodgepole pine master ring-width chronology, 1905-2002 (n = 18, series intercorrelation = 0.54). (A) The master ring-width series shows an age-related geometric trend in ring widths. (B) A horizontal standardization was applied to remove the long-term trend and highlight the interannual variation in ring-width. (C) The sample depth curve shows the number of cores contributing to the chronology in each year.
The canopy trees formed a single cohort that established c. 1900, probably after fire
(Figure 3). Pith dates at core height were 1905 and 1915. Initial growth was rapid, which supports the interpretation that these trees established following a stand-level disturbance that created open conditions. Ring width gradually declined and narrow rings following 1940 represent the stem exclusion stag of stand development (Oliver and Larson, 1990). This stage is marked by inter-tree competition that reduces radial growth rates and causes tree deaths via self-thinning. Nine of 16 trees died between 1939 and 1955 (Figure 3, Table 1, Appendix 1). Tree deaths in 1944 and 1949 correspond with an abrupt suppression of live trees between 1942 and 1948. Inter-annual variation in ring width increased after 1960, possibly in response to increased growing space and resource availability after the onset of stand self-thinning. Five trees died between 1964 and 1977. The most recent tree death in 1997 corresponds with the 1995 to 1997 growth suppression.
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Table 1. Statistical crossdating of lodgepole pine large woody debris. Samples are arranged by stage of decay and type of debris. Decay class
Type of LWD
Sample type/number
Pith date Outer-ring date
Correlation with master
2 Bridge Core AB03 1926 1997 0.68 2 Bridge Disk 10A 1932 1968 0.50 2 Bridge Core AB07 1907 1954 0.67 2 Bridge Core AB09 1914 1949 0.27 Core AB10 1912 1948 0.39
2
Collapsed bridge on bank
Core AB01
1913
1977
0.48
3 on streambed Disk 4A 1949 1977 0.42 3 Collapsed bridge Disk 1A NA-decay 1946 0.49 3 Collapsed bridge Disk 18A 1916 1964 0.37 3 On streambed Disk 20A 1930 1970 0.42 3 On streambed Disk 5A 1916 1950 0.43
3 Collapsed bridge on bank
Disk 09A
1912
1952
0.45
4 on streambed Disk 09B 1925 1955 0.62 4
On/embedded in streambed
Disk 11A 1924 1939 0.48
4
On streambed/ embedded in bank
Disk 12A 1909 1944 0.51
4 Embedded in bank Disk 2A 1912 1932 0.54 4 Embedded in
streambed Disk 17A 1965
0.51
4 Embedded in bank Disk 13A 1916 1952 0.49 4 Embedded in bank Disk 14A 1926 1965 0.51 4 Embedded in
streambed Disk 6A Not datable at this time
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White Spruce
The standard chronology for white spruce extended from 1786 to 2002 and included 33
ring-width series with an inter-correlation of 0.51 (Figure 4). Negative marker years, rings that were consistently narrow among sampled trees and may be used for visual crossdating, were 1836, 1837, 1860, 1889, 1916, 1923, 1926, 1968, and 1971. The only marker year common to pine and spruce was 1916, suggesting that these two species respond differently to inter-annual variations in climate.
Figure 4. White spruce master ring-width chronology, 1786-2002 (n = 33, series intercorrelation = 0.51). (A) The master ring-width series shows long-term trends in ring width. (B) A horizontal standardization was applied to remove the long-term trends and highlight the interannual variation in ring-width. (C) The sample depth curve shows the number of cores contributing to the chronology in each year.
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The white spruce stand appears to be in a later stage of forest development than the lodgepole pine stand. The white spruce canopy dominants established over 120 years from c.1780 to 1900 (Figure 5). Narrower rings near the pith of most trees indicated that the spruce established in the shade beneath a closed canopy. Radial growth was generally slow; it increased from 1890 to 1940, decreased until 1970 and has fluctuated around the long-term mean since then. Radial growth rate was highest from 1926 to 1968. Comparison of the ring-widths of individual white spruce with the master chronology showed a marked decline in radial growth prior to death for several trees (Appendix 2). Mortality of white spruce was episodic (Table 2). At least three trees died c. 1900 and seven of 14 trees died during the 1990s. The oldest spruce logs had been dead since the mid-to-late 1800s. Large woody debris of white spruce was more challenging to crossdate than dead lodgepole pine since there was not a clear age-related trend in the radial growth of the spruce. We are most confident in the outcomes for wood in decay class 1 and 2. Generally, spruce in decay classes 3 and 4 had shorter ring-width series and were more decayed. For two samples, disks 22A and 31A, two possible dates of tree death are reported since we could not conclusively discern between them using statistical and visual crossdating (Table 2). Additional wood disks or ring-width series from additional radii on existing disks are needed to determine when these trees died.
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Table 2. Statistical crossdating of white spruce large woody debris. Samples are arranged by stage of decay and type of debris. Decay class
Type of LWD Tree Number Pith date Outer-ring
Correlation with master
1 Bridge Core AB16A 1914 2001 0.53 Core AB16B 1914 1993 0.43
2 Bridge Core AB14 1804 1997 0.51 2 Bridge Core AB17 1912 1998 0.44 2 Bridge Core AB18 1925 1989 0.38 2 Bridge Core AB19B 1992 0.39 2 Bridge Disk 28A 1787 1982 0.44 3 Low bridge Disk 23A 1764 1947 0.53 3 Low bridge,
embedded in bank Disk 31A 1836 or
1796 1953 or
1918 0.44 0.44
3 Embedded in bank Disk 36A 1793 1897 0.54 3 Low bridge,
embedded in bank Disk 32A 1762 1905 0.47
4 Embedded in bank and streambed
Disk 25A NA-decay 1855 0.50
4 Embedded in streambed
Disk 26A NA-decay 1899 0.61
4 Embedded in bank Disk 22A 1758 or 1797
1873 or 1912
0.56 0.47
4 Embedded in streambed
Disk 21A Not datable at this time
Residency of Large Woody Debris
Although sample sizes are small, we can make preliminary interpretations about rates of
decomposition of large woody debris. For both lodgepole pine and white spruce, the age of woody debris generally increased with decay class (Figure 6). However, there was significant overlap in age between decay classes for pine. For spruce, classes 1 and 2 were overlapping, but classes 3 and 4 were discrete. A direct comparison of these two study sites suggests that white spruce may decay more slowly than lodgepole pine decays. Spruce in decay classes 3 and 4 had been dead 49 to 147 years; pine in decay classes 3 and 4 had been dead 25 to 70 years. Differences in site conditions (temperature and soil moisture) and the types (surface versus embedded) and position of woody debris (percent exposed and depth of burial) may also explain the apparent differences in decay rates of the two species.
The longevity of woody debris documented in this study is greater than that reported in other riparian zones. Working in British Columbia, Hogan (1987) found that residency times of woody debris ranged from 40 to >90 years. In a simulation experiment, Hyatt and Naiman (2001) reported that the depletion rate of coniferous woody debris followed an exponential decay curve where 80% of debris pieces were <50 years old, but noted that some pieces persisted up to 1400 years. They calculated a half-life of 20 years for conifer wood, meaning that almost all conifer wood would disappear before 50 years. In our study, many samples older than 50 years showed signs of decay but were structurally sound and could be dated using tree-ring methods. LWD submerged in water and embedded in stream banks decayed slowly and persisted more than
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100 years. Thus, understanding large woody debris dynamics has important implications for short-term and long-term management of riparian zones. To be ecologically sustainable, forest management must account for impacts on the amount and type of woody debris in riparian forests, since it will influence stream morphology, aquatic habitat, and biodiversity for the next century. Recommendations for Future Work
This study clearly demonstrates that tree-ring analyses including crossdating may be used
to quantify years of tree death and to calculate residence times and decay rates of woody debris of lodgepole pine and white spruce. This pilot study was constrained to examine two species at only two sites (one species per site). We make the following recommendations for future research of large woody debris in the foothills of Alberta:
• Include black spruce with white spruce and lodgepole pine • Develop species-specific chronologies from a network of sites to represent the study
region. Sample the oldest trees possible to maximize the length of ring-width chronologies to allow crossdating of the oldest woody debris.
• Increase the number of sample sites, but limit sampling to small streams that do not transport woody debris so that in situ decomposition may be assessed.
• Increase the number of samples per site; note that some samples may be too decomposed to crossdate.
• Sample complete cross-sections whenever possible to allow analysis of multiple radii and to maximize the length of ring-width series.
• Sample terrestrial coarse woody debris for comparison with riparian large woody debris of the same species and at the same sites.
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Acknowledgements
We are grateful for financial support from Weldwood of Canada, Hinton Division, Foothills Model Forest and the Chisolm-Dogrib Research Initiative. Thanks to S. Wilson for assistance in the field and L. Parsons for assistance in the lab.
Literature Cited Cook, E.R. 1985. A time series analysis approach to tree-ring standardization. Ph.D. Dissertation,
University of Arizona, Tucson. Cook, E.R. and R.L. Holmes. 1986. Users Manual for Program ARSTAN. Pp. 50-65 in Holmes,
R.L., R.K. Adams and H.C. Fritts, eds. Tree-Ring chronologies of Western North America: California, Eastern Oregon and Northern Great Basin. Laboratory of Tree-Ring Research, University of Arizona, Tucson AZ, U.S.A.
Daniels, L.D., Dobrý, J., Feller, M.C., and Klinka, K. 1997. Determining year of death of logs and snags of Thuja plicata in southwestern coastal British Columbia. Canadian Journal of Forest Research 27: 1132-1141
Duncan, R.P. 1989. An evaluation of errors in tree age estimates based on increment cores of Kahikatea (Dacrycarpus dacrydioides). New Zealand Natural Science16: 31-37.
Hogan, D. L. 1987. The influence of large organic debris on channel recovery in the Queen Charlotte Islands, British Columbia, Canada. In: Erosion and Sedimentation in the Pacific Rim. Proceedings of the Corvallis Symposium, held August, 1987. IAHS Publication No. 165, Corvallis Oregon.
Holmes, R. L. 1983. Computer-assisted quality control in tree-ring dating and measuring. Tree Ring Bulletin 43: 69-78.
Hyatt, Timothy L. and Robert Naiman. 2001. The residence time of large woody debris in the Queets River, Washington, USA. Ecological Applications. 11(1): 191-202
Maser, C., Anderson, R. G., Cromack Jr., K., Williams, J. T., and Martin, R. E. 1979. Dead and Down Woody Material. Pp. 78-95 in Thomas, J.W. (ed.) Wildlife habitats in managed forests - the Blue Mountains of Oregon and Washington. USDA Forest Service Agricultural Handbook 553. Washington, DC.
McCleary, R., Widk, C. and J. Blackburn. 2002.Comparison between field and GIS derived descriptors of small streams within the west-central foothills of Alberta. Fish and Watershed Program, Foothills Model Forest, Hinton Alberta. April 2, 2002. 40pp.
Oliver, C. D. and B. C. Larson. 1990. Forest stand dynamics. McGraw-Hill Inc. USA Stokes, M. A. and T. L. Smiley. 1968. An introduction to tree ring dating. University of
Chicago Press. Chicago, Illinois, USA
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APPENDIX 1 – LARGE WOODY DEBRIS OF LODGEPOLE PINE Site Site 1 (723) Species Lodgepole pine Tree number 01 Sample number 2002 –01A (disk) Sample position Near base of tree Decay class 3 (no bark, with branch nubs) Type of LWD collapsed bridge (elevated) Sample diameter 12 cm (maximum) Number of rings 34 Outer-ring 1946 Pith date 1913 Initial Growth Fast
Tree 01 = Foreground, right side of photo
Roots on right upstream bank Diameter of disk = 12cm
Outer ring
dates Statistical correlation
with master series Visual crossdating and biological relevance
1946 0.49 Negative marker rings align Similar trend to master series
1956 <0.53
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Site Site 1 (723) Species Lodgepole pine Tree number 02 Sample number 2002 – 02A (disk) Sample position Cut near bank, position on tree is not known Decay class 4 Type of LWD On streambed and embedded in bank Sample diameter 10.5 cm (maximum) Number of rings 21 Outer-ring 1932 Pith date 1912 Initial Growth Fast
Tree 02 = Left side, moss-covered debris Diameter of disk = 10.5cm
Outer ring
dates Statistical correlation
with master series Visual crossdating and biological relevance
1932 0.54 No pronounced suppression = died early in stand development before crown closure
1951 0.47 Weaker correlation
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NOTE: TREE 03 WAS NOT SAMPLED Site Site 1 (723) Species Lodgepole pine Tree number 04 Sample number 2002 - AB01 (increment core) Sample position On land, 140cm from roots, diameter = 15.5cm Decay class 2 Type of LWD Bridge Sample diameter 15.5 cm Number of rings 64 Outer-ring 1977 Pith date 1913 Initial Growth Fast
Tree 04 = Tree top in foreground, Roots on left upstream bank
Outer ring
dates Statistical correlation
with master series Visual crossdating and biological relevance
1977 0.48 Negative marker rings align 1992 0.48 Marker rings do not align
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Site Site 1 (723) Species Lodgepole pine Tree number 04 Sample number 2002 – 04A (disk) Sample position Segment of wood on the streambed Decay class 3 Type of LWD On streambed, above baseflow, within bankfull Sample diameter 10 cm (maximum) Number of rings 45 Outer-ring 1977 Pith date 1933 Initial Growth Fast
Tree 04 = Tree top in foreground,
Roots on left upstream bank Diameter of disk = 10cm
Outer ring
dates Statistical correlation
with master series Visual crossdating and biological relevance
1977 0.42 Although weaker correlation, good match to temporal trend in master series
1952 0.55 1992 0.65
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Site Site 1 (723) Species Lodgepole pine Tree number 05 Sample number 2002 – 05A (disk) Sample position NA Decay class 3 Type of LWD On the streambed, parallel to stream, end in water Sample diameter 12 cm (maximum) Number of rings 35 Outer-ring 1950 Pith date 1916 Initial Growth Fast
Tree 5 = Left to right along streambank,
elevated but sloping to the water Diameter of disk = 12cm
Outer ring
dates Statistical correlation
with master series Visual crossdating and biological relevance
1950 0.43 1940s corresponds with suppression in master series
1965 0.52 Stronger correlation, poor match of trends
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Site Site 1 (723) Species Lodgepole pine Tree number 06 Sample number 2002 – 06A (disk) Sample position NA Decay class 4 in channel and 5 buried in bank Type of LWD Embedded in bank, LWD diagonal across wetted channel Sample diameter 10.5 cm (maximum) Number of rings 37 Outer-ring Not datable at this time Pith date Not datable at this time Initial Growth Fast
Tree 06= Advanced stage of decay (right) Tree07 = Broadleaf species, recent (left)
Tree 06= Advanced stage of decay (back) Tree07 = Broadleaf species, recent (front)
Diameter of Disk 06= 10.5cm
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Site Site 1 (723) Species Lodgepole pine Tree number 08 Sample number 2002 - AB03 (increment core) Sample position 330cm from ground, diameter = 20cm Decay class 2 Type of LWD Bridge Sample diameter 20 cm Number of rings 72 Outer-ring 1997 Pith date 1926 Initial Growth Fast
Tree 08 = Recent, bark present (centre)
Outer ring
dates Statistical correlation
with master series Visual crossdating and biological relevance
1997 0.68 Negative marker rings align 1978 0.42 Marker rings do not align
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Site Site 1 (723) Species Lodgepole pine Tree number 09 Sample number 2002 – 09A (disk) Sample position 150 cm from roots in the creek bed Decay class 3 in channel and 5 in bank Type of LWD Collapsed bridge with some wood on land and some on streambed Sample diameter 10 cm (maximum) Number of rings 41 Outer-ring 1952 Pith date 1912 Initial Growth Fast
Tree 09 = Excavating of terrestrial disk Diameter of disk = 10 cm
Outer ring
dates Statistical correlation
with master series Visual crossdating and biological relevance
1952 0.45 Negative marker years align General trend matches master series
1954 0.51 Poor alignment of negative marker rings 1994 0.42 Poor match to general trend in master series
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Site Site 1 (723) Species Lodgepole pine Tree number 09 Sample number 2002 – 09B (disk) Sample position 600 cm from roots in the creek bed Decay class 3 in channel and 5 in bank Type of LWD Collapsed bridge with some wood on land and some on streambed Sample diameter 17 cm (maximum) Number of rings 30 Outer-ring 1955 Pith date 1926 Initial Growth Fast
Tree 09 = Collapsed bridge in foreground Diameter of disk = 17cm
Outer ring
dates Statistical correlation
with master series Visual crossdating and biological relevance
1955 0.62 marker rings align, similarity in trend 1991 0.34
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Site Site 1 (723) Species Lodgepole pine Tree number Tree 10 Sample number 2002 – 10A (disk) Sample position Upland location near roots Decay class 2 (branch stubs present) Type of LWD Bridge Sample diameter 23 cm Number of rings 37 Outer-ring 1968 Pith date 1931 Initial Growth Fast
Tree 10 = Background, supporting safety vest Diameter of disk = XXcm
Outer ring
dates Statistical correlation
with master series Visual crossdating and biological relevance
1968 0.68 Highest correlation; declining trend consistent with master ring-width series
1995 <0.54 Branch stubs present but bark missing 1988 <0.36 Low correlation
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Site Site 1 (723) Species Lodgepole pine Tree number 11 Sample number 2002 – 11A (disk) Sample position NA – only part of stem is present Decay class 4 Type of LWD On streambed and embedded in bank Sample diameter 15 cm (maximum) Number of rings 16 Outer-ring 1939 Pith date 1924 Initial Growth Fast
Tree 11 = foreground, first on left
Outer ring
dates Statistical correlation
with master series Visual crossdating and biological relevance
1939 0.48 Negative marker rings align General trend is similar to master series
1988 0.44
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Site Site 1 (723) Species Lodgepole pine Tree number 12 Sample number 2002 – 12A (disk) (see also core #8) Sample position Near roots located in channel Decay class 4 Type of LWD On streambed and embedded in bank Sample diameter 12 cm (maximum) Number of rings 36 Outer-ring 1944 Pith date 1909 Initial Growth Moderate – not an open grown ring width pattern
Tree 12 = Centre-left, roots in centre of channel and top buried in left upstream bank
Diameter of disk = 12 cm
Outer ring
dates Statistical correlation
with master series Visual crossdating and biological relevance
1944 0.51 Highest correlation, trend is similar to master 1942 0.42 Very similar date but lower correlation
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Site Site 1 (723) Species Lodgepole pine Tree number 13 Sample number 2002-13A (disk) Sample position Sampled from edge of bank (tip into the channel) Decay class 4 Type of LWD Embedded in bank Sample diameter 12.5 cm (maximum) Number of rings 37 Outer-ring 1952 Pith date 1916 Initial Growth Fast
Tree 13 = Not visible, embedded in bamk Diameter of disk = 12.5 cm
Outer ring
dates Statistical correlation
with master series Visual crossdating and biological relevance
1952 0.49 High correlation, general trend is similar
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Site Site 1 (723) Species Lodgepole pine Tree number 14 Sample number 2002 – 14A (disk) Sample position NA – debris is at least 3m long and embedded in streambed Decay class 4 Type of LWD Embedded in bank Sample diameter 17.5 cm (maximum) Number of rings 40 Outer-ring 1965 Pith date 1926 Initial Growth Fast
Tree 14 = Centre-right, parallel to stream Diameter of disk = 17.5 cm
Outer ring
dates Statistical correlation
with master series Visual crossdating and biological relevance
1965 0.51 Consistent high correlations Negative marker rings align
1964 0.34 1952 <0.52
27
NOTE: TREE 15 = ALDER Site Site 1 (723) Species Lodgepole pine Tree number Tree 16 Sample number 2002 - AB07 (increment core) Sample position 100cm from ground, diameter = 21cm Decay class 2 Type of LWD Bridge Sample diameter 21 cm Number of rings 48 Outer-ring 1954 Pith date 1907 Initial Growth Fast
Tree 16 = Right side, behind D. Andison
Possible outer ring date Statistical correlation with
master ring-width series Visual crossdating and
biological relevance 1954 0.67 Narrow markers align No other reasonable option
28
Site Site 1 (723) Species Lodgepole pine Tree number 17 Sample number 2002 – 17A (disk) Sample position NA – debris = 1m long in streambed Decay class 4 Type of LWD Embedded in streambed Sample diameter 11.5 cm (maximum) Number of rings 31 Outer-ring 1965 Pith date 1935 Initial Growth Fast (no suppression evident) Diameter of disk = 11.5 cm
Outer ring
dates Statistical correlation
with master series Visual crossdating and biological relevance
1965 0.51 Higher correlation, better match to trend 1950 0.41
29
Site Site 1 (723) Species Lodgepole pine Tree number 18 Sample number 2002 – 18A (disk) Sample position 130cm from roots Decay class 3 Type of LWD Collapsed bridge Sample diameter 15.5 cm (maximum) Number of rings 48 Outer-ring 1964 Pith date 1917 Initial Growth Fast
Tree 18 = Lower centre, collapsed bridge
Diameter of disk = 15.5 cm
Outer ring
dates Statistical correlation
with master series Visual crossdating and biological relevance
1964 0.37 Weaker correlation, but marker rings align General trend similar to master series
1975 0.48 Higher correlation but departure from trend
30
Site Site 1 (723) Species Lodgepole pine Tree number 19 Sample number 2002 - AB09 (increment core) (see also AB10) Sample position 250cm from ground, diameter = 19cm Decay class 2 Type of LWD Bridge Sample diameter 19 cm Number of rings 35 Outer-ring 1949 Pith date 1914 Initial Growth Fast
Tree 19 = Left, intact bridge
Possible outer ring date Statistical correlation with
master ring-width series Visual crossdating and
biological relevance 1949 0.27 Although lower correlation,
the negative marker rings align
1942 0.35 Poor alignment of the negative marker rings
31
Site Site 1 (723) Species Lodgepole pine Tree number 19 Sample number 2002 – AB10 (increment core) (see also AB09) Sample position 250cm from ground, diameter = 19cm Decay class 2 Type of LWD Bridge Sample diameter 19 cm Number of rings 37 Outer-ring 1948 Pith date 1912 Initial Growth Fast
Tree 19 = Left, intact bridge
Possible outer ring date Statistical correlation with
master ring-width series Visual crossdating and
biological relevance 1948 0.39 Negative marker rings align 1947 0.43 Marker rings are offset
32
Site Site 1 (723) Species Lodgepole pine Tree number 20 Sample number 2002 – 20A (disk) Sample position NA - short piece of debris on streambed Decay class 3 Type of LWD On streambed Sample diameter 6.5 cm (maximum) Number of rings 41 Outer-ring 1970 Pith date 1931 Initial Growth Moderate
Diameter of disk = 6.5 cm
Outer ring
dates Statistical correlation
with master series Visual crossdating and biological relevance
1970 <0.56 Negative marker rings align General trend similar to master series
1957 <0.56 1966 <0.46
33
APPENDIX 2 - LARGE WOODY DEBRIS OF WHITE SPRUCE Site Site 2 (193) Species White spruce Tree number 21 Sample number 2002 –21A (disk) Sample position From bank, excavated to reveal wood, unknown position
on stem Decay class 4 Type of LWD Embedded bridge, half submerged during bankfull, moss
on top Sample diameter 20.5 cm (maximum) Number of rings N.A. Outer-ring Not datable at this time Pith date Not datable at this time Initial Growth N.A.
Tree 21 = Bridge with accumulated moss
Disk could not be crossdated. Outer ring
dates Statistical correlation
with master series Visual crossdating and biological relevance
1946 0.49 Negative marker rings align Similar trend to master series
1956 <0.53
34
Site Site 2 (193) Species White spruce Tree number 22 Sample number 2002 –22A (disk) Sample position Partly submerged and embedded in bank, decay in middle, sample
excavated from right upstream bank Decay class 4 Type of LWD Embedded in bank Sample diameter 14 cm (maximum) Number of rings 116 Outer-ring Option 1 = 1873; Option 2 = 1912 (see below) Pith date Option 1 = 1758; Option 2 = 1797 Initial Growth Moderate
Tree 22 = Blue flagging upstream,
low visibility as in the stream and bank Diameter of disk = 14 cm
Outer ring
dates Statistical correlation
with master series Visual crossdating and biological relevance
1873 0.56 High correlation; similar trend to master series 1912 0.47 Lower correlation; weaker similarity to master
35
Site Site 2 (193) Species White spruce Tree number 23 Sample number 2002 –23A (disk) Sample position Partly embedded bridge, bottom near water level at baseflow Decay class 2 terrestrial and 3 in channel Type of LWD Bridge Sample diameter 18.5 cm (maximum) Number of rings 184 Outer-ring 1947 Pith date 1764 Initial Growth Moderate
Tree 23 = Upstream view Diameter of disk = 18.5 cm
Outer ring
dates Statistical correlation
with master series Visual crossdating and biological relevance
1947 0.53 High correlation; decline post three negative marker rings c. 1920
1973 0.46 Lower correlation; 1830s markers do not align
36
Site Site 2 (193) Species White spruce Tree number 24 Sample number 2002 –AB12, AB13, AB14 (increment cores) Sample position AB12 @100cm; AB13 @210cm, AB14 @220cm Decay class 2 Type of LWD Embedded in bank Sample diameter Diameter at core height = 32 cm Number of rings 186 Outer-ring 1997 Pith date 1812 Initial Growth Moderate
Tree 24 =Upstream view of bridge
Outer ring
dates Statistical correlation
with master series Visual crossdating and biological relevance
1997 0.28 Lower correlation; but bark and fine branches intact suggesting recent tree death
1963 0.36
37
Site Site 2 (193) Species White spruce Tree number 25 Sample number 2002 –25A (disk) Sample position Deep in bank and stream bed, excavated to extract disk Decay class 4 Type of LWD Embedded in bank Sample diameter 8 cm Number of rings 44 Outer-ring 1855 Pith date NA – decayed Initial Growth NA - decayed
Tree 25 =Upstream view, deeply buried in bed Diameter of disk = 8 cm
Outer ring
dates Statistical correlation
with master series Visual crossdating and biological relevance
1885 0.50 High correlation; negative marker rings align with 1830’s and suggest possible cause
1904 0.41 Narrow rings precede narrow marker year
38
Site Site 2 (193) Species White spruce Tree number 26 Sample number 2002 –26A (disk) Sample position NA – debris was 1m long, unknown position on stem of live tree Decay class 4 Type of LWD Embedded in streambed Sample diameter 9.0 cm (maximum) Number of rings 53 Outer-ring 1899 Pith date 1847 Initial Growth Moderate
Diameter of disk = 9.0 cm
Outer ring
dates Statistical correlation
with master series Visual crossdating and biological relevance
1899 >0.60 High correlation; similar trend to master series 1924 0.45
39
Site Site 2 (193) Species White spruce Tree number 28 Sample number 2002 –28A (disk) Sample position Sampled stump near channel Decay class 2 Type of LWD Bridge Sample diameter 23.0 cm (maximum) Number of rings 200 Outer-ring 1982 Pith date 1787 Initial Growth Fast
Tree 28 =Bridge upstream of D. Andison Diameter of disk = 23.0 cm
Outer ring
dates Statistical correlation
with master series Visual crossdating and biological relevance
1982 0.44 Lower correlation; similar trend to master series 1994 0.50 Higher correlation but trend are offset
40
Site Site 2 (193) Species White spruce Tree number 30 Sample number 2002 –AB16 (increment core) Sample position Core taken at 170cm Decay class 1 Type of LWD Bridge – intact and elevated Sample diameter Diameter at core height = 16 cm Number of rings 88 Outer-ring 2001 Pith date 1914 Initial Growth Moderate
Tree 30 =Background, elevated log
Outer ring
dates Statistical correlation
with master series Visual crossdating and biological relevance
2001 0.36 Lower correlation, negative marker rings align 1993 0.42 Differences between cores is consistent with
cambial dieback prior to death
41
Site Site 2 (193) Species White spruce Tree number 31 Sample number 2002 –31a (disk) Sample position Middle of bridge Decay class 3 Type of LWD Low bridge, embedded in banks Sample diameter 16.0 cm (maximum) Number of rings 123 Outer-ring Option 1 = 1953; option 2 = 1918 Pith date Option 1 = 1836; option 2 = 1796 Initial Growth Moderate
Tree 31= Low bridge, embedded in bank Diameter of disk = 16 cm
Outer ring
dates Statistical correlation
with master series Visual crossdating and biological relevance
1953 0.44 Decline and death may be explained by the negative marker years c. 1910-30
1918 0.44 Departures from the master series post 1880 are suspect
42
Site Site 2 (193) Species White spruce Tree number 32 Sample number 2002 –32a and 32b(two radii on one disk) Sample position Left upstream side of bridge Decay class 3 Type of LWD Low bridge, embedded in banks, 3cm soil and moss on top Sample diameter 24.0 cm (maximum) Number of rings 148 Outer-ring 1905 Pith date 1762 Initial Growth Fast
Tree 32 =Sampled bridge, centre Diameter of disk = 24 cm
Outer ring
dates Statistical correlation
with master series Visual crossdating and biological relevance
1905 0.47 Trends similar to master series 1952 0.47 Departure from trend in master series
43
Outer ring
dates Statistical correlation
with master series Visual crossdating and biological relevance
1902 0.48 Trends similar to master series, negative marker rings align
1950 0.55 Departure from trend in master series, negative marker rings do not align
44
Site Site 2 (193) Species White spruce Tree number 33 Sample number AB17 (increment core) Sample position 100cm from roots Decay class 2 (branches present) Type of LWD Bridge – above bankfull Sample diameter Diameter at core height = 12 cm Number of rings 104 Outer-ring 1998 Pith date 1895 Initial Growth Slow
Tree 33= Bridge above bankful
Outer ring
dates Statistical correlation
with master series Visual crossdating and biological relevance
1998 0.44 High correlation, branches suggest recent death 1933 0.34 Lower correlation, inconsistent with position of
other woody debris
45
Site Site 2 (193) Species White spruce Tree number 34 Sample number AB18 (increment core) Sample position 60 cm from roots Decay class 2 (branches present, no needles) Type of LWD Bridge – top of snag, across stream channel Sample diameter Diameter at core height = 35 cm Number of rings 65 Outer-ring 1989 Pith date 1925 Initial Growth Fast
Tree 34= Top of snag bridged stream, foreground
Outer ring
dates Statistical correlation
with master series Visual crossdating and biological relevance
1989 0.38 High correlation, general trend similar to master
46
Site Site 2 (193) Species White spruce Tree number 35 Sample number AB19 (increment core) Sample position 70 cm from roots Decay class 2 Type of LWD Bridge – above bankfull Sample diameter Diameter at core height = 35 cm Number of rings 73 Outer-ring 1992 Pith date 1920 Initial Growth Moderate
Tree 35= Bridge above bankful, centre
Outer ring
dates Statistical correlation
with master series Visual crossdating and biological relevance
1992 0.39 High correlation, negative markers align, recent 1923 0.30 Lower correlation, poor alignment of negative
marker rings
47
Site Site 2 (193) Species White spruce Tree number 36 Sample number 2002-36a (disk) Sample position NA – section taken from bank Decay class 3 Type of LWD Embedded in bank, above baseflow but saturated with water Sample diameter 16.5 cm (maximum) Number of rings 105 Outer-ring 1897 Pith date 1792 Initial Growth Fast
Tree 36= Embedded in bank Diameter of disk = XXcm
Outer ring
dates Statistical correlation
with master series Visual crossdating and biological relevance
1897 0.54 High correlation, negative markers align, recent 1949 0.40 Lower correlation, poor alignment mid-1800s
48