Forest Investment Account (FIA) - Forest Science Program
FIA Project Y103073

    Natural Regeneration, Mortality and Residual Growth Response 25 Years after Partial Cutting on the Coast
Project lead: Louise de Montigny (Ministry of Forests and Range)
Author: de Montigny, Louise E.
Subject: Forest Investment Account (FIA), British Columbia
Series: Forest Investment Account (FIA) - Forest Science Program
There are a large number of Provincial coastal growth and yield research experiments, and these have been assessed and ranked in terms of their ability to provide quality data. The resulting Coastal GY Field Experiments program consists of only those experiments and installations that can provide high quality data and achieve their treatment response objectives. Priority remeasurements this year include:
EP703 Extensive Studies of Fertilizing and Thinning - 73 plots from 6 installation will be remeasured (described above). EP703 was initiated in 1971 to investigate the growth response of Douglas-fir and western hemlock at three levels of fertilization and three levels of thinning in a replicated, factorial design. The experiment originally encompassed 940 permanent plots located at 85 installations throughout coastal BC. Of the original 85 installations, 62 have been highly ranked for importance to the program and most of these high priority installations have had their 8th measurement. In addition to tree diameter, height and condition codes, data has been collected on pre-treatment forest conditions, tree ages, crown width, pathological indicators, site information, soil texture, nutrients and moisture regimes, foliar nitrogen, on-site weather stations, understorey vegetation, mortality and ingrowth. The data from this experiment is the single, largest source of data for coastal stands in BC and has provided the most important validation and calibration data for second-growth coastal hemlock and Douglas-fir. The data has been used by research organizations and consultants in BC, the Pacific northwest, and internationally. It has been used to model the spread and effects of root rot over time, effects of fertilizing and thinning, stand development, crown response and other projects that require long-term tree measurement data.
EP 62, 63, 64, 66, 283 Successive Thinnings in a Natural Stand of Douglas-fir (The Schenstrom Plots). This was the first experiment ever established in B.C. in 1929 at Cowichan Lake by Sig Schenstrom in a naturally regenerated 18 year-old stand of Fd. There are 5 treatment plots including a control, heavy crown and and low thinnings, and very heavy crown and low thinnings. The plots have been remeasured after 10m height growth (about every 10 years) and were last remeasured in 1999. The original objectives were: 1. To develop a yield table based on a series of successive remeasurements. 2. To compare the yield of several plots thinned by different methods.

EP429 Spacing Trials of Douglas-fir, Western Redcedar and Grand Fir in Pure and Mixed Stands. Established in 1963 (the plantation is 46 years old in 2009) as an espacement trial of three spacings 1.8, 2.7 and 3.7m, and six species combinations: pure Fd, Cw and Bg, and mixes Fd-Cw, Fd-Bg, and Cw-Bg for a total of 18 plots. Each plots is 0.04 ha, and the number of trees varies by spacing. The objective is to compare the effects of a) spacing and b) species-mix on the survival and growth and yield of plantation of Douglas-fir, western red cedar, and grand fir.

E.P. 1065 – 02 Pruning Western Hemlock
Located at Jordan River, South Island Forest District and Naka Creek, Port McNeill Forest District, this pruning experiment was established in 1992 within a plantation originally established as a progeny trial -experiment EP 813 (411, 418). The Jordan River study was planted with western hemlock in spring 1981, and Naka Creek in spring 1982. All plots were spaced to 4 metre before pruning in 1992. There are 15 (36 tree) plots at both Jordan River and Naka Creek and pruning treatments were none (control), 4.5, 3.5, 2.5, or 1.5 metres of crown removal. Naka Creek has an additional 12 (48 tree) plots. The objective is to determine and compare the impact of different severities of pruning on the growth, yield and value of coastal western hemlock. The installation has been remeasured every 5 years and was last remeasured in 2005. The Jordan River site is now for sale as private land and this likely will be the final measurement at this installation.

E.P. 1065 – 03 Pruning Western Redcedar
Located near Port McNeill, this experiment consists of western redcedar pruned to different levels of crown removal in 1994 when the stand was 15 years old. There are twelve 0.1 ha plots (with a 0.1ha buffer). The treatments include no treatment (control), and 20, 30, 40, 50, and 60% crown removal. The objective is to determine and compare the impact of pruning on the growth, yield and value of western redcedar based on remeasurements and observations from permanent sample plots. The experiment was last remeasured in 2005.
EP 1121 Effects of Coastal Hardwoods on Mixed Stand Development. Red alder and bigleaf maple are common components of low elevation CWH zone forests in South-western British Columbia and can have beneficial effects in a forest such as contributing to biodiversity, to long-term site productivity through addition of nitrogen to the soil, to rates of nutrient cycling through influence on characteristics of litter and soil flora and fauna and to ameliorating root disease. Despite the benefits they can be aggressive competitors in conifer stands, and this EP studies the effects of different amounts and spatial arrangements of broadleaves on growth and survival of conifers and broadleaves, stand dynamics and long-term sustainability. This research includes three experimental designs: 1) replacement series; 2) additive series; and 3) "cluster" series. Data is used for calibrating and testing mixedwood growth models and provides information on competition thresholds and key processes as a basis for mixedwood management and stand tending decisions in broadleaf-conifer mixtures that must balance timber production, biodiversity, and long-term sustainability. Measurement this year is for the bigleaf maple experiment at Halpenny.
EP 1256 Robert’s Creek Alternative Silvicultural Systems Research Program
This study, located at Robert’s Creek on the Sunshine Coast, is a collaborative research program established in 1995. The overall objective of this study is to describe and compare ecosystem processes and characteristics in mesic, Douglas-fir (with a monor component of western hemlock and western red cedar forests) of the Robert's Creek Study Forest under four harvesting methods including: 1) a conventional clearcut harvest, 2) a two-pass uniform shelterwood harvest, 3) an extended rotation involving multiple commercial thinnings followed by a two-pass shelterwood cut, and 4) not cutting (permanent long-term control). The results be will be used to assess the ecological, economic and social values of alternatives to clearcut-based silvicultural systems. The growth and yield component of this study has specific objectives which are: 1) To compare between-treatment differences in stand structure before and after treatments, including tree size, density, species composition, crown characteristics and harvesting damage, and 2) To compare between-treatment differences in stand development over time including residual tree growth response, crown development, rates of mortality and ingrowth and incidence of disease. Remeasurement schedule is every 4 years and this was last measured in 2004.
In addition to these priority measurements, the workplan is to complete the analysis and reporting on 25 year response of growth, regeneration and mortality of EP 703. Although the experiment was meant to examine effects of thinning in pure stands, in fact, the treatments ranged from 20 to 50% basal area removal across mixed species stands varying in age from 15 years to 75 years and can be used to assess response of stands with high retention harvesting, and for thinning in situations where extended rotations are desirable. The analysis provides the first ever look at 25 year stand dynamics across the range of installations from southern to northern Vancouver Island.
Related projects:  FSP_Y081073FSP_Y092073


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Updated August 19, 2010 

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