Hardwood Silviculture (HSC) Research Locations

Transcription

1 Hardwood Silviculture (HSC) Research Locations 1

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3 Installation 322, Ryderwood, Weyerhaeuser Site #4113 Notes: Elevation 8ft; slope 1-2%; aspect Northeast; Douglas-fir site index (5yr)=13ft; Red alder soil site index (5yr)=1ft. Soil: Centralia silt-loam, deep, well-drained, moderately textured, parent material residuum and colluvium derived from sandstone. Cable and tractor logged and broadcast burned in 199. Planted 4/11-13/9 with 1+ bare root seedlings. 1 st year survival 87%. Winter 1992/93: 3 year measurement Winter 1995/96: 6 year measurement. Plots 4 (12tpa) and 7 (525tpa) both thinned to 273tpa. Plot 6 (23tpa) pruned to 6ft. Winter 1998/99: 9 year measurement. Plot 8 (525tpa) thinned to 266tpa and Plot 3 (12tpa) thinned to 33tpa. Plot 6 (23tpa) pruned to 12ft. Winter 21/2: 12 year measurement. Plot 6 (23tpa) pruned to 22ft. All treatments completed. Winter 26/7: 17 year measurement. Winter 211/12: 22 year measurement. Heavy storm damage in Plot 9. Winter 216/17: 27th year measurement. Perimeter trees painted in orange. DBH lines painted in blue. Height trees flagged w/misc colors. Next action: Winter 221/22: 32nd year measurement. 3

4 Outline Site Selection o April 218, Connie Harrington o General Indicators o Harrington Soil/Site Method o DNR Site Selection Tool Planting o Stock o Outplanting Site Quality Range o Ryderwood vs. HSC Effect of Density o DBH o HT Precommercial Thinning (PCT) o Density Management Diagram o Rules of Thumb o PCT Example Timing & Density o PCT Economics Density Management- Ryderwood Summary- Ryderwood Red Alder vs. Douglas-fir: Economics 4

5 Selecting Suitable Sites Red alder occupies sites with a range of physical properties but best growth achieved on the more limited well-drained upland or alluvium sites Good drainage but not swamps Avoid heavy frost pockets Avoid summer drought and heat stress With nearby trees Site index curves have been developed for natural stands of red alder using a base age of 5 years. Without nearby trees or bare ground The most common way of determining site index (base age of 5 years) uses the soilsite method developed by Harrington (1986) Soils data can be most readily found at the NRCS website 5

6 DNR Red Alder Site Selection Tool The DNR has developed a draft of a geospatial RA Site Index model using the evaluation method from the Harrington A Method of Site Evaluation for Red Alder paper. They have run the model covering all of the LIDAR covered DNR lands and preliminary validation results are encouraging. They are currently working to run a statewide comparison of measured RA site index to predicted SI from the model using HSC field data to help validate the geospatial site index calculation on non-dnr (W WA & OR) lands. If the model performs well across the region, the intention is to have a publicly available, geospatial red alder site index model for all of western OR and WA. 6

7 Seedlings Seed zones are similar to Douglas-fir What is a quality seedling? Healthy branches or buds along the entire length of stem Be sure to order in advance Sources? Clones? Outplanting Red alder must be planted in spring, mid-march through mid-april after the risk of frost is over but before summer drought stress Stock very easily damaged, handle gently Red alder seedlings are susceptible to heat stress so deep planting and minimal scalping is recommended Finding a crew familiar with red alder is very important 7

8 Site Quality Range HSC Type 2 Site Index (2 year) # of Sites ' 5-55' 55-6' 6-65' 65-7' 7-75' 75-8' 8-85' Site Index Class Method Site Index (ft) 2yr 5yr Harrington WyCo Weiskittel Average

9 Ryderwood (#322) vs. All Sites (n=5) 27 year DBH Ryderwood All Sites (Mean & Max) 12 1 DBH (in) tpa 23tpa 525tpa 12tpa Control Treatment Ryderwood (#322) vs. all Sites (n=5) 27 year Height Height (ft) tpa 23tpa 525tpa 12tpa Control Treatment Ryderwood All Sites (Mean & Max)

10 Effect of Density 14 Ryderwood (#322) Control Plot DBH DBH (in) Stand Age Ryderwood (#322) Control Plot Height 1tpa 23tpa 525tpa 12tpa Height (ft) Stand Age 1 1tpa 23tpa 525tpa 12tpa 3 2 1

11 Ryderwood (#322) Control Plot Live Crown Ratio Live Crown Ratio tpa 23tpa 525tpa 12tpa Stand Age Ryderwood (#322) Control Plot Relative Density.2.1. Relative Density tpa 23tpa 525tpa 12tpa Stand Age 11

12 Precommercial Thinning Density Management Diagram PCT Timing & Density PCT Economics Density Management Diagram Defines relationship between growing space and tree size Very useful tool for making decisions regarding stand density (i.e. thinning) Recommended management zone is between lines C and D (shaded area) Line C- Operating Maximum, Relative density=45% Line D- Competition Threshold, Relative density=25% 12

13 Ryderwood (#322) Relative Density Relative Density tpa Control 525tpa Control 525tpa Thin Age 6 525tpa Thin Age Stand Age Ryderwood (#322) DBH DBH (in) Stand Age 13 23tpa Control 525tpa Control 525tpa Thin Age 6 525tpa Thin Age 9 4 2

14 Precommercial Thinning- Rules of Thumb Medium Site: SI2=6-7ft (SI5=8-1ft) High Site: SI2>7ft (SI5>1ft) Planting Density ~55tpa Timing Relative Density= 25%, DBH~5in Relative Density= 45%, DBH~6.5in Med Site ~1-15 years old High Site~ 5-1 years old Crown Ratio~5% Med Site ~12 years old High Site~ 9 years old Intensity Dependent on desired final log diameter/rotation age Rule of thumb- Form factor /DBH) ~.7, or a 1in reduction in diameter every 1ft TPA DBH 3 Log Dia Note: Be cautious when thinning from very high densities to very low densities 14

15 Precommercial Thinning- Example Hypothetical PCT tree list for two sites planted at 6tpa Medium Site: SI2=65ft High Site: SI2=75ft 2 PCT Timings: RD=25% & RD=45% SI2=65ft- 1 & 13 SI2=65ft- 6 & 1 2 PCT Intensities: 15tpa (DBH=13, log dia=9 ) 25tpa (DBH=9, log dia=6 ) PCT Example- SI2=65ft, Planted 6tpa 3 year volume, 6" min top 6-7in 8-9in 1-11in 12+ in bdft/acre Unthinned 25RD15 25RD25 45RD15 45RD25 15

16 18 PCT Example- SI2=75ft, Planted 6tpa 3 year volume, 6" min top bdft/acre in 8-9in 1-11in 12+in Unthinned 25RD15 25RD25 45RD15 45RD PCT- Take Home #1 For both sites, CR=5% fell in between both RDs For the Medium site Thinning reduced total volume (~15%) Unthinned had the highest proportion of small logs No small logs when thinned heavy For the High site Thinning generally increased total volume (~15%) Again, unthinned had the highest proportion of small logs Thinning heavy shifted log diameter dramatically 16

17 Precommercial Thinning- Example Red alder log prices (recently quoted from a regional log buyer) Log Dia $/MBF 6 $586 7 $ $ $ $88 Cost assumptions SILVICULTURAL ACTIVITY HSC # tpa PCT to age 5 ADMIN $/AC TMT COST/AC TMT YEAR PV $/AC PREHARVEST SPRAY BURNING PILING POST BURN SPRAY SITE PREP SPRAY (W/O BURN) PRE-PLANT TRAPPING SEEDLINGS PLANTING GRASS/HERB SRPAY 1X POST PLANT TRAPPING REPLANT COST GRASS/HERB SRPAY 2X RELEASE SPRAY MANUAL RELEASE 1X PRUNE 8' (23 TPA) PRUNE15' (23 TPA) PRUNE 22' (23 TPA) PCT TO 24TPA Guiding rate=5.5% NPV & BLV dependent on guiding rate. IRR is not. Rotation length is at maximum NPV 17

18 Precommercial Thinning Example-Economics Medium Site (SI2=65ft), Planting Density=6tpa Scenario Unthinned PCT RD25, 15tpa PCT RD25, 25tpa PCT RD45, 15tpa PCT RD45, 25tpa PCT Age NA Harvest Yield (MBF) Rotation Age (YRS) Log Value NPV ($) -$61 $168 $19 $63 $59 IRR (%) 5.3% 6.1% 5.9% 5.7% 5.7% BLV/SEV ($) -$78 $22 $142 $8 $75 High Site (SI2=75ft), Planting Density=6tpa Scenario Unthinned PCT RD25, 15tpa PCT RD25, 25tpa PCT RD45, 15tpa PCT RD45, 25tpa PCT Age NA Harvest Yield (MBF) Rotation Age (YRS) Log Value NPV ($) $395 $895 $863 $633 $66 IRR (%) 6.8% 8.4% 8.% 7.7% 7.6% BLV/SEV ($) $59 $1,264 $1,148 $875 $878 PCT- Take Home #2 For the Medium site Thinning does reduce rotation age Light thinning increased volume All thinning treatments slightly increased NPV, IRR & BLV For the High site Heavy thinning reduced rotation age by 4 to 5 years Heavy thinning reduced volume compared to unthinned Light thinning increased volume by bumping more logs into the 6 dia class All thinning treatments dramatically increased NPV, IRR & BLV 18

19 Density Management-Ryderwood HSC #322: Projected Volume; Age 35 by Log Diameter Class bdft/acre in 8-9in 1-11in 12in bdft/acre 2 235C 525C 525 1st T 525 2nd T 2 Ryderwood Summary This stop- HSC #322/WeyCo #4113 is a top performing red alder site across the region. Using the soilsite method of estimating site index (Harrington 1986), site index (base age 5 years) was 1ft. Site index estimates of twelve other HSC sites greater than 2 years old ranged from 85ft to 115ft. Therefore, tree and stand growth responses (i.e. DBh and HT) from this site could be considered optimal or exceptional. The silvicultural treatments presented here (plant at 235tpa & leave alone [235C], plant at 525tpa & leave alone [525C], plant at 525tpa and thin to 24tpa at crown closure [525 1 st T], and plant at 525tpa & thin to 24tpa when HLC=15-2ft [525 2 nd T]) fall within what is currently considered operational and furthermore, allow for meaningful comparisons across treatments. Stand density management provides opportunities for foresters to influence stand yield, individual tree size, and stem form. Relative density and the associated relative density diagram developed by Puettman, et. al. (1993) is a useful tool in deciding the timing (i.e. window ) and intensity (post-thinning or residual density) of pre-commercial thinning. The recommended management zone (RD=25% to 45%) is the stand 19

20 condition that is a compromise between individual tree growth, stand yield, and mortality. Using data from this site the following were observed: o For the 235C treatment, the recommended management zone (RD=25% to 45%) occurred between the ages of 13 & 2. o For the 525tpa planting density treatment (525C), the plot was in the recommended management zone (RD=25% to 45%) between the ages of 6 &1. o For the st T treatment, thinning occurred at age 6; just as the stand was entering the management zone (RD=26%). It was thinned to a relative density below what is recommended (RD=16%). o For the 525 2nd T treatment, thinning occurred at age 9; just as the stand was approaching the upper limit of the management zone (RD=44%). It was thinned to a relative density just below what is recommended (RD=21%). o By age 27, the 525C and st T treatment reached the self-thinning line (RD=65%). The increased diameter growth resulting from an increase in resources (i.e. thinning) is, among other factors, a function of crown size. Therefore, identifying crown size is another useful way of deciding when to pre-commercially thin. A simple and useful measure of crown size is live crown ratio (LCR). For red alder plantations, it is generally considered that a 5% LCR of the trees/stand is a desirable trigger for when to PCT- thinning when LCR>5% sacrifices stand yield, while thinning when LCR<5% sacrifices individual tree growth. In regards to LCR, the following were observed: o For the 235C treatment, the trees/stand reached LCR=5% at age 2. o The 525C treatment was 12 years old when LCR dropped below 5%. o The LCR at time of thinning for the st T, and nd T was 84% and 66%, respectively. So, using the 5% rule, these treatments were thinned early. o PCTing maintained higher LCRs than the unthinned 525C treatment (~37% vs 27%). Diameter: o Trees either planted at a wider spacing (235C) or thinned to a wider spacing (525 1 st T & nd T) had, on average, diameters 2 to 3 inches (3%) greater than the closer spaced treatment (525C) at age 27. Height: o Height at age 27 differed by treatment although differences were relatively small. Stands planted at a wider spacing (235C) were shortest (74ft), followed by thinned stands (~79ft) with closer spaced stands (525C) were tallest (84ft). Board foot volume (BDFV) at 35 years: o Using the data collected at age 22 and the red alder growth and yield model (RAP-ORGANON), board foot volume per acre by log diameter class was projected to age 35 (merchandising specifications= log length 32ft, minimum log length 12ft, minimum log diameter 4in, stump height 1ft, and trim 6in). o At age 35, BDFV ranged between 18MBF and 22MBF. o The greatest volumes were found in the 525C stand (21.6MBF) and the st T (21.8MBF). Although these two stands had nearly identical total volumes, log diameter distributions varied greatly- the 525C stand had a much higher proportion of smaller logs. o The 235C stand had the lowest volume (18.2MBF) as well as the greatest range in log sizes. 2

21 Red Alder vs. Douglas-fir: Economics Red Alder (4tpa) Red Alder (6tpa & PCT) Douglas-fir (4tpa & PCT) SILVICULTURAL ACTIVITY TMT COST/AC TMT YEAR TMT COST/AC TMT YEAR TMT COST/AC TMT YEAR PREHARVEST SPRAY $55 (1.) $55 (1.) SITE PREP SPRAY $12 (.5) $12 (.5) $11 (.5) SEEDLINGS $228. $342. $144. PLANTING $12. $18. $115. REPLANT COST $1 1. $1 1. MANUAL RELEASE $12 3. $12 3. $1 3. PCT $12 1. $12 1. TOTAL COSTS $743 $1,37 $589 Douglas-fir management scenario provided by DNR Red alder seedling cost=$.57/tree Red alder planting cost=$.3/tree Douglas-fir seedling cost=$.36/tree Douglas-fir planting cost=$115/acre PCT Age 1 to 25tpa Red Alder Douglas-fir 4tpa 6tpa 6tpa PCT 4tpa PCT Yield (MBF) Rotation Age Log Value ($/M) $798 $798 $798 $754 NPV $852 $497 $666 $374 IRR 9.% 7.1% 7.6% 6.5% SEV $1,24 $64 $886 $395 Red alder 6 minimum top Red alder logging & haul cost = $275/M, Douglas-fir logging & haul cost = $25/M Log values are based on July, 218 WA DNR mill log prices Harvest yields and years until harvest based on max NPV Note: If using a red alder 5 minimum top, Yield increases by 48%, 33%, & 7% for the 4tpa, 6tpa, & 6tpa PCT treatments, respectively. 21