Release Treatments
RELEASE TREATMENTS
Ralph D. Nyland Department of Forest and Natural Resources Management SUNY College of Environmental Science and Forestry
Syracuse, NY 13210
Nyland - 2010
All rights reserved Use of all or parts of this permission prohibited without express consent of Ralph D. Nyland
Background reading:
Chapter 16, in Nyland, R.D. 2002. Silviculture: Concepts and Applications. Waveland Press. Long Grove, IL. 2ed.
Sources cited:
Baker, F.S. 1950. Principles of Silviculture. McGraw-Hill. NY.
Bormann, D.B., and G.E. Lineks. 1979. Pattern and Process in a Forested Ecosystem. Springer-Verlag. NY.
Brodie, J.D., P.J. Kuch, and C. Row. 1987. Economic analysis of the silvicultural effects ofvegetation management at the stand and forest levels. Pp. 365-395, Chapt. 12 in Forest Vegetation Management for Conifer Plantations. J.D. Walstad and P.J. Koch (Eds.). John Wiley & Sons. NY.
Ford-Robertson, F.C.. 1971. Terminology of Forest Science, Technology, Practice, and Products. Multi- lingual Forestry Terminology Series No. 1. Soc. Am. For., Wash., DC.
Heitzman, E.F. 1991. Influences of Pin Cherry (Prunus pennsylvanica L. f.) on Growth and Development of Young Even-aged Northern Hardwoods. M.S. thesis. SUNY Coll. Environ. Sci., and For. Syracuse, NY
Heitzman, E.F., and R.D. Nyland. 1994. Influences of pin cherry on growth and development of young even-aged northern hardwoods. For. Ecol.Mnage. 67:39-48.
1 Helms, J.A. 1998. The Dictionary of Forestry. Soc. Am. For., Bethesda, MD.
Kimmins, J.P. 1987. Forest Ecology. MacMillan Publ. NY.
Ristau, T.E. and S.B. Horsley. 2006. When is pin cherry (Prunus pensylvanica L.) a problem in Allegheny hardwoods ? North. J. Appl. For.: 23(3:204-210.
Let’s recapitulate somewhat ...
... about even-aged stands with adequate numbers of well-distributed young trees
2 Those even-aged stands develop in a predictable manner …
Rational maximum rotation for commodities
We focus on this segment of stand development ...
... with rotation length fixed by economic factors
3 Borman and Likens 1979
The phases of interest ...
Kimmins 1987 … at least with traditional objectives
As stands develop, trees differentiate in heights ...
... into “distinct” crown classes
4 With a differentiation in diameters as well ...
... about 30-35 years old
... into this type of diameter distribution at even young ages
… 31 years after clearcutting
5 Trees in the poorest crown positions weaken, and many die ...
Baker 1950
cing the Greatly redu … tree numbers
After 38 years
… beginning early in the aggradation phase After 31 years
6 But released trees grow better ...
... the outcome
During early phases of development ...
… we may consider early tending
... known as a RELEASE TREATMENT
7 Because rapidly-developing herbs may interfere with seedling development …
… including ferns not reduced by site preparation
8 And because sometimes undesirable trees grow into upper canopy positions …
… interfering with trees of better species and / or quality
Consider pin cherry as an example of the latter …
Heitzman and Nyland (1994) report important negative effects with ≥ 3000/ac pin cherry (any size) at year 3 …
Ristau and Horsley (2006) set the threshold at 385/ac >5 ft tall at year 3 to oppress seedling regeneration …
9 Consider this effect ...
With LITTLE pin cherry
Due to only 3000 pin cherry per acre
Heitzman 1991
… abundant pin cherry reduces the stocking of other species
10 … even affecting the long-term production potential in some cases
Note the effects of crowding ...
... bigger crowns ... better growth ... same height
Crowded Released
11 In a young stand a release treatment would look like this …
… first, wait for some minimum degree of development
… usually to address some commercial standard (e.g., after dead length increases to 1 to 2 logs high)
... then free desirable trees at an appropriate spacing
But remember, release keeps the lower branches alive ….
… potentially reducing lower bole quality
12 … note the potential effect on lower bole straightness
…low forking
… and starting too early may also promote epicormic branches on the lower bole
13 But released trees grow better ...
… crop trees selected at uniform spacing
... the outcome
… released
14 … and hopefully developing into trees of good quality
RELEASE TREATMENT
Freeing a young desirable stand not past sapling stage …
… from competition of undesirable trees (and other plants) that threaten to suppress the sought- after crop
- mostly uncovering crop trees overtopped by undesirable trees and other plants
- allocating the growing space to the chosen trees by eliminating other plants that dominate a site
After Helms 1998
15 ... like this with spruce-fir in Maine
We have three kinds of release treatments ...
... consider the earliest a manager might use
16 Consider WEEDING
- eliminating or suppressing mainly herbaceous vegetation
... during the seedling stage
- frees the trees from other plants
After Ford-Robertson 1971
... reducing herbs that inhibit tree seedling survival and development
17 Not controlled Weeded
...weeding reduces the interference
... mist blowing of herbicide effective for large areas
18 J and R Forestry … note the pattern of spray from the blower
J and R Forestry ... the effect
19 ... or take this case
... planted conifers
20 ... spot release
... sprayed around individual trees
21 ... the outcome
... even with herbs regrown
... early release had a lasting effect on seedling development
22 ... consider woody interference in a young plantation
The negative effects from not taking action ...
Brodie et al. 1987
23 ... aircraft allow efficient treatment of large areas
... the effect
24 ... free to grow
Consider CLEANING ...
- a cutting in a sapling stand
- to free the best trees from undesirable ones of comparable age that overtop or threaten the crop trees
- to control species composition and crop quality
After Ford-Robertson 1971
25 The concept ...
This case with plantations ...
26 ... aspen interfering with spruce
... released
27 For cleaning ... … we can make natural stands look like plantations
... create artificial “rows”
28 … exposing crown of the dominant trees on two sides
... and you can mechanize this operation
29 … the outcome, about 30 years later
The outcome from cleaning …
30 Or you can space the trees to a “grid” ...
Spaced … ... and released
31 ... released
... free to grow
How many stems to release?
- only trees that offer promise of a good / adequate payback
- only enough to form the future final crop
- only trees that will benefit from a release
… NOT TREES ALREADY FREE TO GROW … NOT trees already free to grow
32 ... sufficient for an ideal long-term spacing
Another example ...
... late in the sapling stage
... or at the early pole stage (pre-commercial thinning)
33 ... in ponderosa pine
Cleaning …
... by removing some of the same species
34 How many trees / stems to cut?
- sufficient to stimulate the crop trees
... a crown touching method now recommended
- NOT trees that also release undesirable residuals
... keeping the best at appropriate spacing
35 LIBERATION CUTTING ...
- freeing a sapling stand from competition of older overtopping vegetation
- usually freeing saplings from shading of undesirable older trees
Modified after Helms 1998
The concept …
36 ... need to take off the old culls
X X X X X X X X X X X X X
… as marked
37 ... liberated by cull removal
... same need here
38 These trees removed by…
- cutting - frilling with chemicals - foliar spray - basal spray - soil sterilent
... applying a herbicide
39 US For. Serv. ... a more sophisticated device
US For. Serv. ... or this
40 ... the need
... the result
41 ... free to grow
... but by taking some trees you may affect the habitat for some wild creatures
42 Dead …
… habitat gone
Some cautions ...
Release treatment is a LAST-DITCH EFFORT to salvage an unfavorable situation
… the poor position of the crop trees may reflect ecologic conditions unsuited to the desired species
You must consider how long the chosen crop tree has been oppressed, and IF it will respond to release
… since release treatments seek to reverse a successional tendency, you need to decide if you can halt or redirect the natural trend
43 So why release the conifers in this situation?
... release is not always prudent
a pumpkin … Really, it was
… p erhaps
After Nissen 2010
44