FRDA Report: Black Cottonwood and Balsam Poplar Managers ...

More documents

Recommendations

Info

Balsam poplar can establish shortly after formation of sand or␣ gravel bars in river channels, attain dominance 15–25 years after site␣ formation, and maintain dominance for␣ 50–75 years before␣ declining. 3.6 Succession and Competition • Cottonwood and balsam poplar possess all the characteristics of early successional species: low shade tolerance, positive regeneration response to soil disturbance, rapid juvenile growth, prolific seed production, relatively short life span, good self-pruning, and later replacement by more shade-tolerant associates. • Balsam poplar is more versatile than aspen in both vegetative and seedorigin reproduction. Cottonwood competition with conifers is most severe on productive bottomland sites. The manager can use understory species as indicators of site quality for cottonwood in British Columbia. Good black cottonwood sites are characterized by vigorous growth of salmonberry, nettles, sword fern, lady fern, and red elderberry. Medium sites are characterized by red-osier dogwood, baneberry, honeysuckle, common snowberry, Nootka rose, and sometimes thimbleberry. On poor sites, horsetails and willows are dominant and such areas are often subject to prolonged flooding. In general, black cottonwood growing in association with willows is an indicator of relatively poor sites. Cottonwood and balsam poplar figure prominently in British Columbia’s initiatives to identify vegetation complexes and to define classes of vegetation potential involving the predicted rate of herb and shrub development following disturbance. Management implications of four recognized classes are summarized as follows, with cottonwood– balsam poplar showing its greatest potential role in sites with very high vegetation potential: Class Description Low Slow initial rate of herb and shrub development following disturbance. Little or no need for controlling vegetation to ensure adequate regeneration. Competition for moisture may be important on some dry sites. Medium Moderate initial rate of herb and shrub development. Generally little need for controlling competing vegetation, although sites should be reforested promptly. High Fast initial rate of herb and shrub development. Generally a need to plant promptly following harvest and to plan in advance of harvest on controlling vegetation development to ensure successful regeneration. Very High Extremely fast initial rate of herb and shrub development. Successful coniferous regeneration will require prompt planting with large, healthy, vigorous stock, and spot or broadcast treatment of competing vegetation. Sites with very high vegetation potential should be considered for broadleaf or mixedwood management (e.g., floodplain sites). 38
The main cottonwood-associated species that usually concern forest managers in␣ the Prince Rupert Forest Region because of their competition with conifers are as␣ follows: Major competing species accompanying cottonwood Seral origin Vegetation complex or balsam poplar of competing species1 Cottonwood on floodplains Lonicera involucrata BB/SB in ICH, SBS, and BWBS Zones Cornus sericea BB Sambucus racemosa BB/SB Rubus parviflorus BB/SB Alnus crispa ssp. sinuata BB/SR Alnus tenuifolia BB/SR Calamagrostis canadensis BB/SR Cinna latifolia BB/SB?/SR? Symphoricarpos albus BB/SB Cottonwood-alder on Alnus rubra SR/SB(BB) floodplains in CWH Zone Rubus spectabilis BB/SB Cornus sericea BB/SB Oplopanax horridus BB Sambucus racemosa BB/SB Rubus parviflorus BB/SB Lonicera involucrata BB/SB Ribes bracteosum SB(BB) Mixed broadleaf species on Populus tremuloides SR/BB various sites in ICH, SBS, Betula papyrifera BB/SR and BWBS Zones Salix spp. BB/SR Alnus tenuifolia BB/SR Alnus crispa ssp. sinuata BB/SR 1 SR = seed rain; BB = bud bank; SB = seed bank In the vegetation complex examples shown above, each complex consists of a list of species that tend to be associated with one another on ecologically similar sites. The lists have a silvicultural bias and thus emphasize species that may affect crop tree growth positively or negatively. The complexes are also useful for assessing potential wildlife forage values. Not all the species in each complex should always be expected to occur together on a given site. Depending on local conditions, species dominance varies␣ considerably. Although foresters can gain some insights from pre-harvest and adjacent stand conditions to predict species composition of post-harvest competing species, they are still hampered by elements of chance when trying to predict seral vegetation trends. That element of chance can be reduced somewhat if there is a knowledge of available propagules, in the form of bud banks, seed banks in the soil, or seed rain from nearby ecosystems. For a given type of disturbance in a given area, the experience and observation of local forest managers are the best predictors of successional stages, especially if that experience and observation are recorded in a way that can be used and integrated by others. Calamagrostis canadensis and Epilobium angustifolium are pioneer species that rapidly invade disturbed sites, especially in the boreal mixedwood region. Silviculturally they are important because they limit establishment of coniferous seedlings. However, on sites where balsam poplar is present, heavy competition from poplar root suckers after logging can decrease the normally very aggressive post-disturbance development of Calamagrostis. 39
Page 1 and 2: Black Cottonwood and Balsam Poplar
Page 3 and 4: Funding for this publication was pr
Page 5 and 6: ACKNOWLEDGEMENTS Preparation of thi
Page 7 and 8: 5 MANAGING COTTONWOOD-BALSAM POPLAR
Page 9 and 10: FIGURES 1 Geographic distribution o
Page 11 and 12: 1 INTRODUCTION This handbook brings
Page 13 and 14: The one common thread in these alte
Page 15 and 16: TABLE 2. Some silvical and silvicul
Page 17 and 18: Begin by basing decisions for silvi
Page 19 and 20: If the answer to any of these quest
Page 21 and 22: TABLE 3. Forest land areas in which
Page 23 and 24: Information Sources: Brayshaw 1965;
Page 25 and 26: TABLE 5. Biogeoclimatic units and s
Page 27 and 28: TABLE 7. Biogeoclimatic units and s
Page 29 and 30: TABLE 8. Continued Biogeoclimatic u
Page 31 and 32: TABLE 9. Continued Biogeoclimatic u
Page 33 and 34: In northeastern British Columbia, f
Page 35 and 36: Cottonwood and balsam poplar are di
Page 37 and 38: Root systems of both cottonwood and
Page 39 and 40: TABLE 12. Silvicultural implication
Page 41 and 42: Cottonwoods that are␣ established
Page 43 and 44: TABLE 13. Characteristic vegetation
Page 45 and 46: Large quantities of seed are produc
Page 47: FIGURE 10. Black cottonwood coppice
Page 51 and 52: Information Sources: Conard 1984; D
Page 53 and 54: Currently available information for
Page 55 and 56: The remainder of this section consi
Page 57 and 58: Height (m) 65 60 55 50 45 40 35 30
Page 59 and 60: Dominant height (m) 40 35 30 25 20
Page 61 and 62: TABLE 16. Common insect, disease, a
Page 63 and 64: TABLE 16. Continued COMMON INSECTS
Page 65 and 66: A B C E D FIGURE 22. Foliar disease
Page 67 and 68: Information Sources: Hiratsuka and
Page 69 and 70: Information Sources: Klinka and Fel
Page 71 and 72: TABLE 17. Black cottonwood free-gro
Page 73 and 74: TABLE 20. Currently suggested stock
Page 75 and 76: TABLE 21. Currently suggested stock
Page 77 and 78: Information Sources: McAuliffe 1989
Page 79 and 80: Highest growth potential of hybrid
Page 81 and 82: Information Sources: Ronald and Ste
Page 83 and 84: Total height (m) 25 20 15 10 5 0 1
Page 85 and 86: For Populus trichocarpa - P.␣ del
Page 87 and 88: Poplars figure prominently in today
Page 89 and 90: In northern British Columbia and in
Page 91 and 92: Information Sources: Comeau and Boa
Page 93 and 94: A non-herbicidal method to control
Page 95 and 96: Information Sources: McLennan and K
Page 97 and 98: stands with scattered large cottonw
Page 99 and 100:
Cottonwood stands on alluvial flood
Page 101 and 102:
FIGURE 32. Dead down coarse woody c
Page 103 and 104:
TABLE 26. Wildlife species in Briti
Page 105 and 106:
Black cottonwood trees are used ext
Page 107 and 108:
Low fluvial benches that are subjec
Page 109 and 110:
FIGURE 33. In many interior valleys
Page 111 and 112:
Information Sources: Schiechtl 1980
Page 113 and 114:
A major priority for cottonwood res
Page 115 and 116:
Information Sources: McLennan and M
Page 117 and 118:
.␣ 1995b. Forest Practices Code o
Page 119 and 120:
Hiratsuka, Y. 1987. Forest tree dis
Page 121 and 122:
Mitchell, C.P., J.B. Ford-Robertson
Page 123 and 124:
van Oosten, C. 1991. Poplar trials
Page 125 and 126:
mycelium A group or mass of hyphae
show all

FRDA Report: Black Cottonwood and Balsam Poplar Managers ...

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?