A treatment designed to regenerate a decadent aspen dominated stand. The desired future condition is dense aspen with an overstory of red pine, white pine, and spruce. The harvest occurred in winter 2010-11 and went according to plan. The prescription failed to note the presence of some diversity within the stand, perhaps missing an opportunity to further diversify the stand. After harvest, the site included significant non stump sprouting paper birch regeneration in certain areas apparently from seed sources 150 yards outside of the harvest area a few others within the harvest area. These sources were generally northwest and west of the regeneration pockets, bringing to mind the possible importance of residual seed trees being on the upwind side of prevailing winds and target regeneration areas.
Harvest mature aspen before it deteriorates and loses commercial value. Manage for an aspen dominated stand with scattered over story of red/white pine and spruce.
Pre-treatment stand description and condition
Stand establishment and management history:
71 year old semi decadent aspen stand as described in the prescription (attached - see Supplemental Docs).
Pre-treatment species composition:
According to the cruise file this 14-acre treatment area had these volumes in cords by species: (descending order by sample group)
Aspen -190 cords
Paper Birch - 118 cords
Balsam Fir - 23 cords
Red Maple -19 cords
Jack Pine Saw - 7 cords
Pine Pulp (jack or red) - 6 cords.
Pre-treatment growth and stocking:
Maintain an even aged aspen dominated stand within increased diversity. Superior National Forest forest plan direction specifies that aspen dominated stands in the dry mesic red and white pine landscape ecosystem should have an increase in diversity with a slight decrease of aspen in these stands.
Figure 1: Leave trees 150 yards west of birch regen
Clear cut for aspen regeneration. Reserve any red/white pine. Mark spruce as needed for additional leave trees. Favor clumping of reserve trees to promote better aspen sprouting.
What actually happened during the treatment
Site was harvested with a feller buncher and logs were whole tree skidded to landing in December 2010/January 2011. Harvest commenced on 12/8/2010 with cutting aspen, balsam, paper birch, jack pine and red maple. Cutting ended 1/7/2011
Figure 2: Birch regen facing north
Figure 3: Birch regen facing west
After assessing the unit I found considerable paper birch regeneration in the north east corner of the stand despite there being no mature paper birch in the immediate vicinity. After further investigation I found around six leave trees roughly 150 yards west of the birch regeneration. I also found in the cruise file that the site had a considerable amount of birch pre-treatment that could have dispersed seed before harvest. The remaining portion was flush with aspen, red maple, and black ash and paper birch. The residual paper birch had died along with a few residual aspen. The prescription did not prescribe retaining any paper birch but the retention of these trees provided diversity to the site via windblown seed to the north east corner of the stand.
Stocking survey notes; Supposed to be an aspen site but would be a great northern hardwoods site. Good birch, maple, ash, aspen mix.
Table 1: Post harvest stocking
Plans for future treatments
Natural regeneration with no site preparation was planned for the stand. Stand will be of harvestable age in about 50 years.
Costs and economic considerations
Treatment was an overall success by retaining diversity, but prescription was not very accurate and the site could've had a different outcome. Diversity could have increased considerably if perimeter paper birch, ash, and white spruce would have been reserved outside of layout or a interior. Reserving ash, white spruce and red maple could have also increased future diversity. Because of whole tree skidding a suitable seed bed was created in the winter for fall dispersed seed. This site is also a northern mesic hardwood forest which is suitable to the species that regenerated.
Supplemental planting of southern species could’ve been explored for climate change adaptability.
Summary / lessons learned / additional thoughts
The prescription for this stand seemed a little insufficient, it did not mention reserving any birch trees, the reserving of the tress must have happened after the prescription was written, it should be noted in the prescription. If I were writing this prescription I would have emphasized reserving large > 10” white spruce and paper birch to increase species diversity. The existing condition in the prescription is also vague, it merely mentions that is a 71 year old aspen stand. There is obviously more diversity within the stand that was not mentioned. The prescription does mention reserving red and white pine but after my site visit I did not notice a component of these species. This reemphasizes the importance of thorough site visits before writing the prescription. Overall, I believe this stand met Forest Plan goals by maintaining an aspen dominated 0-9 age class within the mesic red and white pine landscape ecosystem. This stand also promoted Forest Plan direction by maintaining diversity and structural heterogeneity within aspen dominated forests.