Aspen Clearcut with Significant Paper Birch Regeneration Despite Minimal Paper Birch Reserves (USFS-SNF)

Stand Information

State or Province:

Minnesota

Nearest city or town:

Angora

Describe the location:

Laurentian Ranger District, Superior National Forest

Landowner:

U.S Forest Service

Cover-type:

Aspen-Birch

MN ECS Native Plant Community System:

Mesic Hardwood

Plant community or habitat classification and growth stage:

Dry Mesic White Pine-Red Pine Landscape Ecosystem (MHn44?) winter visit

Forest Health Threats:

Black spruce/dwarf mistletoe

Estimated year of stand origin:

1938

Additional information about stand origin:

71 year old semi decadent aspen as described in 2009

Silviculture System:

Clearcut

Brief silvicultural objective:

Harvest the mature Aspen before it deteriorates and loses commercial value, while increasing diversity to push for a more resilient stand.

Soils:

The majority of the stand is ecological land type 14 which consists of upland, moderately well drained, sandy loam to silt loam soils with a subsurface layer of dense soil that retains water for longer periods of time in some locations, and plant communities that have relatively high requirements for nutrients and moisture. Subsurface layer of dense soil will retain water long enough to create temporarily saturated soil in wet conditions and be more susceptible to rutting and compaction.

Stand area:

14 acres

Treatment area:

14 acres

Overview

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 occured in winter 2010-11 and went according to plan. The prescirption 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.

Silviculture Objective(s)

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:

Not available

Landowner objectives/situation:

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.

Silviculture Prescription

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

Post-treatment assessment

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.

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

Not available

Other notes

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.

Climate Adaptation Considerations

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.

Supplemental content ("appendices")