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2005 marks the fourth year of a 20-year reclamation
program for Bois Forte's 7300 acres of wild rice on Nett
Lake. Over the last century, engineering alterations of
centuries-old hydrological regimes led to biological
species shifts and decreased wild rice production. Control
dams to migrate periodic basin flushing events were once
considered central for managing wild rice production.
Subsequent investigations demonstrate that rigid water
level management encourages colonization by hardy
perennial plants with extensive root systems. These
outcompete and subsequently suppress wild rice production.
Periodic, extreme basin flushing is today considered essential to wild rice stand maintenance. Extreme hydrological events interrupt and reset colonization by aggressive perennial plants, and provide "opportunity space for less-competitive annual wild rice seed. In 2002, prior to beginning this reclamation program, less than 2800 acres of Nett Lake's 7300 potential rice-bearing acres were in production (38%). Estimated total production was 400,000 pounds (average 143 pounds/acre). Beds were largely thin (less than 10 stems/square foot), and kernel yield was considered far below what is possible. Remaining lake surface acres were either open water, or colonized by several perennial plant species. |
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Phase I of the Nett Lake Restoration Program
involves the physical removal of
rooted emergent plant communities and restoration of
opportunity space for wild rice re-colonization. This is a
stabilizing measure, intended to stop or reduce the rate of
wild rice production decline. Phase II of the program will
be implemented starting in 2006. This phase will include
more intensive land management actions to reduce beaver
impoundment and stagnancy. We will
also establish multiple, one-acre
cultivation plots in barren sediment
areas to evaluate effectiveness of the
weed-cutting barge as a cultivator for
dormant wild rice seed.
In 2003, after a lengthy federal permitting process, the Band used its own financial resources to purchase one vegetation-cutting barge and one vegetation harvesting barge. Federal funding in the amount of $180,000 was also received for project support. Support included construction of storage facilities, construction of barge landing areas, and ongoing operations and maintenance costs. In the foreshortened 2003 field season, barges cleared emergent plants from 15 surface area acres. Total rice bed area was approximately 3000 acres, and ratio of rice bed acres to total lake acres was 41%. Total estimated yield in 2003 was 700,000 pounds, equivalent to 233 pound/acre. In 2004, those acres previously cleared and cultivated by the barges subsequently produced wild rice beds with higher stem densities/acre and greater kernel yield. 2004 clearing operations began in mid-May and ceased in early September, resulting in a total of 30 acres cleared of nuisance vegetation. During this time it was found that the single harvester presently on- site cannot effectively keep up with and collect all plant material produced by the AVG-cutting barge. In order to prevent uncollected plant material from dispersing within the larger lake area, the cutting barge needs to reduce its cutting speed, thus slowing the slowing rate of surface area clearing. In 2004, total estimated rice yield was 1,170,000 pounds, over a total of 3400 acres. The ratio of rice bed acres to total lake acres was 46%; average kernel weight 344 pounds/acre. In fall 2004, Bois Forte purchased a second harvester barge. This barge was put in to service in spring 2005. During field season 2005, a total of 35 acres was cleared. Estimated rice production in 2005 has continued to increase. This is especially telling, in light of widespread rice crop failure experienced in state-managed rice lakes across the region. In 2005, ratio of rice acres to lake area acres was 48%. An estimated 1.3 million pounds of green rice was produced, yielding an average weight per acre of 371 pounds/acre. Weed removal and sediment cultivation appears after four years to have positive effect on wild rice production. Additional plot evaluations to be carried out in phase II of the program will help to further quantify restorative effects of barge activity. |
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