The spring melt meant that Goose Island was underwater for most of the spring, which meant tree planting had to be delayed until it was hot and muddy. However, St. Paul District foresters Andy Meier, Sara Rother and Lewis Wiechmann were up to the challenge, taking one foot of mud and two feet of reed canary grass at a time, to plant the island’s new seedlings.
“One of the Corps’ environmental stewardship goals is to improve the habitat in the floodplains,” Rother said. “We’re reestablishing a forest cover to shade out the invasive reed canary grass and promote regeneration for a future forest and a future seed source for wildlife.”
Looking at land cover data from the going back to the time of European settlement, in Pools 3-9, the area has gone from about 45% of the area being forested to about 26% of the area being forested, so about a 50% loss, Meier said.
One of the most resilient trees to flooding, deer, vegetation and environmental stress is the swamp white oak tree, Meier said. Compared to other trees, swamp white oaks have a longevity of 250-300 years. On the other hand, cottonwood trees live 100-120 years and maple trees live 120-140, he explained.
Elevation is also a factor when planting trees on an island. “At lower elevations, trees like swamp white oak, river birch and honey locusts can handle a little bit more flooding,” Meier said. “On higher elevation sites where there’s less flooding, trees like hackberry, bitternut hickory, northern red oak and other species thrive better in floodplain areas.
“In the long run, we’re trying to maximize diversity across the landscape. The more diversity in species, the more resilience to environmental threats. We think in long time scales,” Meier said.
Most of the regeneration that is naturally occurring in the forests is ash and elm. “That’s why having a diverse forest is important. Historically, these forests were all maple-ash-elm forests with those as the predominant species. Two of those three are affected by diseases. What happens if a disease comes along that affects maple trees?” Meier said.
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