Trees along our Mississippi

This article was written by Rachel Putnam, Kroening Naturalist

During the long dry summer, we have watched the Mississippi River water levels get lower and lower due to drought. What a difference from this spring! As of mid-September, the river was about 15 feet lower than it was during peak flooding in the spring. Rainfall has quite an impact on the river’s water levels: a significant rain event upstream in the watershed will cause the river level here in Minneapolis to rise a bit over the next few days. With so little rain this year, canoeists and kayakers have been finding themselves scraping along rocks in some of the shallower stretches of the river between Coon Rapids Dam and North Mississippi Regional Park.

This fall, though, we expect the river level to rise somewhat (as they typically do in autumn), even if we don’t get much rain in the coming months. What could possibly cause river levels to change besides storms? Trees! Trees suck up lots of water from the ground during the summer, when their green leaves are actively photosynthesizing and “breathing,” or transpiring. In the fall, though, the leaves of our deciduous trees stop photosynthesizing, turn colors and drop. Suddenly those trees need much less water on a daily basis, so there’s more groundwater and river levels are higher.

Cottonwoods are one of the tree species that are adapted to living along riverbanks. Water levels may be low now, but next spring will bring floodwaters swirling around these trees. How does a cottonwood tree ever get started when next year’s flood could wash it away? Cottonwood seeds are tiny, but they can sprout and grow up to six feet in one summer. Hopefully a few will have grown roots deep enough and strong enough to withstand spring floods and live to grow another year.

Interested in learning more amazing facts about the trees in our park? Join us on Saturday, October 14 for a naturalist-led walk on tree identification. See below for a list of other programming offered at Kroening Nature Center in October.

Campfire Sing · Tuesday October 3, 6-7:30 p.m. Free, ages 18+ (activity #143491). Join us for a campfire and smores, sing along with Dean on guitar and take a walk with a naturalist. ​

Nature Nuts: Storybook Stroll · Wednesday October 4, 9:30-10:30 a.m. Free, ages 2-8 with an adult (activity #143520). Visit the park and enjoy a self-guided story walk. New story every week.

Homeschool Day: Soil Significance · Thursday October 5, 1-3 p.m. $5/person, ages 5-14 (activity #143504). Learn about different soil types and characteristics through hands-on investigations.​

Nature Art: Gourd Time · Saturday October 7, 11 a.m.-noon. $3/person, all ages (activity #143509). Discover gourd-geous gourds! Explore their unusual shapes, colors and textures while creating art projects to take home for autumn decorations. ​

Nature Nuts: Storybook Stroll · Wednesday October 11, 9:30-10:30 a.m. Free, ages 2-8 with an adult (activity #143519) Visit the park and enjoy a self-guided story walk. New story every week.

Feathered Friday · Friday October 12, 9-10:20 a.m. $2/person, ages 18+ (activity #145835).

Learn about bird behaviors, calls, and diets while strolling through different habitats with a naturalist.

Outdoors: Fall Tree Identification · Saturday October 14,​ 2-3:30 p.m. Free, ages 18+ (Activity #143532) Walk with a naturalist to learn how to identify trees in the park by their leaves.​

Nature Nuts: Storybook Stroll · Wednesday October 25, 9:30-10:30 a.m. Free, ages 2-8 with an adult (activity #143521). Visit the park and enjoy a self-guided story walk. New story every week.

Nature Art: Nature on the Land: James Brunt · Friday October 27, 10 a.m.-noon. Free, ages 18+ (activity #145997). ​Learn about sculptor and photographer James Brunt, then try creating your own piece to share with the group.​

Feathered Friday · Friday October 27, 9-10:20 a.m. $2/person, ages 18+ (activity #143485).

Learn about bird behaviors, calls and diets while strolling through different habitats with a naturalist.

Nature Art: Pumpkin Painting and Pie · Friday October 27, 6:30-8 p.m. Free, ages 18+ (activity #146037). Enjoy a piece of pie and paint a pumpkin all in one night! Designed for adults with disabilities in partnership with Minneapolis Community Education ACCESS program.​

Animal Tracking · Saturday October 28, 10-11:30 a.m. Free, ages 18+ (activity #145994). ​

Join tracker Bill Kass, first in the classroom and then outdoors, to learn how to find and identify the signs of animals that call the park home.

Family Funday: Animal Masquerade Party · Saturday October 28, 1-3 p.m. Free, all ages (activity #143492).​ Come as your favorite animal and enjoy an afternoon of nature games and fun, including making a nature mask!​