Flood Tolerant Trees in Worst-Case Floodplain and Urbanized Scenarios

Summary: Jeffrey Dawson of the University of Illinois at Urbana-Champaign sees flood tolerant trees as survivors of worst-case floodplain and urbanized scenarios.

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Baldcypresses (Taxodium distichum) are renowned for their flood tolerant capabilities; baldcypress (right foreground), Wacissa River, south central Jefferson County, eastern Panhandle, Florida; Thursday, Dec. 8, 2011, 04:42: U.S. Fish and Wildlife Service, CC BY 2.0 Generic, via Wikimedia Commons

Flood tolerant trees address floodwater impacts of eroded banks, excess sediment and fertilizer and pesticide surface runoff, according to Flood-Tolerant Trees in the Urban Sphere in the August 2014 Arborist News issue.

Jeffrey Dawson of the University of Illinois at Urbana-Champaign bares pivotal wetland tree roles in sequestering carbon, shading oxygenated waters and yielding timber undamaged by floodwaters. Riparian, wetland communities genetically tolerating, or not, inundated, saturated soils correlate with hydric wet bottomlands, floodplains and swamps or with mesic moist and xeric dry uplands. Upland trees demand efficient, oxygen-rich aerobic root respiration and display chlorosis-yellowed leaves, crown dieback, defoliation, epicormic trunk-anchored sprouts, stunted shoots and undersized leaves when spring flood-stressed.

Flood-induced baldcypress knees, Shumard oak buttresses and tag alder adventitious water roots effectuate anchorage and diffusion of carbon dioxide from, and oxygen into, intracellular air spaces.

Annual spring floods always float large seed crops produced and released by flood tolerant temperate floodplain trees whereas flood-stressed species furnish large crops after brief flooding. They give "new soil substrates," deposited by floodwaters, and sand bars dense, "even-aged stands" of cottonwood, elm, green ash, river birch, silver maple, sycamore and willow.

Baldcypress, black willow, larch, pumpkin ash, water elm and water tupelo have strong survival rates in anaerobic (oxygen-poor), clayey, compacted, floodwater-deposited, gas exchange-impervious or waterlogged soils. Alders, boxelder, green ash, hawthorns, honeylocust, persimmon, pin oak, red maple, river birch, silver maple, sweetgum, sycamore, water hickory and water locust indicate second highest tolerances.

Black walnut, blackgum, eastern cottonwood, hackberry, hickory (pignut, shellbark), northern catalpa, oak (bur, cherrybark, Shumard, swamp chestnut, willow), pecan, red mulberry and sugarberry juggle weak tolerances.

Protective fencing keeps pedestrian and vehicular traffic out of the area from the trunk to the drip line formed by the tips of the longest branches. It lets limited oxygen diffuse sufficiently to support "active, metabolic uptake of mineral nutrients" by fine roots in the top 18 inches (45.7 centimeters) of soil.

Tree wells likewise minimize nutrient deprivation and oxygen starvation by maximizing oxygen diffusion to weaken compaction and flood tolerant tree roots not buried by grade changes.

Avoidance sometimes needs to be the policy and the practice regarding the interaction of floodplain and upland trees with urban water systems and with water bodies. Capillary rise of negative- and positive-bonded water molecules occurs above water tables elevated by long-term flooding or by new reservoirs and offers upland trees fatal consequences.

Strongly compaction and flood tolerant trees such as willows prevent fertilizer, pesticide and silt runoff down, and provide stability to, lake, reservoir, river and stream banks. At the same time, they quicken the failure rates of dams, dikes and levees by creating root channels that ultimately qualify as conduits of leaking water.

Cottonwood, sycamore and willow tree roots relish "low-oxygen, water-saturated" soils near, and "nutrient-rich" wet sewage within, clay tile sewer lines whose seals break with gradual settling.

Sewer line invasions surface less in epoxy-sealed plastic pipes than in clay tiles oakum-caulked with "strands of hemp rope soaked in tar" to make waterproof seals.

American beech, black and northern red oaks, and shagbark hickory transplant to aerated, drained, upland-like soils while their tougher floodplain neighbors take on worst-case urbanized scenarios.

In "Flood-Tolerant Trees in the Urban Sphere," Jeffrey Dawson identifies silver maples (Acer saccharinum) as moderately flood-tolerant; floodplain forest dominated by silver maples, Mississippi River floodplain: Steven Katovich/USDA Forest Service/Bugwood.org, CC BY 3.0 United States, via Forestry Images

Acknowledgment

My special thanks to:
talented artists and photographers/concerned organizations who make their fine images available on the internet;
University of Illinois at Urbana-Champaign for superior on-campus and on-line resources.

Image credits:

baldcypress (Taxodium distichum), Wacissa River, south central Jefferson County, eastern Panhandle, Florida; Thursday, Dec. 8, 2011, 04:42: U.S. Fish and Wildlife Service, CC BY 2.0 Generic, via Wikimedia Commons @ https://commons.wikimedia.org/wiki/File:Baldcypress_on_the_Wacissa_River,_Florida.jpg

floodplain forest dominated by silver maples (Acer saccharinum), Mississippi River floodplain: Steven Katovich/USDA Forest Service/Bugwood.org, CC BY 3.0 United States, via Forestry Images @ http://www.forestryimages.org/browse/detail.cfm?imgnum=5468265

For further information:

Dawson, Jeffrey. August 2014. "Flood-Tolerant Trees in the Urban Sphere." Arborist News 23(4): 12-18.
Available @ http://viewer.epaperflip.com/Viewer.aspx?docid=196db40b-5077-488d-bf6d-a3710095f0e0#?page=12

Gilman, Ed. 2011. An Illustrated Guide to Pruning. Third Edition. Boston MA: Cengage.

Hayes, Ed. 2001. Evaluating Tree Defects. Revised, Special Edition. Rochester MN: Safe Trees.

Marriner, Derdriu. 14 June 2014. “Integrated Vegetation Management of Plants in Utility Rights-of-Way.” Earth and Space News. Saturday.
Available @ https://earth-and-space-news.blogspot.com/2014/06/integrated-vegetation-management-of.html

Marriner, Derdriu. 12 April 2014. “Tree Twig Identification: Buds, Bundle Scars, Leaf Drops, Leaf Scars.” Earth and Space News. Saturday.
Available @ https://earth-and-space-news.blogspot.com/2014/04/tree-twig-identification-buds-bundle.html

Marriner, Derdriu. 15 February 2014. “Tree Twig Anatomy: Ecosystem Stress, Growth Rates, Winter Identification.” Earth and Space News. Saturday.
Available @ https://earth-and-space-news.blogspot.com/2014/02/tree-twig-anatomy-ecosystem-stress.html

Marriner, Derdriu. 14 December 2013. “Community and Tree Safety Awareness During Line- and Road-Clearances.” Earth and Space News. Saturday.
Available @ https://earth-and-space-news.blogspot.com/2013/12/community-and-tree-safety-awareness.html

Marriner, Derdriu. 13 October 2013. “Chain-Saw Gear and Tree Work Related Personal Protective Equipment.” Earth and Space News. Sunday.
Available @ https://earth-and-space-news.blogspot.com/2013/10/chain-saw-gear-and-tree-work-related.html

Marriner, Derdriu. 12 October 2013. “Storm Damaged Tree Clearances: Matched Teamwork of People to Equipment.” Earth and Space News. Saturday.
Available @ https://earth-and-space-news.blogspot.com/2013/10/storm-damaged-tree-clearances-matched.html

Marriner, Derdriu. 17 August 2013. “Storm Induced Tree Damage Assessments: Pre-Storm Planned Preparedness.” Earth and Space News. Saturday.
Available @ https://earth-and-space-news.blogspot.com/2013/08/storm-induced-tree-damage-assessments.html

Marriner, Derdriu. 15 June 2013. “Storm Induced Tree Failures From Heavy Tree Weights and Weather Loads.” Earth and Space News. Saturday.
Available @ https://earth-and-space-news.blogspot.com/2013/06/storm-induced-tree-failures-from-heavy.html

Marriner, Derdriu. 13 April 2013. “Urban Tree Root Management Concerns: Defects, Digs, Dirt, Disturbance.” Earth and Space News. Saturday.
Available @ https://earth-and-space-news.blogspot.com/2013/04/urban-tree-root-management-concerns.html

Marriner, Derdriu. 16 February 2013. “Tree Friendly Beneficial Soil Microbes: Inoculations and Occurrences.” Earth and Space News. Saturday.
Available @ https://earth-and-space-news.blogspot.com/2013/02/tree-friendly-beneficial-soil-microbes.html

Marriner, Derdriu. 15 December 2012. “Healthy Urban Tree Root Crown Balances: Soil Properties, Soil Volumes.” Earth and Space News. Saturday.
Available @ https://earth-and-space-news.blogspot.com/2012/12/healthy-urban-tree-root-crown-balances.html

Marriner, Derdriu. 13 October 2012. “Tree Adaptive Growth: Tree Risk Assessment of Tree Failure, Tree Strength.” Earth and Space News. Saturday.
Available @ https://earth-and-space-news.blogspot.com/2012/10/tree-adaptive-growth-tree-risk.html

Marriner, Derdriu. 11 August 2012. “Tree Risk Assessment Mitigation Reports: Tree Removal, Tree Retention?” Earth and Space News. Saturday.
Available @ https://earth-and-space-news.blogspot.com/2012/08/tree-risk-assessment-mitigation-reports.html

Marriner, Derdriu. 16 June 2012. “Internally Stressed, Response Growing, Wind Loaded Tree Strength.” Earth and Space News. Saturday.
Available @ https://earth-and-space-news.blogspot.com/2012/06/internally-stressed-response-growing.html

Marriner, Derdriu. 14 April 2012. “Three Tree Risk Assessment Levels: Limited Visual, Basic and Advanced.” Earth and Space News. Saturday.
Available @ https://earth-and-space-news.blogspot.com/2012/04/three-tree-risk-assessment-levels.html

Marriner, Derdriu. 19 February 2012. “Qualitative Tree Risk Assessment: Risk Ratings for Targets and Trees.” Earth and Space News. Sunday.
Available @ https://earth-and-space-news.blogspot.com/2012/02/qualitative-tree-risk-assessment-risk.html

Marriner, Derdriu. 18 February 2012. “Qualitative Tree Risk Assessment: Falling Trees Impacting Targets.” Earth and Space News. Saturday.
Available @ https://earth-and-space-news.blogspot.com/2012/02/qualitative-tree-risk-assessment.html

Marriner, Derdriu. 10 December 2011. “Tree Risk Assessment: Tree Failures From Defects and From Wind Loads.” Earth and Space News. Saturday.
Available @ https://earth-and-space-news.blogspot.com/2011/12/tree-risk-assessment-tree-failures-from.html

Marriner, Derdriu. 15 October 2011. “Five Tree Felling Plan Steps for Successful Removals and Worker Safety.” Earth and Space News. Saturday.
Available @ https://earth-and-space-news.blogspot.com/2011/10/five-tree-felling-plan-steps-for.html

Marriner, Derdriu. 13 August 2011. “Natives and Non-Natives as Successfully Urbanized Plant Species.” Earth and Space News. Saturday.
Available @ https://earth-and-space-news.blogspot.com/2011/08/natives-and-non-natives-as-successfully.html

Marriner, Derdriu. 11 June 2011. “Tree Ring Patterns for Ecosystem Ages, Dates, Health and Stress.” Earth and Space News. Saturday.
Available @ https://earth-and-space-news.blogspot.com/2011/06/tree-ring-patterns-for-ecosystem-ages.html

Marriner, Derdriu. 9 April 2011. “Benignly Ugly Tree Disorders: Oak Galls, Powdery Mildew, Sooty Mold, Tar Spot.” Earth and Space News. Saturday.
Available @ https://earth-and-space-news.blogspot.com/2011/04/benignly-ugly-tree-disorders-oak-galls.html

Marriner, Derdriu. 12 February 2011. “Tree Load Can Turn Tree Health Into Tree Failure or Tree Fatigue.” Earth and Space News. Saturday.
Available @ https://earth-and-space-news.blogspot.com/2011/02/tree-load-can-turn-tree-health-into.html

Marriner, Derdriu. 11 December 2010. “Tree Electrical Safety Knowledge, Precautions, Risks and Standards.” Earth and Space News. Saturday.
Available @ https://earth-and-space-news.blogspot.com/2010/12/tree-electrical-safety-knowledge.html