ri-pair-ee-uhn: What’s NEW in your neighborhood riparian zone?


Riparian Zones are the green zones along creeks and lakes that "buffer" the creek from things like erosion, flood, and pollution run-off. If these buffers are over-grazed, or in the case of urban creeks, "over-mowed" the results to native plants, trees, and water quality can be greatly compromised. For many years, scientists and city planners have been acutely aware of the harmful biological consequences over-mowing can create, but not until recently have studies been suggested to quantify the actual impact. I'm fortunate enough to be part of a "Riparian Restoration Team" in Austin, Texas this summer that is tackling this problem by the (Long) horns.

Different metrics or standards are used to measure the degree of degradation a creek has sustained. Scientists use tools called sondes to calculate water temperature, conductivity, the pH and the dissolved oxygen levels which tell them how safe the water is to sustain micro-invertebrate life. Constant low levels of dissolved oxygen mean less oxygen is available for living things. Increased pollution runoff from increased urban development upstream can cause higher levels of nutrients flowing downstream into the creeks. Flooding waters can also cause a disturbance or "shock" to the delicate balance coexisting in the microclimate of a creek system. While this sounds horribly dismal and depressing, the good news is that city dollars don't need to be spent on doing much. Instead, maintenance crews need to be educated on how to do less. Like eliminating mowing within a 25 ft. buffer area on either side of the creek and lake. When a riparian area is allowed to passively "heal" itself, the natural diversity of plant growth will help stabilize the soil preventing further erosion, create more shade which cools the water temperature, slow down water from entering the creek which helps clean it, and most interesting for fellow birding and butterfly enthusiasts, maintain a healthy diversified environment that attracts more species to the area.

The City of Austin is participating in several projects to heal and aid in riparian recovery. A scientific study has been introduced to measure and compare the rate of degradation or break down of leaf material in both degraded creek sites and healthy reference sites. The functional group diversity of the identified macro-invertebrate species can help inform researchers on what types of bugs can survive in the creeks based on the kinds of food they are able to find.

Non-profit agencies are joining city departments such as Parks and Recreation in many of these efforts, including TreeFolks whose volunteers successfully planted over 600 new seedlings in 7 different riparian zone sites. The planting of seedlings vs. container trees is important, especially in drought stricken central Texas. These seedlings are spaced fairly close together and near a water supply with little maintenance required. Container trees in contrast require larger amounts of watering to sustain their root systems and therefore run a higher risk of not surviving without rain. Native seedlings such as Shumard Oak, American Beauty Berry, Plain leaf Sumac, Green Ash, Carolina Buckthorn, Mexican Plum, Rough-leaf Dogwood, and Bald Cypress among others were planted in riparian zones and upland along 7 different park sites. The growth and survivorship of these seedlings generate further questions for researchers interested in determining which native trees have the best likelihood of surviving a drought and where the best placement might be with regard to available sunlight. Predicted canopy cover or shade provided by these full grown trees protects the understory. That's why reforesting the riparian zones is the next phase of urban riparian recovery and our best defense against further degradation of our creeks.

Austin's Adopt A Creek program is in full swing and represents a community link between Austin's Watershed Protection, Keep Austin Beautiful and Neighborhood Associations. Citizens can conduct their own creek clean-ups, label storm drains, participate in revegetative efforts such as sapling, native grasses and wildflowers plantings, and ecological monitoring. The sky's the limit! Or rather, stream recovery is flowing smoothly! Please look to these 2 sites for ongoing "riparian zone repair" updates and get back to Nature!

The first step would be to identify a section (approximately ¼- ½ mile) of an Austin stream that your group would be able to make a 2 year adopting commitment. There you can fill out an application form. After that you will be contacted by KAB staff that will help coordinate your volunteer workdays. 

A 2nd webpage links to the City of Austin Watershed Protection, where you can find ongoing Citizen Science instructional web pages and Links.

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