Ecological Restoration BIO 409 Dr Mc Ewan Lecture

Ecological Restoration (BIO 409) Dr. Mc. Ewan Lecture 7: Stream Restoration

• Characteristics of Streams • Threats to Streams • Stream Restoration Practice

Basic Terminology

Floodplain: Is the terrestrial area adjacent to flowing water. , that overflows during floods. In many cases there are small floodplains associated with “bankfull conditions. ” There also broader floodplains that contain larger, more infrequent floods.

Bankfull conditions are important for understanding the river/stream and are an essential characteristic used in restoration. -Bankfull width -Bankfull depth. -Bankfull discharge (flow rate * the bankfull area of the water surface)

-Bankfull discharge (flow rate * the bankfull area of the water surface) -Solve for area to calculate area. - Flow. Can be measured with gear. Or a simple way is throw in a bobber and measure the time it takes to float some distance. Not for reasearch- but some practitioners may use this method.

Meander – curve or bend in the waterway Oxbow lake- former curve that has sealed off from the main waterway.

Sinuosity

Riffle and Pool Habitat -Riffles are rocky shallow areas with fast moving water. Water churns, high oxygen content. Biologically very active areas.

Riffle and Pool Habitat -Pools are deeper water areas. Slower moving water. -Most streams are characterized by a never ending sequence of riffles and pools.

Runs- are similar to riffles in that the water is fast moving and shallow. Different in that, generally, stones are not above the water. This allows for more light penetration. Larger streams have riffles, pools and runs.

Substrate type: Stony- Cobbles (rocks). Can be large or small Soil- Silty, clay, etc Riffles are stony, runs can be stony or have a soil substrate, pools are often silty

Duration: Ephemeral: Rarely full, usually only during the rainy season. Sometimes these streams are called “flashy. ” Often found in upland forests. Dry, stony channels. Intermittent- Full of water during part of the year. Usually full in spring early summer, drying out in later summer and early fall during hot dry conditions. Perennial Stream- Full year round, assumed to never dry out.

Stream order: 1 st 2 nd 3 rd

Watershed

River Continuum Concept -connections from headwaters to lower reaches. -biological connectivity -importance of riparian/aquatic connectivity -aquatic freshwater foodwebs are often based on terrestrial inputs. One of the most important energy sources is terrestrial autotrophic organisms (ie, streambank plants)

Summary of Basics: -Restoration begins with identifying the morphological characteristics of the “reference stream reach” (ie, reference conditions for stream restoration). Width, depth, flow, bankfull discharge, bottom materials, riffles and pool habitats. -Riparian habitat is often a secondary consideration, but is ecologically critical.

Restoration Needs: 1) Addressing channelization 2) Dams 3) Nutrient inputs

Channelization is probably the most important threat to streams in the Midwest - One way to “control” waterways, and also to drain the landscape, is channelization. - By channelizing a stream the water moves out of the system rapidly. - Channelization essentially destroys the stream biology - Channelization sometimes is associated with cement.

Channelization is probably the most important threat to streams in the Midwest

Holding other things constant- channelization significantly decreases stream ecological integrity. Norris and Mc. Ewan (in prep)

Ecological restoration of stream system often begins by dealing with channelization. This is a task for engineering. One needs to reestablish meanders. This is often a task that requires major Earth moving equipment. It cannot be accomplished otherwise. In the Miami Valley, there are many stream projects ongoing, and they start with this kind of major landscape alteration. Note that the stream will move, over the long term, and find the path of least resistance…

Ecological restoration of stream system often begins with engineering. Need to establish sinuosity. Then substrate. Manage flow. Establish natural riparian vegetation.

Dam it

Dam it

Dam it http: //www. dnr. state. oh. us/water/tabid/3357/Default. aspx

Growing vast monocultures of corn and soybeans necessitates the use of proportionally vast amounts of fertilizer. This fertilizer is used by the plants, but is very ephemeral in the system, often running through to stream systems. Nitrate and Phosphate in particular move into stream systems, wreck the streams, and then flow downstream into larger rivers and ultimately into terminal water bodies such as the Chesapeake Bay or the Gulf of Mexico. This is a major cause of hypoxia. : Ohio corn fields. To be overly simplistic and dramatic: Ohio farmers are robbing Gulf Coast fishermen

Most states have adopted Best Management Practices (BMP) for agriculture and forestry. These are based around the idea of creating a Riparian Buffer Zone. The idea is that if you keep forests growing along the stream side the forest plants will immobilize the nutrients, preventing them from entering the stream. BMPs also deal with things like livestock walking around in the streams, or driving your tractor across the streams (stream crossings) They work, but are poorly followed and essentially unenforced. Restoration can address this issue to some extent by focusing on Riparian Forests…