A Systems Approach to Reed Canarygrass Control: From Theory to Practice (2007 - 2014)

Reference:  Annen (2011). Manipulating internal system feedbacks to accelerate reed canarygrass (Phalaris arundinacea) control:  From theory to practice. Ecological Restoration 29(3): 222-224.

Background:  Southern Wisconsin sedge meadows are unique wetland plant communities co-dominated by sedges and Canada bluejoint grass (Carex-Scirpus-Calamagrostis vegetation associations). Prior to European settlement, approximately 1,000,000 acres of Wisconsin was covered by sedge meadow. It is difficult to assess the present acreage of high-quality, relatively undisturbed sedge meadow because much of the acreage the WDNR considers remnant sedge meadow exists in the wet meadow condition (an alternative disturbed state that arises when wet prairie or sedge meadow is disturbed by nutrient enrichment or artificial drainage, characterized by aggressive, tall, nutrient-loving forbs and cool-season grasses). Recent research by Joy Zedler of UW-Madison concluded that tussock sedge meadows are in decline throughout the Midwest, and sedge meadow losses in Wisconsin might be higher than 80%.  Reasons for the decline in acreage of high-quality sedge meadow remnants include losses due to artificial drainage for agricultural purposes, flashy hydroperiods and material inputs resulting from incorporating wetlands into stormwater infrastructure, and wildfire suppression, all of which correlate with invasion by reed canarygrass (Phalaris arundinacea).  Fortunately, reed canarygrass invasions can be successfully reversed in many degraded sedge meadow remnants. This case study illustrates how Integrated was able to reverse a RCG invasion in a 26-acre southern sedge meadow remnant in a SW Wisconsin hunting and nature preserve.   

Initial Site Condition: At the beginning of this project, 15.5 acres of the sedge meadow was dominated by reed canarygrass and other tall, aggressive, nutrient-loving native species typical of disturbed wet meadows (including saw-tooth sunflower, Canada thistle, and Canada goldenrod). In the absence of periodic fire, the site had successionally converted to shrub-carr dominated by black willow, box elder, and honeysuckle. The presence of these shrubs and trees with high evapotranspiration rates exacerbated the existing hydrological disturbances and led to further water level drops.  Soil nutrient levels were high (10.7 ppm NH4-N, 9.2 ppm NO3-N, 57 ppm avail. PO4).  

Actions Taken:  To address the hydrological disturbances, drainage tiles were probed and removed, and the drainage ditch was filled. A passive flood control gate was installed upstream of the ditch fill.

Outcomes:  Reversal of the reed canarygrass invasion not only led to native species recruitment and a species-rich, diverse community, but also changed the physical structure of the vegetation community (refer to before and after pictures). This outcome had far-reaching positive influences on the presence and abundance of several at-risk species across multiple trophic levels. Additionally, reversion to the remnant sedge meadow condition enhanced the wetland's value for waterfowl production. Furthermore, this project provided revenue for 8 contracting firms, 2 consulting firms, and local vendors. Restoration is good for the economy and these are jobs that can't be outsourced overseas.

Reference:  Annen (2011). Manipulating internal system feedbacks to accelerate reed canarygrass (Phalaris arundinacea) control:  From theory to practice. Ecological Restoration 29(3): 222-224.

Background:  Southern Wisconsin sedge meadows are unique wetland plant communities co-dominated by sedges and Canada bluejoint grass (Carex-Scirpus-Calamagrostis vegetation associations). Prior to European settlement, approximately 1,000,000 acres of Wisconsin was covered by sedge meadow. It is difficult to assess the present acreage of high-quality, relatively undisturbed sedge meadow because much of the acreage the WDNR considers remnant sedge meadow exists in the wet meadow condition (an alternative disturbed state that arises when wet prairie or sedge meadow is disturbed by nutrient enrichment or artificial drainage, characterized by aggressive, tall, nutrient-loving forbs and cool-season grasses). Recent research by Joy Zedler of UW-Madison concluded that tussock sedge meadows are in decline throughout the Midwest, and sedge meadow losses in Wisconsin might be higher than 80%.  Reasons for the decline in acreage of high-quality sedge meadow remnants include losses due to artificial drainage for agricultural purposes, flashy hydroperiods and material inputs resulting from incorporating wetlands into stormwater infrastructure, and wildfire suppression, all of which correlate with invasion by reed canarygrass (Phalaris arundinacea).  Fortunately, reed canarygrass invasions can be successfully reversed in many degraded sedge meadow remnants. This case study illustrates how Integrated was able to reverse a RCG invasion in a 26-acre southern sedge meadow remnant in a SW Wisconsin hunting and nature preserve.   

Initial Site Condition: At the beginning of this project, 15.5 acres of the sedge meadow was dominated by reed canarygrass and other tall, aggressive, nutrient-loving native species typical of disturbed wet meadows (including saw-tooth sunflower, Canada thistle, and Canada goldenrod). In the absence of periodic fire, the site had successionally converted to shrub-carr dominated by black willow, box elder, and honeysuckle. The presence of these shrubs and trees with high evapotranspiration rates exacerbated the existing hydrological disturbances and led to further water level drops.  Soil nutrient levels were high (10.7 ppm NH4-N, 9.2 ppm NO3-N, 57 ppm avail. PO4).  

Actions Taken:  To address the hydrological disturbances, drainage tiles were probed and removed, and the drainage ditch was filled. A passive flood control gate was installed upstream of the ditch fill.

Outcomes:  Reversal of the reed canarygrass invasion not only led to native species recruitment and a species-rich, diverse community, but also changed the physical structure of the vegetation community (refer to before and after pictures). This outcome had far-reaching positive influences on the presence and abundance of several at-risk species across multiple trophic levels. Additionally, reversion to the remnant sedge meadow condition enhanced the wetland's value for waterfowl production. Furthermore, this project provided revenue for 8 contracting firms, 2 consulting firms, and local vendors. Restoration is good for the economy and these are jobs that can't be outsourced overseas.

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