Wet Meadow Plant Associations, Malheur National Wildlife Refuge, Harney County, Oregon

• Main Author: Christy, John A.
• Other Authors: Oregon State University. Institute for Natural Resources
• Format: Report
• Language: English; unknown
• Published: Oregon Biodiversity Information Center, Institute for Natural Resources
• Subjects: Malheur National Wildlife Refuge (Or.); Carex aquatilis
• Online Access: https://ir.library.oregonstate.edu/concern/technical_reports/wd3761449

Report by Portland State University's Oregon Biodiversity Information Center (ORBIC), part of the Oregon University System's Institute for Natural Resources. In July 2012, we sampled 131 plots in wet meadow habitat at the southern end of the Malheur National Wildlife Refuge. Analysis of the data identified eleven different plant associations: Alopecurus pratensis, Carex aquatilis var. aquatilis, Carex nebrascensis, Carex pellita, Carex praegracilis, Carex sheldonii, Distichlis spicata, Juncus balticus, Leymus triticoides, Phalaris arundinacea, and Sparganium eurycarpum. Plant associations spanned a wetland gradient from seasonally moist to seasonally or perennially flooded, but surface water had left most stands at time of sampling. Mean Wetland Indicator Status scores help to place the plant associations within gradients in soil moisture and alkalinity. The Alopecurus pratensis and Phalaris arundinacea associations are dominated by exotic, invasive species and appear to be outcompeting native plant associations. Phases of the Carex praegracilis association appear to be replaced by the Alopecurus pratensis association, while the Carex pellita, Juncus balticus, and Leymus triticoides associations may be replaced by the Phalaris arundinacea association. The Carex aquatilis and Sparganium eurycarpum associations were undersampled and provide only an estimate of composition. Most associations are consistent with what has been included in the National Vegetation Classification.