Distribution and habitat characteristics of Chloropyron maritimum palustre (bird’s beak) in the South Slough estuary

Chloropyron maritimum palustre, known as bird’s beak, is a lowland marsh plant that is threatened by the loss of coastal salt marsh habitat. As a hemiparasite it’s roots have structures that receive materials from certain other plants, this function has been proven to reduce competitive dominant plants and promote plant species diversity. Bird’s beak has been listed as endangered by the state of Oregon, and a majority of its population is located in the South Slough estuary. This experiment set out to find the distribution of bird’s beaks throughout the South Slough estuary and to observe if habitat characteristics (salinity, elevation, sediment grain size, soil salinity, associated plant species) influence it’s presence. To monitor it’s distribution accessible areas were mapped and recorded on a map created with ARCGIS. Bird’s beak was present in salt marsh sites from the mouth to the middle of the South Slough, while it was absent at upper marsh sites. High summer water salinities (30-33 ppt) occurred from the mouth of South Slough to the southern boundary of bird’s beak distribution while mid to low salinities coincided with the absence of bird’s beak. Sites with bird’s beak had significantly higher percentage of sand (avg 45%) composing their soil than sites without (avg 16%, p<0.05). Soil salinities of sites with bird’s beak were 27-44 ppt, and sites without bird’s beak were similar (31-44 ppt). Elevations of bird’s beak sites ranged from 1.52-2.53 m, and sites without bird’s beak were 2.12-2.14 m. Bird’s beak primarily occurred with the plant species Limonium californicum, Plantago maritima, Sarcocornia perennis, and Jaumea carnosa, while sites without bird’s beak were dominated by Carex lyngbyei, J. carnosa, and Triglochin maritima. Overall bird’s beak habitat in the South Slough estuary was characterized by high summer water salinity, sediments with high percentage sand, and associated with the plant species L. californicum, P. maritima, and S. perennis. Soil salinity and elevation did not significantly differ between sites with and without bird’s beak.