Baikal sedge (Carex sabulosa) COSEWIC assessment and status report: chapter 9

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Population Sizes and Trends

Carex sabulosa has been recorded on six dune systems at four areas in the Yukon (Figure 4, Table 1).  One of the sites, an historic one at Christmas Bay, Kluane Lake, was not relocated during this study. If it still persists, this C. sabulosa population is extremely small, since the entire windward side of Christmas Bay was searched in 2003 and only a few, small, sometimes unstable sandy areas were found. Each of the locations, at Carcross and Takhini River, has two separate dune systems. Two other, much smaller, dune systems or blowouts also occur along the Takhini River between the larger systems treated in this report. They were not examined in detail but they contained fewer than 10 000 ramets.

The largest dune system in the southern Yukon, covering almost 40 ha, is found at the Kaskawulsh/Dezadeash Rivers in Kluane National Park. Estimates of ramet numbers range from three to four million at this site (Table 1). The Carcross dune systems had ramet numbers ranging from 38 to 196 thousand covering areas of 4.8 to 13.1 ha while the Takhini River dune systems had ramet numbers ranging from 168 to 294 thousand covering areas of 8.4 to 9.6 ha.

Population trends at all but the two Carcross dune systems have probably remained stable in recent years since dune areas have remained relatively stable (see Habitat trends). Clones of Carex sabulosa at the Bennett Lake dunes have probably declined by 10 or 15% in recent years due to reduction in dune size. At the Klondike Highway dunes there has been some loss of clones on the areas of the dunes where heavy recreational vehicle use taken place. Data is not available but this loss has probably not been substantial since the areas destroyed are mainly those where heavy use has compacted the soils (Figure 10).