. Range-wide status assessment of cirsium longistylum (long-styled thistle) . Figure 12. Permanent monitoring plot (15' radius) near Neihart, Little Belt Mountains. No data is available for rosettes in 1993. This plot is actually occupied by C. hookerianum, not C. longistylum. A final semi-quantitative assessment was conducted using the approaches outlined by Regan, Master and Hammerson (2004) and adapted by the Montana Natural Heritage Program for use in ranking Animal Species of Concern (MTNHP 2004). Both of these similar assessment methods assign points to factors such as number of occurre
. Range-wide status assessment of cirsium longistylum (long-styled thistle) . Figure 12. Permanent monitoring plot (15' radius) near Neihart, Little Belt Mountains. No data is available for rosettes in 1993. This plot is actually occupied by C. hookerianum, not C. longistylum. A final semi-quantitative assessment was conducted using the approaches outlined by Regan, Master and Hammerson (2004) and adapted by the Montana Natural Heritage Program for use in ranking Animal Species of Concern (MTNHP 2004). Both of these similar assessment methods assign points to factors such as number of occurrences, population size, area or range extent, trends and threats. Some factors may not be used if data is missing or an estimate of the parameter is too uncertain. The points from the most pertinent criteria are added together to form a final score for the species. Lastly, a heritage rank of 1 to 5 at a global and/or state level is assigned based on the final score. The ranking criteria and scores assigned to C. longistylum are found in Table 2 using the two slightly different scoring methods. Table 2. Ranking factors and assigned scores for the C. longistylum assessment. The first numbers in the Point Allocation column are those used in the scoring method of Regan, Master and Hammerson (2004) and the second numbers in the column are those used in the method outlined by the MTNHP State rank criteria for Animal Species of Concern. See Regan, Master and Hammerson (2004) and MTNHP (2004) for a complete discussion of the methodologies. Factor Parameter Estimate Category Point Allocation # of Occurrences 21-80 C 3/Not used Condition of Occurrences Some (13-40) with good or excellent viability D 0/Not used Population Size 10,000-100,000 plants F 0/0 Area of Occupancy 20-100 km2 (5,000- 25,000 acres) D Not Geographic Range 1,000-5,000 km2 (400- 2,000 sq. miles) D Not used/Not used Long-term Trend Relatively stable {+- 25% change) E 0 Short-term Trend Short-term trend unknown
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