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COSEWIC assessment and status report on the American Chestnut in Canada

Appendix: Comparison of Reproductive and Blighted Individuals Over Three Time Periods

A) Incidence of Flowering/Fruiting; Number of Individuals Reproductive (F) or Non-reproductive (NF), with Percentages Shown in the Diagram

SurveyTree dbh (cm)
0-910-1920-2930-3940-4950+
NFFNFFNFFNFFNFFNFF
1986383211125170160405
19971532361615126265646
200318210762418184213418

 

Figure 1: Percentage of Reproductive Trees by Size Class

Chart 1: Percentage of reproductive trees by size class

* Indicates significant differences among the three surveys.


B) Incidence of Blight; Number of Individuals with Blight (B) or No Blight (NB) Symptoms, with Percentages Shown in the Diagram

SurveyTree dbh (cm)
0-910-1920-2930-3940-4950+
NBBNBBNBBNBBNBBNBB
1986350321771481143241
199773823913151218148382
200313047673917201590863

 

Figure 2: Percentage of Blighted Trees by Size Class

Chart 2: Percentage of blighted trees by size class.

* Indicates significant differences among the three surveys.

Brian Husband analysed the data of the three surveys referenced in the report and prepared the above charts. All statistics were based on Chi-square Contingency Analysis, which determines whether the frequency of trees with and without flowering or blight differs among the three surveys.

 

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