area extended east to Little Missouri River 

 alluvium derived from shale parent material. Soils 

 are aridisols and entisols. Their low permeability 

 and relatively infertile, acidic composition 

 exacerbate the affects of the harsh climate. 



4. REGIONAL CLIMATE: The extreme southeastern corner 

 of Montana has an arid continental climate with a 

 relatively long 120-130 day growing season and 

 extreme temperatures, including some of the state's 

 warmest growing season temperatures (Cunningham 

 1982) . 



POPULATION BIOLOGY 



1. PHENOLOGY: The inconspicuous flowers of Ouercus 

 macrocarpa emerge in spring before leaf-out and 

 mature as the new leaf buds are beginning to open. 



Acorns had almost reached full size by the time of 

 fieldwork in late August, but are not mature until 

 after frost. 



2. POPULATION SIZE AND CONDITION: Population size is 

 estimated at roughly 10,000 individuals, present on 

 over 1000 acres, with densities ranging from 1 

 tree/acre to ca. 20 trees/acre. 



Only two trees were cored in the ridge and river 

 settings. Heart rot in the river cores 

 interrupted the record. 



The largest tree in the river setting was 18" DBH 

 (4.9' circumference), estimated at 110 years. 

 A "typical" tree in the ridge settings was 6" DBH 

 estimated at 60 years. The former has a faster 

 growth rate and was established before settlement. 

 The latter dates back to the Great Drought. 



3. REPRODUCTIVE BIOLOGY 



a. TYPE OF REPRODUCTION: Sexual outcrossing. 



b. POLLINATION BIOLOGY: Wind-pollinated. 



C. SEED DISPERSAL AND BIOLOGY: Squirrels are 

 the most highly adapted seed dispersing 

 vectors. Fox squirrels (Sciurus 

 niger ) and red squirrels ( Tamiasciurus 

 hudsonicus ) are both documented from this area 

 of the state, the former feeding exclusively 

 on deciduous trees, and the latter favoring 



