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become covered or nearly so, the dune-complex has been chang.ed into 

 a heath. Blowouts occurring in the heath are, in general, revegetated 

 with heath plants rather than with invaders. This will be discussed 

 later, under the general topic of blowouts. 



This association is a transitory one of northern affinities, and all 

 the evidence goes to show that it is very gradually being driven en- 

 tirely from the region. In the northern part of this area it has dis- 

 appeared already. In the central part north of Dead Lake the Quer- 

 cus velutina association is taking its place. For a little ways south 

 of Dead Lake it is being slowly replaced by pine trees. The only 

 places where the heath is reproducing itself are still farther south, al- 

 though at the same time the prairie is coming in from the westward 

 more rapidly to take its place. 



LIST OF THE SPECIES OE THE HEATH ASSOCIATION 



Dominant Species 

 Juniperiis horizontalis 

 Arctosfaphylos 'nva-iirsi 



Secondary Species 

 Solidago nein oralis 



Relic Species 

 Andropogon scoparius 

 Calam ovilfa longifolia 

 Salix glaucophylla 

 Koeleria cristata 

 Salix syrticola 



Invading Species 

 Ceanothiis ainericaniis 

 Popidus dcltoides (1.5 m. high) 

 Quercus velutina 

 Potentilla fruticosa 

 Aster ptarndcoides 

 Paniciim virgatum 

 Popidiis candicaus (0.6 m. high) 

 Liatris scariosa 



Jtiniperns cominunis depressa 

 Juniperus virginiana (one plant) 



Pctalosteiniiui piirpureum f. are- 

 nariuin 



Prunus puinila 

 Artemisia caiidata 

 Jnnciis balticns littoralis 

 Sorghastriun nutans 



Piniis strobus 

 Pimis laricio 

 Pinus silvestris 

 Poa compressa 

 Hypericnin kahuianitm 

 Aster azureus 



Tilia americana (one plant 0.5 m. 

 high) 



THE PINE EOREST ASSOCIATION 



General Location and History. — South of the Dead Lake there is 

 approximately a square mile of ground forested by coniferous trees, 



