Bciyntaii and Stallard: climax formations 365 



(1) Chara-Philoiria Associes 



As to causes, consocies and secondary species the initial stage 

 here is the same as the initial stage leading up to the pine forest 

 climax which is discussed on page ?>i7. 



(2) CastaHa-XyiiipIiaca Associes 



This associes is similar to the corresponding associes in the de- 

 velopment of the pine forest climax through hydrarch succession. 

 (See discussion on page 337.) 



(3) Scirpus-Zizaiiia Associes 



See discussion of corresponding associes on page 338 from which 

 this shows no essential variation. A striking feature of this associes 

 as found in Star and Dead lakes in Otter Tail County is the very 

 extensive area of Ziaania which completely filled some of the long 

 shallow^ arms of these lakes. From shore it had the appearance of 

 meadows of Zisania, though with a rowboat or canoe one could go 

 anywhere through it. Shores exposed to severe wave-action or to 

 the action of wind-driven ice as the ice breaks up in the spring are 

 free of Zisania and usually also of Scirpas, Typha and others of 

 this associes. 



(4) Carcx Associes 



Causes : The filling up of lakes or ponds by the washing-in of 

 eroded material from the sides and by the accumulation of decayed 

 plant remains results in the reduction of the water-level along the 

 shore. This permits the invasion of plants of this associes. 



Consocies : The following are typical dominants of this associes : 



Cares aqiiatilis Carcx lanuginosa 



Car ex diandra Car ex trichocarpa 



Car ex filifonnis 



Carcx aquatilis and C. trichocarpa are less prominent than in 

 the corresponding associes of hydrarch succession culminating in the 

 climax pine forest, their place being taken usually by C. filiformis, 

 C. lanuginosa and C. diandra. In many places the associes occupies 

 only a narrow zone while in others it is more extensive. As in the 

 development of the Pinus association so here the Carex associes 

 may follow directly after the Castalia-NympJiaea stage with only 

 a sparse growth of Zisania or Zisania and Scirpus intervening, or 

 these may be entirely absent. 



