96 SUCCESSION 



however, that this is an ultimate formation, as Krassnoff 

 and Warming indicate. 



Fliche (1888) investigated the behavior of forest plant- 

 ations in lower Burgundy, and reached the following con- 

 clusions, many of which are of general application. The 

 original plantations, chiefly birch and exotic cultivated 

 species, were overgrown by the indigenous oaks and beeches, 

 except on poor ground. Shrubs, bushes and most herbs 

 disappear as the growth of the trees renders the light more 

 and more difEuse, In new plantings, the grasses and field 

 weeds disappear the first year, and are replaced by the 

 weeds of fallow fields. The latter are overgrown the very 

 next year by bushes, with which shrubs soon associate 

 themselves, until finally the invading trees drive out all but 

 a few shade-loving species. Migration into these areas is 

 chiefly by birds and winds, the latter bringing by far the 

 larger number of seeds, though the former are really more 

 effective because of the greater chance of ecesis. The de- 

 finitive ecesis of a species is independent of its mobility, as 

 is seen by the fact that the immobile Fagales completely re- 

 place the very mobile birches and pines. Prom his work, 

 the author derives two general rules of reforestation, which 

 also hold in large part for similar natural successions, 

 ' 'Erstlich ist es fehlerhaf t, Moose und Gestrtipp {Juniperus, 

 Oenista, Prunus,) auf gleiche Stufe zu stellen mit den Acker- 

 unkrautern und darum auszurotten : beide verbessern den 

 Boden, bereiten ihn ftir den Wald vor, fOrdern die Keimung 

 der Samen, und schtitzen, wie an mehreren Beispielen 

 gezeigt wird, die aufschiessenden Baumchen: sind diese 

 erstarkt, so verschwindet das Gestrlipp von selbst; das 

 Moos aber leistet noch weitere Dienste. Sodann gedeiht 

 der Wald dann am besten und regeneriert sich auch ohne 

 Zuthun des Menschen von selbst, wenn er die Arten, and in 

 dem Verhaltnis enthalt, wie sie in der jeweiligen Gegend 

 einheimisch, und eben den beztiglichen Wachstumsbeding- 

 ungen am besten angepasst sind ; und eben dieses Verhalt- 

 niss stellt sich in einem sich selbst tiberlassenen Walde 

 immer wieder her. ' ' 



