184 



BROOKLYN BOTANIC GARDEN MEMOIRS 



Klebahn^ figures an Ortstein Kiefer where the tap-root striking the 

 hardpan is bent over, being unable to penetrate that soil layer. 

 Graebner narrates how such pine trees grow for a time, but finally, 

 after reaching a certain age, begin to go back, or decline in vigor, until 

 they succumb, and he describes how certain pine trees more fortu- 

 nately situated by natural planting over holes through the Ortstein 

 (Ortsteintopfe) are able to send their tap-roots into the deeper soil 

 layers.^ Under such conditions tall thrifty pine trees will be scattered 

 here and there over the surface of the heathland, while the majority 

 of the trees, that become established in the region, are dwarf and 



Fig. 7. Pine-barrens (pine-heath) near Lake Ronkonkoma, Long Island. 

 July 20, 1913. 



languishing. Similar conditions are found in the plains of New 

 Jersey where the low, dwarf pine trees live for a number of years and 

 finally succumb, to be replaced by other trees that pass through a 

 similar existence. Hence the dwarf basket pines of the New Jersey 

 Coremal are all short-lived. Thus hardpan and fire are the two most 

 important factors which have perpetuated the heath vegetation of the 

 New Jersey plains (Coremal), while the surrounding region with more 



* Klebahn, H. Grundziige der allgemeinen Phytopathologie, p. 14. 



* Graebner, P. Die Heide Norddeutschlands. Die Vegetation der Erde 

 5: 125. 



