232 



The Plant World 



of all these becks is Richard Linde's beautifully illustrated pro- 

 duction entitled Die Lueneburger Heide. 



Geologically, the region is not unlike northern Michigan 

 and Wisconsin, a series of low, indefinite moraines, with broad 

 plains lying between them, the latter diversified by numerous 

 streams and small ponds and stretches of bog or moor. The 

 dry land is predominantly sandy, so much so that dune com- 

 plexes have developed in many localities, and the heavy rainfall 

 apparently finds its way readily to the stream channels and the 

 marshes, thus leaving the surface sands in a comparatively drv 

 state during the greater portion of the summer season. The 

 winters here are long and the ground is snow-covered for a great 

 part of the time, although the' temperatures are by no means 

 extreme. 



Fig. 1. The edge of the forest — near Bergen 



The comparatively short growing season, together with the 

 rapid drainage of the soil, and its lack of soluble salts, are prob- 

 aly the main reasons for the heath character of the vegetation. 

 The Heide is physiologically arid, albeit it has a large rainfall 

 and a high humidity. The vegetation of the sandy areas is 

 characterized T bv an almost exclusive growth of the northern 



