CONTINENTAL NOTES — GERMANY. 23I 



of the original forests, their roots were not attacked by the 

 disease, and they grow quite normally in the midst of pest- 

 stricken forests. The existence of such healthy forest-areas 

 is not confined to the better classes of soils, nor to any special 

 iocality, nor to particularly favourable situations. 



Zimmermann, by his painstaking practical investigations, has 

 satisfactorily proved that the theories ascribing the early 

 collapse of the pine afforestation to conditions of climate or 

 soil peculiar to the Lueneburger Heide, are untenable, and that 

 the statements made in support thereof, regarding the existence 

 of the pest on forest soils, are based on wrong data and are 

 contrary to the facts of the case. 



The scarcity of timber in the Lueneburger Heide led to the 

 afforestation of practically valueless waste lands with conifers, 

 a hundred years before similar attempts were made in other 

 parts of Germany, with the result that the root-pest was first 

 observed in these parts and seemed to exist nowhere else. 

 Under these circumstances it was natural and excusable, though 

 unfortunate, that the reasons for the prevalence of the disease 

 should be looked for in local conditions, and that, owing to this, 

 investigations into its origin were started on false lines, leading 

 into the quagmire of speculative and untenable solutions 

 which, though impossible to prove, were put forward with the 

 greatest authority in numerous publications. 



Thus the raw humus (dry peat) has many adversaries, has 

 been called the pest of the forest and other bad names. 

 Graebner professes to find in it the direct cause of the root-rot, 

 in that it closes the soil against the circulation of oxygen, 

 but it is evident that dry peat has no relation, whatsoever, 

 to the root-pest, which rages equally in the east of the 

 Lueneburger Heide, where raw humus is almost entirely 

 absent, whereas in some of the best and soundest pine forests 

 it covers the soil up to a depth of 50 and even 80 centimetres. 

 Experiments have moreover shown that dry peat, if properly 

 applied, is the most effective manure for the pine. 



Next as regards poverty of soil, to which many ascribed the 

 failure of the afforestation in the heather tracts, P. Graebner, 

 a botanist of note, writes in his handbook on heather culture : 

 *' It must strike everybody, who, even casually, passes through 

 the heather tracts of North-West Germany or in other countries, 

 that a cultivated plant which enjoys a complete normal develop- 



