260 RIKARD STERNER 



also of importance to the vegetation. These precipitations show in some respects 

 a different distribution from that of tlie summer half-year. Even now, however, 

 the western slope of the South Swedish hij^hland presents the highest amounts 

 and the regions to the east of it the lowest. 



When precipitations are to be estimated with regard to their importance to the 

 vegetation, it is necessary to take into consideration not onh- tlieir amount but 

 also their distribution in time. 



In the work of Hamberg just mentioned (p. 46) there are accounts for South 

 Sweden of the average number of yearly periods of precipitations of five days' 

 length or more. The differences between various parts of South Sweden prove 

 to be (luite insignificant. 



A comparison with other parts of Europe shows that with regard to precipitations, 

 and especially as to their annual distribution, South Sweden holds an intermediate 

 position between Continental and Atlantic Europe (cf. Hamberg 191 1, pp. 15, 

 18 ff.) A characteristic of the East European precipitation conditions is the fact 

 that the height of summer gets the bulk of the precipitations. July shows the high- 

 est amounts of rainfall. Western Europe, on the other hand, has its maximum 

 of precipitations in the autumn or the winter. In South Sweden the maximum 

 of precipitations falls in August. An exception from these rules is formed only 

 by the Ostgota-plain (Linkoping), possibly the central part of the Malar-plain 

 (Vasteras), and the neighbourhood of Kalmar Sound (Kalmar), which regions 

 show a slight maximum in July, and finally Stromstad, which has its maximum 

 in October. 



But wliile in south-eastern Sweden the August maximum ditiers only slightly 

 from that of July — but considerably from that of September and October — 

 it is just the contrary in south-western Sweden. Here we find in several places 

 amounts of rainfall in October which come very near to those of the maximum 

 in August. 



As to the distribution of precipitations throughout the year there is thus a 

 considerable difference between south-eastern and south-western Sweden, and a 

 remarkable coincidence between the state of things in south-eastern Sweden and 

 those of the continental Europe. 



Table 5 shows the amount of the yearly average of precipitation within difterent 

 parts of South Sweden according to Hamberg (1. c.) and in some places in Cen- 

 tral and South-East I^urope according to Mann (1. c). The coincidence 

 between the Kalmar district and the Russian stations is striking. 



When the amounts of rainfall given above are estimated with regard to their 

 importance in phytogeography, they suffer of course from one source of error. 



The rainfall which is measured in a rain-gauge can onl\- to a certain extent 

 affect plants. We must take into consideration the fact that a great part of it 



