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Recent changes in flora and vegetation 291Fig. 4. Solitary old oak (Que1·cusrobu1·), the thickest in Sweden(diam. over 4 m) on moraine richin erratics. In the backgroundclosed coniferous forest growingon earlier thinly wooded grazingland. Sma.land, N orra K vill, Rumskulla.March 15, 1961. PhotoBengt Pettersson.Some areas of meadowland have been transformedinto grazing land where the original vegetationis even more impoverished since commercialfertilizers are used to improve the production.Only in a few districts we can find remainingmeadowland still managed in an ancient way,with deciduous trees from which earlier leaf-fodderwas harvested, as may be obvious from their presentgrowth-form. Juniper and spruce have often invadedthe open ground and the latter will graduallysuffocate the deciduous tree vegetation in the longrun (cf. Fig. 7). Similar changes have taken placein the old grazing land. There are many examplesof closed spruce forest which has succeeded openpasture with solitary old birches showing signs ofhaving been cut for leaf-fodder. The invasion ofspruce into deciduous forest thinned out by humanactivities was observed and discussed alreadyduring the 19th century (cf. KELLGREN 1890,SERNANDER 1892, 1894).The expansion of beech in southernmost Swedenparallels in some degree the invasion of sprucefarther northwards. BJERKE (1957) found thatdense beech woods have been established since abouta century on earlier pasture where old oaks andbeeches grew scattered in a vegetation which originallylooked like a savanna. BJERKE assumes thatthis succession was caused by pigs which happenedto replace cattle as grazing animals.The vegetation of meadows and pastures wascomposed of many species including those whichhad been successively introduced to the rurallandscape of Sweden from Central Europe duringthe course of time ever since the Neolithic Age(cf. STERNER 1922, p. 363, SANDBERG 1948, p. 192).They are vanishing from the country of today.Another part of these species belonged to thenative flora, many species of which might originallyhave had only restricted sites of open groundat their disposal, but later spread over open groundcreated by man and domestic animals. Some of themare again decreasing or even on the verge of extinctionin many areas.In former times animal husbandry was based to agreat extent on the spacious wooded pastures ofwhich only a part was fenced in. These woodlandsin the surroundings of cultivated ground had beenthinned out in order to create pastures. In mostparts of the country, the grazing cattle and sheeproamed freely over unfenced areas, wooded orheath-like (cf. FRODIN 1954).In the middle of the 18th century there appeareda law that enforced the landowners to keep theirgrazing land fenced-in (cf. BENGT PETTERSSON 1949,p. 378). This regulation was gradually put in forcein the southern part of the country and had profoundeffects on the vegetation.In the vast coniferous forests suitable sectionsActa Phytogeog1·. Suec. 50