56559 P1060315

148 JANUSZ OSTOJA-ZAGÓKSKI

approximatdy about 2500 kcal, which oan bo calculalcd as about 750 g of food daily per mcm ber of the population. Multiplymg thc&c dala by the averagc number of mhabiłants of one fortified sctUcmcnt we get about 1000 kg of food daily. U should be tmphasized herc that thosc quantitics should be considcrcd indispcnsiblo for tbc biological survival of the cxamincd population.

Thought should be given in tum—to the pcrccntago in whioh this demami could be oovercd by the basie branch of cconomy, the t i II lago of land. As we remem ber the surface of areas for tillagc was about 16 sq.km i.e. 1600 ha. Considermg the neoessiiy of prescrvation of the rotation cycles, indispensible for the regencration of the M>il. 1 5 of the whole arca, i.e. about 320 ha was probably simultancously cxpioitcd. If the number of inhabitants of one ecumcn was, on the avcragc, about 1000 people, this will be about 0.3 ha per mcm ber of tho torritorial commune. It should be remembered that the cereal crops were smali but the demand for plant Products could be covcred—at least partially—by the intcn$ivo cultivation of root crops and vegctab!es. We may thercforc accept that I ha of arabie land provided about 100 kg of dry plant products, i.e. about 320 tonns of plant substancc from the whole tillagc arca Dividmg the obtamed rcsults by the number of days in a ycar we get approximalcly about 850 of food daily. Conseąucntly, plant production co-vered 75% of the food demand. An essential supplcmcntary role in completion of tbc food basis was piaycd by agrieullural occupations other than farming. such as breeding of caZtle, galhering, fishing and huntmg- Because of the lack of specia-linie data it it difficult to dcfinc tha participation of particular branches of these oooupations in generał nourishmen*. Therc is no doubt, however, that leading herc wras caitlc breeding. The most importanl basc in the cconomy was the breeding of aattie, swine and smali ruminantt: sheep and goat.

In some periods, the above mentioned proportions arc shifting as the role of the smali rummants inereases (Ostoja-Zagórsk i, 1973). This is undoubtcdly oonncctcd whh the inereasing demand for food. Indcpcndcntly from the Ievcl and capacity of the eon tern porań eous husbandry, other forms of cconomic activitiy musi have piaycd an essential role in the completion of the daily food ratę, among other things fishing. huntmg and galhering. Summing up the above remarks, we may assumc that the role of occopanons other than farming. in the cconomy of human populations in the north-westem zonę of the Oder and Yistula rivcr basins—m the Hallstatt penod—depended not only on substantial supplemcnting of the daily demand for food (as they had to provide about 150-200 kg of food daily), but also on providing a surplus pcrmitimg an accum ulali on of rcscrves.

Changęs in the natural environmeni causa/ by climatic transformat ions and intensification of human activities

A detcrioration of dimatic conditions which took place in Cetnral Europę, a the Uirn of the sub-BoreaJ and sub-Atlanbc periods, was distinclly rcflected in the levcl of cconomy of thosc days and mhibiled as it scems—tho intensivc changcs in settlcmcnt paltem. The above mentioned climatic changcs werc characterizod mainly

by i considcrublc drop of the ycarly mcan temperaturo and incrcascd rainfall, which tubttuiliaUy deteriorated hydrogiaphio conditions. It it not ncccssary—I think—to stress tliat the lattcr were a dedding factor in thecharactcr of the natural cnvironment and influeneed chanecs in the structurc of settkment. Hm incrcasc of rainfall caused a systematie rai&c of watcr-lcvcl in the natural water basins, which wat particularly pciccptiblc in the Oder and Yistuła river basm zonę (Skarżyńska. 1967). The proccss of gradual raise of the watcr-lcvcl in rivers and laket caused disturbanoes in the ycarly rhythm of ground-watert. Their high Ievcl during the whole ycar basically prcvcntcd a drainage of the intcnsively eaploitcd flood plains, espccially aflcr spring and Winter floods.

The systcmaticalły incrcasing poutive water balance caused a gradual turning into marshes the humic soils, the mam zones of cultivation (Strzemski, 1964). In individual ecumcns designed by settlcmcnts of the Biskupin typc, the zones of mten-sivc agricultural cxpIoitation subttantialły diminithed.

The marshed flood plains impeded the cahhritioo of pułsc crops and «cgetables. The higher parts of the territorios— desphe considcrablo deforestation—could not be used as cultivation arcas becaute of the compactne*» of their soils. The necessity, thcrcforc appeared of intensivc ezploitation of the tcrraccs above floodplains. How-cvcr. considering the kind of their soils, as well as the situation in relation to the watcr-lcvcl in the water basins. they were of little we for intensivc gardening and were used as smali plots of ground mamly for the oultivatioo of oercals. The syste-matic shrmking of dircct farming zones undoubtcdly caused a gradual dominishing of tho rotntioń ćyclo, which--in tum—influeneed the systematie towering of the capacity of the soil, gainod during natural soil-forming processes (Odum, 1959). This automatioally caused a lowering of the cffidency of the agriculture. A sub-scqucnt conscquence of the abovc signalkd processes, was tho diminishing of the natural potsibilhies of cxtcmivc farming and the inerease of noo-Cuamg occupa-lions. Their mtcnsification undoubtcdly influeneed the uwcttlmg of the ccotogic balance in particular cco-systcms. Thcso ccologic tnuuformations takmg place in particular ecumons were influeneed, on the one hand, by the prcvious!y mentioned climatic changcs, and. on the other. by cxtcnsive mismanagement of man. The shrinkmg of zones of dircct farming cxploitatioh, duc to turning into marshes, of the floodplains, caused a trunsfcrcncc of intensiyely cuhivatcd regions to less favou-lublc form tho contemporancous point of vicw—the flrol tcrraccs and higher arcas of tho pcriodically deforested upper parts of valleys. The shortening of rotation cyclcs of the cultivatcd territorics and intensificatioo of noo-fanniog oocupations caused an incrcascd proccss of ccological dcvastation of particular scttlemcnt micro-regiow. The situation was additionally worsened duc to a strong stabilizalion of scttkmcats and uncvcn distribution of population in the occupied ecumcns (coooentration in the fortilłcd settiements and their vicinity). Intensive and prolonged cxploitatioo of the same natural forms led to considcrablo emaciation of the soil (Hammond, 1971).

The abow mentioned fnctors, i.e. climatic chan ges and teologie devasUtion of tho sottlod mioro-regions, were tho dircct causo -as wo may presumc—of the oollapso of the economic and lator also soltloment structurc (dodino of Ute defensivo