This paper analyses migrations of Vlach communities from the Dinaric area to the imperial border area in the Slavonian interfluve of the 16th century and the impact of these farmer colonists on the Drava River basin ecosystem and vice versa. The paper investigates changes to the environment caused by pastoralisation and deforestation on the one hand, and the dynamics of adjustments and consistency of Vlach socio-economic structures on the other. The changes are estimated in terms of how much they reflected the ability to adjust in the new climate conditions, and how much they were a result of the economic cycles and the steering processes conducted by the imperial structures. Apart from the environmental and the economic factors, this was also the result of the imperial conflict-prone military and political strategies on the border. History has shown that the most successful adaptations usually take place in the realm of economic structures. Thus, among the Vlachs, sheep farming was in gradual decline and extensitve livestock animal was losing its importance. The most difficult to adopt was the other culture’s value system, and especially the mindset and the customs, and in the case of the Eastern Orthodox Vlachs, also the religion. It can be concluded that until the end of the 17th century, the Vlach communitites, both on the Ottoman border and in the Varaždin generalate, were completely agrarian, but they preserved their tradicional organization of “knežina” and extended family structures.U radu se analiziraju migracije vlaških zajednica iz dinarskih prostora na područje imperijalnog pograničja u slavonskom međurječju 17. stoljeća, te interaktivni utjecaj ovih stočarskih kolonista na ekosustav dravskog porječja i obrnuto. Propitujuse promjene u okolišu izazvane pastoralizacijom i krčenjem šuma s jedne te dinamika prilagodbi i postojanosti vlaških socioekonomskih struktura s druge strane. Sagledava se koliko su promjene bile odraz sposobnosti prilagodbe u novom podneblju, a koliko posljedica konjukturnih ciklusa i usmjeravajućih procesa imperijalnih struktura. Osim ekoloških i ekonomskih faktora, to je bila velikim dijelom i posljedica imperijalnih konfliktnih vojno-političkih strategija na granici. Povijesno iskustvo nam govori da su se uspješnije adaptacije najčešće događale u sferi ekonomskih struktura. Tako je kod Vlaha ovčarstvo bilo u postupnom opadanju, a ekstenzivno stočarstvo je gubilo na značaju. Najteže i najsporije se usvajao vrijednosni sustav druge kulture, naročito kad su u pitanju mentaliteti i običaji, a u slučaju pravoslavnih Vlaha i vjeroispovijest. Može se zaključiti da su vlaške zajednice do kraja 17. stoljeća, kako u osmanskom serhatu tako i u Varaždinskom generalatu, bile sasvim agrarizirane, ali su pritom sačuvale svoju organizaciju knežina i strukture proširene obitelji
