who had developed a farming technique called shifting cultivation
Slash-and-burn
Large families or clans wandering in the lush woodlands long continued to be the most common form of life through human prehistory . Axes to fell trees and sickles for harvesting grain were the only tools people might bring with them . All other tools were made from materials they found at the site , such as fire stakes of birch , long rods ( Vanko ) , and harrows made of spruce tops . The extended family conquered the lush virgin forest , burned and cultivated their carefully selected swidden plots , sowed one or more crops , and then proceeded on to forests that had been noted in their wanderings . In the temperate zone , the forest regenerated in the course of a lifetime . So swidden was repeated several times in the same area over the years . But in the tropics the forest floor gradually depleted . It was not only in the moors , as in Northern Europe , but also in the steppe , Savannah , prairie , pampas and barren desert in tropical areas where shifting cultivation is the oldest type of farming . Cultivation is similar to slash - and - burn . ( Clark 1952 91 -- 107 ) . 
Large families or clans wandering in the lush woodlands long continued to be the most common form of life through human prehistory . Axes to fell trees and sickles for harvesting grain were the only tools people might bring with them . All other tools were made from materials they found at the site , such as fire stakes of birch , long rods ( Vanko ) , and harrows made of spruce tops . The extended family conquered the lush virgin forest , burned and cultivated their carefully selected swidden plots , sowed one or more crops , and then proceeded on to forests that had been noted in their wanderings . In the temperate zone , the forest regenerated in the course of a lifetime . So swidden was repeated several times in the same area over the years . But in the tropics the forest floor gradually depleted . It was not only in the moors , as in Northern Europe , but also in the steppe , Savannah , prairie , pampas and barren desert in tropical areas where shifting cultivation is the oldest type of farming . Cultivation is similar to slash - and - burn . ( Clark 1952 91 -- 107 ) .
Large families or clans wandering in the lush woodlands long continued to be the most common form of life through human prehistory. The extended family conquered the lush virgin forest, burned and cultivated their carefully selected swidden plots, sowed one or more crops and then proceeded on to forests that had been noted in their wanderings. It was not only in the moors, as in Northern Europe, but also in the steppe, Savannah, prairie, pampas and barren desert in tropical areas where shifting cultivation is the oldest type of farming.
Large families or clans wandering in the lush woodlands long continued to be the most common form of life through human prehistory . The extended family conquered the lush virgin forest , burned and cultivated their carefully selected swidden plots , sowed one or more crops , and then proceeded on to forests that had been noted in their wanderings . It was not only in the moors , as in Northern Europe , but also in the steppe , Savannah , prairie , pampas and barren desert in tropical areas where shifting cultivation is the oldest type of farming .