TECH TREK: Greene Street in SoHo is becoming a Little Sweden. Fjallraven has signed a lease for a 3,600-square-foot flagship at 38 Greene Street on the corner of Grand Street, joining countrymen Acne at 33 Greene Street and Gudrun Sjoden at No. 50. Fjallraven, which means arctic fox in Swedish, began in the Fifties when founder Ake Nordin decided to build a better backpack. He did so using a wooden frame. As people started spending more time in nature, the need for durable, weather-resistant clothing arose and Fjallraven answered the call with G-1000 Eco fabrics and zippered ventilation. A Barents parka has a hydratic membrane that protects from moisture and Supreme Microloft padding to keep low temperatures at bay. It costs $600. The company sponsors trekking events such as the Fjällräven Polar a 300 kilometer-long winter adventure across the arctic tundra where participants steer a dog sled from Signaldalen, Norway, to the forests around Jukkasjärvi, Swedish Lapland. This is Fjallraven’s second store in Manhattan. A unit at 262 Mott St. bowed three years ago. Chris Owles, a broker at Sinvin Realty represented the owner, Zar Property, and Josh Lewin of Isaacs & Company represented Fjallraven.