The present invention relates to biodegradable polymer mixtures comprising i) 40% to 95% by weight, based on the total weight of components i to ii, of at least one polyester based on aliphatic or aliphatic and aromatic dicarboxylic acids and aliphatic dihydroxy compounds; ii) 5% to 60% by weight, based on the total weight of said components i to ii, of polyalkylene carbonate, particularly polypropylene carbonate; iii) 0% to 60% by weight, based on the total weight of said components i to iii, of at least one biodegradable homo- or copolyester selected from the group consisting of polylactic acid, polycaprolactone and polyhydroxyalkanoate, and/or of an inorganic or organic filler; iv) 0% to 10% by weight, based on the total weight of said components i to ii, of an epoxy-containing copolymer based on styrene, acrylic ester and/or methacrylic ester, and v) 0% to 15% by weight of an additive selected from the group consisting of lubricant, antiblocking agent, antistat, UV absorber, UV stabilizer, thermal stabilizer, dye, pigment, colorant, plasticizer, fertilizer and active crop protection ingredient. The present invention further relates to processes for producing biodegradable polymer mixtures, to the use of biodegradable polymer mixtures in the production of moldings, films or fibers and also moldings, films or fibers comprising biodegradable polymer mixtures.