The Crown finds many claims of purchase to be invalid. Before Polynesians arrive in New Zealand the land is covered in forest, grasses, alpine plants and swamplands. Widespread deforestation occurs, especially in the South Island, as Maori burn trees and tussock to round up moa and drive them toward hunters. Maori cultivate kumara, taro, gourds, and yams in warmer northern areas. Shellfish and fish are an important food in coastal regions.
Fern root is a staple part of the diet.
Maori migrate with the seasons to use different food sources. Food resources are protected by customs like raahui or a ban on use of a resource in a certain area. Despite this 35 species of native birds become extinct and others are depleted. Forest cover is reduced by 505 over the first 1000 years of Maori settlement. Missionaries encourage Maori to diversify their agriculture.