FCP

River Environment Classification

REC2 includes a geospatial map showing all streams in New Zealand, classified into stream orders. The FCP uses this to map all 3rd-order streams within our three study areas (Gisborne, Hawkes Bay, Nelson City, Tasman and Marlborough). Each 3rd-order stream and its surrounding subcatchment is classified as a CMU (see image below). The CMUs defined using this method range in size from 100 ha to 5,000 ha, with an average of 700 ha. The image below shows that not all CMUs have significant areas of plantation forest. For example, in the west of the Wairoa catchment, most CMUs are in indigenous forest. Only a few have significant areas of plantation forest, and any effects of clearfell harvesting will occur in these CMUs.

The Wairoa catchment in Hawkes Bay, showing CMUs as well as the main (stream order 3 and higher) branches of the Wairoa River.