New Tools Help Manage Rivers in Forests

Staying connected with science developments often provides opportunities to innovate in ways not first envisaged by those who initiated the science. In one recent example, work undertaken by NIWA to develop a Rivers Environments Classification (REC) has been applied by PF Olsen to help manage rivers and streams in the forests it manages.

The REC is a spatial dataset that classifies all river segments according to a variety of factors that influence their primary physical state.

With over 2,685 km of streams to look after in all the forests PF Olsen manages and 1,058 km within our Forest Stewardship Council Certified estate, Kit Richards, PF Olsen's Environment Manager could see an immediate potential for application of this dataset.

"One of our challenges is that we constantly acquire, at short notice, new forests to manage on behalf of clients" says Kit. "We may know nothing much about the streams within the area yet our harvest planners may have to prepare initial estimates and concepts for planning and budgeting. By linking our Riparian Management Rules to the stream classes, through our GIS and Forest Information and Planning System (FIPS), we can immediately understand some of the likely constraints. We can then generate the rules that contractors will have to follow for the stream categories in an area they are working in and present these on harvest plan maps and prescriptions".

As well as providing a framework for PF Olsen's riparian rules, the system also enables analysis of the variations between the types of river systems we have to manage in different regions. In more recent times the Department of Conservation has developed a spatial model that relates data from the national freshwater fisheries database to the REC system to create the Fresh Water Environments NZ (FWENZ) system. This can provide predictions of probability of occurrence of native fish including threatened species within stream sections. This information too is very helpful to PF Olsen managers when planning operations.