Forest Inventory Updates Following Insect Defoliation. Linking Stand Models with Remote Sensing of Stand Condition : 19th IUFRO World Congress

1990

S. 45-31

3 Abb., 13 Lit. Ang.

Unselbständiges Werk

200086020

Effective forest management planning requires an up-to-date forest inventory and accurate projections of future stand yields. Accurate inventories and yield projections are particularly important in the many regions with tight timber supply/demand balances. Use of Geographic Information System (GIS) technology by many agencies has facilitated management planning and opened many possibilities for inventory updating, but is also has increased the costs of inventory data bases. In this paer, we discuss inventory updating methodology being developed for use in New Brunswick, Canada, that involves linking stand models and remote sensing of stand condition. Updating methodology will involve assessment of critical characteristics of individual stands by ground-based or aerial surveys or remote sensing, and the use of stand models to project development. Separate stand models are being developed for establishment, growth, and stable/decline phase stands. The two major factors causing rapid changes to New Brunswick's forest inventory are defoliation by spruce budworm (Choristoneura fumiferana (Clem.) ) and a preponderance of mature and overmature stands that are cloase to breakup; both factors can result in reduced stand volumes. The mature and overmature stand updating system currently under development in a multi- agency, 1988-1992 project therefore includes: (1) annual detection of current defoliation at the stand level by aerial survey or airborne MEIS scanner, (2) periodic (five-year) assessment of stand condition (cumulative defoliation or net volume increment) using Landsat Thematic Mapper, and (3) a stand model which can utilize a five-year defoliation scenario, current stand condition, and the inventory stand description to project future stand yield. A description of each of these components is given, including the stage of development and probability of success, and the prognosis for inventory updating is discussed.