Chapter 2 Introduction to the Provincial NSYT Production Process

The Provincial NSYT dataset is a comprehensive province-wide yield product generated from the Rank 1 (R1) layer of the VRI. The R1 layer was selected because it represents the leading forest layer within each polygon and provides a consistent provincial basis for yield estimation. Yield projections were developed using the Variable Density Yield Projection version 7 (VDYP7) and are intended to support strategic forest analysis, TSRs, FLP, cumulative effects assessments, forest estate modelling, carbon analysis, and other provincial forest management applications. The resulting dataset provides a standardized natural stand yield curve for each eligible forest feature in the provincial inventory, creating a common analytical foundation for forest planning and decision-making.

Development of the provincial NSYT required extensive preparation and quality assurance of the underlying inputs before yield generation could occur. Input datasets were assembled from provincial VRI, VDYP input layers, VDYP input polygons, species composition records, and supporting tables. A series of validation and correction procedures were implemented to identify and resolve issues related to missing rank assignments, species composition, age and height estimates, basal area, crown closure, density attributes, vegetation cover information, and other inventory anomalies. These steps ensured that the final VDYP inputs were standardized, internally consistent, and suitable for generating reliable provincial-scale yield projections.

The following chapters document both the development of the provincial NSYT dataset and the assessments undertaken to evaluate its suitability for operational use. Chapter 3 describes the preparation of the VDYP input database, including data loading, quality assurance procedures, rank layer assignment methodologies, species composition correction, age and height validation, and the updates applied to vegetation and inventory attributes. Chapter 4 summarizes the VDYP projection parameters, assumptions, and model inputs that were ultimately used to generate the final provincial NSYT yield curves. Chapter 5 describes the process used to integrate the Provincial NSYT with the Provincial MSYT dataset, creating a single provincial yield library that includes merchantable volume and dominant height projections for both natural and managed stands.

The final chapters focus on validation of the provincial product. Chapter 6 presents a comparison between NSYT-derived projected volumes and the existing live stand volume estimates contained within the VRI. This assessment evaluates the consistency between the new NSYT dataset and the currently published provincial inventory information and helps identify differences arising from age treatments, interpolation methods, yield modelling assumptions, and inventory inputs. Chapter 7 evaluates the implications of using an R1-only projection approach by comparing polygon-level yields generated from the provincial NSYT methodology against yields produced using all eligible forest layers within a polygon. This analysis quantifies the differences between simplified R1-based projections and traditional multi-layer VDYP projections and provides an assessment of the extent to which the provincial NSYT approach reproduces polygon-level yields across the provincial land base. Collectively, these assessments provide confidence that the Provincial NSYT dataset is a robust, transparent, and operationally useful yield product suitable for a wide range of provincial planning and modelling applications.