Deterministic Models of Growth and Mortality for Jack Pine in Boreal Forests of Western Canada

Vlad Strimbu,Mike Bokalo,Philip Comeau

doi:10.3390/f8110410

Abstract

We developed individual tree deterministic growth and mortality models for jack pine (Pinus banksiana Lamb.) using data from permanent sample plots in Alberta, Saskatchewan and Manitoba, Canada. Height and diameter increment equations were fitted using nonlinear mixed effects models. Logistic mixed models were used to estimate jack pine survival probability based on tree and stand characteristics. The resulting models showed that (1) jack pine growth is significantly influenced by competition; (2) competitive effects differ between species groups; and (3) survival probability is affected by tree size and growth, stand composition, and stand density. The estimated coefficients of selected growth and mortality functions were implemented into the Mixedwood Growth Model (MGM) and the simulated predictions were evaluated against independently measured data. The validation showed that the MGM can effectively model jack pine trees and stands, providing support for its use in management planning.

Highlights

Jack pine (Pinus banksiana Lamb.) is the most widely distributed pine species in Canada’s boreal forest, with a geographical distribution from Alberta to Nova Scotia
The data used for this study covered a large area across the western Canadian boreal forest (Figure 1), with 422 permanent sample plots located in the provinces of Alberta, Saskatchewan and Manitoba
Parameter estimates and asymptotic standard errors were obtained for both diameter breast height (DBH) and height increment models (Table 2)

Summary

Introduction

Jack pine (Pinus banksiana Lamb.) is the most widely distributed pine species in Canada’s boreal forest, with a geographical distribution from Alberta to Nova Scotia. Together with other pine species, it accounts for 2.67 × 109 m3 of growing stock, more than 11% of the Canadian boreal tree volume [1]. It is an important source of round timber, construction lumber and pulpwood [2]. Numerous factors influence the growth and mortality of jack pine. Soil type can affect regeneration indirectly [8] and influence growth responses to climate [9] or control the mixing with aspen [10]. High intensity fires can hinder regeneration [11], but medium intensity fires increase tree diversity and delay replacement by other species [12]. Pre-commercial thinning and fertilization improves tree growth [13,14], with the largest effect being observed for young trees [15] and represent potentially viable silvicultural investments [16]

Objectives

Methods

Results

Discussion

Conclusion