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Introduction

Preface

The New Brunswick Gene Conservation Working Group was formed in 1997. The goal of the group is to develop gene conservation strategies for native New Brunswick trees and shrubs. The first step in achieving this goal was to identify which species require attention and may need a gene conservation strategy. This was done by assessing a number of factors for each species. For example, 1) is the species rare; 2) is there a serious threat from disease or insect pests that will impact this species; 3) is the preferred habitat of the species in great demand for other uses?

This guide does not list all native New Brunswick tree and shrub species; rather, it lists 26 species that may require gene conservation strategies. This guide is intended to help identify these species and to increase awareness of the importance of these natural resources.

The information used to evaluate whether a species requires conservation attention was taken from a wide variety of sources (forest inventory databases, historical information, and herbaria) and in consultation with woodlot owners, conservationists, and people from industry and provincial and federal forestry agencies. This list is not static; it will be constantly evolving, with various species being added and removed.

What is a gene?

A gene is an information-containing element that is made of deoxyribonucleic acids (DNA) and occupies a specific position on a chromosome. Genes are the hereditary units.

What is conservation?

Gene conservation is the preservation of the hereditary unit, a gene. This type of conservation is usually accomplished through the planned management of natural resources. This allows for the retention of natural balance, diversity and evolutionary chance in the environment.

What is a Species?

Species is often considered the basic unit of biological classification, falling below the classification of genus. For example, red spruce and black spruce are two different species in the spruce (Picea) genus.

What is a Population?

Population refers to a group of organisms of the same species living within a sufficiently restricted geographical area where any member can potentially mate with any other member.

What is the Range of a Species?

The range of the species is the geographical area (distribution) in which the species can be found. Typically range maps show where a species grows naturally. The exact boundary of a species range is often unknown.

What is a Hybrid?

For the purpose of this guide a hybrid is a plant resulting from a cross between parents that are not genetically the same. These parents can be different species, resulting in hybrid offspring. For example, black spruce pollen can fertilize red spruce ovules (precursors to seeds). The seed that is formed is a hybrid of the red and black spruce and this seed can germinate, producing a red x black spruce hybrid seedling. This red x black spruce hybrid has the genes of both species (parents). Hybridization is a term used to describe the process that produces hybrids.

What is Introgression?

One type of hybridization is introgressive hybridization, where the genes of one species are incorporated into the genes of another species. For example, if the range of two species, such as red and black spruce, overlap and fertile hybrids are produced, these hybrids will backcross (that is a cross of the hybrid to either red or black spruce) with the more abundant species in the range. This process will result in a population of individuals most of whom resemble the more abundant species (e.g., black spruce) but who also possess some characteristics (genes) of the other species (e.g., red spruce).

What is Rare?

Rare is a difficult term to define, because rarity cannot be quantified. It suggests that a plant species is uncommon, few in number or part of a small, scattered group. When referring to rarity, it is the scale that is important. For example, a species may be rare in one of its many populations or it may be rare in its geographical range. We are using rare in the context that a species is represented by a single population or that it may be few in number in its populations, geographical range, or in its habitat.

What is a Species of Concern?

In order to determine which tree and shrub species are at risk, we developed screening criteria. For a species to be considered at risk and in need of conservation measures, ‘yes’ had to be the answer for at least one of the following questions.

¹Criteria value
²Rating value