Introduction

Background

Urban forests provide the residents of the cities with many benefits including sequestration of gaseous pollutants and particles; energy conservation; noise buffering; provision of wildlife habitat; storm-water attenuation; and increased aesthetic and property values (1-15). These benefits are directly or indirectly related to the leaf area of plants; particularly trees and shrubs, which comprise the forest cover in urban areas (16).

In turn, management and enhancement of the urban forest resources is necessary to alleviate the effects of urban sprawl. Management decisions to enhance the urban forest resources require information about the abundance and health, as well as the potential to increase the green cover.

To facilitate planning and decision making regarding the increase of the urban canopy cover, measurable criteria such as Leaf Area Density (LAD) Potential Leaf Area Density (PLAD) are developed (16). Several research projects aimed at assessment and quantification of LAD and PLAD have been implemented in various parts of North America. For instance, Kenney (2008) (17) assessed PLAD for the City of Toronto. Wu et al. 2008 (18) investigated suitable tree planting sites in the City of Los Angeles. Urban Forest Effects (UFORE) model (19) implemented by the United States Department of Agriculture (USDA) Forest Service in several urban areas in North America, is a good example of how the relation between urban forest cover and the environmental variables such as air contaminant emissions can be investigated.

Introduction

Rationale and objective

Arundel et al (2006) used a remote sensing methodology to quantify vegetation cover in the City of Vancouver (20). Although, their study was focused on downtown area, the maps they produced show lower vegetation cover for the East Side, compared to the other parts of the city. While this methodology can be applied to obtain a current understanding of the urban vegetation cover of the City of Vancouver, the information about canopy cover is not currently available among the public GIS data of the City of Vancouver. In particular, ground based assessment of the existing urban forest cover, or information about potentially suitable locations to increase tree cover are not widely documented.

This project proposes a survey design to quantify such information. At this initial stage, the focus is placed on the East Side Vancouver. With the growth of the city, it is likely that the City of Vancouver's emission profiles would differ from its existing levels in the near future. Hence, it is important to have information about the urban forest cover available for any decision to enhance the urban forest resources.

The primary objective of the proposed survey is the estimation of potential leaf area density. Using the survey plan, additional objectives can be: 1) to provide a current estimate of tree cover; 2) to measure tree and shrub species diversity; 3) to record the state of urban forest health; 4) to collect data from non-vegetation components of the city such as impervious systems; 5) to incorporate environmental variables to study in relation to the urban forest cover.