Earth Partnership for Schools

WOODLAND RESTORATION INTERACTIVE WORKSHOP > HOW TO RESTORE WOODLAND AT YOUR SCHOOL > STUDY THE SITE > INVENTORY EXISTING WOODLAND

 

Introduction

If you are planning a woodland restoration, one of the first steps is assessing the vegetation currently present at the restoration site. This information gives you the starting point for the restoration and is the basis for the restoration plan.

 

Tree inventory

An inventory of trees on the site provides useful information that will help you to answer some of the following questions:

  • How many different species of trees are on the site?
  • Is the site dominated by native trees or by exotics?
  • Are there unwanted trees that need to be removed from the site?
  • Are there native trees missing from the site that need to be added?
  • What size(s) of trees are on the site?
  • Are important native species present as larger, older trees, and/or as small, younger trees?
  • Is the density of trees appropriate?

 

The inventory is done by recording the species name and DBH (diameter at breast height) of every tree in a series of quadrats located along a transect (line) across the site. Record your data on data sheets which can be found at the bottom of the Tree Inventory Activity page. Standard size for each quadrat is 10 m x 10 m, but this size can be adjusted as needed to meet your situation.

 

Shrub/Ground Layer Inventory

The inventory of the shrub and herbaceous ground layer will answer some of the following questions:

  • How many different species of shrubs and herbaceous plants are on the site?
  • Are native or exotic species growing on the site?
  • What is the cover of the individual ground layer species?
  • Are native plants missing from the site that need to be added?
  • Are there any patterns or associations, (i.e., because of sun/shade, change in soil or topography, specie to specie) evident in the understory?
  • Has the ground layer been adversely affected by trampling?
  • Where are there areas with educational or esthetic value.

 

The inventory of the understory on the site can be accomplished using one of four different sampling strategies. Choose the method that best meets your needs at the present time. Whatever method you choose, be aware that an inventory will need to be compiled once in the spring then later in the year. This is because some of the woodland plants are ephemerals. Ephemerals appear, blossom and fruit before the trees leaf out, then disappear from sight.

 

The four shrub/ground layer sampling methods are:

  • A Species list: Compile a list of the understory plants that you observe during a walk-through of your site.
  • Transect sampling : Run transects through the site and record what species are growing at predetermined intervals on the transects. This method is useful for studying patterns along a gradient. The length of a transect varies. Ten meter line transects with one meter intervals is a reasonable length for students to work with.
  • Quadrat Sampling: List species present in a defined area. Quadrat sampling is similar to the tree inventory sampling method. This approach provides the means to measure frequency and the abundance of species.
  • Visual Estimation Quadrat Sampling: This method of sampling involves listing the species present and estimating the space they cover. The two choices for recording data are:
    1. Map all species in a quadrat showing approximate cover of each species.
    2. List species present and estimate the area covered in a quadrat. Cover may be recorded as fractions or percentages. Random individuals are only listed.

 

The following is a field sheet showing comparison diagrams for visual estimation of percent cover:

Percent Cover Field Sheet