Land and site selection

Sourcing project sites can be a challenge depending on how you are developing your tree planting program. You may already have land identified for a project underway and are looking for funding to implement it, or you have a program or project in the planning stages and are looking for suitable sites to support your program goals. Either way, it is important to understand that every site has a different history, and so your objectives, appropriate species, site preparation and even long-term maintenance will stem from the first site visit that you carry out.  

Your project will have a higher success rate if your site visit is comprehensive, where each step is described in detail early in the planning stages. Your tending and maintenance plan will rely substantially on the species and stock type you decide to plant, which are determined directly from the information collected in your site visit. It is also important that you evaluate whether the site you’re visiting is suitable for planting trees, keeping in mind that not every site is suitable for tree planting (Brancalion and Holl, 2020)^[1].

All forests were created from some form of disturbance and a moderate amount of disturbance is what keeps forests in a healthy dynamic state (see the intermediate disturbance hypothesis, Connell (1978)^[2]. Forest disturbance varies across Canada, with insect damage and wildfire making up the majority. Other disturbance types include windstorms, flooding, ice storms, and drought. Often, you will see more than one disturbance in any given forest. For beginner project managers, it is recommended to acquire a basic working knowledge of forest ecology before beginning any tree planting operation. Knowing the basics about forest establishment, tree competition, stand dynamics and succession, tree growth and overall forest ecology will only serve to enhance the success rate of your project.

You will need to plan ahead for the seasonal timing to plant your trees for the greatest success of your project.  The season you decide to plant your trees in depends on nursery stock and your staffing capacity, but if your nursery is flexible on seasonal timing for your planting and you have the staffing, the most influential site-based factors are soil texture (clay soils will heave after freezing), temperature and water availability. Trees planted in the spring will benefit from water availability from snowmelt and will be planted at the time of year when the trees are most focused on aboveground leaf growth and photosynthetic processes will accelerate. On the contrary, trees planted in the fall will benefit from cooler temperatures and the tree’s energetic allocation will be focused more on the belowground structures like the fine and coarse root structures as the leaves start to senesce and fall to the ground. As long as you have a 6-week window after planting with warm soils for roots to establish into the new site, fall planting can be just as successful as spring. Summer plantings can also take place in certain sites, but the nursery must be providing you with hotlifted stock and also plan for water availability on-site during and after planting if possible.

Conifer species are used more often in tree planting projects in Canada for several reasons. Pine, spruce, and fir are the most commercially valuable trees in the forest industry, and therefore are readily available at tree nurseries. They are also natural pioneer species, making reforestation with these species follow natural succession patterns. Hardwoods are more complex when considering species selection, because of the seed sourcing, stock types available, site preparation, tree planting and tending limitations. Hardwoods are also more palatable to browsing wildlife like deer and other mammals, so they often experience higher levels of herbivory than conifers and therefore sometimes need interventions like fencing, guards or wildlife repellant. 

If you are planning to integrate a species-at-risk into your planting prescription, be sure to consult the recovery strategy for that particular species. Ensuring the provenance and quality of seed used in the establishment of species-at-risk is important so that the population is being supported according to best practices. 

Historically, non-native species were planted across Canada as ornamental trees or in an effort to overcome poor environmental conditions such as soil structure loss and desertification. Some introduced species have become naturalized and do not pose a risk to local ecosystems (e.g. Norway spruce has been widely naturalized in Ontario), but others became invasive and spread into nearby native environments threatening the ecosystem health of the region. Speak to a local forester or traditional knowledge keepers in the area about whether a particular non-native species has an invasive habit in that area before introducing it to the ecosystem. For more information on invasive species for the area you’re planting trees, consult the local government and NGO resources. The Canadian Coalition for Invasive Plant Regulation (CCIPR) provides comprehensive Canadian Invasive Plant Lists wherein you can reference provincial resources for invasive species.