To ensure park ecosystems are healthy we need to know how their components and processes are changing over time. This is done through Ecological Integrity (EI) Monitoring.
EI Monitoring provides park managers with critical information on ecosystem health.
Over the past century, the forests of Terra Nova National Park have experienced several stressors that have impacted its ecological integrity.
- Fires, a natural forest ecosystem component, have been suppressed thus affecting forest regeneration.
- New species have been introduced to the Island of Newfoundland, causing a shift in native plant and animal populations.
- The native Newfoundland Marten had disappeared from most of the Island, including the forests of Terra Nova National Park.
Documenting change over time allows park managers to guide and assess management decisions in the maintenance and restoration of ecological integrity.
Pre- and post-monitoring of prescribed burn sites informs us on how forests looked before fire and how fire helps them to regenerate. Fire opens up the forest canopy, allows light to get in, creates growing space and returns essential nutrients to the soil.
Post prescribed burn © Parks Canada
Annual aerial surveys assess moose population numbers. © Parks Canada
Moose Exclosure© Parks Canada
These moose exclosures were erected in an insect- disturbed area in 1991. Today, the area inside the exclosures has shown significant growth. The area outside continues to be browsed by moose, preventing tree regeneration.
Over-browsing by moose on balsam fir and hardwoods is preventing forest regeneration. In a healthy forest, regeneration continually creates trees of various ages—from new seedlings all the way up to mature trees. This variety provides a diversity of habitats, as well as young trees to replace mature trees as they die. The browse pressure on saplings is measured to indicate the severity of impact, as well as the number of trees likely to make it to maturity and replace the forest canopy.
Within randomly selected plots in Terra Nova National Park, balsam fir saplings and hardwoods are counted to determine the proportion that has been browsed. Plots are considered healthy if fewer than 20% of stems found within the plot are browsed. With normal sapling densities, this proportion would allow enough individual trees to escape browsing pressure and replace the forest canopy.
The data found thus far shows that browsing pressure on balsam fir and hardwood trees in Terra Nova National Park is much greater than in a healthy forest.
The majority of the park’s balsam fir/mixed hardwood forest stands remain in poor condition due to stress associated mainly with moose browsing. It is hoped that reducing moose numbers will allow more saplings to escape browsing pressure and result in improvements in forest health over the coming years.
Species at Risk
Parks Canada staff use "mark-recapture" surveys each year to monitor the population of the Newfoundland Marten.
© Parks Canada
Parks Canada staff use “mark-recapture” surveys each year to monitor the population of the Newfoundland Marten. Marten are tagged and released to determine success in re-establishing marten populations in forests in and around Terra Nova National Park.
Protected areas like Terra Nova National Park offer critical habitat for species at risk. Terra Nova National Park is home to several species at risk, including the Newfoundland Marten (Martes americana atrata), the Red Crossbill (Loxia curvirostra percna) and the Boreal Felt Lichen (Erioderma pedicellatum). Through ecological monitoring and partnerships with researchers, Parks Canada is able to keep track of how these populations are evolving.