Mammalian Herbivory | Boreal At Memorial

Herbivory by the Moose and Hare

In the Boreal Forest, browsing by mammalian herbivores can have a significant impact on forest structure, especially in areas where populations of browsers are high. Moose and Hare are particularly well known for their role in changing the forest landscape by selectively foraging on certain species of trees.

An over abundant population of moose on the island of Newfoundland has been the cause of concern for several forestry officials in the area. In response to the large number of Moose, a cull has been implemented in Gros Morne and Terra Nova National Parks in the last two years, areas that are normally forbidden to hunters. In 2010 it was said that there were 4500 to 5000 moose on the west coast of the island and that a cull of 3500 to 4000 would be need in Gros Morne National Park to keep the moose population under control. Parks Canada says that the moose have been eating too many young trees and that the cull is necessary for the preservation of fragile forest land.

Mammalian herbivory is generally regarded as an important factor in the nutrient cycling process in the Boreal. Litter from browsed plants are found to have higher nutrient concentrations and faster decomposition rates. However, dense moose populations such as those found on the island of Newfoundland can have severe negative effects on forest regeneration after a disturbance such as fire or insect outbreaks. In areas such as Terra Nova National Park, the dense moose population has almost completely eradicated an entire Balsam Fir forest during the regeneration process after a Spruce Budworm outbreak.

A moose browsing Balasm Fir in Gros Morne National Park, Newfoundland and Labrador, Canada. Photo from Ronin Photography.

Left: Moose prefer to eat Willow and Birch but in the Boreal where such deciduous trees are uncommon a large part of their diet is Balsam Fir. Photo from nlstuff.com

Right: Snowshoe Hare also prefer to eat Willow and Birch but eat Black Spruce as well. Photo from www.123rf.com

Our own research shows that over-abundant Moose populations have a detrimental effect on Balsam Fir forest regeneration.

References

Moose Cull Planned in Newfoundland Parks. Prince George Citizen [Prince George] 12 Jan 2010, pg. 7

Browse Control. The Long Term Ecological Research Network. 2012. University of New Mexico. 22 Nov 2012. http://www.lternet.edu/research/keyfindings/browse-control

Moose Cull Begins in Two Newfoundland National Parks for Second Consecutive Year. Canada.com. 2012. Postmedia Network Inc. 22 Nov 2012. http://o.canada.com/2012/10/09/moose-cull-begins-in-two-newfoundland-national-parks-for-second-consecutive-year/

Burgerud, A.T. and Manuel, F. (1968). Moose Damage to Balsam Fir-White Birch Forests in Central Newfoundland. The Journal of Wildlife Management. 32(4). Pp. 729 - 746

In this course we studied two areas that were affected by the last major outbreak of the Spruce Budworm in the 1970’s. One are was in Pippy Park which had a relatively low Moose population due to the close proximity of the St. John’s, NL metro area. In Pippy Park we found that the Balsam Fir forest was regenerating as normal with a very dense population of healthy saplings. In stark contrast, the other area we studied; Terra Nova National Park is located in a rural area of Newfoundland. The dense population of Moose in this area has all but completely wiped out the regenerating Balsam Fir, making it difficult to find a single healthy Fir seedling.