In this randomly selected, typical aerial view of Crown forest on Quadra Island, the permanent, ballasted logging roads occupy 8.2 percent of the area of the recent clearcuts.
LOGGING IN BC has required the construction of an extensive, expensive road network. At approximately 700,000 kilometres long, these industrial-duty roads have gouged out a vast area of previously productive forest and covered it over with blasted rock and gravel. The public has paid for these roads through reduced stumpage payments. They’re poor, if not impossible places for trees to grow and have a wide range of further negative impacts.
In BC, logging roads and landings are allowed to occupy up to seven percent of the area of a cutblock, but the actual loss may be higher.
A recent report at The Narwhal by Sarah Cox described a study in Ontario that examined the extent of such forest loss in that province. Cox reported that researchers there found “logging scars created by roads and landings…occupied an average of 14.2 percent of the area logged.” So our province’s seven percent restriction could well be an underestimation of the forest base that’s being lost. But let’s use seven percent and calculate how much forest has been lost.
Sierra BC’s recent report, Clearcut Carbon (document at end of story), put the total area logged in BC between 2005 and 2017 at 3,597,291 hectares, which included private land on Vancouver Island.
If seven percent of that area was covered with roads and landings, the area of forest lost over that 13-year period would be 251,810 hectares. That’s an area larger than Vancouver Island’s largest protected area, Strathcona Park.
Besides the sheer amount of forest lost to logging roads, road building results in many negative, sometimes cascading consequences for wildlife, aquatic health, and the ecological integrity of the forest.
You cannot build a road without compacting soils. Soil compaction, which can last for decades, restricts root growth and greatly minimizes the nutrients available to vegetation in these areas. Soil compaction also reduces the oxygen and water available to vegetation and negatively effects the microorganisms found in the soil.
The loss or disturbance of organic layers that is also a consequence of building these roads, affects mycorrhizal fungi, which are important to many tree species in accessing nutrients. Damage to the fungi network can lead to trees suffering from moisture stress and reduced growth rates; to difficulty getting seedlings established; to negative impacts for long-term forest resilience.
Increased, excessive rates of soil erosion are another consequence of logging roads. The erosion leads to sedimentation of nearby water courses, thereby impacting the aquatic systems of the forest. Because roads break up the existing soil and remove the ground cover that assists in the natural distribution of rainfall and runoff, high volumes of sediment flow into these watersheds. Aquatic species dependent on clean, clear water are naturally impacted.
We know that the survival rates of many fish species significantly decrease as fine sediment levels increase. Deposited on the stream bed, fine sediment degrades spawning areas, reduces pool refuge habitat, decreases winter refuge areas for juveniles, and impedes feeding visibility.
Likewise, sensitive amphibian and invertebrate species are also adversely affected by increased sediment loads, decreasing in abundance and diversity as sediment levels rise.
Because invertebrates, amphibians, and fish are important prey species for many mammals, birds and bats, these too are affected by logging roads. The whole biological integrity of the forest is thereby impacted.
The construction of logging roads can also change natural streamflow patterns and alter stream channel morphology. Roads, ditches, and newly created gullies form new, large networks of flow paths across the landscape. These logged areas sustain much higher discharge volumes after a storm event than they ever did when the forest was intact—and have proven far more likely to suffer from major landslides and erosion events (which again deposit abnormally high levels of sediment into area streams).
Fragmentation of the landscape is also a problem stemming from the building of roads. Roads function as barriers for wildlife dispersal and migration. Many species are unable to cross these barriers and therefore have their range and distribution altered, often leading to drastic consequences on a local scale.
Finally, logging roads, in allowing humans greater access to previously inaccessible landscapes, increase the risk of forest fires—humans are the cause of a significant portion of forest fires. The accessibility also allows for the introduction of non-native species, dramatically altering the natural balance of the forest ecosystem. Roads also serve as vectors for the spread of disease by allowing easier access for a potential threat than would otherwise exist.