Trail Running Impacts
By Jennifer Dick, Manager of Interpretation, Royal Botanical Gardens.
I’ve been a hiker since I could walk. Exploring new trails to see different landscapes, learn to identify new plants, and observe wildlife is one of my absolute favourite things to do in my spare time and on holidays.
I started running several years ago and it’s something I’ve also grown to love. The idea of running along beautiful trails and landscapes seemed like a perfect combination. Yet, I’ve felt a niggling of doubt as to whether it really is the best way to experience nature, especially in protected areas.
Here at Royal Botanical Gardens, our trails are built for passive recreation like hiking and birdwatching and running is not permitted on any of our trails. But why is that?
It turns out that trail running has some pretty big effects on the trails and the surrounding ecosystem. A 2018 study in Hong Kong compared a trail after a running event with a similar trail used for hiking.1 The researchers found six major impacts on the running trail: tread width, tread incision, surface composition, soil compaction, soil texture, and aggregate size. There was significant widening and deepening of the trail. The soil was coarser and more compacted. More roots were exposed, and leaf litter disturbed. There were more rills and gullies. The study found that while the impacts of hiking on a trail are similar to running, the intensity and rate of impacts with trail running are considerably higher.
Another recent study in Spain discovered that running trails experience extremely high rates of erosion.2 The trails had higher erosion than bare agricultural soils, or soils after forest fires and extreme rainfall events. These results are unsurprising given the findings for the study in Hong Kong regarding soil compaction and texture changes. The result of both of these studies also make sense given that the force of running feet is considerably higher than those walking.3 Extra force on push off, and the impact of gravity and your personal mass as you land mean that the force exerted by running feet is considerably higher than when those feet are walking. More force means more compaction.
Why does that matter? Well, all those trees and understorey plants that are giving you a great dose of vitamin-N(ature) on your run have roots that extend along the trail edge and even under the trail. Too much compaction, pressure, and erosion will stress and even kill them. An important component of healthy soil is the space in-between the soil particles. Plants need these spaces for root growth as well as gas exchange when they ‘breathe’. Compress the soil, drive out the air and moisture and the roots will soon die. Without the root ecosystem to bind it, the soil will erode. The plants near the edge of the trail will die back, and the trail will widen from use. Once the tree canopy opens, sun-loving invasive species will be able to find a niche into in the forest. The extra erosion also impacts frogs, fish, and turtles as sediments are washed into our wetlands.
Now that I know the impacts, I’m pledging to do my part and stick to hiking on RBG trails since those trails are through sensitive habitats with species at risk. Trail running is permitted in other areas in our region though so here are some tips to have a great run in a responsible way.
1. Do your research
If there is a trail you are eyeing for a run, do a quick search online to see if running is permitted there. Multiuse trails are usually a safe bet. Some are paved but there are quite a few that aren’t if you are looking for the feel of the earth under your feet. Remember, if you live in the Golden Horseshoe, there are thousands of people using the same trails as you each week. Hundreds may be runners and if you are running on narrow, earthen trails, you’re part of the challenge to the sustainability of these fragile landscapes. Choose wider trails that are managed for heavy use, where the soil surface is protected by woodchips or gravel and overland water flow is managed.
2. Stick to middle
To minimize trail widening, run in the middle of the path as much as possible. That means getting your feet mucky and going straight through a puddle or two. This also helps limit the spread of invasive plants since your treads won’t be picking up their seeds along the trail edges.
3. No shortcuts
Stick to the trail to protect the landscape and avoid trampling sensitive plants or disturbing ground nesting birds. If you run with a dog like I do, keeping them on leash also minimizes disturbance and the spread of invasive seeds. There are plenty of species at risk in our area, both animals and plants, that do better without more habitat fragmentation and disruption.
4. Clean your treads
Invasive species often make their way into trail systems on footwear, so if you are trying out trails in a different area, make sure to first give your soles a cleaning to remove clumps of dirt that may contain seeds.
5. Leave nothing behind
Pack out everything you bring with you and if you can, take out an extra piece of trash that you spot along the way.
6. Give back
Support the organizations that maintain the trails you love. Get a membership, make a donation, or consider volunteering to help with trail cleanups, invasive species pulls, or planting native species.
I hope you enjoy your next hike at RBG and if you know a good trail elsewhere that is designated for running, let me know. I hope to see you out on the trails!
1 Ng, Sai-Leung, Yu-Fai Leung, Suet-Yi Cheung, and Wei Fang (2018). “Land degradation effects initiated by train running events in an urban protected area of Hong Kong.” Land Degradation & Development, vol 29, no 3, pp. 422–432
2 Salesa, David, and Artemi Cerdà (2019). “Four-year soil erosion rates in a running-mountain trail in eastern Iberian Peninsula.” Geographical Research Letters, vol 45, no 1, pp 309–331
3 Ho, I-Ju, Yi-You Hou, Chich-Haung Yang, Wen-Lan Wu, Sheng-Kai Chen, and Lan-Yuen Guo (2010). “Comparison of Plantar Pressure Distribution between Different Speed and Incline During Treadmill Jogging.” Journal of Sports Science & Medicine, vol 9, no 1, pp 154–160