Open Collections

Nelson, Hillary; English, Paul; Sarang, Puneet

The expansion of trail networks in parks may threaten understory plant diversity and ecosystem function. As trails become denser, edge effects from human trampling and dog activity can impact these plant communities to a greater extent. However, the specific impacts of human and dog-related disturbances on understory vegetation remain poorly understood. This study examines how plant community structure, including percent cover, abundance, and diversity, varies with distance from recreational trails under different dog-leash regulations. We conducted understory plant surveys, analyzing percent cover and diversity along four 18-metre transects, placed perpendicular to two trails in a popular urban park, where one trail was leash-required, and the other, leash-optional. We predicted plots closer to the trail would have a lower Shannon Diversity Index than plots further from the trail. Additionally, the relationship between species diversity and distance from the trail will be steeper on the leash-required trail than on the leash-optional trail. Our results showed a significant increase in total percent cover with distance approximately 10 metres from the on-leash trail, while at distances greater than 10 metres, there was a significant decrease in total plant cover. The initial increase in total plant cover up to ~10 metres from the on-leash trail may reflect reduced trampling or moderate disturbance that promotes plant growth. However, the subsequent decrease in cover beyond 10 metres could suggest a shift in environmental conditions or competitive dynamics away from the trail edge. We observed a significant increase in phylogenetic diversity with distance from the off-leash trail, which could suggest that dog activity near the trail may filter for closely related, disturbance-tolerant species, thereby reducing evolutionary diversity in those areas, but only for off-leash trails, contrary to our prediction. However, on-leash trails had no significant patterns in phylogenetic diversity with distance from the trail, but did have a significant relationship with total percent cover with distance from trail. This may indicate that leash policies are successful in reducing dog disturbances, but without these disturbances, understory diversity could be lower in some areas. Although our results were limited by sample size, and we were unable to tease apart the influences of confounding environmental variation, our findings indicate the importance of incorporating both human and dog disturbance into conservation planning. Future studies should consider temporal monitoring, finer-scale abiotic controls, and genetic analyses to better understand these dynamics.

Text

University of British Columbia. BIOL_V 406

Vancouver : University of British Columbia Library

10.14288/1.0448886

Science, Faculty of; Botany, Department of; Zoology, Department of

Undergraduate

DSpace