Open Collections

Cruz, Arleen; Fung, Vivia; Lu, Stephanie; Tavakol, Setayesh

Ecological disturbances such as logging and fire can lead to long-term modification of forest ecosystems through changes in soil conditions and species composition. Forest community assembly trajectories may differ between these disturbance types and between disturbance severities, but whether divergence in community structure can occur in a temperate rainforest ecosystem and how long these effects last is not fully understood. Therefore, we compared understory vegetation in two separately disturbed parts of Pacific Spirit Park, one site being clear-cut, and subsequently burned in 1910, and one selectively logged before 1930. Using a quadrat sampling method, we gathered percent coverage and plant species diversity in 20 quadrats and used these measurements to compare diversity and species composition between sites. We compared data using t-tests, F-tests, and graphs in RStudio. We predicted that the selectively logged area would have higher species richness and abundance since seed sources and soil quality may have been preserved due to lower disturbance severity. However, our results did not support this. The clear-cut & burned site contained higher species richness (10 species vs. 6), greater Shannon diversity, and more compositional variability. Polystichum munitum was significantly more abundant in the clear-cut & burned site, and PCA indicated distinct species composition along PC2, with P. munitum and G. shallon associated with burned plots. Several species exhibited significant differences in abundance variability. These results suggest that at large time scales, temperate rainforest ecosystems may be able to rebound to similar levels of diversity regardless of the initial intensity of disturbance. Limitations such as small sample size, non-random sampling, and exclusion of environmental covariates may have affected our findings. This study highlights the importance of long-term monitoring and comprehensive ecological assessment to better understand forest resilience and guide management practices in the face of increasing disturbance frequency from anthropogenic pressures.

Text

University of British Columbia. BIOL_V 406

Vancouver : University of British Columbia Library

10.14288/1.0448972

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

Undergraduate

DSpace