Tag: A3 Trends in Restoration

PM Session Oral Presentation

The 2012 Environmental Leadership Program (ELP) is divided into six teams. The Stream Stewardship Team has devoted our efforts to the restoration and enhancement of McKenzie River side-channel ecosystems. In recent years, declining salmon populations have peaked both political and social interests in the Pacific Northwest. Our restoration efforts have been focused on the rejuvenation of Coho salmon spawning grounds and surrounding habitats in the McKenzie River side channels. Habitat enhancement methods includ- ed the placement of large woody debris, propagation of native plant species, and removal of invasive vegetation. We have monitored previous ELP management in order to assess the effectiveness of riparian restoration at this site. Our results indicate a significant de- crease in invasive vegetation and a high survival rate of planted native species. Furthermore, in-stream restoration efforts have proven successful in creating pools and sediment gradients beneficial to salmon spawning habitat. Management of the McKenzie side channel site has proven largely successful and could potentially be adapted to other locations in future restoration projects.

This experiment explored stomata densities of the epiphytic Pleurothallis aristata and Maxillaria sp. orchids under experimental conditions of dry and humid environments. Pleurothallis aristata is in the sub-tribe Pleurothallidinae and lacks pseudobulbs, while Maxillaria sp. has pseudobulbs. The purpose of the experiment was to test if there was a difference in stomata densities between the two species, and if there was a difference in mean percent stomata open in humid and dry environments. Stomata impressions were taken from the leaves of twenty individuals of each species using clear nail polish peels that were examined under a compound microscope. The results show that there is a significant difference in stomata density between the Pleurothallis aristata and the Maxillaria sp. (Rank Sum Test, t=55, n1=10, n2=10, p<0.05). The results also show that both species had a higher percentage of open stomata in humid environments than in dry environments (Wilcoxon sign rank test). An explanation for these results is that Maxillaria sp. has a pseudobulb for water storage, has a larger leaf surface area, and therefore has higher stomata density. Both species would also close their stomata in drier conditions in order to reduce water loss and desiccation. This research is significant because it relates to problems such as climate change and shifting of biomes, as some species may be more likely to succeed in periods of prolonged drought or less humidity.