As Dr. Roy Rea spoke for the moose for they have no tongues, this past week Dr. John Rex spoke for the voiceless small streams affected by harvesting and development in Northern BC. Small streams are defined as those with bank full widths of less than 3m (classified as S3, S4 or S6); they can be perennial, ephemeral or intermittent. Despite their small size, they are important because they influence downstream conditions, provide migratory corridors, are the most sensitive to disturbance, and are numerous and encountered often during development.

Dr. Rex’s research involved the testing of the effectiveness of the minimum prescription of 10 stems (of merchantable timber >15cm DBH)/ 100m. This prescription aimed to meet two main management objectives: To maintain 50-75% background shade/to keep stream temperature constant, and to maintain the long and short-term supply of wood to streams. Regarding the first objective, shade levels were measured pre and post harvest and subsequent years after. The team found that 2 years post harvest, shade returned to nearly pre harvest conditions, however higher air and water temperatures were observed due to a change in stand structure around streams (pre: canopy, mid and ground; post: lower insulating canopy). The large wood supply objective was fulfilled depending on the species composition of the stream. Shorter trees like pine are more abundant near the stream, where as the taller spruce are farther away. The overall conclusion was that smaller buffers for small streams = less recovery, hence the necessity of having a 10m buffer. A particularly important takeaway was that there are no natural disturbances that remove all wood debris from streams. This is a salient point, and further argument for the idea that mother nature is the best forest manager, and our forest management practices should mirror natural processes as best as we can. Further climate change will exacerbate the problems already observed in these small streams. Dr. Rex’s final message was a plea for communication and collaboration between researchers, First Nations, Government and Industry. The only potential for change will come from a multi-faceted and holistic approach, where everyone is working together for the greater good.

I think Dr. Rex was an excellent presenter with the right amount of humour to keep the audience engaged. Jargon was minimized and I think that everyone understood the message. A question that arose during the writing of this blog post is; Are the 10m buffer zones just machine free zones (ie. Handfallers can go in and remove trees) or is it a total buffer?