The Schaffer Lecture was established in 1981 for the purpose of disseminating scientific information and achievement among forestry students, professional foresters, scientists and the public. The late Dr Schaffer, in whose honour the lectureship is named, played an important role in the development of industrial forestry in Hungary, his native country, and after 1940 in Canada. Initially, he worked for Pacific Veneer Ltd of New Westminster and in 1944 he was instrumental in founding Western Plywood Ltd, where he was executive vice president. Dr Schaffer felt strongly about the importance of scientific research in forestry, which he considered the basis of sound forestry practice, and this lecture series is a fitting memorial to him.
February 18, 2014 – 5:30 – 6:30 pm
Forest Sciences Centre, Fletcher Challenge Theatre #1005
Colden Baxter – Fire and ice: responses by stream-riparian ecosystems to shifting disturbance regimes and some consequences for forest management
Forests and streams are ecologically inseparable and are, therefore, coupled in their vulnerability to changing climate. Climate change is driving shifts in the dynamics of natural disturbances in forested watersheds worldwide, with consequences for stream-riparian ecosystems that are uncertain. For example, the frequency and severity of wildfires is increasing. Most studies have focused on short term effects of fire on streams, but understanding responses in the mid-term (5-15 years post-fire) is critical because as climate change shortens fire return intervals what had been envisioned as a “stage” in recovery is becoming characteristic of larger proportions of watersheds. Similarly, in temperate watersheds the dynamics of ice (ice cover and ice break-up events) are an important natural disturbance whose response to changing climate is poorly understood. In general, inter-annual variation in ice regimes may be increasing, and rivers that may historically have experienced a single ice break-up event can now have several in a single winter. Here I summarize findings from a series of studies that shed light on ecological responses to changing fire and ice regimes. By virtue of reciprocal flows of materials and organisms, these responses reverberate between land and water. Changes in a terrestrial disturbance like fire alters fluxes of light and organic matter to streams with consequences for aquatic organisms but, in turn, changes in emergence of adult aquatic insects influence terrestrial organisms like forest birds, bats and spiders. Likewise, changes in an aquatic disturbance like ice break-up can change habitat and alter sources of energy for aquatic organisms, but may also mediate shifts in predator-prey dynamics of terrestrial wildlife. In the face of changing climate, examples like these point to the need for diverse linkages between land and water to be a more explicit focus of the science and management of forested watersheds.
Dr. Colden V. Baxter
Stream Ecology Center, Department of Biological Sciences
Idaho State University
Dr. Baxter is an Associate Professor in the Dept. of Biological Sciences at Idaho State University. He grew up farming and ranching, principally in northwest Montana, and received his academic training in biology and geology (BA, Univ. Oregon), ecology (MS, Univ. Montana), fisheries science and philosophy of science (Ph.D., Oregon State Univ.), and ecosystem studies (postdoctoral fellowship, Colorado State Univ. & Hokkaido Univ., Japan). He teaches courses in freshwater biology, field ecology, and philosophy of science. Research conducted by Dr. Baxter and his lab group at Idaho State University’s Stream Ecology Center focuses on rivers and streams, but more generally on the ecological linkages between water and land. Reciprocal connections such as those between streams, floodplains, and riparian forests are critical to watershed ecosystems, and they couple land and water in their vulnerability to the agents of global environmental change. Research led by Dr. Baxter is aimed at improving our understanding of the basic nature of such connections and the consequences of their disruption by human activities, but also contributing to better-informed conservation and stewardship.