Environmental Sciences Seminar Series Abstracts
Dr. Melanie Jones
Date: January 19, 2012
Title: An alternative view of ectomycorrhizal function: the role of ectomycorrhizal fungi in nutrient cycling and the effect of anthropogenic and natural perturbations
Abstract: Most plant biologists and forest managers view ectomycorrhizal fungi through the lens of mutualist symbiont to trees. From this common phytocentric point of view, ectomycorrhizal fungi are studied, valued and managed based on their role in improving the nutrient status of their host trees and facilitating seedling establishment. Another important role of ectomycorrhizal fungi, one that is less commonly considered, is their role in nutrient cycling in forest soils. This presentation will describe evidence that ectomycorrhizal fungi play a major role in nutrient cycling by producing some of the hydrolytic and oxidative enzymes involved in the depolymerization of soil organic matter. I will discuss how various forms of anthropogenic and natural perturbation affect the ability of ectomycorrhizal fungal communities to carry out this important ecosystem function.
Dr. Paul Handford
Date: January 26, 2012
Title: The ecology of cultural variation in a South American sparrow
Abstract: The Rufous-collared sparrow, Zonotrichia capensis, is a common and widespread South American songbird. Like its North American cousin, the White-crowned sparrow, this bird shows substantial geographical variation in its learned song, often organised in space as distinct local forms, called "dialects". This talk will introduce the bird & its dialects and describe what we've found out about their significance.
Dr. Jason Pither
Date: February 2, 2012
Title: Drivers of stochastic and deterministic community assembly: insights from forests, shrublands, lakes, and computers
Abstract: A common theme in our Biodiversity and Landscape Ecology Research Facility is an interest in identifying why stochastic and deterministic assembly processes vary in their relative importance among ecological communities. We are especially interested in isolating the unique influences that landscape or regional factors have on local community assembly. This seminar will provide an overview of our research that addresses this issue, including: (1) Using thousands of standardized vegetation survey plots associated with BC's Biogeoclimatic Ecosystem Classification system (BEC), we are quantifying how landscape complexity (e.g. topographic heterogeneity) influences variation in plant species composition among otherwise environmentally similar sites. (2) Using spatially-explicit metacommunity simulations, we are discovering that the spatial patterning of environmental conditions in the broader landscape can interact in sometimes surprising ways with dispersal rate and capacity to affect local community assembly.
Dr. Garth Mowat
Date: February 16, 2012
Title: The relationship between population dynamics and habitat use of terrestrial carnivores
Abstract: Most jurisdictions use population size as the most common metric to assess wildlife health while considerable research, many conservation decisions, and much on the ground effort is focused on habitat used by individuals in those populations. While the connection between animal populations and the place they live-habitat-is obvious at the coarsest view, there are few documented functional connections between animal population size and the habitat they chose. Applied habitat studies tend to be descriptive in nature and measure a convenient metric of habitat quantity against some measure of choice of the individual animal. This choice is most often a behavioural decision and the researchers often then assume that a habitat that is chosen by an animal is important or even required. This assumption is rarely tested.
Remote methods of sampling animals, especially those involving genetic identification of individuals, have allowed researchers to sample carnivores at much larger scales than previously. It is possible to sample areas that encompass entire populations of the study species while only sampling the habitat choice of an individual a few times during the study. The focus of sampling is hence turned away from individuals, as in radiotelemetry based studies, and towards populations such that increasing the sample size means sampling more individuals. At these scales, choice is no longer simply a measure of behaviour but is also influenced by differences in population density among ecosystems.
In this presentation I will demonstrate, using 4 case studies, that habitat selection is not necessarily functionally connected to population density, or population change, at the scales we often study them. Typically descriptive habitat use studies measure some combination of both behavioural choice of individuals and ecological differences in population density. The thesis of my argument is that habitat studies must be specifically linked to population dynamics of the study species via the testing of hypotheses that describe known links between resources or, other limiting factors and population dynamics. Simple descriptive studies of use rarely add general knowledge about the species which can be used to make deductive decisions in other times and places.
Dr. Judy Myers
Date: March 1, 2012
Title: Reducing the dominance of an invasive weed: the story of biological control of diffuse knapweed
Abstract: North American grasslands are the home to an array of introduced plant species. Recently controversy has arisen as to whether introduced species should be a major concern or just part of the homogenization of global ecosystems. While exotic plant intruders are here to stay, the dominance of diffuse knapweed in rangelands of western North America has declined in the last decade. I will discuss the history of this successful biological control program, experimental evidence that points to the impact of the most influential agent, efforts to clarify the species identification of this agent and finally the impact of reducing the dominance of one introduced species on the diversity of native and other exotic species in these grasslands.
Dr. Max Bothwell
Date: March 8, 2012
Title: Blooms of rocksnot (Didymosphenia geminata): Environmental change or an invasive species?
Abstract: Starting in 1989 blooms of Didymosphenia geminata began appearing in the Heber River on Vancouver Island. Within 5 years D. geminata blooms had spread to 12 pristine, nutrient-poor rivers on Vancouver Island that were known to have had very low algal biomass in the past. Investigations to determine the environmental cause of the blooms during the1990s proved inconclusive. Studies on the impact of solar ultraviolet radiation on D. geminata community development also failed to find any significant species selective effect. Following the occurrence of blooms on Vancouver Island, D. geminata began appearing in many other regions and countries in the Northern Hemisphere and in the mid-2000s in the Southern Hemisphere. British Columbia Provincial Steelhead Tag data were analyzed to explore the possibility that the blooms of D. geminata on Vancouver Island in the 1990s might have resulted from an invasion of Vancouver Island streams by a new strain of D. geminata during a period of intense recreational fishing pressure in the late 1980s.
Recent research in New Zealand into factors controlling the cellular growth rates and bloom formation by D. geminata have confirmed the anomalous behaviour that “blooms” only form under conditions of extremely low phosphorus. Increased extracellular polysaccharide stalk formation under P-starvation provides one possible mechanism for this unusual circumstance. Since D. geminata is known to be endemic to North America, perhaps the “blooms” of this native species actually signal the onset of widespread oligotrophication of lakes and rivers around the world. Evidence that this might be the case will be discussed.
Dr. Tom Sullivan
Date: March 16 (Friday), 2012
Title: Bioenergy or biodiversity: Whither the future for woody debris and wildlife habitat?
Abstract: Woody debris is an important component of forest ecosystems, but its management is a contentious issue on harvested sites. Downed wood contributes to habitat for a variety of wildlife species, reserves of nutrients and water, sources of microsites and substrates, and long-term site productivity. However, much woody biomass is burned on site or may be used as feedstocks for production of bioenergy. This latter initiative may be a worthwhile endeavour, but will we sacrifice biodiversity and wildlife habitat for bioenergy? Are there alternative ways for managing debris, in situ, on harvested sites? Can strategic management of woody debris be used to construct long-term habitat and connectivity over cutblocks, particularly on large salvage harvest units? Is there a vision for managing this important component of habitat and biodiversity? Does the debate of “ethics versus science” appear yet again?
Dr. Jeannette Whitton
Date: March 22, 2012
Title: Baby steps for SARA: Assessing the early performance of Canada's Species at Risk Act
Abstract: Environmental legislation provides a key tool in balancing competing interests with the potential to negatively impact biodiversity. Canada’s Species at Risk Act, SARA, was enacted in 2003 to fill a legislative gap and help protect and recover species at risk. SARA includes a four-step process: scientists prioritize and assess species, and the government makes decisions about listing (or not). The third stage involves the development of recovery strategies for endangered, threatened and extirpated species. This is then followed by the development of an action plan. Previous analyses of SARA’s performance have focused on listing decisions and overall progress, and suggest biases in listing decisions. As part of a graduate course in Conservation Biology, our group conducted an analysis of finalized recovery plans (2006-2011) under SARA. We scored 374 species in need of recovery strategies for a suite of traits that includes species characteristics, the achievement of timelines related to SARA, characteristics of threats, recovery goals and objectives, and designation of critical habitat. We found that there are still significant delays in producing recovery strategies, and that the goals set out in these strategies set a low bar for species recovery. We see an increase over time in the proportion of recovery strategies that include critical habitat designation, but Recovery Action Planning continues to lag, with only four finalized Action Plans in place by the end of 2011. Taken together, indicate that the tools that SARA provides for protecting species are not being fully implemented.
Dr. Richard Beamish
Date: April 5, 2012
Title: The synchronous failure of Pacific salmon and herring reproduction in 2007 in the Strait of Georgia and the poor return of sockeye salmon in 2009
Abstract: Variability in survival occurs in all fish populations.Extremes in this variability would be expected to be rare. Synchrony in the extremes among virtually all species in a particular ecosystem may be unique. In the Strait of Georgia, in the winter and spring 2007, ocean and climate conditions were highly anomalous. At the same time, all species of juvenile Pacific salmon had poor growth or poor survival or both. Young-of-the-year Pacific herring also had the poorest survival on record. This unique event helps explain the poor return of sockeye to the Fraser River in 2009. The event and the subsequent inquiry identify the importance of longterm monitoring and the continuing need for research.
Dr. Maja Krzic
Date: April ?, 2012
Title: TBA
Abstract: Forthcoming.