Current CREATE projects(For a list of other topics of interest, see the Research page and contact the theme leaders.)
Interaction of foliar litter chemistry and climate as it affects litter decay and microbial community diversity along a climatic gradient in Douglas-fir forests.
(supervisors: J.A. Trofymow, R. Winder, C.P. Constabel)
Litter decay represents one of the largest terrestrial sources releasing CO2 to the atmosphere and contributing to C storage in the soil. Climate, litter quality (primarily chemistry), and soil biota are prime factors controlling litter decay. Climate change may shift the distribution of climatic zones on east Vancouver Island and elevated CO2 may change leaf litter chemistry, both potentially affecting litter decay rates. A study is planned to quantify those effects by examining decay of standard poplar leaf litters with a range of tannin and nitrogen concentrations, in monitoring plots along climatic transects on east coast Vancouver Island and to examine the response of the microbiota to the novel litter chemistries. Results are to be used to test litter decay models, determine the microclimate specific litter decay and nutrient release rates, and relative influence of litter chemistry and microbiota on those rates.
Analysis of transcription factors involved in biosynthesis of carbon-rich secondary metabolites in poplar
(supervisors: C.P. Constabel, A. Seguin)
Forests are major sinks for atmospheric carbon, and temperate forests store large amounts of carbon. Trees can contain high levels of secondary plant metabolites, and in poplar, phenolic metabolites can comprise up to 30% DW of leaf biomass. Understanding the biosynthesis and regulation of such phenolics is crucial for understanding carbon allocation within the plant. This project aims to dissect the transcriptional network regulates phenolic biosynthesis and which determines how carbon is allocated to major phenolic pathways in poplar. We have recently identified several new MYB-type transcription factor genes implicated in the regulation of phenolic and flavonoid biosynthesis in poplar. One of these is hypothesized to be a positive regulator of proanthocyanidins (condensed tannins), whereas the other appears to be a repressor gene. The proposed project will investigate the functions of these regulatory genes in proanthocyanidin and phenolic metabolism in poplar, using a variety of approaches including promoter activation and transient expression assays, yeast two-hybrid analysis, chromatin immunoprecipitation assays (CHIP), and plant transformation coupled with metabolomic and genomic analysis.
Understanding cedar leaf blight (Didymascella thujina) resistance mechanisms and genetic correlations among fitness traits affected by climate change in a durable western redcedar (Thuja plicata) population
(supervisors: B. Hawkins, J. Ehlting, C.P. Constabel, J. Russell)
Durable breeds encompassing an array of biotic and abiotic challenges are a necessity for gene resource management under a changing climate. Current and future challenges to western redcedar, an important commercial conifer species in British Columbia, include growth and stress, ungulate damage, heartwood durability and cedar leaf blight (CLB). CLB is an important disease on western redcedar causing growth reduction and plantation failure. The blight has been more prevalent over the last decade and is projected to increase to potentially epidemic levels in some areas as climatic conditions become more favorable to sporulation. Little is known about resistance to the disease, however, individuals have been identified that are resistant to the blight. Morphological and physiological traits including cuticular and stomata properties may play a role in resistance, as well as constitutive secondary compounds and induced responses. Secondary compounds are important for deer browse resistance and heartwood durability, and may play a role in cedar leaf blight resistance. Understanding resistance mechanisms to CLB and the underlying genetic correlations with other fitness traits will be important in developing durable breeds under a changing climate to ensure future adaptability of western red cedar forests.
Climate change and cone physiology
(supervisors: P. von Aderkas, B. Anholt)
Sustainable forestry in the face of a changing climate depends on the reproductive capacity of trees, as well as the adaptability of their reproductive mechanisms. Lodgepole pine is the backbone of BC forestry. Lodgepole pine common gardens exist in 60 locations in the province. These allow us to measure tree features and how they alter by latitude. Since latitude is an analogue for climate change, these studies are directly useful in assessing species adaptability. Cone physiology of this species shows variation due to natural selection as well as variation due to plasticity. Cone variation affects seed yield. We are proposing to measure various factors that affect cone and seed yield of this important species. A number of experiments will be conducted to elucidate the mechanisms of cone variation.
If you are interested in one of the projects, please contact the supervisor identified for that project.