NSERC grants at Laurentian University Subventions du CRSNG `a l ...

39Peter RyserEcological significance of plant biomass turnoverA grant of $31,000 per year.Une subvention de 31 000 $ par année.Discovery Grant – Subvention à la découverteThe distribution of plant species is largely determinedby their ability to cope with the environmentalconditions in different habitats, conditions such asthe availability of nutrients, water and light. A plant’sability to acquire these resources is in this respect animportant and well-studied trait. Equally important,but less studied, is the plant’s ability to avoid losses of the once acquiredresources, i.e., its turnover rate. Resource acquisition is closely related togrowth rate, resource loss with lifespan of leaves and roots. There is generallya reverse relationship between growth rate and organ lifespan: plantswhich grow fast usually produce short-lived leaves and roots.The aim of this project is to investigate factors underlying this tradeoffbetween growth and lifespan, and the consequences for species’ performancein different environments. The focus lies in leaf and root lifespan in relationto disturbance and growing season length. Furthermore, biomass turnovercharacteristics of vegetation strongly influence nutrient and carbon cyclingin ecosystems, an aspect that will be studied as well. The project consistsof garden and field experiments. Short-term investigations of plant structurewill be combined with long-term experiments about interactions betweenthe species. An important aspect is that roots, which are often neglected insuch studies, will be investigated as well. The project concerns basic questionsabout ecological and evolutionary mechanisms, but it is also potentiallyimportant for understanding the consequences of changes in land use and climate.