The research interest of our group spans a broad range of topics, including community ecology, species diversity, biological conservation, landscape ecology, ecological methodologies and modeling, and spatial statistics. Using both analytical and empirical approaches, we are involved in:
synthesizing macroecological patterns of abundance and distribution of species in landscapes,
investigating and testing mechanisms that promote population persistence and species coexistence,
providing scientific support to the conservation of biodiversity and sustainable management of ecosystems.
Macroecology of biodiversity - Macroecology is a newly emerging ecological discipline that aims to understand the rules for the division of food and space among species at all scales. As such, macroecological approaches emphasize the importance of synthetic, analytical and statistical analyses for understanding ecological systems. Adopting these approaches, we continue our strong interest in this area to synthesize and explain diversity patterns. Our current research activities include synthesizing local-regional diversity patterns from the theory of island biogeography, predicting species-abundance relationship from population processes, and working to bridge the gap between the neutral and niche theories of biodiversity.
Landscape patterns of metapopulation - Ecologists have made remarkable progress in understanding how populations distribute and persist in intact and equilibrium landscapes, but much less is known about how they fare in degraded and fragmented ecosystems. This knowledge gap has been recognized as the major obstacle for conservation and sustainable management of ecosystems. The theory of metapopulation dynamics is based on the notion that discrete local populations are connected by movement of individual organisms. Central to the theory is the incidence function that underpins the interpretation of metapopulation dynamics and predicts the fate of component populations. Interestingly, this incidence function is of the same form and the same biological interpretation as the occupancy-abundance model developed in macroecology. This commonality permits interpretation of macroecological patterns in the light of fundamental metapopulation dynamic processes. Our current interest is to investigate the persistence of fragmented metapopulation in landscapes from the perspectives of macroecology and population genetics.
Predicting infestation and mortality rates for lodgepole pines attacked by the mountain pine beetle in BC - Supported by the Pacific Forestry Centre, Canadian Forest Service (Victoria, BC) we investigate the patterns and mechanisms of lodgepole pine tree selection and attack by the mountain pine beetle for developing methods to predict infestation risk and attack rates. Because of the pheromone system for aggregating beetle populations and the limited dispersal capability, beetles do not randomly select trees in a stand, rather they show a contagious colonization pattern, i.e., a tree with infested proximate neighbors is expected to be more likely attacked than a tree far away. This attack pattern is however complicated by other factors such as beetle population density, tree canopy architecture, silhouettes, diameter, age, vigor, stand density and habitat conditions etc., all of them have been shown to influence, to various degrees, tree selection and attack by the beetles. This study aims to develop predictive models using detailed field stem mapping techniques and spatial modeling. The robustness of the models will be tested against geographical variation across regions from south to north in British Columbia because a factor may be important in one region but may not be so in another. The tested models will allow us (1) to model the spatial process of beetle attacks, (2) to quantify and assess the relative importance of the various factors (beetle density, crown depth, diameter, height, spatial pattern, stand density and habitat conditions), (3) to develop methods and criteria for characterizing susceptible/resistant trees for silvicultural (salvage) treatments, and (4) to provide proven models (e.g., MPBSIM) for large-scale simulation to improve their predictions. (MPBI 1.04B Report)
Model-based spatial statistics - Spatial statistics is a rather new but fast-developing statistical discipline. It is becoming increasingly important in ecology and in natural resources research and management. The traditional applications of spatial statistics in ecology have been restricted to pattern detection (i.e., testing spatial patterns) and then interpreting the patterns so tested. However, this has gradually been changing. Another equally, if not more important, direction of spatial statistics in ecology is model-based inferences , in which modeling (rather than testing) a spatially correlated ecological phenomenon is the major concern. We believe that this will become an important field in the very near future. We have been actively involved in this area through our interest in modeling species distribution in landscapes. We engage in developing methods for modeling spatially correlated binary, counting and point ecological data, with an immediate interest in modeling spatially correlated binary data (e.g., present/absent spatial data, species distribution maps).
Conservation of biodiversity - At this moment we are interested in developing methods for estimating species loss rates caused by habitat destruction and for prioritizing conservation plans in order to protect the largest number of species in a region. The data we work with are the type of distribution (i.e., presence/ absence data) because such data can be readily acquired nowadays through the means of remote sensing and aerial photogrammetric technologies. This research will result in developing methods in detecting biodiversity cold and hotspots and how these cold and hot spots change with spatial scales.