We have entered the Anthropocene, a new era that demarcates the influence of humans on the biosphere. Our research is broadly focused on the causes of biodiversity change and its consequences for the stability and functioning of ecosystems. As a corollary we hope to gain a better understanding of how the effects of anthropogenic environmental change can be mitigated. We use experiments in the field and lab (the photos to the right give an idea of what they look like), theory, and databases to tackle the following research questions:
1. Biodiversity, ecosystem services and landscape connectivity
The spatial insurance hypothesis (Loreau, Mouquet and Gonzalez 2003, Gonzalez et al. 2009) states that altering habitat connectivity affects both biodiversity and ecosystem function functioning. We are testing this idea in laboratory and field-based experimental systems. But we are also conducting research to apply this understanding to design ecosystem networks for the greenbelt of Montreal.
Testing the spatial insurance hypothesis:
We have tested the hypothesis by measuring the impact of manipulating habitat connectivity in experimental metacommunties of a natural and diverse moss microecosystem (Staddon et al. 2010; images top right). Habitat isolation induced the extinction of large-bodied apex predators, that resulted in compensatory increases in prey species abundance (Gonzalez and Loreau 2009). This trophic cascade was associated with significantly altered carbon and nitrogen fluxes in fragmented treatments. The ecosystem impacts persisted for several generations after the initial loss of connectivity. Local extinctions and disruption of ecosystem processes were mitigated, and even reversed, by the presence of corridors in the connected metacommunities, although these beneficial effects were unexpectedly delayed. Our research is showing that knowledge of spatial processes is essential to understand how habitat fragmentation alters the link between biodiversity and ecosystem functions in natural landscapes.
Ecological networks for the greenbelt of greater Montreal. Our overall goal is to design robust ecological networks for Montreal that maintain resilient and sustainable ecological dynamics under projected schedules of climate and land use change over the coming century. The ecological network will be designed to foster biodiversity and the provision of ecosystem functions and services in the exurban landscapes of Montreal.
Visit our project webpage to find out more.
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The greater Montreal region showing the forest loss and fragmentation (dark green) that has resulted from urban (grey) and agricultural (light green) land use.
2. "Networks of networks": The structure and function of ecological networks.
The impacts of habitat transformation on biodiversity are complex and can be difficult to test and demonstrate. Network approaches to biodiversity science have provided a powerful set of tools and models that are beginning to present new insight into the structural and functional effects of habitat transformation on complex ecological systems. We study habitat loss and fragmentation jointly affect biodiversity by altering both habitat and ecological interaction networks. That is, the explicit study of ‘networks of networks’ (Gonzalez et al. 2011). While a lot is known about the consequences of habitat loss for habitat network topology, and for the structure and function of simple antagonistic and mutualistic interaction networks, few studies have evaluated the consequences for large interaction networks with complex and spatially-explicit architectures. We are doing theory and experiments that tackle the ecology of networks of networks. Model systems include laboratory (pictured above right) and natural networks (Chisholm, Lindo and Gonzalez 2011), simulation studies of the emergence and evolution of food webs on spatial networks (e.g., Pillai, Gonzalez and Loreau 2010) and their stability during environmental change (Gouhier, Guichard and Gonzalez 2010).
3. Eco-evolutionary dynamics of environmental change
Evolutionary Rescue: Global environmental change is causing unprecedented rates of population extirpation, giving rise to concern that the rate of environmental change may exceed the capacity of populations to adapt. In many cases environmental change is so widespread and rapid that that individuals can neither accommodate to them physiologically nor migrate to a more favorable site. Extinction will ensue, unless the population adapts genetically through natural selection. According to theory whether populations can be rescued by evolution depends upon several crucial variables: population size, the supply of genetic variation and the degree of maladaptation to the new environment. Using robot-based techniques in experimental evolution we are testing the conditions for evolutionary rescue. We use yeast (Saccharomyces cerevisiae) and bacteria (e.g. Pseudomonas sp.) as model organisms. In a striking match with theory we found that evolutionary rescue is possible, and that the recovery of the population may occur within twenty-five generations (Bell and Gonzalez 2009). Results so far reveal that rapid evolution is an important component of the response of small populations to environmental change, and confirms the value of considering the interaction between ecology and evolution when their dynamics occur on the same time scales (see also Bell and Gonzalez 2011). We have also studied the eco-evolutionary dynamics of antibiotic resistance (e.g., Perron, Gonzalez and Buckling 2007, 2008).
See the special issue Evolutionary Rescue in Changing Environments
4. The ecological impacts of economic inequality
Humans, both individually and collectively, are powerful drivers of environmental change. In collaboration with Greg Mikkelson and Garry Peterson we have studied how socioeconomic factors (for example economic inequality) affect biodiversity loss (Mikkelson et al. 2007, Gonzalez 2007). Tim Holland conducted a MSc on the problem and corroborated our earlier results that suggest that economic inequality is a significant predictor of biodiversity loss and that statistical models do better when inequality is included as an independent variable (Holland, Peterson and Gonzalez 2009).
Current research is evaluating the effects of economic inequality as a predictor of the incidence of invasive species at the national scale. Early results by Emma Weisbord for her honours thesis suggest that economic inequality can explain national variation in the numbers of invasive species.
Variation in national income equality around the world as measured by the national Gini coefficient. The Gini coefficient is a number between 0 and 1, where 0 corresponds with perfect equality (where everyone has the same income) and 1 corresponds with perfect inequality (where one person has all the income, and everyone else has zero income).