The Problem

A fundamental challenge facing ecologists today is understanding the complexity of ecological systems in the face of rapid and widespread anthropogenic change.​ Here at the PIE lab, we seek to understand how biodiversity is being impacted by people, so we can better identify, predict, and mitigate threats. We study all kinds of environmental change, but are most interested in two major causes of biodiversity declines worldwide...

Urbanization

Species Introductions

The System

We study plant-insect communities for several reasons!

Plants and insects play important roles in ecosystem function. Plants form the base of nearly all terrestrial food chains on Earth and insects provide critical ecosystem services like pollination and nutrient cycling.
 
Insects are valuable ecological indicators. Their presence, abundance, and behaviour can reflect the condition of the environment. Insects like butterflies are particularly sensitive to changes in temperature and habitat structure.

Insects and plants are tightly linked through specialized interactions. Many plants rely on insects and many insects in turn rely on plants! Studying the interactions between the two can provide valuable insights into ecological processes ranging from behaviour and adaptation to the dynamics of entire communities.
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We are especially interested in community ecology because it allows us to look at biodiversity as a whole, rather than focusing on species in isolation. In our view, this integrated approach makes community ecology not only useful, but exciting!

The Approach

To do our research, we use a variety of techniques like field studies, experimental approaches, data synthesis, GIS, and modeling.

Current Projects

Species Introductions
​The rate that species are being introduced beyond their native ranges is increasing around the world, and by extension so are their interactions with native biodiversity. On one hand, non-native species can threaten native biodiversity through effects like competition and habitat alteration. On the other hand, some non-native species play positive roles in native ecosystems by provisioning food resources and habitat. The overall role of non-native species is definitely complex and is something that we're interested in studying at the PIE Lab!

Seebens et al. 2020 Nature

​An ongoing project in the lab focuses on investigating how non-native plants contribute to the nectar diets of native butterflies. Most butterflies are generalist nectar feeders and, as a result, are often observed foraging on non-native plants. This could benefit butterflies by supplementing their nectar diets and even extending the time frames available for foraging. But this could also harm butterflies if non-native nectar is poor quality or if they displace native plants that are important hosts for developing caterpillars. We're interested in exploring why butterflies choose to forage on non-native plants (and all nectar sources in general), if this has any effects on butterfly survival and reproduction, and what the broader implications are for the butterflies and plants in the community. 

​Another project of interest to the lab focuses on determining the factors that lead to non-native species becoming 'invasive' - that is, non-native species that are widespread, abundant, and cause negative impacts on native biodiversity. How do non-native species establish self-perpetuating populations after being introduced? How does range expansion occur and what factors lead to non-native species becoming widespread?

Urbanization, Functional Traits, and Biotic Homogenization
​More than half the global human population live in urban areas and this is projected to continue increasing over the next several decades. Urbanization can have major impacts on biodiversity through habitat loss, urban heat islands, pollution, and much more. At the same time, cities are not devoid of biodiversity and a surprising variety of species can thrive in urban areas. Understanding how species survive and adapt to urban conditions can provide insights into how species overcome challenging environments and contribute towards enhancing urban biodiversity for the benefit of both nature and people. 

United Nations 2019

An ongoing project in the lab focuses on the role of functional traits in structuring urban biological communities. Because urbanization often creates similar environments around the world, cities offer an exciting opportunity to test for convergence in these traits. Identifying how species respond to urbanization because of their traits can also shed light on what species are most vulnerable and if urban ecosystems are likely to be functional. We're interested in exploring how urbanization shapes functional traits at both the inter- and intraspecific levels using butterflies and plants as model systems. 

Another project that the lab is interested in focuses on biotic homogenization - a phenomenon where communities become more similar to each other, either over time or space. This similarity can be measured in terms of species identities (taxonomic), traits (functional), or genetic make-up (genetic). The urban biotic homogenization hypothesis (UBH) proposes that urban communities tend to be more similar, probably because cities are challenging environments that only a subset of species can tolerate. We're interested in exploring how and why urban biotic homogenization occurs, particularly for insects which are less well studied compared to other taxonomic groups. We're also interested in exploring the potential consequences of UBH for ecosystem function.

Landscape Ecology of Butterflies
Butterflies are valuable ecological indicators because of their sensitivity to the environment, including the landscape context. Butterflies have long been used as model organisms to study landscape effects such as species-area relationships, land use change, fragmentation, and connectivity. In North America, citizen science repositories like eButterfly and GBIF provide a unique opportunity to evaluate the effects of landscape structure on butterflies at broad-scales since high quality data are available across years and latitudes. We're interested in exploring ideas like how habitat heterogeneity impacts butterfly diversity and what landscape factors associated with urbanization are the causes of butterfly declines in cities. We're also interested in exploring how landscape structure impacts butterfly range expansions, for both invasive and native (but expanding) butterflies.