The influence of cultivation in plant invasion

My postdoctoral research reflects my interest in cultivation, and a major aspect involves leading the construction of a global database of cultivated plants. Broadly, I’m seeking to better understand the way that the traits of cultivated plants and the environment in which plants are cultivated (both present-day and historical) influence which plants establish in a new area. Large scale, macroecological analyses are the best way to move forward with this line of inquiry. Knowing what species were cultivated, when they were cultivated, and where they were cultivated is important for understanding why only some of the plants that were introduced to a new area and cultivated there establish and potentially become invasive while others do not (see Kinlock et al. 2022 GEB for an analysis of plants introduced/cultivated in Great Britain).

I have also been investigating historical patterns of cultivation, which are very important because the plants that people have cultivated in an area over time create an ecological and evolutionary context that influences the environment as we experience it today (see Kinlock et al. 2022 PPP for an exploration of this context in the US).

The structure of plant interactions in communities

This line of research was the basis of my dissertation work, and can be split into three parts:

Characterizing the structure of plant-plant interactions in communities via a meta-analysis of plant interaction networks

I gathered estimates of plant-plant interactions from 31 communities in the literature, and re-interpreted them as networks of plant competition and facilitation. I calculated network metrics and combined the metrics across communities using meta-analysis to make generalizations about plant community structure with a quantitative foundation. I found that competition was the dominant interaction, but its average intensity was not particularly strong. The average intensity of intraspecific interactions was not significantly different from interspecific interactions. Overall, interactions were imbalanced and communities were transitive. However, within some individual networks, facilitation, strong intraspecific competition, balanced interactions, and intransitivity were observed. Additionally, I found that the prevalence of competitive, imbalanced interactions, and transitive patterns may have been systematically biased as a result of the types of experiments and study systems favored by plant ecologists (Kinlock 2019 Am Nat).

Multilevel network architecture of plant-plant interactions in an invaded old field community

I conducted a field and garden experiment in an old field at the Yale Myers Forest in northeastern Connecticut to measure all interactions between woody species at multiple life stages: between seedlings and between seedlings and adults. I used these pairwise interactions as the basis for an analysis of the network-level structure of the community. I sought to bring a new perspective to our interpretation of plant community structure, rather than viewing plant-plant interactions as the sum of competitive effects and responses in a community, I envisioned a more complex system of network interactions at multiple scales. I translated mechanisms for species coexistence into the corresponding network structural features that would be expected if these mechanisms are operating in plant communities. By characterizing network architecture at the scale of an entire community (comparing interactions at different life stages), the substructures that compose the network, and species’ roles within substructures, I found a mixture of both stabilizing and destabilizing network structures, involving intransitive and transitive substructures of different sizes and with different intensities among seedlings and nestedness in the relationships between seedlings and adults. I also found that intransitive substructures were not exclusively stabilizing, transitive structures were not exclusively destabilizing, and the expected outcomes of interactions among species at one life stage were contrary to the expected outcomes at a different life stage (Kinlock 2021 J Ecol).

Testing invasiveness and community invasibility using spatial simulations of invasion

Understanding what aspects of community structure influence invasibility and what invader characteristics influence invasiveness is particularly challenging because we tend to be limited by observational data. To be able to test these hypotheses, we used stochastic spatial lattice simulations of invasion in plant communities. We invaded communities with alien species that had different life history traits and competitive abilities in order to determine which characteristics of the alien species contributed most to their invasiveness. We also simulated communities with different species richnesses and interaction network structures (transitive hierarchies, reversed transitive hierarchies representing a growth versus fecundity trade-off, and intransitive loops) in order to determine which characteristics of the resident community contributed most to its invasibility. These simulations were carried out using a parallelized C++ program that I co-wrote, ecolattice. We found that communities with more species were more resistant to invasion; and also that communities in which competition was intransitive were more invasible, while communities with transitive competition were more resistant to invasion (though there was a complex interaction with species richness). Among high-richness communities, those with reversed competitive hierarchies at different life stages were the most resistant to invasion. While the relationship was complex, structural features that promoted species coexistence in communities were generally associated with an increase in invasibility. We also found that invasiveness was primarily driven by life history, including fecundity and dispersal abilities, rather than their competitive effect on the resident community (competitive response was, however, influential). Last, we found that spatial patterns in the resident community were associated with invasion; communities with more intraspecific clustering and interspecific segregation were more invasible, both patterns that are associated with increased niche differentiation among species (Kinlock & Munch 2021 Oikos).

Other projects

  • I have led and been a part of several meta-analyses to quantify evidence and to document patterns about well-known ecological phenomena, including the latitudinal diversity gradient (Kinlock et al. 2017 GEB) and the correlation between native and exotic species richness at many spatial scales and extents (Peng et al. 2019 Ecology). I’m also more generally interested in how meta-analysis can be used to answer ecological questions, especially by using hierarchical meta-analytic models to partition variation.

  • I’ve helped design undergraduate biology teaching and assessment materials that are structured using the core concepts of AAAS Vision and Change Undergraduate Biology Education Initiative. We specifically focus on pathways and transformations of matter and energy, a concept crucial for understanding current issues like climate change (Kinlock et al. 2020 CourseSource).

  • I’ve worked with a team designing and implementing a population dynamic simulation, informed by bioenergetic models, that estimates the impacts of invasive carp on native paddlefish in the Mississippi River (Kinlock et al. 2020 Freshw Biol).

  • I was a part of a project assessing the potential risk of biological invasions on green roofs, including the risk of planted invasive plants spreading from green roofs as well as the risk of invasive plants dispersing to and establishing on green roofs (Kinlock et al. 2015 Isr J Ecol Evol).