
RESEARCH
While we know that the distribution of some species is changing, it is actually very difficult to make reliable inferences as to which species are declining and by how much from the often messy and complex historical and spatial datasets that we have to work with — for example, historical museum records, where species occurrences are aggregated from studies with different sampling procedures.
In order to address this gap, my research focuses on determining if and how statistical models can be applied to historical records without yielding biased trends.
In my research I also apply these statistical models to determine how the distribution of pollinators has changed through time, where museum records provide lots of information.
I am also interested in determining which drivers (e.g. pesticide use, climate change, land use change, etc.) are causing the most decline of the most pollinator species.
Relevant Publications:
Guzman, L. M., Johnson, S.A., Mooers, A.O., M'Gonigle, L.K.
Biological Conservation. 257:109141
2021
15

Occupancy‐detection models with museum specimen data: promise and pitfalls.
Shirey, V., Khelifa, R., M'Gonigle, L.K., Guzman, L. M.
Methods in Ecology and Evolution
2022
22
Climate change winners and losers among North American bumble bees.
Jackson, H.M., Johnson, S.A., Morandin, L. A., Richardson, L.L., Guzman, L. M.*, M'Gonigle, L.K.*
Biology Letters
2022
21
Metacommunity dynamics
Another aspect of my research is to understand the processes that shape communities, for example I have combined experiments and modelling to understand how the structure of body size in a community affects the stability of food webs. In more recent work, I used large-scale simulations and machine learning to identify the signal of metacommunity processes in ecological time series. Next, I want to use these simulations to understand how metacommunity time series are structured.

Relevant Publications:
A process-based framework and model for metacommunity ecology.
Thompson, P. L., Guzman, L. M., Meester, L.D., Horváth, Z., Ptacnik, R., Vanschoenwinkel, B., Viana, D.S., Chase, J.M.
Ecology Letters. 23(9), 1314-1329
2020
Guzman, L. M., Thompson, P. L., Viana, D.S., Vanschoenwinkel, B., Horváth, Z., Ptacnik, R., Jeliazkov, A., Gascón, S., Lemmens, P., Anton-Pardo, M., Langenheder, S., Meester, L.D., Chase, J.M
Ecology
2022
18
Prey body mass and richness underlie the persistence of a top predator.
Guzman, L. M., Srivastava, D.S.
Proceedings of the Royal Society B. 286(1902), 20190622.
2019
7
Genomic variation among populations provides insight into the causes of metacommunity survival.
Guzman, L. M., Srivastava, D.S.
Ecology. 101(12), e03182
2020