Research area

Genomic demography

Using genomes to predict how forest populations change

We connect genetic variation recorded within tree genomes to the demographic processes that shape forest communities through time.

Collaborative research: This work is conducted in collaboration with James O’Dwyer at the University of Illinois Urbana-Champaign and the O’Dwyer Lab, and with Jim Lutz at Utah State University.

Old-growth temperate forest at the Wind River Forest Dynamics Plot in Washington
Wind River Forest Dynamics Plot. Photo: Jim Lutz.

The central idea

Genomes retain a memory of population change

Population size, competition and life history leave recognizable signatures in patterns of genetic variation. By combining these genomic signatures with forest census data, we can estimate how strongly different tree populations fluctuate and improve predictions of future community dynamics.

Figure 1: A pipeline for genomic demography, combining population genomic and forest census data to predict population fluctuations
Study overview. A genomic-demography workflow linking population genomic data, forest censuses and a model of population dynamics. From O’Dwyer et al. (2025), Science. View the publication. Photo credit within figure: Dorothy Loudermilk.

Figures from the study

Figures from O’Dwyer et al. (2025), Science. View the publication.

Map of tree species and sampled individuals in the Wind River Forest Dynamics Plot
Figure 1. The forest community and genomic sampling. The study links genomic data to a mapped forest plot at Wind River, Washington. Filled points mark sampled trees, while open points show other individuals from the eight focal species that dominate the plot.
Comparison of genomically predicted and observed population fluctuations across eight tree species
Figure 2. Genomes predict population fluctuations. Observed changes in species’ relative abundance are compared with predictions derived from genomic estimates. Their agreement shows that genetic data can recover how strongly tree populations fluctuate through time.
Relationship between tree population size and genomic estimates of demographic variance
Figure 4. Abundance reflects demographic strategy. Species with larger forest populations also show greater inferred year-to-year demographic variance. This pattern supports life-history complementarity by connecting relative abundance to differences in population dynamics.

Why it matters

Long-term forest censuses remain essential, but genomic data can add predictive information from a single sampling period. This creates a new path for forecasting population dynamics in diverse forests where decades of demographic observations may not yet exist.