About

Jason Donaldson is a faculty member at Duke University Program in Ecology, providing interdisciplinary training in all aspects of ecology. His work encompasses physiological and behavioral ecology; population and evolutionary ecology; community and landscape ecology; biogeochemistry; and ecosystem and global change ecology. Donaldson's research highlights include studying the genetics of adaptation, ecological forecasting of forest communities, tracking birds and storms, and understanding ecosystems in flux. His contributions focus on learning from history, data storytelling, forecasting disease dynamics and distributions in changing environments, and accurately defining stream nutrient concentration and stream health.

Research topics

• Ecology
• Biology

Selected publications

• The generality of cryptic dietary niche differences in diverse large-herbivore assemblages

  Proceedings of the National Academy of Sciences · 2022 · 80 citations

  • Biology
  • Ecology

  Ecological niche differences are necessary for stable species coexistence but are often difficult to discern. Models of dietary niche differentiation in large mammalian herbivores invoke the quality, quantity, and spatiotemporal distribution of plant tissues and growth forms but are agnostic toward food plant species identity. Empirical support for these models is variable, suggesting that additional mechanisms of resource partitioning may be important in sustaining large-herbivore diversity in African savannas. We used DNA metabarcoding to conduct a taxonomically explicit analysis of large-herbivore diets across southeastern Africa, analyzing ∼4,000 fecal samples of 30 species from 10 sites in seven countries over 6 y. We detected 893 food plant taxa from 124 families, but just two families-grasses and legumes-accounted for the majority of herbivore diets. Nonetheless, herbivore species almost invariably partitioned food plant taxa; diet composition differed significantly in 97% of pairwise comparisons between sympatric species, and dissimilarity was pronounced even between the strictest grazers (grass eaters), strictest browsers (nongrass eaters), and closest relatives at each site. Niche differentiation was weakest in an ecosystem recovering from catastrophic defaunation, indicating that food plant partitioning is driven by species interactions, and was stronger at low rainfall, as expected if interspecific competition is a predominant driver. Diets differed more between browsers than grazers, which predictably shaped community organization: Grazer-dominated trophic networks had higher nestedness and lower modularity. That dietary differentiation is structured along taxonomic lines complements prior work on how herbivores partition plant parts and patches and suggests that common mechanisms govern herbivore coexistence and community assembly in savannas.

  DOI

• A handbook for the standardised sampling of plant functional traits in disturbance-prone ecosystems, with a focus on open ecosystems

  Australian Journal of Botany · 2020 · 82 citations

  • Biology
  • Ecology

  Plant functional traits provide a valuable tool to improve our understanding of ecological processes at a range of scales. Previous handbooks on plant functional traits have highlighted the importance of standardising measurements of traits to improve our understanding of ecological and evolutionary processes. In open ecosystems (i.e. grasslands, savannas, open woodlands and shrublands), traits related to disturbance (e.g. herbivory, drought, and fire) play a central role in explaining species performance and distributions and are the focus of this handbook. We provide brief descriptions of 34 traits and list important environmental filters and their relevance, provide detailed sampling methodologies and outline potential pitfalls for each trait. We have grouped traits according to plant functional type (grasses, forbs and woody plants) and, because demographic stages may experience different selective pressures, we have separated traits according to the different plant life stages (seedlings saplings and adults). We have attempted to not include traits that have been covered in previous handbooks except for where updates or additional information was considered beneficial.

  DOI

Frequent coauthors

• Catherine L. Parr

  University of Liverpool

  25 shared

• Sally Archibald

  University of the Witwatersrand

  16 shared

• T. Michael Anderson

  Wake Forest University

  15 shared

• Gareth P. Hempson

  University of Glasgow

  14 shared

• Ricardo M. Holdø

  University of Georgia

  12 shared

• Johan Pansu

  Université Claude Bernard Lyon 1

  11 shared

• Simon Chamaillé‐Jammes

  Université de Montpellier

  10 shared

• Mariska te Beest

  8 shared

Similar researchers at Duke University

• Robert J. Lefkowitzh-328
• Avshalom Caspih-242
• Darell Doty Bignerh-190
• Christopher Bang Newgardh-175
• Kun Shan Carolyn Leeh-168