About

Here in the Davies Lab, we study how climate change and forest fragmentation impact biodiversity. We work in the Wog Wog Fragmentation Experiment in southeastern Australia: a large-scale, long-term experiment, now in its 38th year. The experiment was established by CSIRO scientists in 1985. We continue to collaborate with CSIRO and others on our quest to understand how life rebounds from environmental disturbance. Our work is funded by the National Science Foundation.

Research topics

• Biology
• Ecology
• Chemistry
• Agronomy
• Artificial Intelligence
• Environmental science
• Computer Science
• Economics
• Geography
• Econometrics
• Statistics
• Mathematics
• Botany
• Environmental chemistry
• Soil science

Selected publications

• Opportunities and challenges for monitoring terrestrial biodiversity in the robotics age

  Nature Ecology & Evolution · 2025-05-22 · 12 citations

  articleOpen access

  With biodiversity loss escalating globally, a step change is needed in our capacity to accurately monitor species populations across ecosystems. Robotic and autonomous systems (RAS) offer technological solutions that may substantially advance terrestrial biodiversity monitoring, but this potential is yet to be considered systematically. We used a modified Delphi technique to synthesize knowledge from 98 biodiversity experts and 31 RAS experts, who identified the major methodological barriers that currently hinder monitoring, and explored the opportunities and challenges that RAS offer in overcoming these barriers. Biodiversity experts identified four barrier categories: site access, species and individual identification, data handling and storage, and power and network availability. Robotics experts highlighted technologies that could overcome these barriers and identified the developments needed to facilitate RAS-based autonomous biodiversity monitoring. Some existing RAS could be optimized relatively easily to survey species but would require development to be suitable for monitoring of more 'difficult' taxa and robust enough to work under uncontrolled conditions within ecosystems. Other nascent technologies (for instance, new sensors and biodegradable robots) need accelerated research. Overall, it was felt that RAS could lead to major progress in monitoring of terrestrial biodiversity by supplementing rather than supplanting existing methods. Transdisciplinarity needs to be fostered between biodiversity and RAS experts so that future ideas and technologies can be codeveloped effectively.

  PublisherOA PDFDOI

• Correction: Genome size influences plant growth and biodiversity responses to nutrient fertilization in diverse grassland communities

  PLoS Biology · 2025-05-20 · 1 citations

  erratumOpen access

  [This corrects the article DOI: 10.1371/journal.pbio.3002927.].

  PublisherOA PDFDOI

• Marsh Madness: Using Video Games and a Case Study to Explore Food Webs and Ecosystem Services in Carpinteria Salt Marsh Reserve

  CourseSource · 2024-01-01

  articleOpen access

  As the complexity and interconnectedness of our world increases, we are continually expected to be capable of complex, non-linear thinking in order to successfully tackle and solve the challenges we face in the 21^st century. Tackling these challenges requires &ldquo;systems thinking,&rdquo; in which problem solving must consider interconnected components within a whole to solve complex problems. However, high school and undergraduate training often focus on linear cause-and-effect relationships, failing to help students develop a systems approach to problem solving. Food web ecology lends itself well to developing systems thinking skills, as species depend on one another for resources, form complex systems, and provide benefits to society, known as ecosystem services. We developed a case study based on Carpinteria Salt Marsh Reserve that incorporates both active- and game-based learning to teach students about socio-ecological systems and food web ecology and to use systems thinking. This case study was designed for two 75-minute class periods and uses a freely available web-based game developed by the authors. The case introduces food web ecology and ecosystems services, and as such, it is helpful if students have basic knowledge of food webs prior to the case. After implementing this case study in an undergraduate introductory ecology course, we found that students often (i) improved their content knowledge regarding food webs and ecosystem services, (ii) recognized the importance of species interactions and direct/indirect threats for ecosystem services, and (iii) considered multiple types of information to make decisions. <em>Primary Image:</em>&nbsp;Carpinteria Salt Marsh Reserve in Santa Barbara, California, USA. Salt marsh in front of mountains in Santa Barbara, California, overlaid with food web data from the Food Web Game. Photo by Aislyn Keyes. Data for food web game from R. F. Hechinger, K. D. Lafferty, J. P. McLaughlin, B. L. Fredensborg, T. C. Huspeni, J. Lorda, P. K. Sandhu, J. C. Shaw, M. E. Torchin, K. L. Whitney, and A. M. Kuris, Ecology 92:791, 2011, https://doi.org/10.1890/10-1383.1.

  PublisherOA PDFDOI

• Genome size influences plant growth and biodiversity responses to nutrient fertilization in diverse grassland communities

  PLoS Biology · 2024-12-11 · 14 citations

  articleOpen accessCorresponding

  Experiments comparing diploids with polyploids and in single grassland sites show that nitrogen and/or phosphorus availability influences plant growth and community composition dependent on genome size; specifically, plants with larger genomes grow faster under nutrient enrichments relative to those with smaller genomes. However, it is unknown if these effects are specific to particular site localities with speciifc plant assemblages, climates, and historical contingencies. To determine the generality of genome size-dependent growth responses to nitrogen and phosphorus fertilization, we combined genome size and species abundance data from 27 coordinated grassland nutrient addition experiments in the Nutrient Network that occur in the Northern Hemisphere across a range of climates and grassland communities. We found that after nitrogen treatment, species with larger genomes generally increased more in cover compared to those with smaller genomes, potentially due to a release from nutrient limitation. Responses were strongest for C3 grasses and in less seasonal, low precipitation environments, indicating that genome size effects on water-use-efficiency modulates genome size-nutrient interactions. Cumulatively, the data suggest that genome size is informative and improves predictions of species' success in grassland communities.

  PublisherDOI

• Space Mission Ecology: Making Connections Among Science Disciplines Through the Lens of a Unique Plant

  CourseSource · 2024-01-01

  articleOpen access

  With this case study, we aim to increase awareness of essential services plants provide to society, as well as the importance of fundamental aspects of ecology for other disciplines and the interconnectedness among different fields of science in general. The case study was designed to be implemented in two 75-minute class periods in an introductory university-level ecology course. This case study provides an interdisciplinary perspective by defining learning goals at the nexus of science and society, explicitly emphasizing (and embracing) the interconnectedness among different fields of science via student exploration and how an often under-appreciated sub-discipline of biology&mdash;plant science&mdash;is useful for other disciplines. We use plants from the family Lemnaceae (duckweeds or water lenses) as a hook to introduce what is needed to create a self-sustaining ecosystem in a habitat on the surface of a moon or planet, in orbit, or during long-duration crewed spaceflight. Following the 5E model of curriculum design, students explore their chosen scientific literature before presenting their findings. The structure of the case study and student presentations facilitate making connections between scientific practices, peers, and ecological concepts, enhancing understanding of science&#39;s interconnected nature and the importance of plants. After implementation of this case study in a Principles of Ecology course, students felt more comfortable interacting with, and making claims about, scientific material, better recognized the interdisciplinary nature of science, and were more aware of essential services plants provide for humans. <em>Primary Image:</em>&nbsp;Creating a bioregenerative ecosystem in space. A diagram showing how duckweed plants and astronauts are connected and support each other. An artistic image of duckweed&mdash;a tiny plant that floats on water&mdash;is on the left side of the figure and is connected to an artistic representation of an astronaut on the right.

  PublisherDOI

• Widening global variability in grassland biomass since the 1980s

  Nature Ecology & Evolution · 2024-08-05 · 21 citations

  articleOpen access
  PublisherOA PDFDOI

• Biodiversity impacts of the 2019–2020 Australian megafires

  Nature · 2024-11-13 · 90 citations

  articleOpen access

  With large wildfires becoming more frequent1,2, we must rapidly learn how megafires impact biodiversity to prioritize mitigation and improve policy. A key challenge is to discover how interactions among fire-regime components, drought and land tenure shape wildfire impacts. The globally unprecedented3,4 2019–2020 Australian megafires burnt more than 10 million hectares5, prompting major investment in biodiversity monitoring. Collated data include responses of more than 2,000 taxa, providing an unparalleled opportunity to quantify how megafires affect biodiversity. We reveal that the largest effects on plants and animals were in areas with frequent or recent past fires and within extensively burnt areas. Areas burnt at high severity, outside protected areas or under extreme drought also had larger effects. The effects included declines and increases after fire, with the largest responses in rainforests and by mammals. Our results implicate species interactions, dispersal and extent of in situ survival as mechanisms underlying fire responses. Building wildfire resilience into these ecosystems depends on reducing fire recurrence, including with rapid wildfire suppression in areas frequently burnt. Defending wet ecosystems, expanding protected areas and considering localized drought could also contribute. While these countermeasures can help mitigate the impacts of more frequent megafires, reversing anthropogenic climate change remains the urgent broad-scale solution. Data collected from more than 2,000 taxa provide an unparalleled opportunity to quantify how extreme wildfires affect biodiversity, revealing that the largest effects on plants and animals were in areas with frequent or recent past fires and within extensively burnt areas.

  PublisherOA PDFDOI

• Author Correction: Widening global variability in grassland biomass since the 1980s

  Nature Ecology & Evolution · 2024-08-19 · 2 citations

  erratumOpen access
  PublisherOA PDFDOI

• Clarifying the effect of biodiversity on productivity in natural ecosystems with longitudinal data and methods for causal inference

  Nature Communications · 2023 · 123 citations

  • Computer Science
  • Artificial Intelligence
  • Ecology

  Causal effects of biodiversity on ecosystem functions can be estimated using experimental or observational designs - designs that pose a tradeoff between drawing credible causal inferences from correlations and drawing generalizable inferences. Here, we develop a design that reduces this tradeoff and revisits the question of how plant species diversity affects productivity. Our design leverages longitudinal data from 43 grasslands in 11 countries and approaches borrowed from fields outside of ecology to draw causal inferences from observational data. Contrary to many prior studies, we estimate that increases in plot-level species richness caused productivity to decline: a 10% increase in richness decreased productivity by 2.4%, 95% CI [-4.1, -0.74]. This contradiction stems from two sources. First, prior observational studies incompletely control for confounding factors. Second, most experiments plant fewer rare and non-native species than exist in nature. Although increases in native, dominant species increased productivity, increases in rare and non-native species decreased productivity, making the average effect negative in our study. By reducing the tradeoff between experimental and observational designs, our study demonstrates how observational studies can complement prior ecological experiments and inform future ones.

  PublisherOA PDFDOI

• Drivers of soil microbial and detritivore activity across global grasslands

  Communications Biology · 2023-12-01 · 15 citations

  articleOpen access

  Covering approximately 40% of land surfaces, grasslands provide critical ecosystem services that rely on soil organisms. However, the global determinants of soil biodiversity and functioning remain underexplored. In this study, we investigate the drivers of soil microbial and detritivore activity in grasslands across a wide range of climatic conditions on five continents. We apply standardized treatments of nutrient addition and herbivore reduction, allowing us to disentangle the regional and local drivers of soil organism activity. We use structural equation modeling to assess the direct and indirect effects of local and regional drivers on soil biological activities. Microbial and detritivore activities are positively correlated across global grasslands. These correlations are shaped more by global climatic factors than by local treatments, with annual precipitation and soil water content explaining the majority of the variation. Nutrient addition tends to reduce microbial activity by enhancing plant growth, while herbivore reduction typically increases microbial and detritivore activity through increased soil moisture. Our findings emphasize soil moisture as a key driver of soil biological activity, highlighting the potential impacts of climate change, altered grazing pressure, and eutrophication on nutrient cycling and decomposition within grassland ecosystems.

  PublisherOA PDFDOI

Recent grants

• Habitat Fragmentation: Predicting Long Term Extinction Dynamics from Transient Dynamics and Species Traits

  NSF · $412k · 2009–2014

• CAREER: Effect of the matrix on extinction risk: a large scale experiment at Wog Wog

  NSF · $728k · 2014–2021

Frequent coauthors

• Brett A. Melbourne

  University of Colorado Boulder

  80 shared

• Elizabeth T. Borer

  University of Minnesota

  39 shared

• Eric W. Seabloom

  University of Minnesota

  38 shared

• Suzanne M. Prober

  Commonwealth Scientific and Industrial Research Organisation

  34 shared

• W. Stanley Harpole

  Helmholtz Centre for Environmental Research

  33 shared

• Carly J. Stevens

  Lancaster University

  32 shared

• Yann Hautier

  Utrecht University

  31 shared

• Rebecca L. McCulley

  University of Kentucky

  29 shared