bioRxiv Science⌕ Search
Home/Archive/bioRxiv

bioRxiv · 10.1101/165548

Spores and soil from six sides: interdisciplinarity and the environmental biology of anthrax (Bacillus anthracis)

Carlson, C. J.·Getz, W.·Kausrud, K.·Cizauskas, C.·Blackburn, J.·Bustos Carrillo, F. A.·Colwell, R.·Easterday, W. R.·Ganz, H.·Kamath, P.·Okstad, O. A.·Turner, W.·Kolsto, A.-B.·Stenseth, N. C.
View original source ↗Export metadata ↓

Abstract

Environmentally Transmitted Diseases Are Comparatively Poorly Understood And Managed, And Their Ecology Is Particularly Understudied. Here We Identify Challenges Of Studying Environmental Transmission And Persistence With A Six-Sided Interdisciplinary Review Of The Biology Of Anthrax (Bacillus Anthracis). Anthrax Is A Zoonotic Disease Capable Of Maintaining Infectious Spore Banks In Soil For Decades (Or Even Potentially Centuries), And The Mechanisms Of Its Environmental Persistence Have Been The Topic Of Significant Research And Controversy. Where Anthrax Is Endemic, It Plays An Important Ecological Role, Shaping The Dynamics Of Entire Herbivore Communities. The Complex Eco-Epidemiology Of Anthrax, And The Mysterious Biology Of Bacillus Anthracis During Its Environmental Stage, Have Necessitated An Interdisciplinary Approach To Pathogen Research. Here, We Illustrate Different Disciplinary Perspectives Through Key Advances Made By Researchers Working In Etosha National Park, A Long-Term Ecological Research Site In Namibia That Has Exemplified The Complexities Of AnthraxS Enzootic Process Over Decades Of Surveillance. In Etosha, The Role Of Scavengers And Alternate Routes (Waterborne Transmission And Flies) Has Proved Unimportant, Relative To The Long-Term Persistence Of Anthrax Spores In Soil And Their Infection Of Herbivore Hosts. Carcass Deposition Facilitates Green-Ups Of Vegetation To Attract Herbivores, Potentially Facilitated By Anthrax Spores Role In The Rhizosphere. The Underlying Seasonal Pattern Of Vegetation, And Herbivores Immune And Behavioral Responses To Anthrax Risk, Interact To Produce Regular \"Anthrax Seasons\" That Appear To Be A Stable Feature Of The Etosha Ecosystem. Through The Lens Of Microbiologists, Geneticists, Immunologists, Ecologists, Epidemiologists, And Clinicians, We Discuss How Anthrax Dynamics Are Shaped At The Smallest Scale By Population Genetics And Interactions Within The Bacterial Communities Up To The Broadest Scales Of Ecosystem Structure. We Illustrate The Benefits And Challenges Of This Interdisciplinary Approach To Disease Ecology, And Suggest Ways Anthrax Might Offer Insights Into The Biology Of Other Important Pathogens. Bacillus Anthracis, And The More Recently Emerged Bacillus Cereus Biovar Anthracis, Share Key Features With Other Environmentally-Transmitted Pathogens, Including Several Zoonoses And Panzootics Of Special Interest For Global Health And Conservation Efforts. Understanding The Dynamics Of Anthrax, And Developing Interdisciplinary Research Programs That Explore Environmental Persistence, Is A Critical Step Forward For Understanding These Emerging Threats.

Source connections

Explore related subjects

ecologyPreprint

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Carlson, C. J., Getz, W., Kausrud, K., Cizauskas, C., Blackburn, J., Bustos Carrillo, F. A., Colwell, R., Easterday, W. R., Ganz, H., Kamath, P., Okstad, O. A., Turner, W., Kolsto, A.-B., Stenseth, N. C.. 2017-07-20. Spores and soil from six sides: interdisciplinarity and the environmental biology of anthrax (Bacillus anthracis). https://doi.org/10.1101/165548

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

bioRxiv2026

Validating static food web model diet matrices using stable isotope simulation

End-to-end ecosystem models, such as Ecopath with Ecosim (EwE), are valuable tools for resource management. Within these frameworks, trophic interactions, typically derived from stomach contents analyses, govern system-wide energy flow via consumption. However, stomach contents data may be unrepresentative of long-term average diets and assimilated consumption due to factors including differential digestion rates and identifiability of prey, introducing model uncertainty. Because trophic interactions define model structure, variation in modeled diets can alter predictions and management conclusions. Consequently, evaluating and reducing uncertainty in diet matrix compositions is critical for operational acceptance of ecosystem models. Stable isotope analysis provides complementary, time-integrated insight into average diets, but its application for EwE validation has largely been limited to evaluating trophic levels and isotopic niche space. Here, we present a quantitative framework for simulating consumer stable isotope signatures across food webs from parent ecosystem models using a matrix-based mixing model. Using a published Northern Gulf of Mexico EwE model as a case study, we demonstrate Monte Carlo simulation to propagate uncertainty from basal source signatures and trophic discrimination factors. Comparison of predicted signatures with empirical {delta}13C and {delta}34S measurements enables validation of primary carbon sources and benthic-pelagic pathway contributions, revealing agreement in isotope space alongside mismatch in energy pathways. Diagnostic residuals identify discrepancies in diet composition. Model scoring provides a reproducible framework for ranking alternative diet configurations. Redundancy analysis further identifies within-group species coverage differences between stomach contents and isotope datasets as a primary driver of mismatch, highlighting an important consideration for sampling design.

ecology↗
bioRxiv2026

Enhancing Germination and Assessing the Longevity of Native Plants' Seeds with Dormancy through Different Priming Techniques

Vachellia pachyceras and Convolvulus oxyphyllus are native species of arid and semi-arid desert regions, including Kuwait. They are inherently adapted to extreme conditions characterized by high temperature, prolonged drought and limited rainfall. They contribute significantly, to restore the ecosystem by providing food and shelter for wildlife. Despite their ecological importance, seed germination in both species is constrained by dormancy, and natural recruitment of seedlings is limited by narrow and unpredictable rainfall windows, severely restricting opportunities for establishment. In this context, seed priming is an effective pre-sowing technique that enables uniform and rapid germination within the short window of favorable conditions. This study aims to identify the optimal seed-priming techniques for these two keystone native species and to assess the effect of priming on seed longevity. The seeds were scarified to remove the physical dormancy prior to priming treatments. Relative seed longevity was measured for primed seeds through artificial ageing and analyzed using probit analysis and analysis of variance. Results showed that hormonal priming [(mechanical scarification + 100 ppm gibberellic acid (GA3)] for six hours and hydropriming (mechanical scarification + soaking in water) for 8 hours (h) were effective treatments among the tested priming treatments for V. pachyceras. The estimated p50 value (i.e., number of days to lose seed viability to 50%) was 22 days for hormonal priming and 21 days for hydropriming. Mechanical scarification followed by one and half hour of hydropriming was the most effective in C. oxyphyllus (p50 = 74 days). Based on these results, the longevity of V. pachyceras and C. oxyphyllus could be considered medium. Further studies are needed to determine the effectiveness of seed priming on additional ecologically and economically important native species to achieve success in revegetation programs.

ecology↗
bioRxiv2026

Restoration decisions in highly variable systems: Whether, when, and how to enhance kelp

In highly variable ecosystems, natural variability can obscure signals of decline that warrant intervention, as there is often a lack of long-term data needed to distinguish between declines that are transient and likely to recover naturally and those that would be permanent without intervention. Implementing restoration for a species involves deciding on a threshold condition at which to intervene, duration that this threshold needs to be met before intervening, life stages at introduction, and amounts to introduce. Current bull and giant kelp restoration efforts in California were spurred by persistent kelp loss that started in 2013 following a disease outbreak among predators of the primary herbivore and a marine heatwave. We asked how decisions about intervention cue, threshold, wait time, life stage at introduction, and amount affect population outcomes against a backdrop of environmental variability. We analyzed additional context-dependencies on grazing and climate intensity. To address these questions, we built and parameterized a stochastic stage-structured model for bull and giant kelp, in which we simulated kelp enhancement approaches under a range of grazing and climate scenarios. In a global sensitivity analysis of kelp enhancement decisions, we found that grazing intensity and life stages at introduction were the most influential determinants of kelp biomass and persistence outcomes. The kelp enhancement approach involving temporarily introduced juveniles restored the germ banks of bull and giant kelp, but the two species differed in their responses to that intervention, highlighting that optimal intervention approach is species-dependent. Waiting longer for natural recovery before intervening reduced total intervention effort but also reduced biomass recovery potential. These results support empirical findings from kelp enhancement pilot projects in California and highlight context-dependencies that inform restoration decision-making in kelp forests and other highly variable ecosystems.

ecology↗