Jason R Rohr

University of Notre Dame | ND · Department of Biological Sciences

Batrachochytrium dendrobatidis (Bd), an aquatic pathogenic fungus, is responsible for the decline of hundreds of amphibian species worldwide and negatively impacts biodiversity globally. Prophylactic exposure to the metabolites produced by Bd can provide protection for naïve tree frogs and reduce subsequent Bd infection intensity. Here, we used a r...

Range maps are used to estimate the geographic extent of taxa, providing valuable information for biodiversity and conservation research and management. Freshwater macroinvertebrates are not well-represented in the range map literature relative to freshwater vertebrates. To address this knowledge gap, we provide range maps for 1158 freshwater macro...

Abstract In the late 1990s, the San Miguel Island fox (Urocyon littoralis littoralis) faced near-extinction. Fourteen of the 15 remaining foxes were placed into an island-based captive breeding program used to repopulate the island. Although the fox population in San Miguel reached pre-decline numbers by 2010, a second decline started around 2014,...

Anthropogenic change is contributing to the rise in emerging infectious diseases, which are significantly correlated with socioeconomic, environmental and ecological factors¹. Studies have shown that infectious disease risk is modified by changes to biodiversity2–6, climate change7–11, chemical pollution12–14, landscape transformations15–20 and spe...

The naïve host syndrome hypothesis suggests that pathogens are able to easily invade and become deadly to novel hosts because of a lack of co‐evolutionary history, whereas the local adaptation hypothesis suggests that pathogens are better able to invade local hosts because of their co‐evolutionary history, but rarely do studies on these two hypothe...

Climate change is a well‐documented driver and threat multiplier of infectious disease in wildlife populations. However, wildlife disease management and climate‐change adaptation have largely operated in isolation. To improve conservation outcomes, we consider the role of climate adaptation in initiating or exacerbating the transmission and spread...

Prayer animal release (PAR)—a traditional “compassion‐based” religious practice of releasing captive animals into the wild to improve the karma of the releaser—has been regarded as a major anthropogenic pathway facilitating species invasions worldwide. However, comprehensive, quantitative assessments of PAR‐related invasion risks, crucial for the d...

The Society of Environmental Toxicology and Chemistry (SETAC) convened a Pellston workshop in 2022 to examine how information on climate change could be better incorporated into the ecological risk assessment (ERA) process for chemicals as well as other environmental stressors. A major impetus for this workshop is that climate change can affect com...

An understanding of the combined effects of climate change and other anthropogenic stressors, such as chemical exposures, is essential for improving ecological risk assessments of vulnerable ecosystems. In the Great Barrier Reef, coral reefs are under increasingly severe duress from increasing ocean temperatures, acidification and cyclone intensiti...

Extreme weather events (EWEs; for example, heatwaves, cold spells, storms, floods and droughts) and non-native species invasions are two major threats to global biodiversity and are increasing in both frequency and consequences. Here we synthesize 443 studies and apply multilevel mixed-effects metaregression analyses to compare the responses of 187...

Recent climate change should result in expansion of species to northern or high elevation range margins, and contraction at southern and low elevation margins in the northern hemisphere, because of local extirpations or range shifts or both. We combined museum occurrence records from both the continental U.S. and Mexico with a new eco-physiological...

The pathogenic fungus Batrachochytrium dendrobatidis (Bd) is associated with drastic global amphibian declines. Prophylactic exposure to killed zoospores and the soluble chemicals they produce ( Bd metabolites) can induce acquired resistance to Bd in adult Cuban treefrogs Osteopilus septentrionalis . Here, we exposed metamorphic frogs of a second s...

Many communities in low- and middle-income countries globally lack sustainable, cost-effective and mutually beneficial solutions for infectious disease, food, water and poverty challenges, despite their inherent interdependence1–7. Here we provide support for the hypothesis that agricultural development and fertilizer use in West Africa increase th...

There is a rich literature highlighting that pathogens are generally better adapted to infect local than novel hosts, and a separate seemingly contradictory literature indicating that novel pathogens pose the greatest threat to biodiversity and public health. Here, using Batrachochytrium dendrobatidis , the fungus associated with worldwide amphibia...

Immunity changes through ontogeny and can mediate facilitative and inhibitory interactions among co-infecting parasite species. In amphibians, most immune memory is not carried through metamorphosis, leading to variation in the complexity of immune responses across life stages. To test if the ontogeny of host immunity might drive interactions among...

Documenting trends of stream macroinvertebrate biodiversity is challenging because biomonitoring often has limited spatial, temporal, and taxonomic scopes. We analyzed biodiversity and composition of assemblages of >500 genera, spanning 27 years, and 6131 stream sites across forested, grassland, urban, and agricultural land uses throughout the Unit...

Predicting effects of climate change on plant disease is critical for protecting ecosystems and food production. Climate change could exacerbate plant disease because parasites may be quicker to acclimate and adapt to novel climatic conditions than their hosts due to their smaller body sizes and faster generation times. Here we show how disease pre...

Freshwater ecosystems, including lakes, streams, and wetlands, are responsive to climate change and other natural and anthropogenic stresses. These ecosystems are frequently hydrologically and ecologically connected with one another and their surrounding landscapes, thereby integrating changes throughout their watersheds. The responses of any given...

Losses in biodiversity can alter disease risk through changes in host species composition. Host species vary in pathogen susceptibility and competence, yet how changes in diversity alter host–pathogen dynamics remains unclear in many systems, particularly with respect to generalist pathogens. Amphibians are experiencing worldwide population decline...

Although research has focused on density‐dependent responses of hosts to single‐parasite infections, hosts are exposed to numerous parasites simultaneously under natural conditions and if these exposures lead to infections, they can threaten host populations and ecosystem stability. Moreover, spatiotemporal variation in abundance of co‐occurring pa...

Use of agrochemicals, including insecticides, is vital to food production and predicted to increase 2-5 fold by 2050. Previous studies have shown a positive association between agriculture and the human infectious disease schistosomiasis, which is problematic as this parasitic disease infects approximately 250 million people worldwide. Certain inse...

Background: Schistosomiasis is an emerging disease associated with changes to the environment that have increased human contact rates with disease-causing parasites, flatworms that are released from freshwater snails. For example, schistosomiasis remains a major public health problem in Northern Senegal, where prevalence in schoolchildren often rea...

Global health and development communities lack sustainable, cost-effective, mutually beneficial solutions for infectious disease, food, water, and poverty challenges despite their regular interdependence worldwide ¹⁻⁷ . Here, we show that agricultural development and fertilizer use in west Africa increase the devastating tropical disease schistosom...

Anthropogenic change is contributing to the rise in emerging infectious diseases, but it remains unclear which global change drivers most increase disease and under what contexts. We amassed a dataset from the literature that includes 1,832 observations of infectious disease responses to global change drivers across 1,202 host-parasite combinations...

Anthropogenic change is contributing to the rise in emerging infectious diseases, but it remains unclear which global change drivers most increase disease and under what contexts. We amassed a dataset from the literature that includes 1,832 observations of infectious disease responses to global change drivers across 1,202 host-parasite combinations...

The Gram-negative bacteria Xanthomonas oryzae pv. oryzae, the causative agent of bacterial leaf blight (BLB), received attention for being an economically damaging pathogen of rice worldwide. This damage prompted efforts to better understand the molecular mechanisms governing BLB disease progression. This research revealed numerous virulence factor...

Batrachochytrium dendrobatidis (Bd) has been associated with massive amphibian population declines worldwide. Wildlife vaccination campaigns have proven effective for mitigating damage from other pathogens, and there is evidence that adult frogs can acquire resistance to Bd when exposed to killed Bd zoospores and the metabolites they produced. Here...

[This corrects the article DOI: 10.1371/journal.pntd.0005568.].

Pathogens can alter species composition and ecosystem function by causing direct and indirect effects on communities. Zoospores of the chytrid fungus Batrachochytrium dendrobatidis (hereafter, Bd), a pathogen implicated in worldwide amphibian declines, can be consumed by filter‐feeding zooplankton and can damage mouthparts of infected amphibian lar...

Outbreaks of zoonotic diseases are accelerating at an unprecedented rate in the current era of globalization, with substantial impacts on the global economy, public health, and sustainability. Alien species invasions have been hypothesized to be important to zoonotic diseases by introducing both existing and novel pathogens to invaded ranges. Howev...

Agrochemical use is predicted to increase 2-5 fold by 2050 to meet food demand. Evidence suggests that agrochemical pollution could increase snails that transmit the disease schistosomiasis to 250 million people, but most agrochemicals remain unexamined. Here we quantify the relative effects of fertilizer, six insecticides, and six herbicides on sn...

Schistosomiasis is a debilitating parasitic disease of poverty that affects more than 200 million people worldwide, mostly in sub-Saharan Africa, and is clearly associated with the construction of dams and water resource management infrastructure in tropical and subtropical areas. Changes to hydrology and salinity linked to water infrastructure dev...

Schistosomiasis is a debilitating parasitic disease of poverty that affects more than 200 million people worldwide, mostly in sub-Saharan Africa, and is clearly associated with the construction of dams and water resource management infrastructure in tropical and subtropical areas. Changes to hydrology and salinity linked to water infrastructure dev...

Bluetongue virus (BTV) is an arthropod-borne, segmented double-stranded RNA virus that can cause severe disease in both wild and domestic ruminants. BTV evolves via several key mechanisms, including the accumulation of mutations over time and the reassortment of genome segments.Additionally, BTV must maintain fitness in two disparate hosts, the ins...

Significance Predicting how ecological interactions among vectors or intermediate hosts of human parasites influence transmission potential to humans remains challenging. Here, we focus on human schistosomiasis and demonstrate how resource competition among snails profoundly alters the link between infected snails, the target of control, and schist...

Agricultural expansion is predicted to increase agrochemical use two to fivefold by 2050 to meet food demand. Experimental evidence suggests that agrochemical pollution could increase snails that transmit schistosomiasis, a disease impacting 250 million people, yet most agrochemicals remain unexamined. Here we experimentally created >100 natural we...

Heterogeneities in infections among host populations may arise through differences in environmental conditions through two mechanisms. First, environmental conditions may alter host exposure to pathogens via effects on survival. Second, environmental conditions may alter host susceptibility, making infection more or less likely if contact between a...

Introduced hosts are capable of introducing parasite species and altering the abundance of parasites that are already present in native hosts, but few studies have compared the tolerances of native and invasive hosts to introduced parasites or identified the traits of introduced hosts that make them supershedders of non‐native parasites. Here, we c...

Freshwater systems are critical to life on earth, yet they are threatened by the increasing rate of synthetic chemical pollution. Current predictions of the effects of synthetic chemicals on freshwater ecosystems are hampered by the sheer number of chemical contaminants entering aquatic systems, the diversity of organisms inhabiting these systems,...

Schistosome parasites infect more than 200 million people annually, mostly in sub-Saharan Africa, where people may be co-infected with more than one species of the parasite. Infection risk for any single species is determined, in part, by the distribution of its obligate intermediate host snail. As the World Health Organization reprioritizes snail...

Habitat loss and disease outbreak play a major role in the decline of biodiversity. Habitat degradation is often associated with reduced food resources, which can lead to less investment in host immunity and increased infections. However, pathogens use host resources for replication and pathogen traits, such as infecting hosts internally or short g...

Schistosomiasis is becoming more persistent because of the widespread distribution of intermediate host snails in several regions of Africa, including Senegal. The intermediate snail host of the human intestinal schistosome is Biomphalaria pfeifferi and is permanently present in northern Senegal because of the presence of the abundant freshwater ha...

Predicting the outcome and strength of species interactions is a central goal of community ecology. Researchers have proposed that outcomes of species interactions (competitive exclusion and coexistence) are a function of both phylogenetic relatedness and functional similarity. Studies relating phylogenetic distance to competition strength have sho...

Lethal and sublethal effects of pathogens should theoretically select for host avoidance of these pathogenic organisms. Some amphibians can learn to avoid the pathogenic fungus Batrachochytrium dendrobatidis (Bd) after one infection‐clearance event. Here, we investigated whether four taxonomically distinct amphibians, Cuban tree frogs Osteopilus se...

The herbicide atrazine is one of the most commonly used, well studied, and controversial pesticides on the planet. Much of the controversy involves the effects of atrazine on wildlife, particularly amphibians, and the ethically questionable decision making of members of industry, government, the legal system, and institutions of higher education, i...

Habitat loss and disease outbreak play a major role in the decline of biodiversity. Habitat degradation is often associated with reduced food resources, which can lead to less investment in host immunity and increased infections. However, pathogens use host resources for replication and pathogen traits, such as infecting hosts internally or short g...

A bstract Understanding local-scale variability in disease dynamics can be important for informing strategies for surveillance and management. For example, the amphibian chytrid fungus ( Batrachochytrium dendrobatidis ; Bd), which is implicated in population declines and species extinctions of amphibians, causes spatially variable epizootics and ex...

Temperature constrains the transmission of many pathogens. Interventions that target temperature-sensitive life stages, such as vector control measures that kill intermediate hosts, could shift the thermal optimum of transmission, thereby altering seasonal disease dynamics and rendering interventions less effective at certain times of the year and...

Introduced species pose a threat to biodiversity, and ecological and physiological factors are important in determining whether an introduced species becomes successfully established in a new region. Locomotor performance is one such factor that can influence the abundance and distribution of an introduced species. We investigated the effects of te...

Research on the ‘ecology of fear’ posits that defensive prey responses to avoid predation can cause non-lethal effects across ecological scales. Parasites also elicit defensive responses in hosts with associated non-lethal effects, which raises the longstanding, yet unresolved question of how non-lethal effects of parasites compare with those of pr...

Dams enable the production of food and renewable energy, making them a crucial tool for both economic development and climate change adaptation in low- and middle-income countries. However, dams may also disrupt traditional livelihood systems and increase the transmission of vector- and water-borne pathogens. These livelihood and health impacts dim...

In an era of unprecedented human impacts on the planet, macrosystems biology (MSB) was developed to understand ecological patterns and processes within and across spatial and temporal scales. We used machine‐learning and qualitative literature review approaches to evaluate the thematic composition of MSB from articles published since the 2010 creat...

A Correction to this paper has been published: https://doi.org/10.1038/s41467-020-20854-1.

Priority effect theory, a foundational concept from community ecology, states that the order and timing of species arrival during species assembly can affect species composition. Although this theory has been applied to co‐infecting parasite species, it has almost always been with a single time lag between co‐infecting parasites. Thus, how the timi...

Agrochemical use is predicted to increase 2-5 fold by 2050 to meet food demand. Evidence suggests that agrochemical pollution could increase snails that transmit the disease schistosomiasis to 250 million people, but most agrochemicals remain unexamined. Here we quantify the relative effects of fertilizer, six insecticides, and six herbicides on sn...

Use of agrochemicals, including insecticides, is vital to food production and predicted to increase 2-5 fold by 2050. Previous studies have shown a positive association between agriculture and the human infectious disease schistosomiasis, which is problematic as this parasitic disease infects approximately 250 million people worldwide. Certain inse...

Predicting ecological effects of contaminants remains challenging because of the sheer number of chemicals and their ambiguous role in biodiversity-ecosystem function relationships. We evaluate responses of experimental pond ecosystems to standardized concentrations of 12 pesticides, nested in four pesticide classes and two pesticide types. We show...

Climate change is expected to have complex effects on infectious diseases, causing some to increase, others to decrease, and many to shift their distributions. There have been several important advances in understanding the role of climate and climate change on wildlife and human infectious disease dynamics over the past several years. This essay e...

Climate change alters disease risks Climate change appears to be provoking changes in the patterns and intensity of infectious diseases. For example, when conditions are cool, amphibians from warm climates experience greater burdens of infection by chytrid fungus than hosts from cool regions. Cohen et al. undertook a global metanalysis of 383 studi...

Understanding how alien species assemble is crucial for predicting changes to community structure caused by biological invasions and for directing management strategies for alien species, but patterns and drivers of alien species assemblages remain poorly understood relative to native species. Climate has been suggested as a crucial filter of invas...

A bstract Current predictions of the effects of synthetic chemicals on freshwater ecosystems are hampered by the sheer number of chemical contaminants entering aquatic systems, the diversity of organisms inhabiting these systems, and uncertainties about how contaminants alter ecosystem metabolism. We conducted a mesocosm experiment that elucidated...

Paragraph Vector-borne disease incidences are increasing globally ¹ . In the United States, tick-borne disease cases have tripled since the 1990s 2,3 and cost upwards of 10 billion USD annually 4,5 . Reactive antibiotics can be ineffective at preventing life-long symptoms of tick-borne diseases ⁶ ; thus, disease prevention is vital 1,7,8 . Tick den...

The temperature-dependence of many important mosquito-borne diseases has never been quantified. These relationships are critical for understanding current distributions and predicting future shifts from climate change. We used trait-based models to characterize temperature-dependent transmission of 10 vector-pathogen pairs of mosquitoes (Culex pipi...