US NSF LTER sites

US NSF National Ecological Observatory Network New network for addressing major ecological questions, with Infectious Disease as one major theme Planning for the next 30 years General website Website with latest reports from topics committees (prior to specifying particular systems) : neon_des.html#more neon_des.html#more

Tallgrass prairie in central USA Long-term foliar infection in tallgrass prairie plants

Not as flat as a pancake Flint Hills, Kansas, USA

Variable Burn Interval Annual 2 year 4 year 10 year 20 year Grazing Bison Cattle KONZA PRAIRIE BIOLOGICAL STATION N 3,487 Ha

Long-term plant species composition data Long-term data set with complete plant species cover classes collected in many environments at Konza Prairie See

Sampling scheme within a transect for plant species composition assessment Five quadrats are located along each transect In general, four upland transects and four lowland transects are present in each watershed

Precipitation manipulation – RaMP project

Most important environmental effects Burning is not so important across species (during drought years), but is for some particular species Position on slope is the most important environmental predictor Grazing effects were quite specific to host- pathogen system Host frequency dependence was indicated

Overall effects of burning (during 3 drought years)

Effects of burning on rust of Erigeron strigosus Dendy et al., in preparation

Topographic effect on big bluestem rust Rates of infection by Puccinia andropogonis are greater for midslope sites than bottom or crest sites (P≤0.05) Morgan, Garrett, Todd, and Tisserat (in revision) Crest Midslope Bottom

Precipitation effects on disease A community epidemiology approach studying the responses of visually-distinguishable pathogens of 20 dominant tallgrass prairie plant species Responses to burn return time and topography are less consistent from one host-pathogen system to another and may contribute to stability of plant productivity Garrett et al. (in preparation)

Flowering in Dalea candida as a function of precipitation level and leaf rust infection Garrett et al. (in preparation)

Pathogen HostEnvironment Pathogen community Plant community Environment Agricultural (Managed) SystemNatural (Unmanaged) System External pathogen community Movement of pathogens between agricultural and natural systems and external pathogen populations

BYDV infection in native grasses Grass speciesPAVMAVRMVRPVSGW Indian grass00000 Little bluestem Switchgrass Big bluestem First report of BYDV/CYDV in these grass species: percentage infection based on at least 50 plants of each species PAV is the most common strain in wheat, but was not recovered from the grasses at Konza Prairie In wheat, infection rates by the “tallgrass prairie” strains were common adjacent to prairie but fell off 30 m into wheat fields Garrett, Dendy, Power, Blaisdell, Alexander, and McCarron 2004 Plant Disease

Susceptibility of native grasses to take-all Grass speciesResponse Big bluestemR Little bluestemR Indian grassR SwitchgrassR Sideoats gramaS Blue gramaS Buffalo grassS Native grass seedlings showed nearly complete resistance or susceptibility to the take- all pathogen Exchange between agricultural and natural systems needs study In grasslands there is the potential for apparent competition via shared pathogens Cox, Garrett, Bockus, and Fang (in review)

Ecological genomics and epidemiology Garrett et al., in review

In a study of the dominant tallgrass prairie plant species, Andropogon gerardii, we have been able to detect responses to simulated precipitation change in the field using maize microarrays Travers et al., in review

Systemic acquired resistance (Need nomenclature for new forms of resistance as they are understood) Infection with an incompatible pathogen, or virulent pathogen that causes cell death, can make a plant more resistant to subsequent infection by the same or different pathogens –SAR response in Arabidopsis confers resistance to several diseases (Ryals et al. 1996)

Induced systemic resistance Resistance to pathogens can be influenced by non-pathogenic organisms Systemic changes in disease resistance in response to colonization by rhizosphere- colonizing Pseudomonas have been well- documented (Iavicoli et al. 2003, Cui et al. 2005) Dissection of SAR and ISR signaling systems in Arabidopsis indicate they are controlled by different pathways and signaling molecules with some common components

Landscape ecological genomics Garrett et al., in review