Activities to be performed the purpose of this project is to provide critical information that is needed to develop and implement strategies to protect ione manzanita arctostaphylos myrtifolia…

The University of California, Davis was awarded a $238,895 cooperative agreement from the U.S. Department of the Interior, Bureau of Land Management under the Threatened and Endangered Species Program (CFDA 15.246). The purpose of this 4-year project is to develop and implement strategies to protect the threatened Ione manzanita (Arctostaphylos myrtifolia) from mortality caused by the introduced root pathogen Phytophthora cinnamomi. Key objectives include: 1) Evaluating whether phosphite treatments can slow the spread of the pathogen from infested to healthy Ione manzanita stands, 2) Mapping the current geographic distribution of the pathogen within the plant's habitat, and 3) Investigating epidemiological factors related to pathogen persistence and spread. Expected deliverables include a treatment protocol, updated GIS maps of pathogen distribution, remote sensing methods for continued monitoring, and data on pathogen persistence in soil.

Activities to be performed the purpose of this project is to provide critical information that is needed to develop and implement strategies to protect ione manzanita arctostaphylos myrtifolia stands from mortality caused by the introduced root pathogen phytophthora cinnamomi. Ione manzanita is a listed threatened species that is one of very few species that thrives in the extremely acidic and droughty soils of the ione formation. P. Cinnamomi has completely eliminated ione manzanita from large portions of its previous range, and due to the persistence of this pathogen, no recovery has been evident within affected areas. To conserve existing a. Myrtifolia populations, IT is necessary to employ strategies that minimize the spread of p. Cinnamomi from existing infestations to protect ione manzanitas dwindling habitat. Our objectives are to 1 determine if ultra low volume applications of potassium phosphite to bands of healthy a. Myrtifolia adjacent to mortality centers can slow the spread of phytophthora root ROT caused by p. Cinnamomi from infested areas to healthy native stands of a. Myrtifolia 2 determine the current geographic distribution and extent of p. Cinnamomi within the range of a. Myrtifolia and 3 investigate aspects of disease epidemiology related to pathogen persistence and spread to fill data gaps and inform disease management strategies.expected deliverables outcomes from this study will include 1 a protocol for treating ione manzanita with phosphite to slow the spread of p. Cinnamomi into healthy stands 2 GIS layers showing the updated distribution of mortality due to p. Cinnamomi within ione manzanita habitat 3 validated remote sensing methodology that can be used to continue monitoring the distribution and spread of p. Cinnamomi in ione manzanita habitat 4 data on the persistence of p. Cinnamomi in soil over time in the absence of host plants 5 data indicating which plants that persist in p. Cinnamomiinfested soil are capable of producing p. Cinnamomi inoculum 6 data indicating the depth to which p. Cinnamomi inoculum is distributed in infested soils 7 recommendations for managing both infested and noninfested sites to prevent or minimize additional impacts to ione manzanita populations, including whether infested sites could be treated to allow successful reintroduction of ione manzanita. These study outcomes will benefit USFWS, BLM, cdfw, local governments, native tribes, and others who seek to protect ione manzanita and the integrity of the ione chaparral. Intended beneficiaries ione manzanita and ione manzanita habitat, california native plant communities, native OAK species, the public for wildfire risk reduction, and land managers informed land management decision making, subrecipient activities subrecipients will work closely with the lynch lab to share expertise and existing data from apricum hill and elsewhere to minimize the typical lag and learning curve associated with new projects. Subrecipients have conducted previous research on phosphite applications to ione manzanita at apricum hill and elsewhere and will take the lead role in establishing and treating plots.