lack of detailed information about the species’ life history (e.g., reproduction, seed bank characteristics, dispersal) (MacKay 2003) and its likely high responsiveness to wet/drought cycles make it difficult to assess population trends and to implement appropriate conservation and management measures. Management and Monitoring Considerations MacKay (2003) identified several research needs for informing management of Cushenbury milk-vetch. Foremost, there needs to be research on life history traits and habitat requirements. An understanding of reproductive traits (e.g., responses to environmental conditions, flowering and fruiting, longevity, seed viability) is necessary to monitor population trends and to identify triggers for management. An understanding of mycorrhizal associations and soil nutrients and textures is important for the purpose of managing, enhancing, and reintroducing populations (MacKay 2003). Understanding these factors will also allow for distinguishing population fluctuations and trends related to natural stochastic factors (e.g., rainfall) from anthropogenic factors. An understanding of these factors will also help inform establishment of buffers and habitat linkages needed to protect the integrity of disjunctive populations. Predicted Species Distribution in Plan Area A proxy model for suitable habitat for Cushenbury milk-vetch in the Plan Area was developed using spatial data for suitable and occupied habitat in the Carbonate Habitat Management Strategy (Olsen 2003). There are 66,407 acres of suitable habitat for Cushenbury milk-vetch in the Plan Area. Appendix C includes specific model parameters and a figure showing the modeled suitable habitat in the Plan Area. Literature Cited 67 FR 78570–78610. Final Rule: and Threatened “Endangered Wildlife and Plants; Designation of Critical Habitat for Five Carbonate Plants from the San Bernardino Mountains in Southern California.” December 24, 2002.
lack of detailed information about the species’ life history (e.g., reproduction, seed bank characteristics, dispersal) (MacKay 2003) and its likely high responsiveness to wet/drought cycles make it difficult to assess population trends and to implement appropriate conservation and management measures. Management and Monitoring Considerations MacKay (2003) identified several research needs for informing management of Cushenbury milk-vetch. Foremost, there needs to be research on life history traits and habitat requirements. An understanding of reproductive traits (e.g., responses to environmental conditions, flowering and fruiting, longevity, seed viability) is necessary to monitor population trends and to identify triggers for management. An understanding of mycorrhizal associations and soil nutrients and textures is important for the purpose of managing, enhancing, and reintroducing populations (MacKay 2003). Understanding these factors will also allow for distinguishing population fluctuations and trends related to natural stochastic factors (e.g., rainfall) from anthropogenic factors. An understanding of these factors will also help inform establishment of buffers and habitat linkages needed to protect the integrity of disjunctive populations. Predicted Species Distribution in Plan Area A proxy model for suitable habitat for Cushenbury milk-vetch in the Plan Area was developed using spatial data for suitable and occupied habitat in the Carbonate Habitat Management Strategy (Olsen 2003). There are 66,407 acres of suitable habitat for Cushenbury milk-vetch in the Plan Area. Appendix C includes specific model parameters and a figure showing the modeled suitable habitat in the Plan Area. Literature Cited 67 FR 78570–78610. Final Rule: “Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Five Carbonate Plants from the San Bernardino Mountains in Southern California.” December 24, 2002.
Cushenbury%20Milk-vetch.docx