{"title":"Western Prairie Fringed Orchid Management, Ecology, and Decline\nat Mormon Island","authors":"Andrew J. Caven","doi":"10.32873/unl.dc.tnas.42.1","DOIUrl":null,"url":null,"abstract":"The western prairie fringed orchid (Platanthera praeclara Sheviak & M. L. Bowles; WPFO) was first detected in a vegetative state on\nMormon Island in 1978 and identification was confirmed following a mass flowering event in 1982. From a high count of ~60 plants\nthe WPFO slowly declined and has not been observed since 2000 despite flowering season surveys conducted in 15 of the last 20\nyears. We explore the natural history of the WPFO in the contexts of Mormon Island to establish potential causes for its apparent\ndisappearance and evaluate the possibility it persists in some capacity. Our investigation of secondary data suggests the Mormon\nIsland vegetation community remains relatively intact, including species associated with WPFO occurrence. Examination of the\nranges of known and potential WPFO pollinators suggests that Sphinx drupiferarum, Eumorpha achemon, and Hyles lineata were the\nmost likely pollinators at Mormon Island, and recent observations of these species indicate pollinator decline may not have been\na primary factor in WPFO disappearance locally. Research demonstrates individual WPFOs can occasionally live for decades, are\nable to survive underground as rhizomes for periods of time, and often present above ground as just 1–3 leaves during the growing\nseason. Additionally, the seeds may persist in the soil for a substantial period of time. The WPFO appears to tolerate a reasonably\nwide range of habitat conditions and management regimes but may require a relatively narrow range of circumstances to flower\nen masse, including above average spring precipitation in subsequent years. Mass flowering events may also be stimulated by early\nspring burns that precede above ground vegetative growth and subsequent rest during the growing season, but research is equivocal.\nThough factors such as inbreeding depression and herbicide overspray could have potentially impacted the population, based\non local conditions we suggest the WPFO may persist on Mormon Island in a reduced capacity. We recommend the continuation of\ngrowing season surveys and experimentation with multi-year management strategies that could stimulate growth and flowering.\nKeywords: Western prairie fringed orchid, Platanthera praeclara, Management, Pollination, Ecology, Central Platte River Valley,\nSphingidae","PeriodicalId":91981,"journal":{"name":"Transactions of the Nebraska Academy of Sciences and affiliated societies","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2022-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"1","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Transactions of the Nebraska Academy of Sciences and affiliated societies","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.32873/unl.dc.tnas.42.1","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 1
Abstract
The western prairie fringed orchid (Platanthera praeclara Sheviak & M. L. Bowles; WPFO) was first detected in a vegetative state on
Mormon Island in 1978 and identification was confirmed following a mass flowering event in 1982. From a high count of ~60 plants
the WPFO slowly declined and has not been observed since 2000 despite flowering season surveys conducted in 15 of the last 20
years. We explore the natural history of the WPFO in the contexts of Mormon Island to establish potential causes for its apparent
disappearance and evaluate the possibility it persists in some capacity. Our investigation of secondary data suggests the Mormon
Island vegetation community remains relatively intact, including species associated with WPFO occurrence. Examination of the
ranges of known and potential WPFO pollinators suggests that Sphinx drupiferarum, Eumorpha achemon, and Hyles lineata were the
most likely pollinators at Mormon Island, and recent observations of these species indicate pollinator decline may not have been
a primary factor in WPFO disappearance locally. Research demonstrates individual WPFOs can occasionally live for decades, are
able to survive underground as rhizomes for periods of time, and often present above ground as just 1–3 leaves during the growing
season. Additionally, the seeds may persist in the soil for a substantial period of time. The WPFO appears to tolerate a reasonably
wide range of habitat conditions and management regimes but may require a relatively narrow range of circumstances to flower
en masse, including above average spring precipitation in subsequent years. Mass flowering events may also be stimulated by early
spring burns that precede above ground vegetative growth and subsequent rest during the growing season, but research is equivocal.
Though factors such as inbreeding depression and herbicide overspray could have potentially impacted the population, based
on local conditions we suggest the WPFO may persist on Mormon Island in a reduced capacity. We recommend the continuation of
growing season surveys and experimentation with multi-year management strategies that could stimulate growth and flowering.
Keywords: Western prairie fringed orchid, Platanthera praeclara, Management, Pollination, Ecology, Central Platte River Valley,
Sphingidae