Pub Date : 2020-07-31DOI: 10.2179/0008-7475.85.2.244
Eileen S. Nakahata, Douglas A. DeBerry, Joseph A. Thompson
ABSTRACT We completed a floristic inventory of the James River Park System (JRPS), a ca. 223-hectare (550-acre) multi-unit park along the James River in Richmond, Virginia. The JRPS includes land within the riparian zone along a 13-kilometer (8-mile) stretch of the river that bisects the city, providing two million annual visitors with recreational access to the rapids along the “Falls of the James.” Although the vegetation within the park system is an important attraction for park-goers, information on the flora of the JRPS and this section of the James River corridor is limited. This study updates partial records of the JRPS flora from ca. 50 years ago with collections that were made over the span of three growing seasons from 2016–2018. A total of 566 species and sub-specific taxa were documented from 336 genera and 115 families, including 63 new botanical records for the locality. Native species comprise 69.4% of the overall species richness, with dominant families including Asteraceae, Poaceae, and Cyperaceae. Non-native invasive species are prevalent throughout the park: 51 species are listed on the Virginia Invasive Plant Species List, 21 of which carry a “high” invasiveness rank. Four state-listed rare species were documented within the park, and seven other state-rare “watchlist” species were found. The information presented here is being used to help guide management efforts of the JRPS Invasive Plant Task Force, an organization dedicated to the removal of non-native invasive species, restoration of natural habitats, and preservation of natural communities within the park system.
{"title":"Floristic Inventory of the James River Park System, Richmond, Virginia","authors":"Eileen S. Nakahata, Douglas A. DeBerry, Joseph A. Thompson","doi":"10.2179/0008-7475.85.2.244","DOIUrl":"https://doi.org/10.2179/0008-7475.85.2.244","url":null,"abstract":"ABSTRACT We completed a floristic inventory of the James River Park System (JRPS), a ca. 223-hectare (550-acre) multi-unit park along the James River in Richmond, Virginia. The JRPS includes land within the riparian zone along a 13-kilometer (8-mile) stretch of the river that bisects the city, providing two million annual visitors with recreational access to the rapids along the “Falls of the James.” Although the vegetation within the park system is an important attraction for park-goers, information on the flora of the JRPS and this section of the James River corridor is limited. This study updates partial records of the JRPS flora from ca. 50 years ago with collections that were made over the span of three growing seasons from 2016–2018. A total of 566 species and sub-specific taxa were documented from 336 genera and 115 families, including 63 new botanical records for the locality. Native species comprise 69.4% of the overall species richness, with dominant families including Asteraceae, Poaceae, and Cyperaceae. Non-native invasive species are prevalent throughout the park: 51 species are listed on the Virginia Invasive Plant Species List, 21 of which carry a “high” invasiveness rank. Four state-listed rare species were documented within the park, and seven other state-rare “watchlist” species were found. The information presented here is being used to help guide management efforts of the JRPS Invasive Plant Task Force, an organization dedicated to the removal of non-native invasive species, restoration of natural habitats, and preservation of natural communities within the park system.","PeriodicalId":50984,"journal":{"name":"Castanea","volume":"85 1","pages":"244 - 258"},"PeriodicalIF":0.4,"publicationDate":"2020-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42339328","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-07-31DOI: 10.2179/0008-7475.85.2.259
Stephen Bendele, Lucas J. Sharett, R. Atkinson
ABSTRACT Peatlands in the mid-Atlantic outer coastal plain region contain obligate hydrophyte species which were harvested and replaced by facultative tree species. The Great Dismal Swamp was drained from the colonial era until 1974, when water levels were partially restored. In September 2013, further restoration consisting of two large weirs followed extensive peat-burning fires. This study evaluated depth-to-water-table and vegetation structure both prior to and following weir operation. Wells were installed and depth-to-water-table was recorded continuously from 2013 to 2015 within six of the 15 forested stands where vegetation species dominance was quantified for tree, shrub, herb, and vine strata. Following weir installation in 2013, water tables rose an average of 28.08 cm in 2014 and 32.69 cm in 2015, during the June–July peak of the growing season. Most water levels were too low to meet the federal regulatory indicator of wetland hydrology or the seasonally flooded, saturated hydrologic regime typical of peatlands. After restoration, species dominance and frequency, as well as metrics based on hydrophyte dominance and floristic quality in study plots, were unchanged. Ordinations detected no directional shift in plant community composition among pre- and post-weir periods. Although insufficient time may have passed for shifts in plant communities, additional increases in water level above those reported here appear necessary to restore a pre-disturbance hydrologic regime and plant community structure. However, above some threshold water level, planted trees will exhibit increased mortality and limit reestablishment.
{"title":"Plant Community Response to Hydrologic Restoration in the Great Dismal Swamp","authors":"Stephen Bendele, Lucas J. Sharett, R. Atkinson","doi":"10.2179/0008-7475.85.2.259","DOIUrl":"https://doi.org/10.2179/0008-7475.85.2.259","url":null,"abstract":"ABSTRACT Peatlands in the mid-Atlantic outer coastal plain region contain obligate hydrophyte species which were harvested and replaced by facultative tree species. The Great Dismal Swamp was drained from the colonial era until 1974, when water levels were partially restored. In September 2013, further restoration consisting of two large weirs followed extensive peat-burning fires. This study evaluated depth-to-water-table and vegetation structure both prior to and following weir operation. Wells were installed and depth-to-water-table was recorded continuously from 2013 to 2015 within six of the 15 forested stands where vegetation species dominance was quantified for tree, shrub, herb, and vine strata. Following weir installation in 2013, water tables rose an average of 28.08 cm in 2014 and 32.69 cm in 2015, during the June–July peak of the growing season. Most water levels were too low to meet the federal regulatory indicator of wetland hydrology or the seasonally flooded, saturated hydrologic regime typical of peatlands. After restoration, species dominance and frequency, as well as metrics based on hydrophyte dominance and floristic quality in study plots, were unchanged. Ordinations detected no directional shift in plant community composition among pre- and post-weir periods. Although insufficient time may have passed for shifts in plant communities, additional increases in water level above those reported here appear necessary to restore a pre-disturbance hydrologic regime and plant community structure. However, above some threshold water level, planted trees will exhibit increased mortality and limit reestablishment.","PeriodicalId":50984,"journal":{"name":"Castanea","volume":"85 1","pages":"259 - 276"},"PeriodicalIF":0.4,"publicationDate":"2020-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46617395","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-07-31DOI: 10.2179/0008-7475.85.2.296
A. Floden, T. Avent, Z. Hill, B. Keener
ABSTRACT Clinopodium talladeganum B.R. Keener & Floden is described as a new species from the Talladega Mountains, Alabama, United States. Morphological differences were compared and analyzed using PCA which supported it as a distinct morphological cluster when compared to the sympatric C. georgianum. An updated key to the genus is provided for the southeastern United States.
{"title":"A New Species of Clinopodium (Lamiaceae) from Alabama","authors":"A. Floden, T. Avent, Z. Hill, B. Keener","doi":"10.2179/0008-7475.85.2.296","DOIUrl":"https://doi.org/10.2179/0008-7475.85.2.296","url":null,"abstract":"ABSTRACT Clinopodium talladeganum B.R. Keener & Floden is described as a new species from the Talladega Mountains, Alabama, United States. Morphological differences were compared and analyzed using PCA which supported it as a distinct morphological cluster when compared to the sympatric C. georgianum. An updated key to the genus is provided for the southeastern United States.","PeriodicalId":50984,"journal":{"name":"Castanea","volume":"85 1","pages":"296 - 306"},"PeriodicalIF":0.4,"publicationDate":"2020-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42265415","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-07-31DOI: 10.2179/0008-7475.85.2.285
J. Rentsch, Landon J. Hardee, Caroline E. Shelley, M. Williams
ABSTRACT Neottia bifolia is a small, terrestrial orchid distributed across the southeastern United States and northward up the Atlantic coast into Canada. The genus is well-studied as a model for the evolution of mycoheterotrophy, having both chlorophyllous and putatively achlorophyllous taxa. Despite this, the photosynthetic species, N. bifolia is relatively understudied. We provide results from the sequencing, assembly, and annotation of the complete plastid genome of N. bifolia and examine some evolutionary trends in the genus, using the 10 additional complete Neottia plastid genomes available on GenBank. We find that the plastid genome of N. bifolia is 156,533 base pairs in length with 130 protein-coding genes, including 38 tRNA genes and eight rRNA genes. We find a similar number of rRNAs and tRNAs across the genus, but significantly fewer protein coding genes and an overall smaller plastid genome size in the mycoheterotrophic species. We find support for the monophyly of the mycoheterotrophic species. The placement of N. bifolia varies slightly between inferences, but the species is most frequently placed in a clade with Neottia cordata, Neottia japonica, and Neottia suzuki.
{"title":"The Complete Plastid Genome of Neottia bifolia (Raf.) Baumbach (Orchidaceae): Insights Into Chlorophyllous and Achlorophyllous Plastid Genomes","authors":"J. Rentsch, Landon J. Hardee, Caroline E. Shelley, M. Williams","doi":"10.2179/0008-7475.85.2.285","DOIUrl":"https://doi.org/10.2179/0008-7475.85.2.285","url":null,"abstract":"ABSTRACT Neottia bifolia is a small, terrestrial orchid distributed across the southeastern United States and northward up the Atlantic coast into Canada. The genus is well-studied as a model for the evolution of mycoheterotrophy, having both chlorophyllous and putatively achlorophyllous taxa. Despite this, the photosynthetic species, N. bifolia is relatively understudied. We provide results from the sequencing, assembly, and annotation of the complete plastid genome of N. bifolia and examine some evolutionary trends in the genus, using the 10 additional complete Neottia plastid genomes available on GenBank. We find that the plastid genome of N. bifolia is 156,533 base pairs in length with 130 protein-coding genes, including 38 tRNA genes and eight rRNA genes. We find a similar number of rRNAs and tRNAs across the genus, but significantly fewer protein coding genes and an overall smaller plastid genome size in the mycoheterotrophic species. We find support for the monophyly of the mycoheterotrophic species. The placement of N. bifolia varies slightly between inferences, but the species is most frequently placed in a clade with Neottia cordata, Neottia japonica, and Neottia suzuki.","PeriodicalId":50984,"journal":{"name":"Castanea","volume":"85 1","pages":"285 - 295"},"PeriodicalIF":0.4,"publicationDate":"2020-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46329475","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-06-09DOI: 10.2179/0008-7475.85.1.14
Eric T. Allen, Karen E. Powers, Christine J. Small, T. Wieboldt
ABSTRACT Fifty-seven county records, representing 56 species and 28 vascular plant families, are reported here as new additions to the Virginia flora. All voucher specimen are housed in the Radford University Herbarium (RUHV). Our study examined the entirety of the nearly 10,000-specimen collection at Radford University. Each specimen was manually cross-referenced with current county records; when potentially new county records were discovered, identifications were verified. We also determined whether any new county records were listed as state-, federally-, or globally-imperiled. Among the county records, we also determined the number and distribution of non-native and potentially invasive species. Most specimens were collected from Virginia's Appalachian Mountain region. Of the 56 species, two have conservation ratings of globally and state “vulnerable” (Monotropsis odorata and Aconitum reclinatum). Several others are “globally secure” but of concern in Virginia, including two state-imperiled species (Calopogon tuberosus and Stylophorum diphyllum) and three vulnerable species (Carex shortiana, Pogonia ophioglossoides, and Stachys latidens). We also document the first county records of three invasive species (Ludwigia grandiflora ssp. hexapetala, Poa trivialis, and Securigeria varia). These contributions show how smaller herbarium collections contribute to our understanding of Virginia's natural history and native and non-native flora.
{"title":"Noteworthy Collections: County Additions to the Virginia Flora Vouchered at the Radford University Herbarium","authors":"Eric T. Allen, Karen E. Powers, Christine J. Small, T. Wieboldt","doi":"10.2179/0008-7475.85.1.14","DOIUrl":"https://doi.org/10.2179/0008-7475.85.1.14","url":null,"abstract":"ABSTRACT Fifty-seven county records, representing 56 species and 28 vascular plant families, are reported here as new additions to the Virginia flora. All voucher specimen are housed in the Radford University Herbarium (RUHV). Our study examined the entirety of the nearly 10,000-specimen collection at Radford University. Each specimen was manually cross-referenced with current county records; when potentially new county records were discovered, identifications were verified. We also determined whether any new county records were listed as state-, federally-, or globally-imperiled. Among the county records, we also determined the number and distribution of non-native and potentially invasive species. Most specimens were collected from Virginia's Appalachian Mountain region. Of the 56 species, two have conservation ratings of globally and state “vulnerable” (Monotropsis odorata and Aconitum reclinatum). Several others are “globally secure” but of concern in Virginia, including two state-imperiled species (Calopogon tuberosus and Stylophorum diphyllum) and three vulnerable species (Carex shortiana, Pogonia ophioglossoides, and Stachys latidens). We also document the first county records of three invasive species (Ludwigia grandiflora ssp. hexapetala, Poa trivialis, and Securigeria varia). These contributions show how smaller herbarium collections contribute to our understanding of Virginia's natural history and native and non-native flora.","PeriodicalId":50984,"journal":{"name":"Castanea","volume":"85 1","pages":"14 - 22"},"PeriodicalIF":0.4,"publicationDate":"2020-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41640830","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-06-09DOI: 10.2179/0008-7475.85.1.169
Chris T. Taylor, T. Barger, Evan Kilburn, Alfred R. Schotz, C. Hansen, L. Goertzen
ABSTRACT Initially formed as a Civilian Conservation Corps camp in 1935, Chewacla State Park is a 282 ha property established in 1939. The park is currently managed by the Alabama Department of Conservation and Natural Resources, State Parks Division as a public recreational resource. A floral survey of this area was conducted from August 2014 through May 2019. A total of 704 species (incl. five hybrids) from 415 genera and 137 families were collected in the park. Asteraceae was the largest family with 98 species. Poaceae, Fabaceae, and Cyperaceae were the next largest families with 72, 48, and 48 species, respectively. Carex (Cyperaceae) was the largest genus, represented by 25 species. Seventy species are reported for the first time from Lee County, and one for the state of Alabama. One hundred and thirty-nine (19.7%) non-native species were collected during the surveys. Voucher plant collections made for this study are held at the Alabama Natural Heritage Section Herbarium (ALNHS) and the John D. Freeman Herbarium (AUA) with duplicates sent to the Anniston Museum of Natural History Herbarium (AMAL) and New York Botanical Gardens (NYBG).
{"title":"The Vascular Flora of Chewacla State Park, Lee County, Alabama","authors":"Chris T. Taylor, T. Barger, Evan Kilburn, Alfred R. Schotz, C. Hansen, L. Goertzen","doi":"10.2179/0008-7475.85.1.169","DOIUrl":"https://doi.org/10.2179/0008-7475.85.1.169","url":null,"abstract":"ABSTRACT Initially formed as a Civilian Conservation Corps camp in 1935, Chewacla State Park is a 282 ha property established in 1939. The park is currently managed by the Alabama Department of Conservation and Natural Resources, State Parks Division as a public recreational resource. A floral survey of this area was conducted from August 2014 through May 2019. A total of 704 species (incl. five hybrids) from 415 genera and 137 families were collected in the park. Asteraceae was the largest family with 98 species. Poaceae, Fabaceae, and Cyperaceae were the next largest families with 72, 48, and 48 species, respectively. Carex (Cyperaceae) was the largest genus, represented by 25 species. Seventy species are reported for the first time from Lee County, and one for the state of Alabama. One hundred and thirty-nine (19.7%) non-native species were collected during the surveys. Voucher plant collections made for this study are held at the Alabama Natural Heritage Section Herbarium (ALNHS) and the John D. Freeman Herbarium (AUA) with duplicates sent to the Anniston Museum of Natural History Herbarium (AMAL) and New York Botanical Gardens (NYBG).","PeriodicalId":50984,"journal":{"name":"Castanea","volume":"85 1","pages":"169 - 184"},"PeriodicalIF":0.4,"publicationDate":"2020-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44376538","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-06-09DOI: 10.2179/0008-7475.85.1.159
Justin P. Williams, T. Hawkins
ABSTRACT Curculio and Conotrachelus weevils (Coleoptera: Curculionidae) can render the majority of North American Quercus spp. acorn crops nonviable, thereby reducing food resources for wildlife and limiting opportunities for seedling establishment. Acorn predation by weevils at the individual tree level can be influenced by many factors, and research specifically investigating acorn predation by weevils in seasonally flooded bottomland oak forests is lacking. We placed cone emergence traps in a periodically flooded forest on the Sam D. Hamilton Noxubee National Wildlife Refuge near Brooksville, Mississippi to obtain weevil population parameter estimates, record emergence phenologies, and identify variables that may aid in understanding tree-to-tree variability in acorn predation rates. Forty-three Curculio weevils representing five species emerged from mid-August through early November, and 56% of those captured emerged over an 11-day period in mid-September. Sixty-four Conotrachelus weevils representing two species emerged from mid-August through late November and occurred at nearly twice the density of Curculio weevils. The exotic Asiatic oak weevil, Crytepistomus castaneus, a minor defoliator, emerged from August through early November. We also identified Quercus density, specifically the proportion of oaks that immediately neighbor the host tree, as a potentially important explanatory variable of acorn predation by weevils at the tree level in bottomland forest habitats.
摘要/ ABSTRACT摘要:象鼻虫和圆锥象鼻虫(鞘翅目:象鼻虫科)能使大部分北美栎属橡子作物无法生存，从而减少野生动物的食物资源，限制了幼苗建立的机会。单株水平象鼻虫对橡子的捕食受多种因素的影响，对季节性洪水淹没的洼地栎林象鼻虫对橡子的捕食缺乏专门的研究。我们在密西西比州Brooksville附近的Sam D. Hamilton Noxubee国家野生动物保护区的周期性洪水森林中放置了球果羽化陷阱，以获得象鼻虫种群参数估计，记录羽化物候，并确定可能有助于理解橡子捕食率在树与树之间变化的变量。从8月中旬到11月初，共捕获了5种43只象鼻虫，其中56%的象鼻虫在9月中旬的11天内出现。从8月中旬到11月下旬，共出现了2种Conotrachelus象鼻虫64只，其密度几乎是Curculio象鼻虫的两倍。外来的亚洲橡树象鼻虫(Crytepistomus castaneus)是一种次要的剥叶虫，从8月到11月初出现。我们还发现，在洼地森林生境中，栓皮栎密度，特别是紧挨着宿主树的橡树的比例，是象鼻虫在树水平上捕食橡子的潜在重要解释变量。
{"title":"Acorn Weevil (Coleoptera: Curculionidae) Predation Dynamics in a Mississippi Bottomland Hardwood Forest","authors":"Justin P. Williams, T. Hawkins","doi":"10.2179/0008-7475.85.1.159","DOIUrl":"https://doi.org/10.2179/0008-7475.85.1.159","url":null,"abstract":"ABSTRACT Curculio and Conotrachelus weevils (Coleoptera: Curculionidae) can render the majority of North American Quercus spp. acorn crops nonviable, thereby reducing food resources for wildlife and limiting opportunities for seedling establishment. Acorn predation by weevils at the individual tree level can be influenced by many factors, and research specifically investigating acorn predation by weevils in seasonally flooded bottomland oak forests is lacking. We placed cone emergence traps in a periodically flooded forest on the Sam D. Hamilton Noxubee National Wildlife Refuge near Brooksville, Mississippi to obtain weevil population parameter estimates, record emergence phenologies, and identify variables that may aid in understanding tree-to-tree variability in acorn predation rates. Forty-three Curculio weevils representing five species emerged from mid-August through early November, and 56% of those captured emerged over an 11-day period in mid-September. Sixty-four Conotrachelus weevils representing two species emerged from mid-August through late November and occurred at nearly twice the density of Curculio weevils. The exotic Asiatic oak weevil, Crytepistomus castaneus, a minor defoliator, emerged from August through early November. We also identified Quercus density, specifically the proportion of oaks that immediately neighbor the host tree, as a potentially important explanatory variable of acorn predation by weevils at the tree level in bottomland forest habitats.","PeriodicalId":50984,"journal":{"name":"Castanea","volume":"85 1","pages":"159 - 168"},"PeriodicalIF":0.4,"publicationDate":"2020-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47106447","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-06-09DOI: 10.2179/0008-7475.85.1.146
G. Rogers, R. Wise
ABSTRACT Mitreola petiolata and M. sessilifolia in the Loganiaceae are similar wetland annuals occurring in tropical, subtropical, and temperate regions in the southeastern U.S., Africa, Asia, and Oceania. The flowers of both species have previously been described to open briefly with an apparent window for outside pollination, followed by flower closure and massive pollen germination within the anthers with pollen tubes covering the adjacent stigma. The phenomenon was documented with field observations, floral dissections, and light and scanning electron microscopy. Both species open their flowers for a brief 6–8 hour window. Subsequently, pollen germinates within the closed or closing flower with pollen tubes completely covering the stigma. The prevalence and importance of selfing by precocious pollen germination are discussed.
{"title":"Floral Biology of Mitreola petiolata and M. sessilifolia (Loganiaceae): Chasmogamous Flowers with Massive Post-Anthesis Precocious Pollen Germination","authors":"G. Rogers, R. Wise","doi":"10.2179/0008-7475.85.1.146","DOIUrl":"https://doi.org/10.2179/0008-7475.85.1.146","url":null,"abstract":"ABSTRACT Mitreola petiolata and M. sessilifolia in the Loganiaceae are similar wetland annuals occurring in tropical, subtropical, and temperate regions in the southeastern U.S., Africa, Asia, and Oceania. The flowers of both species have previously been described to open briefly with an apparent window for outside pollination, followed by flower closure and massive pollen germination within the anthers with pollen tubes covering the adjacent stigma. The phenomenon was documented with field observations, floral dissections, and light and scanning electron microscopy. Both species open their flowers for a brief 6–8 hour window. Subsequently, pollen germinates within the closed or closing flower with pollen tubes completely covering the stigma. The prevalence and importance of selfing by precocious pollen germination are discussed.","PeriodicalId":50984,"journal":{"name":"Castanea","volume":"85 1","pages":"146 - 154"},"PeriodicalIF":0.4,"publicationDate":"2020-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46447150","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-06-09DOI: 10.2179/0008-7475.85.1.185
D. L. Eyitayo, B. Mccarthy
ABSTRACT Human landscape modification elicits changes in plant community composition due to altered microclimate conditions. We asked the question whether floristic composition, abundance, species richness, and diversity differ between habitat types in two human-modified landscapes, with contrasting management regimes. We measured species richness and cover of all vascular plants in forest, edge, and corridor habitats of a powerline easement, as well as in a nearby old field. Powerline corridor habitat had 21% more species than adjoining forest habitat and was dominated by shrub and herbaceous species. We also found that soil pH and litter depth are significant predictors of species richness along powerline corridor edges and in open old-field habitat. Particularly, we observed maximum species richness in plots with moderately high soil pH of between 5 and 5.5 along powerline corridor edges and in open old-field habitat. Powerline corridor plots with less surface litter also had higher species richness. Invasive species such as Microstegium vimineum and Rosa multiflora were more abundant in the open old-field habitat maintained annually by mowing than in powerline corridor habitat maintained usually every five years by herbicide spraying and selective removal of trees. Our findings indicate that the diverse floristic composition of powerline corridors support organisms at higher trophic levels and hence provide opportunity for conserving biodiversity within human-modified landscapes.
{"title":"Plant Community Composition in Two Human-Modified Landscapes, a Powerline Corridor and an Old Field","authors":"D. L. Eyitayo, B. Mccarthy","doi":"10.2179/0008-7475.85.1.185","DOIUrl":"https://doi.org/10.2179/0008-7475.85.1.185","url":null,"abstract":"ABSTRACT Human landscape modification elicits changes in plant community composition due to altered microclimate conditions. We asked the question whether floristic composition, abundance, species richness, and diversity differ between habitat types in two human-modified landscapes, with contrasting management regimes. We measured species richness and cover of all vascular plants in forest, edge, and corridor habitats of a powerline easement, as well as in a nearby old field. Powerline corridor habitat had 21% more species than adjoining forest habitat and was dominated by shrub and herbaceous species. We also found that soil pH and litter depth are significant predictors of species richness along powerline corridor edges and in open old-field habitat. Particularly, we observed maximum species richness in plots with moderately high soil pH of between 5 and 5.5 along powerline corridor edges and in open old-field habitat. Powerline corridor plots with less surface litter also had higher species richness. Invasive species such as Microstegium vimineum and Rosa multiflora were more abundant in the open old-field habitat maintained annually by mowing than in powerline corridor habitat maintained usually every five years by herbicide spraying and selective removal of trees. Our findings indicate that the diverse floristic composition of powerline corridors support organisms at higher trophic levels and hence provide opportunity for conserving biodiversity within human-modified landscapes.","PeriodicalId":50984,"journal":{"name":"Castanea","volume":"85 1","pages":"185 - 198"},"PeriodicalIF":0.4,"publicationDate":"2020-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43451530","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-06-09DOI: 10.2179/0008-7475.85.1.42
Elizabeth McMurchie, A. Weeks
ABSTRACT A floristic survey and analysis of community composition were conducted at the Blue Ridge Center for Environmental Stewardship (BRCES) in Loudoun County, Virginia during 2017 and 2018. BRCES comprises 392 hectares of open and forested upland and wetland habitat between the Blue Ridge and Short Hill Mountain in the Northern Blue Ridge physiographic province. In 2014, the majority of BRCES was transferred to the Virginia Department of Conservation and Recreation to be developed into the county's first state park. This study provides the first comprehensive inventory of its vascular flora. In total, 515 vascular plant species belonging to 328 genera and 105 families were identified. Forty-four species and seven varieties and subspecies identified were new records for Loudoun County. Pycnanthemum torreyi and Platanthera peramoena, which are considered rare at the state level under the Virginia Natural Heritage Resources designations S2 (imperiled) and S1 (critically imperiled), were recorded. Eleven 20 m × 20 m forest vegetation plots were used to determine community types as defined by the Virginia Natural Heritage Program. Forested habitat comprised five distinct community types belonging to terrestrial and palustrine systems: Inner Piedmont/Lower Blue Ridge Basic Oak-Hickory Forest, Piedmont/Central Appalachian Rich Floodplain Forest, Northern Piedmont Small-Stream Floodplain Forest, Inner Piedmont/Lower Blue Ridge Basic Mesic Forest, and Piedmont/Central Appalachian Mixed Oak/Heath Forest.
{"title":"Vascular Flora and Ecological Community Assessment of the Blue Ridge Center for Environmental Stewardship, Loudoun County, Virginia","authors":"Elizabeth McMurchie, A. Weeks","doi":"10.2179/0008-7475.85.1.42","DOIUrl":"https://doi.org/10.2179/0008-7475.85.1.42","url":null,"abstract":"ABSTRACT A floristic survey and analysis of community composition were conducted at the Blue Ridge Center for Environmental Stewardship (BRCES) in Loudoun County, Virginia during 2017 and 2018. BRCES comprises 392 hectares of open and forested upland and wetland habitat between the Blue Ridge and Short Hill Mountain in the Northern Blue Ridge physiographic province. In 2014, the majority of BRCES was transferred to the Virginia Department of Conservation and Recreation to be developed into the county's first state park. This study provides the first comprehensive inventory of its vascular flora. In total, 515 vascular plant species belonging to 328 genera and 105 families were identified. Forty-four species and seven varieties and subspecies identified were new records for Loudoun County. Pycnanthemum torreyi and Platanthera peramoena, which are considered rare at the state level under the Virginia Natural Heritage Resources designations S2 (imperiled) and S1 (critically imperiled), were recorded. Eleven 20 m × 20 m forest vegetation plots were used to determine community types as defined by the Virginia Natural Heritage Program. Forested habitat comprised five distinct community types belonging to terrestrial and palustrine systems: Inner Piedmont/Lower Blue Ridge Basic Oak-Hickory Forest, Piedmont/Central Appalachian Rich Floodplain Forest, Northern Piedmont Small-Stream Floodplain Forest, Inner Piedmont/Lower Blue Ridge Basic Mesic Forest, and Piedmont/Central Appalachian Mixed Oak/Heath Forest.","PeriodicalId":50984,"journal":{"name":"Castanea","volume":"85 1","pages":"42 - 64"},"PeriodicalIF":0.4,"publicationDate":"2020-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46686960","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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