DON C. BKAGG (U.S. Department of Agriculture, Forest Service, Southern Research Station). Reference conditions for old-growth pine forests in the Upper West Gulf Coastal Plain. J. Torrcy. Bot. Sot. 129: 261-288. 2002.-Ecosystem restoration has become an important component of forest management, especially on public lands. Howeber, determination of manageable reference conditions has lagged behind the interest. This paper oresents a case studv from Dine-dominated forests in the Upper West Gulf Coastal Plain NJWGCP), with special . . emphasis on southern Arkansas. Decades of forest management, fire exclusion, exotic species invasion, and other ecological changes have converted the small remnants of mature shortleaf (Pirius echirm/cl Mill.) and loblolly pine (Pinus trteda L.) stands into ineffectual models for restoring presettlement-like conditions. However, sufficient information can be gathered from available references to more reliably describe the boundaries of the desired reference environment. Early explorer accounts, maps, survey records, historical trade and technical publications, and modern scientific journals were consulted to reconstruct presettlement (pre1900) forest conditions for pine-dominated landscapes of the UWGCP On average, virgin UWGCP pine forests had considerably more shortleaf pine (especially in the uplands) than contemporary natural stands, with relatively low basal area and standing volume concentrated in large trees. Presettlement pine timber also had less uniform structural and spatial patterns than modern examples of mature pine. Assuming most of the critical processes ilre still present, it appears possible to recreate the compositional and structural attributes of virgin pine forests.
DON C. BKAGG(美国农业部，林务局，南方研究站)。上西海湾沿岸平原原始松林的参考条件。j . Torrcy。机器人。索129:261-288。2002.-生态系统恢复已成为森林管理的重要组成部分，特别是在公共土地上。然而，确定可管理的参考条件已经落后于利益。本文以上西海湾沿岸平原的森林为例进行了研究。重点放在阿肯色州南部。几十年的森林管理、火灾排除、外来物种入侵和其他生态变化已经将成熟短叶林(Pirius echirm/cl Mill.)和火炬松(Pinus trteda L.)的小残余转化为恢复类似预先定居条件的无效模式。但是，可以从可用的参考中收集足够的信息，以更可靠地描述所需参考环境的边界。本文参考了早期探险家的记录、地图、调查记录、历史贸易和技术出版物以及现代科学期刊，重建了UWGCP以松树为主的景观的预定居(1900年以前)森林条件。平均而言，UWGCP原始松林的短叶松(特别是在高地)明显多于当代自然林分，其基础面积相对较小，林分量集中在大树中。与现代成熟松木相比，预定居松木的结构和空间格局也不均匀。假设大多数关键过程仍然存在，似乎有可能重建原始松林的成分和结构属性。
{"title":"Reference conditions for old-growth pine forests in the Upper West Gulf Coastal Plain","authors":"D. Bragg","doi":"10.2307/3088699","DOIUrl":"https://doi.org/10.2307/3088699","url":null,"abstract":"DON C. BKAGG (U.S. Department of Agriculture, Forest Service, Southern Research Station). Reference conditions for old-growth pine forests in the Upper West Gulf Coastal Plain. J. Torrcy. Bot. Sot. 129: 261-288. 2002.-Ecosystem restoration has become an important component of forest management, especially on public lands. Howeber, determination of manageable reference conditions has lagged behind the interest. This paper oresents a case studv from Dine-dominated forests in the Upper West Gulf Coastal Plain NJWGCP), with special . . emphasis on southern Arkansas. Decades of forest management, fire exclusion, exotic species invasion, and other ecological changes have converted the small remnants of mature shortleaf (Pirius echirm/cl Mill.) and loblolly pine (Pinus trteda L.) stands into ineffectual models for restoring presettlement-like conditions. However, sufficient information can be gathered from available references to more reliably describe the boundaries of the desired reference environment. Early explorer accounts, maps, survey records, historical trade and technical publications, and modern scientific journals were consulted to reconstruct presettlement (pre1900) forest conditions for pine-dominated landscapes of the UWGCP On average, virgin UWGCP pine forests had considerably more shortleaf pine (especially in the uplands) than contemporary natural stands, with relatively low basal area and standing volume concentrated in large trees. Presettlement pine timber also had less uniform structural and spatial patterns than modern examples of mature pine. Assuming most of the critical processes ilre still present, it appears possible to recreate the compositional and structural attributes of virgin pine forests.","PeriodicalId":49977,"journal":{"name":"Journal of the Torrey Botanical Society","volume":"123 1","pages":"261"},"PeriodicalIF":0.3,"publicationDate":"2002-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2307/3088699","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68729569","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}
the southern United States and common in old fields and roadsides. This herbaceous, perennial vine has hermaphroditic flowers yet is self-incompatible. Large bees pollinate these flowers that produce fruits that may be eaten by mammals. Although the mode of sexual reproduction suggests the potential for long distance dispersal of genes, this species also displays extensive vegetative reproduction from rhizomes. Vegetative reproduction may reduce the amount of genetic variation within a population and increase differentiation among populations. We report on the macrogeographic allozymic variation within P. incarnata. Plants were collected from three regions in South Carolina (SC) and Georgia (GA). Genetic data were collected from nine polymorphic loci with starch gel electrophoresis of allozymes. In our sample of 168 plants from SC and GA, we observed 82 different multilocus genotypes. Plants with the same multilocus genotype were collected within and among regions. Genetic data indicated that there was little genetic differentiation among regions. These data suggest that there is extensive long distance transport of genes and that the species may rely heavily on sexual reproduction to establish new habitat.
{"title":"Macrogeographic allozyme variation in Passiflora incarnata","authors":"S. Foré, T. Spira","doi":"10.2307/3088703","DOIUrl":"https://doi.org/10.2307/3088703","url":null,"abstract":"the southern United States and common in old fields and roadsides. This herbaceous, perennial vine has hermaphroditic flowers yet is self-incompatible. Large bees pollinate these flowers that produce fruits that may be eaten by mammals. Although the mode of sexual reproduction suggests the potential for long distance dispersal of genes, this species also displays extensive vegetative reproduction from rhizomes. Vegetative reproduction may reduce the amount of genetic variation within a population and increase differentiation among populations. We report on the macrogeographic allozymic variation within P. incarnata. Plants were collected from three regions in South Carolina (SC) and Georgia (GA). Genetic data were collected from nine polymorphic loci with starch gel electrophoresis of allozymes. In our sample of 168 plants from SC and GA, we observed 82 different multilocus genotypes. Plants with the same multilocus genotype were collected within and among regions. Genetic data indicated that there was little genetic differentiation among regions. These data suggest that there is extensive long distance transport of genes and that the species may rely heavily on sexual reproduction to establish new habitat.","PeriodicalId":49977,"journal":{"name":"Journal of the Torrey Botanical Society","volume":"129 1","pages":"326"},"PeriodicalIF":0.3,"publicationDate":"2002-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2307/3088703","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68729640","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}
MORGAN, ERIC C. (Clark Botanic Garden, 193 IU Willets Rd, Albertson, NY 11507). The vascular flora of the Hempstead Harbor Shoreline Trail Natural Area, Long Island, New York. J. Torrey Bot. Soc. 129: 359-362. 2002.-The Hempstead Harbor Shoreline Trail is located in the Town of North Hempstead, Nassau County, Long Island NY. Restoration of the site, concentrating on the removal of alien species, began in September 2001. This flora provides a baseline record of the species present at the onset of restoration. This study is exclusively based upon voucher collections made by the author from September 1998 through October 1999 records the flora of several different habitats including successional woodlands, salt marsh, disturbed clearings, and old field successional areas found at the site. Listed are 60 families, 131 genera, and 168 species. The largest families are the Poaceae (27 species), Asteraceae (25), Fabaceae (9) and Rosaceae (8). Together, these four families comprise roughly 41% of the species present. Three species, Cenchrus tribuloides L., Suaeda linearis Elliot (Moq), and Agastache scrophulariifolia (Willd.) Kuntze. found on site have been designated as rare in NYS.
MORGAN, ERIC C. (Clark Botanic Garden, 193 IU Willets Rd, Albertson, NY 11507)。纽约长岛亨普斯特德港海岸线小径自然区的维管植物群。托里·博特。社会学。129:359-362。2002.-亨普斯特德港海岸线步道位于纽约长岛拿骚县北亨普斯特德镇。2001年9月开始对该地点进行修复，重点是清除外来物种。该植物群提供了在恢复开始时存在的物种的基线记录。本研究完全基于作者从1998年9月至1999年10月收集的凭证，记录了几个不同生境的植物区系，包括在现场发现的演替林地、盐沼、受干扰的空地和旧田演替区。现有60科131属168种。最大的科是豆科(27种)、菊科(25种)、豆科(9种)和蔷薇科(8种)。这四个科加起来约占现有物种的41%。三种:三叶草(Cenchrus tribuloides L.)、Suaeda linearis Elliot (Moq)和Agastache scrophulariifolia(野生)。Kuntze。已被指定为纽约稀有物种。
{"title":"The vascular flora of the Hempstead Harbor Shoreline Trail Natural Area, Long Island, New York1","authors":"E. Morgan, J. Bot","doi":"10.2307/3088706","DOIUrl":"https://doi.org/10.2307/3088706","url":null,"abstract":"MORGAN, ERIC C. (Clark Botanic Garden, 193 IU Willets Rd, Albertson, NY 11507). The vascular flora of the Hempstead Harbor Shoreline Trail Natural Area, Long Island, New York. J. Torrey Bot. Soc. 129: 359-362. 2002.-The Hempstead Harbor Shoreline Trail is located in the Town of North Hempstead, Nassau County, Long Island NY. Restoration of the site, concentrating on the removal of alien species, began in September 2001. This flora provides a baseline record of the species present at the onset of restoration. This study is exclusively based upon voucher collections made by the author from September 1998 through October 1999 records the flora of several different habitats including successional woodlands, salt marsh, disturbed clearings, and old field successional areas found at the site. Listed are 60 families, 131 genera, and 168 species. The largest families are the Poaceae (27 species), Asteraceae (25), Fabaceae (9) and Rosaceae (8). Together, these four families comprise roughly 41% of the species present. Three species, Cenchrus tribuloides L., Suaeda linearis Elliot (Moq), and Agastache scrophulariifolia (Willd.) Kuntze. found on site have been designated as rare in NYS.","PeriodicalId":49977,"journal":{"name":"Journal of the Torrey Botanical Society","volume":"129 1","pages":"359"},"PeriodicalIF":0.3,"publicationDate":"2002-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2307/3088706","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68729709","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}
J. Dilustro, B. Collins, L. Duncan, R. Sharitz, B. Collins, L. Duncan, R. Sharitz
intervals) and differ in soil texture (from sandy to clayey) and intensity of military training (lighter dismounted infantry vs. heavier mechanized training). We characterized surface soil texture and land-use disturbance of 32 sites, each 400 m X 400 m, and asked if canopy and ground layer community measures (species composition and richness, basal area, abundance) differed among sites on the basis of soil texture or land-use. There was significant interaction between land-use and soil texture, with a gradient of soil texture (% clay) from clayey sites within light training areas, to sandy sites in heavier training areas. Road-like features, including active and remnant trails, roads, and vehicle tracks or trails were the most frequent and abundant disturbance feature. Number of disturbance features per site did not differ among land-use/surface soil texture categories. Differences in ground layer and canopy composition among sites reflected disturbance intensity; differences in canopy composition also reflected the proportion of pine. Species richness of ground layer vegetation differed among surface soil texture/land-use categories. There was a richness gradient from heavily disturbed sites with clayey soil, through lightly disturbed sites, to heavily disturbed sites with sandy soil. Our results suggest upland pineoak-hickory forests at Fort Benning range from sandhills scrub oak-pine to pine-hardwood to oak-hickory dominated forests, with greater species diversity in the ground layer of clayey sites. Forestry practices and disturbances associated with mechanized military training favor pine dominance, and maintain open-site, successional or fire-tolerant species in the ground layer. Although intense management toward pine monocultures can reduce within-stand diversity, federal installations such as Fort Benning may help conserve pine-oak-hickory forests in the rapidly developing Sandhills region.
在土壤质地(从沙质到粘土)和军事训练强度(较轻的下马步兵与较重的机械化训练)方面有所不同。我们对32个400 m × 400 m样地的表层土壤质地和土地利用干扰进行了表征，并询问了不同样地的冠层和地面群落测量(物种组成和丰富度、基面积、丰度)是否因土壤质地或土地利用而不同。土地利用与土壤质地之间存在显著的相互作用，土壤质地(粘土百分比)从轻度训练区的粘土样地到重度训练区的沙质样地呈梯度变化。道路样特征，包括活动和残余步道、道路、车辆轨迹或步道是最频繁和最丰富的干扰特征。每个站点的干扰特征数量在土地利用/表层土壤质地类别之间没有差异。不同站点间地表和冠层组成的差异反映了扰动强度;冠层组成的差异也反映了松树的比例。不同表层土壤质地/土地利用类型的地表植被物种丰富度存在差异。土壤丰富度呈现由粘土质重扰动点→轻度扰动点→砂土质重扰动点的梯度。研究结果表明，本宁堡山地松山核桃林类型多样，从沙山灌丛松林到松木硬木林再到以松山核桃林为主的松林，黏土样地地面层的物种多样性更大。与机械化军事训练相关的林业实践和干扰有利于松树的优势地位，并维持了地面层的开放场地、演替或耐火物种。尽管对单一松林的严格管理会减少林内的多样性，但像本宁堡这样的联邦设施可能有助于保护快速发展的沙丘地区的松木-橡树-山核桃林。
{"title":"Soil texture, land-use intensity, and vegetation of Fort Benning upland forest sites1","authors":"J. Dilustro, B. Collins, L. Duncan, R. Sharitz, B. Collins, L. Duncan, R. Sharitz","doi":"10.2307/3088700","DOIUrl":"https://doi.org/10.2307/3088700","url":null,"abstract":"intervals) and differ in soil texture (from sandy to clayey) and intensity of military training (lighter dismounted infantry vs. heavier mechanized training). We characterized surface soil texture and land-use disturbance of 32 sites, each 400 m X 400 m, and asked if canopy and ground layer community measures (species composition and richness, basal area, abundance) differed among sites on the basis of soil texture or land-use. There was significant interaction between land-use and soil texture, with a gradient of soil texture (% clay) from clayey sites within light training areas, to sandy sites in heavier training areas. Road-like features, including active and remnant trails, roads, and vehicle tracks or trails were the most frequent and abundant disturbance feature. Number of disturbance features per site did not differ among land-use/surface soil texture categories. Differences in ground layer and canopy composition among sites reflected disturbance intensity; differences in canopy composition also reflected the proportion of pine. Species richness of ground layer vegetation differed among surface soil texture/land-use categories. There was a richness gradient from heavily disturbed sites with clayey soil, through lightly disturbed sites, to heavily disturbed sites with sandy soil. Our results suggest upland pineoak-hickory forests at Fort Benning range from sandhills scrub oak-pine to pine-hardwood to oak-hickory dominated forests, with greater species diversity in the ground layer of clayey sites. Forestry practices and disturbances associated with mechanized military training favor pine dominance, and maintain open-site, successional or fire-tolerant species in the ground layer. Although intense management toward pine monocultures can reduce within-stand diversity, federal installations such as Fort Benning may help conserve pine-oak-hickory forests in the rapidly developing Sandhills region.","PeriodicalId":49977,"journal":{"name":"Journal of the Torrey Botanical Society","volume":"129 1","pages":"289"},"PeriodicalIF":0.3,"publicationDate":"2002-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2307/3088700","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68729580","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}
and southeastern United States. We analyzed the biogeographic patterns of this species to answer a series of questions regarding its historical dispersal and recent range expansion, and the relationships of a disjunct population in southern Ohio using a combination of genetic analyses based on Inter-Simple Sequence Repeat markers (ISSR) and herbarium studies. Amounts of genetic diversity showed a marked reduction in marginal populations in the far north and northeast of the species range, corresponding to areas where herbarium records show the species has become naturalized during the past 100 years. Our analysis suggests the recognition of three biogeographic lineages within this polymorphic species complex: a Great Plains lineage, an associated Midwestern Mississippian lineage, and an Atlantic Coastal Plain lineage. These lineages have been loosely recognized as taxonomic varieties: the western lineages as F. floridana var. campestris (Small) Fern., and the eastern lineage as F. floridana var. floridana (Nutt.) Moq.; however, our data suggest that the continued recognition of these varieties is not warranted. The disjunct population in Ohio, formerly believed to be a remnant of a once larger distribution and presently state-listed as a rare species, shows patterns of genetic diversity and differentiation comparable to recently established marginal populations in other states, and was most likely derived from the Great Plains or Midwestern lineages.
和美国东南部。利用基于ISSR的遗传分析和植物标本室研究相结合的方法，对该物种的生物地理格局进行了分析，以回答有关其历史分布和近期范围扩展的一系列问题，并对俄亥俄州南部一个分离种群的关系进行了分析。遗传多样性的数量在物种范围的远北部和东北部的边缘种群中显着减少，对应于植物标本室记录显示该物种在过去100年中已经归化的地区。我们的分析表明，在这个多态物种复合体中可以识别出三个生物地理谱系:一个大平原谱系，一个相关的中西部密西西比谱系和一个大西洋沿岸平原谱系。这些谱系在分类学上被粗略地认为是变种:西部谱系为F. floridana var. campestris (Small) Fern。和东部血统的F. floridana var. florida (Nutt.)。Moq。然而，我们的数据表明，继续承认这些品种是不合理的。俄亥俄州的分离种群，以前被认为是曾经较大分布的残余，目前被列为国家稀有物种，显示出与最近在其他州建立的边缘种群相当的遗传多样性和分化模式，并且最有可能来自大平原或中西部血统。
{"title":"Inferring nativity and biogeographic affinities of central and marginal populations of Froelichia floridana (Amaranthaceae) from Inter-Simple Sequence Repeat (ISSR) markers1","authors":"Ross A. McCauley, H. Ballard","doi":"10.2307/3088702","DOIUrl":"https://doi.org/10.2307/3088702","url":null,"abstract":"and southeastern United States. We analyzed the biogeographic patterns of this species to answer a series of questions regarding its historical dispersal and recent range expansion, and the relationships of a disjunct population in southern Ohio using a combination of genetic analyses based on Inter-Simple Sequence Repeat markers (ISSR) and herbarium studies. Amounts of genetic diversity showed a marked reduction in marginal populations in the far north and northeast of the species range, corresponding to areas where herbarium records show the species has become naturalized during the past 100 years. Our analysis suggests the recognition of three biogeographic lineages within this polymorphic species complex: a Great Plains lineage, an associated Midwestern Mississippian lineage, and an Atlantic Coastal Plain lineage. These lineages have been loosely recognized as taxonomic varieties: the western lineages as F. floridana var. campestris (Small) Fern., and the eastern lineage as F. floridana var. floridana (Nutt.) Moq.; however, our data suggest that the continued recognition of these varieties is not warranted. The disjunct population in Ohio, formerly believed to be a remnant of a once larger distribution and presently state-listed as a rare species, shows patterns of genetic diversity and differentiation comparable to recently established marginal populations in other states, and was most likely derived from the Great Plains or Midwestern lineages.","PeriodicalId":49977,"journal":{"name":"Journal of the Torrey Botanical Society","volume":"129 1","pages":"311"},"PeriodicalIF":0.3,"publicationDate":"2002-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2307/3088702","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68729628","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}
STALTER, R. (Dept. Biol. Sci., St. John's Univ., Jamaica, NY 11439) AND E. E. LAMONT (N.Y. Botanical Garden, Bronx, NY 10458). Vascular flora of Jamaica Bay Wildlife Refuge, Long Island, New York. J. Torrey Bot. Soc. 129: 346-358. 2002.-The vascular flora of Jamaica Bay Wildlife Refuge, New York, consists of 456 species within 270 genera and 90 families. Twelve of the species are listed as rare in New York. Largest families are Asteraceae (77 species) and Poaceae (57 species), and largest genera are Polygonum, Cyperus, Aster, Panicum, Trifolium, Carex and Eupatorium. Each taxonomic entry in the checklist is accompanied by an annotation that includes the habitat in which each taxon occurs, frequency of occurrence, rarity status and pertinent synonyms. A summary of the land use history of Jamaica Bay is also presented.
{"title":"Vascular Flora of Jamaica Bay Wildlife Refuge, Long Island, New York","authors":"R. Stalter, E. Lamont","doi":"10.2307/3088705","DOIUrl":"https://doi.org/10.2307/3088705","url":null,"abstract":"STALTER, R. (Dept. Biol. Sci., St. John's Univ., Jamaica, NY 11439) AND E. E. LAMONT (N.Y. Botanical Garden, Bronx, NY 10458). Vascular flora of Jamaica Bay Wildlife Refuge, Long Island, New York. J. Torrey Bot. Soc. 129: 346-358. 2002.-The vascular flora of Jamaica Bay Wildlife Refuge, New York, consists of 456 species within 270 genera and 90 families. Twelve of the species are listed as rare in New York. Largest families are Asteraceae (77 species) and Poaceae (57 species), and largest genera are Polygonum, Cyperus, Aster, Panicum, Trifolium, Carex and Eupatorium. Each taxonomic entry in the checklist is accompanied by an annotation that includes the habitat in which each taxon occurs, frequency of occurrence, rarity status and pertinent synonyms. A summary of the land use history of Jamaica Bay is also presented.","PeriodicalId":49977,"journal":{"name":"Journal of the Torrey Botanical Society","volume":"129 1","pages":"346"},"PeriodicalIF":0.3,"publicationDate":"2002-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2307/3088705","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68729701","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}
to be a strong selective force leading to the evolution of dioecy. The purpose of this study was to examine the effects of inbreeding on Amaranthus cannabinus (L.) Sauer (water hemp), a dioecious annual. Inbred and outcrossed lines were established in the greenhouse for three New Jersey populations of water hemp, one salt marsh population and two freshwater marsh populations. After two generations of crosses, inbreeding depression was observed in the percentage of germination, leaf size, and plant height. However, the response to inbreeding varied considerably among and within the three populations. Overall, inbreeding depression was low, suggesting that the avoidance of inbreeding was not a strong selective drive for the evolution of dioecy in A. cannabinus. Another selective factor that more likely contributed to the evolution of dioecy in water hemp is increased reproductive efficiency through sex-specific selection.
{"title":"Effects of inbreeding in three populations of the dioecious annual Amaranthus cannabinus (Amaranthaceae)1","authors":"M. R. Bram","doi":"10.2307/3088701","DOIUrl":"https://doi.org/10.2307/3088701","url":null,"abstract":"to be a strong selective force leading to the evolution of dioecy. The purpose of this study was to examine the effects of inbreeding on Amaranthus cannabinus (L.) Sauer (water hemp), a dioecious annual. Inbred and outcrossed lines were established in the greenhouse for three New Jersey populations of water hemp, one salt marsh population and two freshwater marsh populations. After two generations of crosses, inbreeding depression was observed in the percentage of germination, leaf size, and plant height. However, the response to inbreeding varied considerably among and within the three populations. Overall, inbreeding depression was low, suggesting that the avoidance of inbreeding was not a strong selective drive for the evolution of dioecy in A. cannabinus. Another selective factor that more likely contributed to the evolution of dioecy in water hemp is increased reproductive efficiency through sex-specific selection.","PeriodicalId":49977,"journal":{"name":"Journal of the Torrey Botanical Society","volume":"129 1","pages":"298"},"PeriodicalIF":0.3,"publicationDate":"2002-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2307/3088701","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68729619","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}
MoRI, S. A., E. F HECKLAU, AND T. KIRCHGESSNER (The New York Botanical Garden, Bronx, New York 10458-5126). Life form, habitat, and nutritional mode of the flowering plants of central French Guiana. J. Torrey Bot. Soc. 129: 331-345. 2002.-The flowering plants of central French Guiana comprise 1918 native species, including 549 species of herbs, 44 species of vines, 45 species of subshrubs, 269 species of shrubs, 245 species of lianas, and 766 species of trees. The habitat of the flowering plants of central French Guiana is primarily terrestrial. A total of 1653 species or 86% of the flora occurs in this habitat. However, the reproductive cycles of a majority of the flowering plants of central French Guiana take place in the crowns of trees. When the number of species of trees is added to the numbers of epiphytes, hemi-epiphytes, and aerial endophytes, tree crowns are the site of about 68% of the flowering plant reproductive activity in this forest. Heterotrophic vascular plants, with 36 species, make up 1.9% of the flora; 98.1% of the flowering plants of central French Guiana are autotrophs. Because of differences in definitions and lack of standardization in sampling, it is difficult to make valid comparisons with studies made in other geographic areas. We address the first problem by providing a glossary of terms used to describe the life form, habitat, and nutritional mode of plants and urge others to develop standardized sampling protocols.
{"title":"Life form, habitat, and nutritional mode of the flowering plants of central French Guiana","authors":"S. Mori, E. F. Hecklau, T. Kirchgessner","doi":"10.2307/3088704","DOIUrl":"https://doi.org/10.2307/3088704","url":null,"abstract":"MoRI, S. A., E. F HECKLAU, AND T. KIRCHGESSNER (The New York Botanical Garden, Bronx, New York 10458-5126). Life form, habitat, and nutritional mode of the flowering plants of central French Guiana. J. Torrey Bot. Soc. 129: 331-345. 2002.-The flowering plants of central French Guiana comprise 1918 native species, including 549 species of herbs, 44 species of vines, 45 species of subshrubs, 269 species of shrubs, 245 species of lianas, and 766 species of trees. The habitat of the flowering plants of central French Guiana is primarily terrestrial. A total of 1653 species or 86% of the flora occurs in this habitat. However, the reproductive cycles of a majority of the flowering plants of central French Guiana take place in the crowns of trees. When the number of species of trees is added to the numbers of epiphytes, hemi-epiphytes, and aerial endophytes, tree crowns are the site of about 68% of the flowering plant reproductive activity in this forest. Heterotrophic vascular plants, with 36 species, make up 1.9% of the flora; 98.1% of the flowering plants of central French Guiana are autotrophs. Because of differences in definitions and lack of standardization in sampling, it is difficult to make valid comparisons with studies made in other geographic areas. We address the first problem by providing a glossary of terms used to describe the life form, habitat, and nutritional mode of plants and urge others to develop standardized sampling protocols.","PeriodicalId":49977,"journal":{"name":"Journal of the Torrey Botanical Society","volume":"129 1","pages":"331"},"PeriodicalIF":0.3,"publicationDate":"2002-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2307/3088704","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68729690","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}
conifer swamp. Our study site, Nelson Swamp, has high documented species richness and supports a large number of state-protected species. Understory cover and species richness at both the quadrat and gap scale were compared among closed canopy areas and gaps in three size classes. To assess differences in the understory environment among the three size classes, we compared light, hydrology, and microtopography. We also tested for correlations between gap species richness and light, wetness, and microsite heterogeneity to determine which aspects of the gap environment might influence vascular plant diversity therein. There was higher quadrat- and gap-level species richness in gaps than in closed canopy areas. Small gaps did not appear to offer a physical environment substantially different from non-gaps, as no differences in their understory communities were apparent. Mid-sized and large gaps had higher species richness, substrate heterogeneity, and water table fluctuation than small gaps. Based on the correlations, the individual factors influencing species richness at the gap scale were depth to water, water level fluctuation, and microtopographic variability, indicating the importance of hydrology over light as a species control. Although gaps and non-gaps shared many of the same species, there were distinct subsets of species that were more important in either type of community. Based on these subsets, closed canopy areas and large gaps can be viewed as two ends of a continuum corresponding to light and hydrology gradients. Out of all the species encountered, 10 percent were found exclusively in gaps, and none were found only under closed canopy. Thus, these gaps are not only sites of higher overall plant growth, but also areas that allow rare species to persist.
{"title":"The role of canopy gaps in maintaining vascular plant diversity at a forested wetland in New York State1","authors":"K. Anderson, D. Leopold","doi":"10.2307/3088774","DOIUrl":"https://doi.org/10.2307/3088774","url":null,"abstract":"conifer swamp. Our study site, Nelson Swamp, has high documented species richness and supports a large number of state-protected species. Understory cover and species richness at both the quadrat and gap scale were compared among closed canopy areas and gaps in three size classes. To assess differences in the understory environment among the three size classes, we compared light, hydrology, and microtopography. We also tested for correlations between gap species richness and light, wetness, and microsite heterogeneity to determine which aspects of the gap environment might influence vascular plant diversity therein. There was higher quadrat- and gap-level species richness in gaps than in closed canopy areas. Small gaps did not appear to offer a physical environment substantially different from non-gaps, as no differences in their understory communities were apparent. Mid-sized and large gaps had higher species richness, substrate heterogeneity, and water table fluctuation than small gaps. Based on the correlations, the individual factors influencing species richness at the gap scale were depth to water, water level fluctuation, and microtopographic variability, indicating the importance of hydrology over light as a species control. Although gaps and non-gaps shared many of the same species, there were distinct subsets of species that were more important in either type of community. Based on these subsets, closed canopy areas and large gaps can be viewed as two ends of a continuum corresponding to light and hydrology gradients. Out of all the species encountered, 10 percent were found exclusively in gaps, and none were found only under closed canopy. Thus, these gaps are not only sites of higher overall plant growth, but also areas that allow rare species to persist.","PeriodicalId":49977,"journal":{"name":"Journal of the Torrey Botanical Society","volume":"33 1","pages":"238"},"PeriodicalIF":0.3,"publicationDate":"2002-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2307/3088774","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68730653","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}
RUFFNER, CHARLES M. AND MARC D. ABRAMS (School of Forest Resources, Pennsylvania State University, University Park, PA 16802). Dendrochronological investigation of disturbance history for a native American site in Northwestern Pennsylvania. J. Torrey Bot. Soc. 129: 251-260. 2002.-Dendrochronological methods were used to identify the disturbance history of a Late Woodland Seneca Iroqouis settlement in northwestern Pennsylvania. The impacts of aboriginal disturbance on the landscape are widely speculative and few studies have attempted to characterize these disturbances. Increment cores taken from a 426 year old white oak forest remnant yielded information on the disturbance regime on this site during Native American (Late Woodland 1550-1700; Historic 1700-1800) and European (post 1800) settlement periods. Disturbances during the early and late native periods were more synchronous and of lower intensity (increase in growth rate) with a disturbance free interval (DFI) of 26.2 ? 4.0 years and 11.0 ? 0.7 years (mean ? SE), respectively. The shorter return interval during the later native period is attributed to the increased population pressure at this site due to immigration of natives in the face of European expansion from the eastern seaboard. The disturbance regime following European settlement is significantly longer with a DFI of 28.5 ? 2.8 years, representing the selective removal of merchantable timber for the sawmill located at the site. Although investigated, no climatic variables showed significant correlation with tree growth to explain these patterns. This study represents a rare opportunity to document the changes in disturbance regime between two drastically different cultures and land uses.
RUFFNER, CHARLES M.和MARC D. ABRAMS(宾夕法尼亚州立大学森林资源学院，宾州大学公园，16802)。宾夕法尼亚州西北部一个美洲原住民遗址干扰史的树木年代学调查。托里·博特。社会学。129:251-260。2002.-采用树木年代学方法确定了宾夕法尼亚州西北部塞内卡易洛魁人晚期林地定居点的干扰历史。土著干扰对景观的影响被广泛推测，很少有研究试图描述这些干扰。从426年的白栎林遗迹中提取的增量岩心获得了美洲原住民(1550-1700年林地晚期;历史上的1700-1800年)和欧洲(1800年后)殖民时期。原生期早期和晚期的干扰更同步，强度更低(生长率增加)，无干扰间隔(DFI)为26.2 ?4.0年和11.0年?0.7年(平均?SE),分别。在土著时期后期，返回间隔较短，这是由于面对欧洲东部沿海的扩张，土著移民增加了该地点的人口压力。欧洲和解后的动荡期明显更长，DFI为28.5 ?2.8年，代表有选择地移除位于该地点的锯木厂的可销售木材。尽管进行了调查，但没有气候变量显示出与树木生长的显著相关性来解释这些模式。这项研究为记录两种截然不同的文化和土地利用之间干扰制度的变化提供了难得的机会。
{"title":"Dendrochronological investigation of disturbance history for a native American site in Northwestern Pennsylvania","authors":"C. Ruffner, M. Abrams, M. Charles","doi":"10.2307/3088775","DOIUrl":"https://doi.org/10.2307/3088775","url":null,"abstract":"RUFFNER, CHARLES M. AND MARC D. ABRAMS (School of Forest Resources, Pennsylvania State University, University Park, PA 16802). Dendrochronological investigation of disturbance history for a native American site in Northwestern Pennsylvania. J. Torrey Bot. Soc. 129: 251-260. 2002.-Dendrochronological methods were used to identify the disturbance history of a Late Woodland Seneca Iroqouis settlement in northwestern Pennsylvania. The impacts of aboriginal disturbance on the landscape are widely speculative and few studies have attempted to characterize these disturbances. Increment cores taken from a 426 year old white oak forest remnant yielded information on the disturbance regime on this site during Native American (Late Woodland 1550-1700; Historic 1700-1800) and European (post 1800) settlement periods. Disturbances during the early and late native periods were more synchronous and of lower intensity (increase in growth rate) with a disturbance free interval (DFI) of 26.2 ? 4.0 years and 11.0 ? 0.7 years (mean ? SE), respectively. The shorter return interval during the later native period is attributed to the increased population pressure at this site due to immigration of natives in the face of European expansion from the eastern seaboard. The disturbance regime following European settlement is significantly longer with a DFI of 28.5 ? 2.8 years, representing the selective removal of merchantable timber for the sawmill located at the site. Although investigated, no climatic variables showed significant correlation with tree growth to explain these patterns. This study represents a rare opportunity to document the changes in disturbance regime between two drastically different cultures and land uses.","PeriodicalId":49977,"journal":{"name":"Journal of the Torrey Botanical Society","volume":"13 1","pages":"251"},"PeriodicalIF":0.3,"publicationDate":"2002-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2307/3088775","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68730669","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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