J. MEISEL, N. TRUSHENSKI AND E. WEIHER (Department of Biology, University of Wisconsin-Eau Claire, Eau Claire, WI 54702). A gradient analysis of oak savanna community composition in western Wisconsin. J. Torrey Bot. Soc. 129: 115-124. 2002. Oak savannas were historically abundant, but they are now rare. Although there is great interest in oak savanna restoration, there is still debate about the nature of the understory composition of oak savannas, especially in lowlands. We sampled 168 quadrats (0.25 m2) in remnant floodplain oak savannas along the Chippewa River, WI, to produce a gradient analysis of vegetation by both taxonomic and guild composition. Community composition varied along two main gradients, as indicated by correlations between DCA scores and environmental factors. The communities mainly varied along a soil quality gradient (primarily nitrogen and organic matter), from sand barrens to wet-mesic savannas, and along a tree canopy cover gradient from open prairie-like areas to areas with heavy canopy. Although significant, fire frequency was of minor importance, but we believe this was partly a sampling artifact. Seven general community types were described, and MANOVA tests showed they differed in terms of guild composition. Forbs tended to dominate most community types, with Solidago species usually among the most abundant species, while C4 graminoids (mostly Andropogon gerardii and Sorghastrum nutans) were dominant only in the poorest soils and relatively open areas. Stepwise regression showed relatively weak relationships between relative guild cover and the measured environmental variables. Only C4 graminoids showed close correspondence to the main gradients affecting taxonomic composition. The other guilds responded to disturbance and distinct soil factors.
J. MEISEL, N. TRUSHENSKI和E. WEIHER(威斯康星大学奥克莱尔分校生物系，奥克莱尔，威斯康星州54702)。威斯康辛州西部栎树草原群落组成的梯度分析。托里·博特。社会学。129:115-124。2002. 橡树稀树草原在历史上曾经非常丰富，但现在已经很少了。尽管人们对热带稀树草原的恢复有着极大的兴趣，但关于热带稀树草原，特别是低地地区的栎树林下植被组成的性质仍然存在争议。我们在威斯康星州Chippewa河沿岸的残余漫滩橡树稀树草原上取样168个样方(0.25 m2)，通过分类和群落组成对植被进行梯度分析。DCA评分与环境因子之间的相关性表明，群落组成沿两个主要梯度变化。群落主要沿着土壤质量梯度(主要是氮和有机质)变化，从荒漠到湿系热带稀树草原，沿着林冠覆盖梯度从开阔的草原到重冠区。虽然很重要，但火灾频率并不重要，但我们认为这部分是采样的产物。描述了7种一般的群落类型，方差分析表明它们在公会组成方面存在差异。在最贫瘠的土壤和相对开阔的地区，以禾本科植物为主，以一枝黄花植物为主，C4禾本科植物以gerardii Andropogon和Sorghastrum nutans为主。逐步回归表明，相对行业覆盖率与测量环境变量之间的关系相对较弱。只有C4禾本科与影响分类组成的主要梯度有密切的对应关系。其他行会对干扰和不同的土壤因子有响应。
{"title":"A Gradient Analysis of Oak Savanna Community Composition in Western Wisconsin","authors":"J. Meisel, N. Trushenski, E. Weiher","doi":"10.2307/3088725","DOIUrl":"https://doi.org/10.2307/3088725","url":null,"abstract":"J. MEISEL, N. TRUSHENSKI AND E. WEIHER (Department of Biology, University of Wisconsin-Eau Claire, Eau Claire, WI 54702). A gradient analysis of oak savanna community composition in western Wisconsin. J. Torrey Bot. Soc. 129: 115-124. 2002. Oak savannas were historically abundant, but they are now rare. Although there is great interest in oak savanna restoration, there is still debate about the nature of the understory composition of oak savannas, especially in lowlands. We sampled 168 quadrats (0.25 m2) in remnant floodplain oak savannas along the Chippewa River, WI, to produce a gradient analysis of vegetation by both taxonomic and guild composition. Community composition varied along two main gradients, as indicated by correlations between DCA scores and environmental factors. The communities mainly varied along a soil quality gradient (primarily nitrogen and organic matter), from sand barrens to wet-mesic savannas, and along a tree canopy cover gradient from open prairie-like areas to areas with heavy canopy. Although significant, fire frequency was of minor importance, but we believe this was partly a sampling artifact. Seven general community types were described, and MANOVA tests showed they differed in terms of guild composition. Forbs tended to dominate most community types, with Solidago species usually among the most abundant species, while C4 graminoids (mostly Andropogon gerardii and Sorghastrum nutans) were dominant only in the poorest soils and relatively open areas. Stepwise regression showed relatively weak relationships between relative guild cover and the measured environmental variables. Only C4 graminoids showed close correspondence to the main gradients affecting taxonomic composition. The other guilds responded to disturbance and distinct soil factors.","PeriodicalId":49977,"journal":{"name":"Journal of the Torrey Botanical Society","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2002-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2307/3088725","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68729963","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}
SMALL, C.J. AND B.C. MCCARTHY (Department of Environmental and Plant Biology, Ohio University, Athens, Ohio 45701). Spatial and Temporal Variation in the Response of Understory Vegetation to Disturbance in a Central Appalachian Oak Forest. J. Torrey Bot. 129: 136-153. 2002.-Understory vegetation in stand-initiating (7 year clearcuts) and understory-reinitiating (> 125 year mature second-growth) oak-dominated forest stands in southeastern Ohio was examined relative to topographic aspect, micro-environmental conditions, and sampling season to explore patterns of understory dynamics and stand development following management disturbance. Plots were established on upper and lower slopes across a range of aspect positions and sampled in spring and summer to capture topographic and seasonal changes in herb layer dynamics. Micro-site light, temperature, and physical soil properties differed significantly with stand age whereas fertility and moisture varied with aspect. Species richness was greater in clearcut than mature forest stands, associated with greater resource availability and spatial heterogeneity. Herb richness and abundance were greater on NWand SE-facing slopes and lower slope positions, corresponding to greater soil moisture and fertility. Greater frequencies of non-native species were also found in resource rich, clearcut plots. Canonical correspondence analysis showed stand age, aspect, and fertility to strongly influence herb layer composition. Non-metric multidimensional scaling showed compositional divergence of spring vs. summer and clearcut vs. mature forest herb samples. Composition of clearcuts and mature forests differed markedly in June, suggesting that management influences may be more pronounced in summer herb communities. Most studies of understory dynamics in eastern forests fail to account for spatial and temporal variations in site and vegetation characteristics, however, understory disturbance response appears strongly linked to these ecosystem properties. A better understanding of these factors is needed to fully understand the effects of forest management on herb layer communities in our eastern forests.
{"title":"Spatial and temporal variation in the response of understory vegetation to disturbance in a central Appalachian oak forest","authors":"Christine J. Small, B. Mccarthy","doi":"10.2307/3088727","DOIUrl":"https://doi.org/10.2307/3088727","url":null,"abstract":"SMALL, C.J. AND B.C. MCCARTHY (Department of Environmental and Plant Biology, Ohio University, Athens, Ohio 45701). Spatial and Temporal Variation in the Response of Understory Vegetation to Disturbance in a Central Appalachian Oak Forest. J. Torrey Bot. 129: 136-153. 2002.-Understory vegetation in stand-initiating (7 year clearcuts) and understory-reinitiating (> 125 year mature second-growth) oak-dominated forest stands in southeastern Ohio was examined relative to topographic aspect, micro-environmental conditions, and sampling season to explore patterns of understory dynamics and stand development following management disturbance. Plots were established on upper and lower slopes across a range of aspect positions and sampled in spring and summer to capture topographic and seasonal changes in herb layer dynamics. Micro-site light, temperature, and physical soil properties differed significantly with stand age whereas fertility and moisture varied with aspect. Species richness was greater in clearcut than mature forest stands, associated with greater resource availability and spatial heterogeneity. Herb richness and abundance were greater on NWand SE-facing slopes and lower slope positions, corresponding to greater soil moisture and fertility. Greater frequencies of non-native species were also found in resource rich, clearcut plots. Canonical correspondence analysis showed stand age, aspect, and fertility to strongly influence herb layer composition. Non-metric multidimensional scaling showed compositional divergence of spring vs. summer and clearcut vs. mature forest herb samples. Composition of clearcuts and mature forests differed markedly in June, suggesting that management influences may be more pronounced in summer herb communities. Most studies of understory dynamics in eastern forests fail to account for spatial and temporal variations in site and vegetation characteristics, however, understory disturbance response appears strongly linked to these ecosystem properties. A better understanding of these factors is needed to fully understand the effects of forest management on herb layer communities in our eastern forests.","PeriodicalId":49977,"journal":{"name":"Journal of the Torrey Botanical Society","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2002-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2307/3088727","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68730017","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}
THOMAS C. BLOOM, JERRY M. BASKIN, AND CAROL C. BASKIN (School of Biological Sciences, University of Kentucky, Lexington, Kentucky 40506-0225, 1209 Glade Street, College Station, Texas 77840, Department of Agronomy, University of Kentucky, Lexington, Kentucky 40546-0091). J. Torrey Bot. Soc. 129: 29-38. 2002.We investigated reproductive phenology and fecundity in a population of the facultative biennial Arabis laevigata var. laevigata over a 2-year period in its rocky deciduous woodland habitat in northcentral Kentucky, USA. In contrast to most facultative biennials, A. laevigata grows in a habitat that may remain stable for a long period of time. Bolting (flower stalk elongation) occurred in March, anthesis peaked in mid April, and seeds matured in June/July. Probability of bolting increased with rosette size, which was highly correlated with number of seeds produced. Only 150 of 233 (64.4%) bolted plants monitored in 1986 and 1987 survived and produced seeds. Adults in 1987 produced taller flower stalks, more siliques per plant, longer siliques, and more seeds per plant than did adults in 1986. Arabis laevigata is similar to other facultative biennials in that onset of reproduction is size-dependent, not age-dependent, and fecundity is positively correlated with rosette size at time of reproduction.
THOMAS C. BLOOM, JERRY M. BASKIN和CAROL C. BASKIN(肯塔基大学生物科学学院，肯塔基州列克星敦40506-0225，大学站Glade街1209号，德克萨斯州77840，肯塔基大学农学系，肯塔基州列克星敦40546-0091)。托里·博特。社会学。129:29-38。2002.在美国肯塔基州中北部的石质落叶林地生境中，研究了兼生二年生阿拉伯树(Arabis laevigata) 2年的繁殖物候和繁殖力。与大多数兼性二年生植物不同，a . laevigata生长在一个可以长时间保持稳定的栖息地。3月抽苔，4月中旬开花，6、7月种子成熟。结茎大小与结籽数高度相关，结茎概率随结茎大小的增加而增加。在1986年和1987年监测的233株栓栽植物中，只有150株(64.4%)存活并结籽。与1986年的成虫相比，1987年的成虫的花柄更高，单株的角果更多，单株的角果更长，单株的种子更多。阿拉伯叶与其他兼性二年生植物相似，繁殖的开始是大小依赖的，而不是年龄依赖的，繁殖时的莲座大小与繁殖力呈正相关。
{"title":"Ecological life history of the facultative woodland biennial Arabis laevigata variety laevigata (Brassicaceae): reproductive phenology and fecundity","authors":"Thomas C. Bloom, J. Baskin, C. Baskin","doi":"10.2307/3088680","DOIUrl":"https://doi.org/10.2307/3088680","url":null,"abstract":"THOMAS C. BLOOM, JERRY M. BASKIN, AND CAROL C. BASKIN (School of Biological Sciences, University of Kentucky, Lexington, Kentucky 40506-0225, 1209 Glade Street, College Station, Texas 77840, Department of Agronomy, University of Kentucky, Lexington, Kentucky 40546-0091). J. Torrey Bot. Soc. 129: 29-38. 2002.We investigated reproductive phenology and fecundity in a population of the facultative biennial Arabis laevigata var. laevigata over a 2-year period in its rocky deciduous woodland habitat in northcentral Kentucky, USA. In contrast to most facultative biennials, A. laevigata grows in a habitat that may remain stable for a long period of time. Bolting (flower stalk elongation) occurred in March, anthesis peaked in mid April, and seeds matured in June/July. Probability of bolting increased with rosette size, which was highly correlated with number of seeds produced. Only 150 of 233 (64.4%) bolted plants monitored in 1986 and 1987 survived and produced seeds. Adults in 1987 produced taller flower stalks, more siliques per plant, longer siliques, and more seeds per plant than did adults in 1986. Arabis laevigata is similar to other facultative biennials in that onset of reproduction is size-dependent, not age-dependent, and fecundity is positively correlated with rosette size at time of reproduction.","PeriodicalId":49977,"journal":{"name":"Journal of the Torrey Botanical Society","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2002-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2307/3088680","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68729740","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}
lations of V. ciliata in Ohio. These southern, edge-of-range populations were compared with genetic variation in four Michigan populations at the middle of this species' range. Allozyme electrophoresis of individuals in populations of this subdioecious species revealed overall levels of genetic diversity (Hes = 0.245) that were higher than expected for an endemic. Though small in size, the two Ohio populations of V. ciliata had intermediate levels of genetic diversity (He = 0.224, 0.254) in comparison to the Michigan populations (He = 0.0540.305). Differences between census population size and effective population size, uneven sex ratios, location within the species' range, and variation in habitat quality all contribute to the level of genetic variation recorded among these V. ciliata populations.
{"title":"Genetic variation among populations of Valeriana ciliata T.&G. (Prairie valerian) in midwestern prairie fens1","authors":"A. Faivre, J. L. Windus","doi":"10.2307/3088681","DOIUrl":"https://doi.org/10.2307/3088681","url":null,"abstract":"lations of V. ciliata in Ohio. These southern, edge-of-range populations were compared with genetic variation in four Michigan populations at the middle of this species' range. Allozyme electrophoresis of individuals in populations of this subdioecious species revealed overall levels of genetic diversity (Hes = 0.245) that were higher than expected for an endemic. Though small in size, the two Ohio populations of V. ciliata had intermediate levels of genetic diversity (He = 0.224, 0.254) in comparison to the Michigan populations (He = 0.0540.305). Differences between census population size and effective population size, uneven sex ratios, location within the species' range, and variation in habitat quality all contribute to the level of genetic variation recorded among these V. ciliata populations.","PeriodicalId":49977,"journal":{"name":"Journal of the Torrey Botanical Society","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2002-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2307/3088681","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68729783","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}
limited to one small area at the edge of the core population. At Dixon Springs, the germinable seed bank was estimated from soil samples collected in Fall 1999 before flowering, and in the subsequent spring. Seedlings emerged from soils placed in a greenhouse from samples collected in the spring. No seedlings emerged from samples collected in the fall. Germinable seed had a 10 times higher density in samples collected near the soil surface than from samples collected at 5-10 cm depth. Seed dispersal occurred within the main population only. Despite the lack of seed dispersal in 1999, seedlings emerged from six of seven subpopulations in spring 2000, with the highest densities where plants had flowered in 1999. These data indicate the presence of a persistent soil seed bank for M. vimineum. Even following summer drought and discounting spring seedling emergence, the size of the seed bank increased by -25% in 1999. Reestablishment of the Dixon Springs population following the 1999 drought was vigorous, but the location of the largest, most fecund plants in 2000 was not the same as in 1999. In 2000, end of season survivorship of M. vimineum among all populations was 40-50%, with 90% of surviving individuals flowering. Performance of M. vimineum varied significantly within and among populations and was related to soil texture and chemistry, and overhead canopy cover. The findings of our study reflect the invasive nature of this plant. A sufficiently large seed bank and a highly plastic morphological response to local microhabitat conditions likely ensures its persistence in invaded sites.
{"title":"Life history of Microstegium vimineum (Poaceae), an invasive grass in southern Illinois.","authors":"D. Gibson, Greg Spyreas, J. Benedict","doi":"10.2307/3088771","DOIUrl":"https://doi.org/10.2307/3088771","url":null,"abstract":"limited to one small area at the edge of the core population. At Dixon Springs, the germinable seed bank was estimated from soil samples collected in Fall 1999 before flowering, and in the subsequent spring. Seedlings emerged from soils placed in a greenhouse from samples collected in the spring. No seedlings emerged from samples collected in the fall. Germinable seed had a 10 times higher density in samples collected near the soil surface than from samples collected at 5-10 cm depth. Seed dispersal occurred within the main population only. Despite the lack of seed dispersal in 1999, seedlings emerged from six of seven subpopulations in spring 2000, with the highest densities where plants had flowered in 1999. These data indicate the presence of a persistent soil seed bank for M. vimineum. Even following summer drought and discounting spring seedling emergence, the size of the seed bank increased by -25% in 1999. Reestablishment of the Dixon Springs population following the 1999 drought was vigorous, but the location of the largest, most fecund plants in 2000 was not the same as in 1999. In 2000, end of season survivorship of M. vimineum among all populations was 40-50%, with 90% of surviving individuals flowering. Performance of M. vimineum varied significantly within and among populations and was related to soil texture and chemistry, and overhead canopy cover. The findings of our study reflect the invasive nature of this plant. A sufficiently large seed bank and a highly plastic morphological response to local microhabitat conditions likely ensures its persistence in invaded sites.","PeriodicalId":49977,"journal":{"name":"Journal of the Torrey Botanical Society","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2002-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2307/3088771","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68730578","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}
SEAGO, JR., J. L. (Department of Biology, State University of New York, College at Oswego, New York 13126) The Root Cortex of the Nymphaeaceae, Cabombaceae, and Nelumbonaceae. J. Torrey Bot. Soc. 129: 19. 2002.-The roots of selected water lilies, Nymphaeaceae and Cabombaceae, and water lotuses, Nelumbonaceae, were examined using epifluorescence, brightfield, and modified darkfield microscopy to determine the characteristics of root cortical structure. The members of the Nymphaeaceae have an endodermis usually with Casparian bands only, many astrosclereids and some transverse diaphragms scattered throughout the aerenchyma, and a hypodermis with a uniseriate exodermis with Casparian bands and suberin lamellae, although there may be some secondary, cellulosic thickening. The Cabombaceae are characterized by small roots with an endodermis with Casparian bands and uneven suberin lamellae, aerenchyma without sclereids or diaphragms, and an exodermis with Casparian bands and distinctive suberin lamellae. The Nelumbonaceae are distinctly different: Nelumbo has an endodermis of Casparian bands, suberin lamellae, and secondarily lignified walls, an aerenchyma without sclereids or diaphragms, and a multiseriate hypodermis with a uniseriate exodermis of Casparian bands and suberin lamellae, and an inner hypodermis with distinctly lignified walls.
SEAGO, JR.， J. L.(纽约州立大学生物系，奥斯威戈学院，纽约13126)锦葵科、卡龙贝科和莲科植物的根皮质。托里·博特。《社会科学》129:19。2002.选取睡莲科和Cabombaceae科的睡莲，以及莲蓉科的荷花，利用荧光显微镜、明场显微镜和改良暗场显微镜对其根皮质结构特征进行了检测。睡莲科的成员有一个通常只有卡斯帕里斯带的内胚层，许多星形胶质和一些横膈膜散布在通气组织中，还有一个具有单一的外胚层，有卡斯帕里斯带和木质片层的下胚层，尽管可能有一些继发的纤维素增厚。cabombacaceae的特点是根小，内胚层有卡斯帕里斯带和不均匀的木质素片层，通气组织没有硬膜或隔膜，外胚层有卡斯帕里斯带和独特的木质素片层。荷兰科有明显的不同:荷兰科有一个由卡斯帕里斯带、木质素薄片和次生木质化壁组成的内皮层，一个没有硬膜或隔膜的通气组织，一个由卡斯帕里斯带和木质素薄片组成的单列外皮层和一个具有明显木质化壁的内皮层。
{"title":"The root cortex of the Nymphaeaceae, Cabombaceae and Nelumbonaceae","authors":"J. L. Seago","doi":"10.2307/3088677","DOIUrl":"https://doi.org/10.2307/3088677","url":null,"abstract":"SEAGO, JR., J. L. (Department of Biology, State University of New York, College at Oswego, New York 13126) The Root Cortex of the Nymphaeaceae, Cabombaceae, and Nelumbonaceae. J. Torrey Bot. Soc. 129: 19. 2002.-The roots of selected water lilies, Nymphaeaceae and Cabombaceae, and water lotuses, Nelumbonaceae, were examined using epifluorescence, brightfield, and modified darkfield microscopy to determine the characteristics of root cortical structure. The members of the Nymphaeaceae have an endodermis usually with Casparian bands only, many astrosclereids and some transverse diaphragms scattered throughout the aerenchyma, and a hypodermis with a uniseriate exodermis with Casparian bands and suberin lamellae, although there may be some secondary, cellulosic thickening. The Cabombaceae are characterized by small roots with an endodermis with Casparian bands and uneven suberin lamellae, aerenchyma without sclereids or diaphragms, and an exodermis with Casparian bands and distinctive suberin lamellae. The Nelumbonaceae are distinctly different: Nelumbo has an endodermis of Casparian bands, suberin lamellae, and secondarily lignified walls, an aerenchyma without sclereids or diaphragms, and a multiseriate hypodermis with a uniseriate exodermis of Casparian bands and suberin lamellae, and an inner hypodermis with distinctly lignified walls.","PeriodicalId":49977,"journal":{"name":"Journal of the Torrey Botanical Society","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2002-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2307/3088677","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68729170","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}
such as catastrophic windthrow can play a major role in the structure and composition of southern Appalachian forests. We report effects of Hurricane Opal followed by salvage logging on vegetation dynamics (regeneration, composition, and diversity) the first three years after disturbance at the Coweeta Hydrologic Laboratory in western North Carolina. The objective of this study was to compare species composition and diversity of understory and groundlayer species in a hurricane + salvage logged (H+S) forest to an adjacent undisturbed forest. Abundance of groundlayer species was much higher in the H+S forest than in the undisturbed forest, and abundance increased over time. Percent cover, density, and species richness were significantly higher in the H+S forest than in the undisturbed forest. In addition, percent cover increased by approximately 85% between 1997 and 1999 in the H+S plots. Shannon's index of diversity (H') based on percent cover was significantly higher in the H+S forest than the undisturbed forest by the third year after disturbance. However, there was no significant difference in H' based on density between H+S forest and the undisturbed forest in either year. In the undisturbed forest, 59 species and 50 genera represented 30 families. By 1999 (the third year after disturbance), the H+S forest retained 93 species, 72 genera and 42 families. The Asteraceae and Liliaceae had the highest number of species in both sampled forests, with more species of Liliaceae in the H+S plots. Micro-relief created from pit and mound topography from uprooting of windthrown trees, shade from the slash-debris left on site from the salvage logging, and shade from the remaining overstory trees created a mosaic of environmental conditions. This environmental heterogeneity could be responsible for the mix of early (shade intolerant) and late (shade tolerant) successional herbaceous species, and a higher species richness and diversity than the undisturbed forest.
{"title":"Vegetation response to large scale disturbance in a southern Appalachian forest: Hurricane Opal and salvage logging","authors":"K. Elliott, S. L. Hitchcock, Lisa M. Krueger","doi":"10.2307/3088682","DOIUrl":"https://doi.org/10.2307/3088682","url":null,"abstract":"such as catastrophic windthrow can play a major role in the structure and composition of southern Appalachian forests. We report effects of Hurricane Opal followed by salvage logging on vegetation dynamics (regeneration, composition, and diversity) the first three years after disturbance at the Coweeta Hydrologic Laboratory in western North Carolina. The objective of this study was to compare species composition and diversity of understory and groundlayer species in a hurricane + salvage logged (H+S) forest to an adjacent undisturbed forest. Abundance of groundlayer species was much higher in the H+S forest than in the undisturbed forest, and abundance increased over time. Percent cover, density, and species richness were significantly higher in the H+S forest than in the undisturbed forest. In addition, percent cover increased by approximately 85% between 1997 and 1999 in the H+S plots. Shannon's index of diversity (H') based on percent cover was significantly higher in the H+S forest than the undisturbed forest by the third year after disturbance. However, there was no significant difference in H' based on density between H+S forest and the undisturbed forest in either year. In the undisturbed forest, 59 species and 50 genera represented 30 families. By 1999 (the third year after disturbance), the H+S forest retained 93 species, 72 genera and 42 families. The Asteraceae and Liliaceae had the highest number of species in both sampled forests, with more species of Liliaceae in the H+S plots. Micro-relief created from pit and mound topography from uprooting of windthrown trees, shade from the slash-debris left on site from the salvage logging, and shade from the remaining overstory trees created a mosaic of environmental conditions. This environmental heterogeneity could be responsible for the mix of early (shade intolerant) and late (shade tolerant) successional herbaceous species, and a higher species richness and diversity than the undisturbed forest.","PeriodicalId":49977,"journal":{"name":"Journal of the Torrey Botanical Society","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2002-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2307/3088682","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68729794","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}
{"title":"The vascular flora of Hoffman and Swinburne Islands, New York Harbor, New York.","authors":"R. Stalter, A. Munir","doi":"10.2307/3088684","DOIUrl":"https://doi.org/10.2307/3088684","url":null,"abstract":"","PeriodicalId":49977,"journal":{"name":"Journal of the Torrey Botanical Society","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2002-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2307/3088684","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68729319","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}
CARLQUIST, S. (Santa Barbara Botanic Garden, 1212 Mission Canyon Road, Santa Barbara, CA 93105). Wood and bark anatomy of Salvadoraceae: relationships, ecology, histology of interxylary phloem. J. Torrey Bot. Soc. 129:10-20. 2002. Quantitative and qualitative data are presented for stem wood of one species each of Azima, Dobera, and Salvadora and for root wood of Salvadora. The liquid-preserved material of Salvadora permitted analysis of interxylary phloem: abaxial to most strands a "residual meristem" adds sieve-tube elements and companion cells to each strand, crushing earlier-formed phloem. Current opinion that Salvadoraceae are a sister family to Bataceae is supported by wood anatomy: they share such features as bands of mostly nonsubdivided axial parenchyma cells, wide multiseriate rays, and and storied structure. Nonbordered perforation plates, found also in other Capparales, are newly reported for Salvadoraceae. Koeberliniaceae have tracheids, Bataceae fibertracheids, thought more primitive than the libriform fibers of Salvadoraceae. Wood of Azima is moderately mesomorphic, perhaps because it grows near beaches where saline or brackish water is available to roots; Dobera and Salvadora have highly xeromorphic wood. The terms "foraminate included phloem" and "concentric included phloem" are misnomers and must be rejected.
{"title":"Wood and bark anatomy of Salvadoraceae: ecology, relationships, histology of interxylary phloem1","authors":"S. Carlquist","doi":"10.2307/3088678","DOIUrl":"https://doi.org/10.2307/3088678","url":null,"abstract":"CARLQUIST, S. (Santa Barbara Botanic Garden, 1212 Mission Canyon Road, Santa Barbara, CA 93105). Wood and bark anatomy of Salvadoraceae: relationships, ecology, histology of interxylary phloem. J. Torrey Bot. Soc. 129:10-20. 2002. Quantitative and qualitative data are presented for stem wood of one species each of Azima, Dobera, and Salvadora and for root wood of Salvadora. The liquid-preserved material of Salvadora permitted analysis of interxylary phloem: abaxial to most strands a \"residual meristem\" adds sieve-tube elements and companion cells to each strand, crushing earlier-formed phloem. Current opinion that Salvadoraceae are a sister family to Bataceae is supported by wood anatomy: they share such features as bands of mostly nonsubdivided axial parenchyma cells, wide multiseriate rays, and and storied structure. Nonbordered perforation plates, found also in other Capparales, are newly reported for Salvadoraceae. Koeberliniaceae have tracheids, Bataceae fibertracheids, thought more primitive than the libriform fibers of Salvadoraceae. Wood of Azima is moderately mesomorphic, perhaps because it grows near beaches where saline or brackish water is available to roots; Dobera and Salvadora have highly xeromorphic wood. The terms \"foraminate included phloem\" and \"concentric included phloem\" are misnomers and must be rejected.","PeriodicalId":49977,"journal":{"name":"Journal of the Torrey Botanical Society","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2002-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2307/3088678","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68729352","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}
Molano-Flores, B. (Illinois Natural History Survey-Center for Biodiversity, 607 E. Peabody Drive, Champaign, Illinois 61820). Pollination biology and flower visitors of the gynodioecious species Lobelia spicata Lam. (Campanulaceae). J. Torrey Bot. Soc. 129: 187-193. 2002.-The pollination biology and flower visitors of Lobelia spicata, an herbaceous prairie perennial, were examined, and this species was found to be xenogamous, self-compatible, and gynodioecious. Hermaphroditic individuals are protandrous, produce nectar, and have secondary pollen presentation (i.e., pump mechanism). Female individuals do not produce nectar. No significant differences were found between the fruit set of open-pollinated hermaphroditic and female flowers. In hermaphroditic bagged flowers seeds were produced (i.e., undeveloped fruits) suggesting self-pollination; however, this was determined to be the result of geitonogamous pollination by thrips. Autogamy is not likely in this species because there is no overlap between the staminate and pistillate phases. This species is pollinated mainly by bees from the genus Augochlorella. Overall, this study shows that L. spicata shares many common characteristics with other species of Lobelia (i.e., L. cardinalis and L. siphilitica) such as protandry, self-compatibility, no autonomous self-pollination, similar flower phenology (i.e., pistillate and staminate phases), and secondary pollen presentation (i.e., pump mechanism). In contrast to these other species, L. spicata blooms early, has smaller flowers, and attracts smaller pollinators.
{"title":"Pollination biology and flower visitors of the gynodioecious species Lobelia spicata Lam. (Campanulaceae)","authors":"B. Molano‐Flores","doi":"10.2307/3088769","DOIUrl":"https://doi.org/10.2307/3088769","url":null,"abstract":"Molano-Flores, B. (Illinois Natural History Survey-Center for Biodiversity, 607 E. Peabody Drive, Champaign, Illinois 61820). Pollination biology and flower visitors of the gynodioecious species Lobelia spicata Lam. (Campanulaceae). J. Torrey Bot. Soc. 129: 187-193. 2002.-The pollination biology and flower visitors of Lobelia spicata, an herbaceous prairie perennial, were examined, and this species was found to be xenogamous, self-compatible, and gynodioecious. Hermaphroditic individuals are protandrous, produce nectar, and have secondary pollen presentation (i.e., pump mechanism). Female individuals do not produce nectar. No significant differences were found between the fruit set of open-pollinated hermaphroditic and female flowers. In hermaphroditic bagged flowers seeds were produced (i.e., undeveloped fruits) suggesting self-pollination; however, this was determined to be the result of geitonogamous pollination by thrips. Autogamy is not likely in this species because there is no overlap between the staminate and pistillate phases. This species is pollinated mainly by bees from the genus Augochlorella. Overall, this study shows that L. spicata shares many common characteristics with other species of Lobelia (i.e., L. cardinalis and L. siphilitica) such as protandry, self-compatibility, no autonomous self-pollination, similar flower phenology (i.e., pistillate and staminate phases), and secondary pollen presentation (i.e., pump mechanism). In contrast to these other species, L. spicata blooms early, has smaller flowers, and attracts smaller pollinators.","PeriodicalId":49977,"journal":{"name":"Journal of the Torrey Botanical Society","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2002-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2307/3088769","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68730550","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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