R. Latham, J. Thompson, Sarah A. Riley, Anne W. Wibiralske
LATHAM, R. E., J. E. THOMPSON, S. A. RILEY AND A. W. WIBIRALSKE (Department of Geology, University of Pennsylvania, Philadelphia, PA 19104-6316). The Pocono till barrens: shrub savanna persisting on soils favoring forest. Bull. Torrey Bot. Club 123: 330-349. 1996.-A previously undescribed shrub savanna community, which we refer to as the Pocono till barrens, occurs mainly on soils weathered from glacial till of Illinoian age on the southern Pocono Plateau of Pennsylvania. Unlike most "barrens" in east-central North America, its soils are not sandy or shallow to bedrock; the same deep, fine-loamy soil series underlie the barrens and nearby northern hardwoods forest. An unusual abundance of rare plant and animal species in and near the barrens has attracted the attention of scientists and biodiversity conservation professionals. In an effort to understand the ecological dynamics of the Pocono till barrens and why the barrens are different from their mostly forested surroundings, we undertook studies of vegetation history, landscape patterns, plant species distributions and water table depth. The Pocono till barrens (1) are old, pre-dating European settlement of the area; (2) have burned frequently and over large areas throughout their recorded history; (3) presently cover more than 22 km2 adjacent to a belt of xeric ridgetop barrens totaling approximately 18 kM2; (4) have in abundance plants usually found in moist or wet soil conditions living side-by-side with those normally associated with xeric habitats; and (5) include several vegetation types which are distributed on the landscape, in part, in association with a soil moisture gradient. The Pocono till barrens appear to flout the conventional wisdom that barrens vegetation reflects droughty, nutrient-poor soils. Although the Pocono till barrens substantially pre-date European settlement of the area, fire is clearly the key to maintenance of barrens vegetation in this system. We hypothesize that biotic factors are more important than abiotic factors in determining distributions of barrens and forest vegetation on the southern Pocono Plateau.
LATHAM, R. E.， J. E. THOMPSON, S. A. RILEY和A. W. WIBIRALSKE(宾夕法尼亚大学地质系，费城，19104-6316)。波科诺荒原:生长在有利于森林的土壤上的灌木稀树草原。公牛。托里机器人。俱乐部123:330-349。1996.-先前描述过的灌木稀树草原群落，我们称之为波科诺荒原，主要发生在宾夕法尼亚州波科诺高原南部伊利诺斯州冰川时期的土壤上。与北美中东部的大多数“不毛之地”不同，这里的土壤不是沙质的，也不是浅到基岩的;这片贫瘠的土地和附近的北方阔叶林也有着同样深厚、细密的壤土。在这片不毛之地及其附近，稀有动植物种类异常丰富，吸引了科学家和生物多样性保护专家的注意。为了了解波科诺荒原的生态动态，以及为什么荒原与周围的森林环境不同，我们对植被历史、景观格局、植物物种分布和地下水位进行了研究。波科诺荒原是古老的，早于欧洲人在该地区定居;(二)在有记载的历史中曾发生过频繁、大面积的火灾;(3)目前覆盖面积超过22平方公里，毗邻干旱脊顶荒地带，总面积约为18平方公里;(4)有大量通常生长在潮湿或潮湿土壤条件下的植物与通常生长在干旱生境的植物并存;(5)包括几种植被类型，它们在景观上的分布部分与土壤湿度梯度有关。Pocono till的贫瘠似乎藐视了传统观念，即贫瘠的植被反映了干旱、营养贫乏的土壤。尽管波科诺荒原在欧洲人定居该地区之前就已经出现了，但在这个系统中，火显然是维持荒地植被的关键。我们假设生物因子比非生物因子更能决定波科诺高原南部的荒地和森林植被的分布。
{"title":"The Pocono till barrens: shrub savanna persisting on soils favoring forest1","authors":"R. Latham, J. Thompson, Sarah A. Riley, Anne W. Wibiralske","doi":"10.2307/2996782","DOIUrl":"https://doi.org/10.2307/2996782","url":null,"abstract":"LATHAM, R. E., J. E. THOMPSON, S. A. RILEY AND A. W. WIBIRALSKE (Department of Geology, University of Pennsylvania, Philadelphia, PA 19104-6316). The Pocono till barrens: shrub savanna persisting on soils favoring forest. Bull. Torrey Bot. Club 123: 330-349. 1996.-A previously undescribed shrub savanna community, which we refer to as the Pocono till barrens, occurs mainly on soils weathered from glacial till of Illinoian age on the southern Pocono Plateau of Pennsylvania. Unlike most \"barrens\" in east-central North America, its soils are not sandy or shallow to bedrock; the same deep, fine-loamy soil series underlie the barrens and nearby northern hardwoods forest. An unusual abundance of rare plant and animal species in and near the barrens has attracted the attention of scientists and biodiversity conservation professionals. In an effort to understand the ecological dynamics of the Pocono till barrens and why the barrens are different from their mostly forested surroundings, we undertook studies of vegetation history, landscape patterns, plant species distributions and water table depth. The Pocono till barrens (1) are old, pre-dating European settlement of the area; (2) have burned frequently and over large areas throughout their recorded history; (3) presently cover more than 22 km2 adjacent to a belt of xeric ridgetop barrens totaling approximately 18 kM2; (4) have in abundance plants usually found in moist or wet soil conditions living side-by-side with those normally associated with xeric habitats; and (5) include several vegetation types which are distributed on the landscape, in part, in association with a soil moisture gradient. The Pocono till barrens appear to flout the conventional wisdom that barrens vegetation reflects droughty, nutrient-poor soils. Although the Pocono till barrens substantially pre-date European settlement of the area, fire is clearly the key to maintenance of barrens vegetation in this system. We hypothesize that biotic factors are more important than abiotic factors in determining distributions of barrens and forest vegetation on the southern Pocono Plateau.","PeriodicalId":9453,"journal":{"name":"Bulletin of the Torrey Botanical Club","volume":"123 1","pages":"330"},"PeriodicalIF":0.0,"publicationDate":"1996-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2307/2996782","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68411538","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Brewer, W. Platt, J. S. Glitzenstein, D. Streng, W. Platt, J. S. Glitzenstein, D. Streng
only slightly greater (- 10%), however, inside gaps than outside gaps in May-burned blocks four months after the May fires. We therefore conclude that golden aster potentially performs better within fire-generated gaps than within dense vegetation dominated by wiregrass, at least in years without lightning season (May) fires. We suggest, however, that such differences between gaps and dense vegetation likely have little effect on the long term performance of golden aster in pine savannas frequently burned in May.
{"title":"Effects of fire-generated gaps on growth and reproduction of golden aster (Pityopsis graminifolia)\"","authors":"J. Brewer, W. Platt, J. S. Glitzenstein, D. Streng, W. Platt, J. S. Glitzenstein, D. Streng","doi":"10.2307/2996778","DOIUrl":"https://doi.org/10.2307/2996778","url":null,"abstract":"only slightly greater (- 10%), however, inside gaps than outside gaps in May-burned blocks four months after the May fires. We therefore conclude that golden aster potentially performs better within fire-generated gaps than within dense vegetation dominated by wiregrass, at least in years without lightning season (May) fires. We suggest, however, that such differences between gaps and dense vegetation likely have little effect on the long term performance of golden aster in pine savannas frequently burned in May.","PeriodicalId":9453,"journal":{"name":"Bulletin of the Torrey Botanical Club","volume":"123 1","pages":"295"},"PeriodicalIF":0.0,"publicationDate":"1996-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2307/2996778","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68410619","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
JORDAN, R. A. AND J. M. HARTMAN (Graduate Program in Ecology and Evolution, P.O. Box 231, Cook College, Rutgers University, New Brunswick, NJ 08903). Effects of canopy opening on recruitment in Clethra alnifolia populations in central New Jersey wetland forests. Bull. Torrey Bot. Club 123: 286-294. 1996.-We measured stem growth and recruitment in three populations of Clethra alnifolia established in wetland forests, in canopy gaps, and in a recently cleared powerline right-of-way (ROW) to assess the ways in which C. alnifolia responded to canopy disturbance. Seasonal growth and density of stems and flowering rates were greater in canopy gaps, although greater overall recruitment occurred in the closed canopy forest. Total stem density, extension growth, and flowering significantly increased in the ROW and were directly related to distance from the ROW edge. Seedling density and new stem recruitment also increased significantly in the disturbed area. Clethra alnifolia demonstrated a "light flexible" response to canopy disturbance, regenerating established populations in the forest primarily through vegetative reproduction and producing greater stem density and aerial cover under disturbed canopies, but requiring significant or long-term canopy disruption to initiate increased sexual reproduction.
JORDAN, R. A. AND J. M. HARTMAN(美国罗格斯大学库克学院生态与进化研究生课程，新泽西州新不伦瑞克08903)。冠层开度对新泽西中部湿地森林落叶草种群补充的影响。公牛。托里机器人。俱乐部123:286-294。1996.我们测量了在湿地森林、冠层间隙和最近清除的电力线权(ROW)中建立的三个落叶杉树(Clethra alnifolia)种群的茎生长和补充情况，以评估落叶杉树对冠层干扰的响应方式。冠层间隙的季节生长、茎密度和开花率更高，尽管在封闭的冠层林中发生了更大的总体补充。茎总密度、伸长生长和开花显著增加，且与距行边距离直接相关。苗木密度和新茎吸收量也显著增加。对冠层干扰表现出“轻灵活”的响应，主要通过营养繁殖和在受干扰的冠层下产生更大的茎密度和空中覆盖来再生森林中的已建立种群，但需要显著或长期的冠层破坏来增加有性繁殖。
{"title":"Effects of canopy opening on recruitment in Clethra alnifolia L. (Clethraceae) populations in central New Jersey wetland forests","authors":"R. Jordan, J. Hartman, J. Hartman","doi":"10.2307/2996777","DOIUrl":"https://doi.org/10.2307/2996777","url":null,"abstract":"JORDAN, R. A. AND J. M. HARTMAN (Graduate Program in Ecology and Evolution, P.O. Box 231, Cook College, Rutgers University, New Brunswick, NJ 08903). Effects of canopy opening on recruitment in Clethra alnifolia populations in central New Jersey wetland forests. Bull. Torrey Bot. Club 123: 286-294. 1996.-We measured stem growth and recruitment in three populations of Clethra alnifolia established in wetland forests, in canopy gaps, and in a recently cleared powerline right-of-way (ROW) to assess the ways in which C. alnifolia responded to canopy disturbance. Seasonal growth and density of stems and flowering rates were greater in canopy gaps, although greater overall recruitment occurred in the closed canopy forest. Total stem density, extension growth, and flowering significantly increased in the ROW and were directly related to distance from the ROW edge. Seedling density and new stem recruitment also increased significantly in the disturbed area. Clethra alnifolia demonstrated a \"light flexible\" response to canopy disturbance, regenerating established populations in the forest primarily through vegetative reproduction and producing greater stem density and aerial cover under disturbed canopies, but requiring significant or long-term canopy disruption to initiate increased sexual reproduction.","PeriodicalId":9453,"journal":{"name":"Bulletin of the Torrey Botanical Club","volume":"123 1","pages":"286"},"PeriodicalIF":0.0,"publicationDate":"1996-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2307/2996777","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68411075","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
BOERNER, R. E. J. AND J. A. BRINKMAN. (Department of Plant Biology, Ohio State University, 1735 Neil Avenue, Columbus, OH 43210 U.S.A.) Ten years of tree seedling establishment and mortality in an Ohio deciduous forest complex. Bull. Torrey Bot. Club 123: 309-317. 1996.-This study quantified tree seedling establishment and mortality over a ten year period (1984-1993) in an Ohio deciduous forest complex which included upland beech-maple (Acer-Fagus) forest, lowland ash-elm (Fraxinus-Ulmus) forest, and young pin oak (Quercus palustris) forest. Annual establishment averaged 316 seedlings/100 m2, of which approximately 70% were ashes and 17% were maples. There were distinct peaks of ash and maple establishment in 1988 and 1990, and of elm establishment in 1986, 1988, and 1991. There were no significant correlations between ash or maple establishment and seasonal precipitation patterns whereas peaks of elm establishment correlated with drier-thanaverage springs. Ash seedlings were more abundant in lowland than upland plots, whereas the pattern for maple seedlings was the reverse. Maple seedlings were most abundant in canopy gaps, whereas ash seedlings were most abundant in wet depressions. Median longevity for most seedlings was 5-7 months, and >95% died within one year. Of the 2553 seedlings monitored, only two grew out of the seedling size class during this decade. In this site, deer browsing was more important than environmental gradients or climate factors in determining seedling longevity and mortality.
r. e. j.布尔纳和j. a.布林克曼。(俄亥俄州立大学植物生物系，1735 Neil Avenue, Columbus, OH 43210 U.S.A.)俄亥俄州落叶森林复合体10年树苗建立和死亡率。公牛。托里机器人。俱乐部123:309-317。1996.本研究对俄亥俄州一个落叶森林复林进行了为期10年(1984-1993)的树苗建立和死亡率的量化研究，该复林包括高地山毛榉枫林(Acer-Fagus)、低地灰榆林(Fraxinus-Ulmus)和幼针栎林(Quercus palustris)。年平均树苗316株/100 m2，其中灰苗约占70%，枫苗约占17%。白蜡树和枫树群落在1988年和1990年有明显的高峰，榆树群落在1986年、1988年和1991年有明显的高峰。白蜡树和枫树的峰值与季节降水模式无显著相关，而榆树的峰值与比平均水平更干燥的春季相关。低洼地白灰苗比高地多，枫苗则相反。枫树幼苗在林隙中最丰富，而灰树幼苗在湿洼地中最丰富。大多数幼苗的平均寿命为5-7个月，约95%的幼苗在一年内死亡。在监测的2553棵幼苗中，在这十年中只有两棵长出了幼苗的大小。与环境梯度和气候因子相比，鹿食对幼苗寿命和死亡率的影响更大。
{"title":"Ten years of tree seedling establishment and mortality in an Ohio deciduous forest complex","authors":"R. Boerner, J. Brinkman, J. Brinkman","doi":"10.2307/2996780","DOIUrl":"https://doi.org/10.2307/2996780","url":null,"abstract":"BOERNER, R. E. J. AND J. A. BRINKMAN. (Department of Plant Biology, Ohio State University, 1735 Neil Avenue, Columbus, OH 43210 U.S.A.) Ten years of tree seedling establishment and mortality in an Ohio deciduous forest complex. Bull. Torrey Bot. Club 123: 309-317. 1996.-This study quantified tree seedling establishment and mortality over a ten year period (1984-1993) in an Ohio deciduous forest complex which included upland beech-maple (Acer-Fagus) forest, lowland ash-elm (Fraxinus-Ulmus) forest, and young pin oak (Quercus palustris) forest. Annual establishment averaged 316 seedlings/100 m2, of which approximately 70% were ashes and 17% were maples. There were distinct peaks of ash and maple establishment in 1988 and 1990, and of elm establishment in 1986, 1988, and 1991. There were no significant correlations between ash or maple establishment and seasonal precipitation patterns whereas peaks of elm establishment correlated with drier-thanaverage springs. Ash seedlings were more abundant in lowland than upland plots, whereas the pattern for maple seedlings was the reverse. Maple seedlings were most abundant in canopy gaps, whereas ash seedlings were most abundant in wet depressions. Median longevity for most seedlings was 5-7 months, and >95% died within one year. Of the 2553 seedlings monitored, only two grew out of the seedling size class during this decade. In this site, deer browsing was more important than environmental gradients or climate factors in determining seedling longevity and mortality.","PeriodicalId":9453,"journal":{"name":"Bulletin of the Torrey Botanical Club","volume":"9 1","pages":"309"},"PeriodicalIF":0.0,"publicationDate":"1996-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2307/2996780","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68410667","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Stem and Leaf Anatomy of Saruma henryi Oliv., Including Observations on Raylessness in the Aristolochiaceae","authors":"W. Dickison","doi":"10.2307/2996773","DOIUrl":"https://doi.org/10.2307/2996773","url":null,"abstract":"","PeriodicalId":9453,"journal":{"name":"Bulletin of the Torrey Botanical Club","volume":"123 1","pages":"261"},"PeriodicalIF":0.0,"publicationDate":"1996-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2307/2996773","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68410799","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
MCCARTHY, B. C. AND D. R. BAILEY. (Department of Environmental & Plant Biology, Ohio University, Athens, OH 45701-2979). Composition, structure, and disturbance history of Crabtree Woods: an old-growth forest of western Maryland. Bull. Torrey Bot. Club 123: 350-365. 1996.-Crabtree Woods is an old stand of mixed Appalachian hardwoods which has been identified as one of the finest examples of this vegetation type in Maryland. Because few botanical studies have been conducted on the Allegheny Plateau of Maryland and because the old-growth nature of this stand is unique in its present landscape, we undertook this study to describe the composition, structure, and disturbance history of the stand. A one hectare permanent plot was established in which all trees, saplings, snags, and logs were quantified. Woody seedlings and herbs were subsampled from 25 quadrats to describe the understory. Increment cores were obtained from all Quercus rubra trees within the plot and used for dendroecological analysis. The stand shows many structural and compositional features characteristic of old-growth forest. The overstory was dominated by Acer saccharum, Q. rubra, and Tilia americana. The stand exhibited a reverse-J diameter distribution typical of old forests and a number of trees were observed to have a diameter >100 cm DBH. Acer saccharum and Hamamelis virginiana were the prominent understory constituents. Quercus rubra was essentially absent from seedling and sapling size classes and does not appear to be regenerating. Logs and snags were abundant and occurred in a variety of decay states and diameter classes. Thirty-nine species of herbs were discovered, with Dicentra canadensis, Urtica dioica, and Impatiens pallida being the most abundant. Stem increment analysis shows multiple periods of recruitment likely associated with gap dynamics. However, certain synchronous releases suggest possible light anthropogenic disturbance (e.g., selective cutting or chestnut salvage).
麦卡锡，b.c.和贝利博士。(美国俄亥俄大学环境与植物生物系，俄亥俄州雅典45701-2979)克拉柏树林的组成、结构和扰动史:马里兰州西部的一种原始森林。公牛。托里机器人。俱乐部123:350-365。1996.crabtree Woods是一个古老的混合阿巴拉契亚硬木林，被认为是马里兰州这种植被类型中最好的例子之一。由于在马里兰州阿勒格尼高原进行的植物学研究很少，并且由于该林分的古老生长性质在其当前景观中具有独特性，因此我们进行了这项研究，以描述该林分的组成，结构和干扰历史。建立了一个1公顷的永久地块，对所有树木、树苗、树枝和原木进行了量化。从25个样方取样木本幼苗和草本植物来描述林下植被。从样地内所有栎树获得增量岩心，用于树木生态学分析。林分表现出许多原生林的结构和组成特征。上层林分以糖槭、红木和美洲椴为主。林分直径呈典型的老林的倒j型分布，有一些林木的直径达到100 ~ 100 cm DBH。糖槭和金缕梅是主要的林下成分。红栎在苗木和幼树大小等级中基本不存在，也不表现出再生的迹象。原木和残障丰富，且发生在不同的衰变状态和直径级。共发现草本植物39种，以加拿大凤仙花(Dicentra canadensis)、荨麻(Urtica diotica)和凤仙花(Impatiens pallida)最多。Stem增量分析显示，多个招聘周期可能与差距动态有关。然而，某些同步释放表明可能有轻微的人为干扰(例如，选择性切割或栗子残留)。
{"title":"Composition, structure, and disturbance history of Crabtree Woods: an old-growth forest of western Maryland'","authors":"B. Mccarthy, D. Bailey, D. Bailey","doi":"10.2307/2996783","DOIUrl":"https://doi.org/10.2307/2996783","url":null,"abstract":"MCCARTHY, B. C. AND D. R. BAILEY. (Department of Environmental & Plant Biology, Ohio University, Athens, OH 45701-2979). Composition, structure, and disturbance history of Crabtree Woods: an old-growth forest of western Maryland. Bull. Torrey Bot. Club 123: 350-365. 1996.-Crabtree Woods is an old stand of mixed Appalachian hardwoods which has been identified as one of the finest examples of this vegetation type in Maryland. Because few botanical studies have been conducted on the Allegheny Plateau of Maryland and because the old-growth nature of this stand is unique in its present landscape, we undertook this study to describe the composition, structure, and disturbance history of the stand. A one hectare permanent plot was established in which all trees, saplings, snags, and logs were quantified. Woody seedlings and herbs were subsampled from 25 quadrats to describe the understory. Increment cores were obtained from all Quercus rubra trees within the plot and used for dendroecological analysis. The stand shows many structural and compositional features characteristic of old-growth forest. The overstory was dominated by Acer saccharum, Q. rubra, and Tilia americana. The stand exhibited a reverse-J diameter distribution typical of old forests and a number of trees were observed to have a diameter >100 cm DBH. Acer saccharum and Hamamelis virginiana were the prominent understory constituents. Quercus rubra was essentially absent from seedling and sapling size classes and does not appear to be regenerating. Logs and snags were abundant and occurred in a variety of decay states and diameter classes. Thirty-nine species of herbs were discovered, with Dicentra canadensis, Urtica dioica, and Impatiens pallida being the most abundant. Stem increment analysis shows multiple periods of recruitment likely associated with gap dynamics. However, certain synchronous releases suggest possible light anthropogenic disturbance (e.g., selective cutting or chestnut salvage).","PeriodicalId":9453,"journal":{"name":"Bulletin of the Torrey Botanical Club","volume":"123 1","pages":"350"},"PeriodicalIF":0.0,"publicationDate":"1996-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2307/2996783","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68411553","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
TESTER, J. R. (Department of Ecology, Evolution and Behavior, University of Minnesota, St. Paul, MN 55108). Effects of fire frequency on plant species in oak savanna in east-central Minnesota. Bull. Torrey Bot. Club 123: 304-308. 1996.-From 1964 through 1984, nine forest sites, ranging in size from 2.6 to 27.5 ha, were each burned from two to 19 times. Percent cover of 13 of 14 true-prairie grasses was positively correlated with burn frequency. Of these, eight have C4 and six have C3 photosynthetic pathways. Cover of 34 of 39 true-prairie forbs, and of Amorpha canescens, increased with frequency of burning. All except Aster oolentangiensis are C3 species. Cover of six of seven native, not prairie, species, all C3, decreased with increasing burn frequency. These data suggest that the adaptation of true-prairie species to repeated burning outweighs the effects of their photosynthetic pathways.
{"title":"Effects of Fire Frequency on Plant Species in Oak Savanna in East-Central Minnesota","authors":"J. Tester","doi":"10.2307/2996779","DOIUrl":"https://doi.org/10.2307/2996779","url":null,"abstract":"TESTER, J. R. (Department of Ecology, Evolution and Behavior, University of Minnesota, St. Paul, MN 55108). Effects of fire frequency on plant species in oak savanna in east-central Minnesota. Bull. Torrey Bot. Club 123: 304-308. 1996.-From 1964 through 1984, nine forest sites, ranging in size from 2.6 to 27.5 ha, were each burned from two to 19 times. Percent cover of 13 of 14 true-prairie grasses was positively correlated with burn frequency. Of these, eight have C4 and six have C3 photosynthetic pathways. Cover of 34 of 39 true-prairie forbs, and of Amorpha canescens, increased with frequency of burning. All except Aster oolentangiensis are C3 species. Cover of six of seven native, not prairie, species, all C3, decreased with increasing burn frequency. These data suggest that the adaptation of true-prairie species to repeated burning outweighs the effects of their photosynthetic pathways.","PeriodicalId":9453,"journal":{"name":"Bulletin of the Torrey Botanical Club","volume":"123 1","pages":"304"},"PeriodicalIF":0.0,"publicationDate":"1996-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2307/2996779","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68410632","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
CRUDEN, R. W., A. M. MCCLAIN (Department of Biological Sciences, University of Iowa, Iowa City, IA 52242) AND G. P. SHRIVASTAVA (School of Environmental Biology, APS. University, Rewa (M.P.), India 486 001). Pollination biology and breeding system of Alliaria petiolata (Brassicaceae). Bull. Torrey Bot. Club 123: 273-280. 1996.-Alliaria petiolata (Bieb.) Cavara and Grande is widely naturalized in the northeastern 1/4 of the United States and adjacent Canada, where it is an aggressive invader of moist woods. The plants are facultatively xenogamous, and the white flowers attract a variety of short-tongued bees and flies. High fruit and seed set by open-pollinated, emasculated flowers demonstrated that flower visitors move pollen between flowers. Cross-pollination resulted from the bees visiting only one or two flowers per plant. High fruit and seed set by bagged flowers demonstrated that flowers self-pollinate in the absence of pollinators. The nectar contained 51% fructose, 44% glucose, and little sucrose, which is typical of the nectars of flowers pollinated by short-tongued bees. The nectar contained no free amino acids, but did contain numbers of peptides, which, when hydrolyzed, yielded most of the amino acids present in floral nectars.
CRUDEN, R. W.， A. M. MCCLAIN(美国爱荷华大学生物科学系，爱荷华州爱荷华市52242)和G. P. SHRIVASTAVA(美国爱荷华大学环境生物学院，美国爱荷华州爱荷华市52242)印度雷瓦大学，印度486001)。芸苔科小葱(Alliaria petiolata)的传粉生物学及育种系统。公牛。托里机器人。俱乐部123:273-280。1996.——小葱属(alliaria petiolata)卡瓦拉和格兰德在美国东北部四分之一的地区和邻近的加拿大被广泛归化，在那里它是潮湿森林的侵略性入侵者。这些植物是兼性异种交配的，白色的花朵吸引了各种短舌蜜蜂和苍蝇。由开放授粉、阉割的花所形成的高果实和种子表明，访花者在花之间传播花粉。异花授粉是由于蜜蜂每株植物只访问一到两朵花。在无传粉者的情况下，袋装花的高结果和高结实率表明花是自花传粉的。花蜜含有51%的果糖，44%的葡萄糖和少量的蔗糖，这是由短舌蜜蜂授粉的花的典型花蜜。花蜜不含游离氨基酸，但含有一定数量的肽，这些肽在水解后产生了花蜜中存在的大部分氨基酸。
{"title":"Pollination biology and breeding system of Alliaria petiolata (Brassicaceae)","authors":"R. Cruden, A. M. McClain, G. P. Shrivastava","doi":"10.2307/2996775","DOIUrl":"https://doi.org/10.2307/2996775","url":null,"abstract":"CRUDEN, R. W., A. M. MCCLAIN (Department of Biological Sciences, University of Iowa, Iowa City, IA 52242) AND G. P. SHRIVASTAVA (School of Environmental Biology, APS. University, Rewa (M.P.), India 486 001). Pollination biology and breeding system of Alliaria petiolata (Brassicaceae). Bull. Torrey Bot. Club 123: 273-280. 1996.-Alliaria petiolata (Bieb.) Cavara and Grande is widely naturalized in the northeastern 1/4 of the United States and adjacent Canada, where it is an aggressive invader of moist woods. The plants are facultatively xenogamous, and the white flowers attract a variety of short-tongued bees and flies. High fruit and seed set by open-pollinated, emasculated flowers demonstrated that flower visitors move pollen between flowers. Cross-pollination resulted from the bees visiting only one or two flowers per plant. High fruit and seed set by bagged flowers demonstrated that flowers self-pollinate in the absence of pollinators. The nectar contained 51% fructose, 44% glucose, and little sucrose, which is typical of the nectars of flowers pollinated by short-tongued bees. The nectar contained no free amino acids, but did contain numbers of peptides, which, when hydrolyzed, yielded most of the amino acids present in floral nectars.","PeriodicalId":9453,"journal":{"name":"Bulletin of the Torrey Botanical Club","volume":"35 1","pages":"273-280"},"PeriodicalIF":0.0,"publicationDate":"1996-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2307/2996775","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68411019","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
WALTERS, B. B. AND E. W. STILES (Graduate Program in Ecology and Evolution, Rutgers University, Piscataway, NJ 08855). Effect of canopy gaps and flower patch size on pollinator visitation of Impatiens capensis. Bull. Torrey Bot. Club 123:184-188. 1996.-We measured pollinator visits of Impatiens capensis flowers found in different-sized patches beneath canopy gaps and beneath closed canopy in a mature, old-growth deciduous forest in New Jersey. Honeybees, bumblebees and halictid bees made up the majority of visitors. Visitation rates per flower increased slightly, but not significantly, in relation to flower patch size (number of open flowers) and floral density. By contrast, pollinator visitation rates, floral density and seed production per pod were all significantly higher in patches located beneath forest canopy gaps compared to patches located beneath closed canopy.
{"title":"Effect of canopy gaps and flower patch size on pollinator visitation of Impatiens capensis","authors":"B. B. Walters, E. Stiles","doi":"10.2307/2996793","DOIUrl":"https://doi.org/10.2307/2996793","url":null,"abstract":"WALTERS, B. B. AND E. W. STILES (Graduate Program in Ecology and Evolution, Rutgers University, Piscataway, NJ 08855). Effect of canopy gaps and flower patch size on pollinator visitation of Impatiens capensis. Bull. Torrey Bot. Club 123:184-188. 1996.-We measured pollinator visits of Impatiens capensis flowers found in different-sized patches beneath canopy gaps and beneath closed canopy in a mature, old-growth deciduous forest in New Jersey. Honeybees, bumblebees and halictid bees made up the majority of visitors. Visitation rates per flower increased slightly, but not significantly, in relation to flower patch size (number of open flowers) and floral density. By contrast, pollinator visitation rates, floral density and seed production per pod were all significantly higher in patches located beneath forest canopy gaps compared to patches located beneath closed canopy.","PeriodicalId":9453,"journal":{"name":"Bulletin of the Torrey Botanical Club","volume":"123 1","pages":"184"},"PeriodicalIF":0.0,"publicationDate":"1996-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2307/2996793","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68411159","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
BARDEN, L. S. (Department of Biology, University of North Carolina at Charlotte, Charlotte, NC 28223). A comparison of growth efficiency of plants on the east and west sides of a forest canopy gap. Bull. Torrey Bot. Club 123:240-242. 1996.-The theoretical distribution of light in a circular forest canopy gap is symmetrically equal on the east and west sides of the gap. However, small plants on the west side of the gap receive maximum light in the morning when air temperature and vapor pressure deficit are relatively low, while plants on the east side receive maximum light in the afternoon when temperature and VPD are high. To test the hypothesis that plants on the west side of a gap are able to use light more efficiently, Microstegium vimineum, a shade-adapted annual grass, was grown in pots in a forest canopy gap, both in the actual open gap and in the extended gap. In the actual gap there was no difference in growth efficiency. However, in the extended gap growth efficiency was 39% greater on the west side than on the east side under equal light (integrated photon flux density). Thus, asymmetry of microclimate on the east and west sides of a canopy gap causes an east-west asymmetry in plant growth efficiency and may induce asymmetry in species composition of understory vegetation.
{"title":"A comparison of growth efficiency of plants on the east and west sides of a forest canopy gap","authors":"L. S. Barden","doi":"10.2307/2996799","DOIUrl":"https://doi.org/10.2307/2996799","url":null,"abstract":"BARDEN, L. S. (Department of Biology, University of North Carolina at Charlotte, Charlotte, NC 28223). A comparison of growth efficiency of plants on the east and west sides of a forest canopy gap. Bull. Torrey Bot. Club 123:240-242. 1996.-The theoretical distribution of light in a circular forest canopy gap is symmetrically equal on the east and west sides of the gap. However, small plants on the west side of the gap receive maximum light in the morning when air temperature and vapor pressure deficit are relatively low, while plants on the east side receive maximum light in the afternoon when temperature and VPD are high. To test the hypothesis that plants on the west side of a gap are able to use light more efficiently, Microstegium vimineum, a shade-adapted annual grass, was grown in pots in a forest canopy gap, both in the actual open gap and in the extended gap. In the actual gap there was no difference in growth efficiency. However, in the extended gap growth efficiency was 39% greater on the west side than on the east side under equal light (integrated photon flux density). Thus, asymmetry of microclimate on the east and west sides of a canopy gap causes an east-west asymmetry in plant growth efficiency and may induce asymmetry in species composition of understory vegetation.","PeriodicalId":9453,"journal":{"name":"Bulletin of the Torrey Botanical Club","volume":"123 1","pages":"240"},"PeriodicalIF":0.0,"publicationDate":"1996-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2307/2996799","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68411375","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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