L. (red maple), is replaced. Fagus grandifolia Ehrh. (American beech) was codominant in the overstory with A. rubrum, and was dominant in the understory. Picea rubens saplings were more frequently found on mounds than other microtopographical positions, but not on mounds that were of recent origin. Picea rubens saplings had an unimodal age-structure characteristic of an even-aged population, which suggests a pattern of episodic regeneration coincident with local windthrow disturbance. Picea rubens that occurred on mounds, rocks, and intact areas tended to be larger and older than those found in pits. The establishment and survival of juvenile P. rubens were limited by the availability of microsites coincident with good seed years, and the suitability of microsites for growth once stems were established. Terminal and lateral growth increments of P. rubens saplings were similar among microtopographical positions and between reference and limed subcatchments before and in the two years after liming. In 1992, the terminal increment of P. rubens was not different from the 1991 terminal increment on treated subcatchments, but in reference subcatchments the terminal increment was less than in 1991. The potential role of P. rubens in future forests is discussed.
{"title":"Forest community composition and juvenile red spruce (Picea rubens) age-structure and growth patterns in an Adirondack watershed","authors":"P. Smallidge, D. Leopold","doi":"10.2307/2997008","DOIUrl":"https://doi.org/10.2307/2997008","url":null,"abstract":"L. (red maple), is replaced. Fagus grandifolia Ehrh. (American beech) was codominant in the overstory with A. rubrum, and was dominant in the understory. Picea rubens saplings were more frequently found on mounds than other microtopographical positions, but not on mounds that were of recent origin. Picea rubens saplings had an unimodal age-structure characteristic of an even-aged population, which suggests a pattern of episodic regeneration coincident with local windthrow disturbance. Picea rubens that occurred on mounds, rocks, and intact areas tended to be larger and older than those found in pits. The establishment and survival of juvenile P. rubens were limited by the availability of microsites coincident with good seed years, and the suitability of microsites for growth once stems were established. Terminal and lateral growth increments of P. rubens saplings were similar among microtopographical positions and between reference and limed subcatchments before and in the two years after liming. In 1992, the terminal increment of P. rubens was not different from the 1991 terminal increment on treated subcatchments, but in reference subcatchments the terminal increment was less than in 1991. The potential role of P. rubens in future forests is discussed.","PeriodicalId":9453,"journal":{"name":"Bulletin of the Torrey Botanical Club","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2307/2997008","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68413706","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}
BowERs, JAIcE E. (U.S. Geological Survey, 1675 W. Anklam Road, Tucson, AZ 85745) AND MARK A. DIMMITr (Arizona-Sonora Desert Museum, 2021 N. Kinney Road, Tucson, AZ 85743). Flowering phenology of six woody plants in the northern Sonoran Desert. Bull. Torrey Bot. Club 121: 215-229. 1994.-Climatic and flowering data from a site in the northern Sonoran Desert of southern Arizona were used to define flowering triggers and developmental requirements for 6 woody plants. These formulations were then used to predict flowering dates at a second northern Sonoran Desert site. It was determined that flowering is triggered by rain in Larrea tridentata (DC.) Cov., Fouquieria splendens Engelm., Encelia farinosa A. Gray, Ambrosia deltoidea (A. Gray) Payne and Acacia constricta Benth., and that flowering is triggered by photoperiod in Cercidium microphyllum (Torr.) Rose & Johnst. The base temperature for floral development in L. tridentata, F. splendens, E. farinosa, A. deltoidea and C. microphyllum is about 10?C. Their mean degree-day requirements range from 414 to 719. Acacia constricta requires 522 degree-days above 15?C. Minimum rainfall triggers varied from 9 mm forAmbrosia to 20 mm for Encelia. Flowering time in C. microphyllum may reflect phylogenetic constraints, while flowering time in F. splendens may be strongly influenced by pollinator availability. Flowering times of the remaining species seem constrained more by climate than by biotic considerations such as phylogeny, seed germination and competition for pollinators.
{"title":"Flowering phenology of six woody plants in the northern Sonoran Desert","authors":"J. E. Bowers, M. Dimmitt, A. Mark, A. Gray","doi":"10.2307/2997177","DOIUrl":"https://doi.org/10.2307/2997177","url":null,"abstract":"BowERs, JAIcE E. (U.S. Geological Survey, 1675 W. Anklam Road, Tucson, AZ 85745) AND MARK A. DIMMITr (Arizona-Sonora Desert Museum, 2021 N. Kinney Road, Tucson, AZ 85743). Flowering phenology of six woody plants in the northern Sonoran Desert. Bull. Torrey Bot. Club 121: 215-229. 1994.-Climatic and flowering data from a site in the northern Sonoran Desert of southern Arizona were used to define flowering triggers and developmental requirements for 6 woody plants. These formulations were then used to predict flowering dates at a second northern Sonoran Desert site. It was determined that flowering is triggered by rain in Larrea tridentata (DC.) Cov., Fouquieria splendens Engelm., Encelia farinosa A. Gray, Ambrosia deltoidea (A. Gray) Payne and Acacia constricta Benth., and that flowering is triggered by photoperiod in Cercidium microphyllum (Torr.) Rose & Johnst. The base temperature for floral development in L. tridentata, F. splendens, E. farinosa, A. deltoidea and C. microphyllum is about 10?C. Their mean degree-day requirements range from 414 to 719. Acacia constricta requires 522 degree-days above 15?C. Minimum rainfall triggers varied from 9 mm forAmbrosia to 20 mm for Encelia. Flowering time in C. microphyllum may reflect phylogenetic constraints, while flowering time in F. splendens may be strongly influenced by pollinator availability. Flowering times of the remaining species seem constrained more by climate than by biotic considerations such as phylogeny, seed germination and competition for pollinators.","PeriodicalId":9453,"journal":{"name":"Bulletin of the Torrey Botanical Club","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2307/2997177","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68415377","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}
on wet stream bottoms, Tsuga-Pinus on wet to mesic stream terraces, mixed mesophytic species within a mesic upland cove, and mixed Quercus on mesic to dry upland slopes. Based on tree recruitment and radial growth patterns, low-intensity exogenous disturbances occurred every 30-60 yr during the presettlement era. Extensive logging during the mid- I 840s was evident throughout the area, and, along with subsequent disturbances, had a profound effect on current forest composition and structure. Tree species responded differently to major anthropogenic disturbance, in terms of growth rate and canopy positioning. In general, Pinus strobus L., Liriodendron tulipifera L. and Quercus responded favorably to disturbance, whereas Acer, Betula alleghaniensis Britton and Tsuga canadensis (L.) Carr recovered more slowly. Current forest age structures reflect different disturbance patterns and rates of recovery, and were categorized as either even-aged, uneven-aged consisting of 2 distinct even-aged cohorts, or uneven-aged with extended recruitment (multiple small-scale disturbances). Successional patterns currently exhibited in all forests may be drastically altered in the future from overbrowsing by whitetailed deer (Odocoileus virginianus) and/or intense shrub competition on tree regeneration.
{"title":"Forest composition, structure, and disturbance history of the Alan Seeger Natural Area, Huntington County, Pennsylvania","authors":"Gregory J. NowackiI, M. Abrams","doi":"10.2307/2997182","DOIUrl":"https://doi.org/10.2307/2997182","url":null,"abstract":"on wet stream bottoms, Tsuga-Pinus on wet to mesic stream terraces, mixed mesophytic species within a mesic upland cove, and mixed Quercus on mesic to dry upland slopes. Based on tree recruitment and radial growth patterns, low-intensity exogenous disturbances occurred every 30-60 yr during the presettlement era. Extensive logging during the mid- I 840s was evident throughout the area, and, along with subsequent disturbances, had a profound effect on current forest composition and structure. Tree species responded differently to major anthropogenic disturbance, in terms of growth rate and canopy positioning. In general, Pinus strobus L., Liriodendron tulipifera L. and Quercus responded favorably to disturbance, whereas Acer, Betula alleghaniensis Britton and Tsuga canadensis (L.) Carr recovered more slowly. Current forest age structures reflect different disturbance patterns and rates of recovery, and were categorized as either even-aged, uneven-aged consisting of 2 distinct even-aged cohorts, or uneven-aged with extended recruitment (multiple small-scale disturbances). Successional patterns currently exhibited in all forests may be drastically altered in the future from overbrowsing by whitetailed deer (Odocoileus virginianus) and/or intense shrub competition on tree regeneration.","PeriodicalId":9453,"journal":{"name":"Bulletin of the Torrey Botanical Club","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2307/2997182","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68415496","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}
LECK, M. A. (Department of Biology, Rider College, Lawrenceville, NJ 08648-3599), C. C. BASKIN AND J. M. BAsKiN (School of Biological Sciences, University of Kentucky, Lexington, KY 40506-0225). Germination ecology of Bidens laevis (Asteraceae) from a tidal freshwater wetland. Bull. Torrey Bot. Club 121: 230-239. 1994.-Eight or more weeks of cold stratification (5?C) were required to break dormancy in achenes of Bidens laevis (L.) BSP from a tidal freshwater wetland. When achenes began to come out of dormancy, they germinated to 50% first at 35/20?C, and then with additional stratification the minimum temperature for 50% germination decreased to 1 5/6?C. Germination of stratified achenes was inhibited by darkness and was completely prevented by hypoxia (inundation in closedjars). Seeds inundated in openjars and those in Petri dishes, however, germinated to > 80%. Germination declined sharply with depth of burial (0, 1, and 5 cm). Moisture regime (drained, saturated, and inundated) also significantly affected germination, but afterripening condition (cold greenhouse or 5?C) altered the effect. Interaction between depth of burial and moisture regime was significant (P 1 yr) following winter afterripening of achenes in the field.
LECK, m.a.(莱德学院生物系，劳伦斯维尔，新泽西08648-3599)，C. C. BASKIN AND J. M. BASKIN(肯塔基大学生物科学学院，列克星敦，肯塔基40506-0225)。潮汐淡水湿地中野蔷薇(菊科)萌发生态学研究。公牛。托里机器人。俱乐部121:230-239。1994.-需要8周或更长时间的冷分层(5℃)才能打破白刺草(L.)瘦果的休眠。BSP来自潮汐淡水湿地。当瘦果开始从休眠状态中出来时，它们在35/20?再加层，萌发50%的最低温度降至1.5 /6℃。成层瘦果的萌发受到黑暗的抑制，缺氧(在密闭的罐子中淹没)完全阻止。然而，淹没在开罐和培养皿中的种子发芽率为80%。随着埋深(0,1和5cm)的增加，萌发率急剧下降。水分条件(排水、饱和和淹水)也显著影响种子的萌发，但催熟条件(低温温室或5℃)改变了这种影响。田间瘦果冬熟后，埋深与水分状况的交互作用显著(P 1 yr)。
{"title":"Germination ecology of Bidens laevis (Asteraceae) from a tidal freshwater wetland1","authors":"M. A. Leck, C. Baskin, J. Baskin","doi":"10.2307/2997178","DOIUrl":"https://doi.org/10.2307/2997178","url":null,"abstract":"LECK, M. A. (Department of Biology, Rider College, Lawrenceville, NJ 08648-3599), C. C. BASKIN AND J. M. BAsKiN (School of Biological Sciences, University of Kentucky, Lexington, KY 40506-0225). Germination ecology of Bidens laevis (Asteraceae) from a tidal freshwater wetland. Bull. Torrey Bot. Club 121: 230-239. 1994.-Eight or more weeks of cold stratification (5?C) were required to break dormancy in achenes of Bidens laevis (L.) BSP from a tidal freshwater wetland. When achenes began to come out of dormancy, they germinated to 50% first at 35/20?C, and then with additional stratification the minimum temperature for 50% germination decreased to 1 5/6?C. Germination of stratified achenes was inhibited by darkness and was completely prevented by hypoxia (inundation in closedjars). Seeds inundated in openjars and those in Petri dishes, however, germinated to > 80%. Germination declined sharply with depth of burial (0, 1, and 5 cm). Moisture regime (drained, saturated, and inundated) also significantly affected germination, but afterripening condition (cold greenhouse or 5?C) altered the effect. Interaction between depth of burial and moisture regime was significant (P 1 yr) following winter afterripening of achenes in the field.","PeriodicalId":9453,"journal":{"name":"Bulletin of the Torrey Botanical Club","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2307/2997178","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68415418","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":"Rediscovery of Solidago sempervirens var. mexicana (Asteraceae) in New York, with Notes on Its Taxonomic History","authors":"E. Lamont","doi":"10.2307/2997183","DOIUrl":"https://doi.org/10.2307/2997183","url":null,"abstract":"","PeriodicalId":9453,"journal":{"name":"Bulletin of the Torrey Botanical Club","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2307/2997183","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68415547","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":"Biosystematic Monograph of the Genus Cucumis (Cucurbitaceae)-Botanical Identification of Cucumbers and Melons.","authors":"M. Nee, Joseph H. Kirkbride join","doi":"10.2307/2997187","DOIUrl":"https://doi.org/10.2307/2997187","url":null,"abstract":"","PeriodicalId":9453,"journal":{"name":"Bulletin of the Torrey Botanical Club","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2307/2997187","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68415093","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":"Heliconia: An Identification Guide.","authors":"T. Zanoni, F. Berry, W. Kress","doi":"10.2307/2997186","DOIUrl":"https://doi.org/10.2307/2997186","url":null,"abstract":"","PeriodicalId":9453,"journal":{"name":"Bulletin of the Torrey Botanical Club","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2307/2997186","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68415084","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":"Catalogue of the Flowering Plants and Gymnosperms of Peru/Catalogo de las Angiospermas y Gimnospermas del Peru.","authors":"Steve Clements, L. Brako, J. Zarucchi","doi":"10.2307/2997188","DOIUrl":"https://doi.org/10.2307/2997188","url":null,"abstract":"","PeriodicalId":9453,"journal":{"name":"Bulletin of the Torrey Botanical Club","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2307/2997188","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68415104","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}
BARTON, A. M. (Department of Biology, University of Michigan, Ann Arbor, MI 48109). Gradient analysis of relationships among fire, environment, and vegetation in a southwestern USA mountain range. Bull. Torrey Bot. Club 121: 251-265. 1994.-I investigated interrelationships among topography, resources/conditions, fire, and woody vegetation over the lower half of an elevational gradient, from arid lowlands to productive intermediate elevations, in the Chiricahua Mountains in southeastern Arizona. With increasing elevation, soil water potential, litter depth, organic carbon, canopy cover, and fire probability increased, whereas forest-floor light levels, soil temperature, pH, and percentage bare soil decreased. With increasing soil moisture levels, plant cover increased and forest-floor light levels decreased. Fire frequency and soil moisture availability were positively correlated. Comparison of the fire data with published studies suggests that relationships between elevational gradients and fire may change in predictable ways from southern to northern latitudes in western North America. First axes of direct (DCCA) and indirect gradient analysis (DCA) showed a strong relationship between vegetation and variables correlated with elevation, including fire and resource variables such as light and soil moisture. Further variation in plant community composition was explained by a second axis that appeared to relate to variation in soil pH and soil texture, probably resulting from differences in parent material. The major environmental variables explaining axis 1 of the DCCA were the same as those found controlling the elevational distributions of tree species in separate single species studies.
BARTON, A. M.(密西根大学生物系，密西根州安娜堡48109)。美国西南部山脉中火灾、环境和植被关系的梯度分析。公牛。托里机器人。俱乐部121:251-265。1994.我调查了地形、资源/条件、火灾和木本植被之间的相互关系，在海拔梯度的下半部分，从干旱的低地到多产的中间海拔，在亚利桑那州东南部的奇里卡华山脉。随着海拔的升高，土壤水势、凋落物深度、有机碳、冠层盖度和火灾概率增加，而森林地面光照水平、土壤温度、pH值和裸土百分比减少。随着土壤水分水平的增加，植物覆盖增加，森林地面光照水平降低。火灾频率与土壤水分有效性呈正相关。将火灾数据与已发表的研究进行比较表明，在北美西部，从南纬到北纬，海拔梯度与火灾之间的关系可能以可预测的方式发生变化。直接梯度分析(DCCA)和间接梯度分析(DCA)的第一轴显示植被与海拔相关变量(包括火灾和光照、土壤湿度等资源变量)之间存在较强的相关性。植物群落组成的进一步变化可以用第二个轴来解释，这个轴似乎与土壤pH和土壤质地的变化有关，可能是由母质的差异引起的。解释DCCA轴1的主要环境变量与在单独的单物种研究中发现的控制树种海拔分布的主要环境变量相同。
{"title":"Gradient analysis of relationships among fire, environment, and vegetation in a southwestern USA mountain range'","authors":"Andrew M. Barton","doi":"10.2307/2997180","DOIUrl":"https://doi.org/10.2307/2997180","url":null,"abstract":"BARTON, A. M. (Department of Biology, University of Michigan, Ann Arbor, MI 48109). Gradient analysis of relationships among fire, environment, and vegetation in a southwestern USA mountain range. Bull. Torrey Bot. Club 121: 251-265. 1994.-I investigated interrelationships among topography, resources/conditions, fire, and woody vegetation over the lower half of an elevational gradient, from arid lowlands to productive intermediate elevations, in the Chiricahua Mountains in southeastern Arizona. With increasing elevation, soil water potential, litter depth, organic carbon, canopy cover, and fire probability increased, whereas forest-floor light levels, soil temperature, pH, and percentage bare soil decreased. With increasing soil moisture levels, plant cover increased and forest-floor light levels decreased. Fire frequency and soil moisture availability were positively correlated. Comparison of the fire data with published studies suggests that relationships between elevational gradients and fire may change in predictable ways from southern to northern latitudes in western North America. First axes of direct (DCCA) and indirect gradient analysis (DCA) showed a strong relationship between vegetation and variables correlated with elevation, including fire and resource variables such as light and soil moisture. Further variation in plant community composition was explained by a second axis that appeared to relate to variation in soil pH and soil texture, probably resulting from differences in parent material. The major environmental variables explaining axis 1 of the DCCA were the same as those found controlling the elevational distributions of tree species in separate single species studies.","PeriodicalId":9453,"journal":{"name":"Bulletin of the Torrey Botanical Club","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2307/2997180","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68415488","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}
recruitment patterns in contrasting landscape elements. To determine seed discovery efficiency by small vertebrates, I planted seeds of mockernut hickory (C. tomentosa (Poir.) Nutt.) with and without their aromatic husk in both forest and hedgerow. Regardless of diaspore type or habitat, seed discovery by herbivores was found to be 85-100% after only 5 days. Gray squirrels (Sciurus carolinensis), the principal predator-disperser, were determined to be equally abundant in both landscape elements. To assess the effects of diffuse competition and predation on seedling establishment and survival, I constructed split-plot shade/exclosure cages into which 576 seedlings were explanted and subsequently monitored (survival and mortality agent) for three years. Browsing by deer and rabbits resulted in considerable mortality after one year, particularly in the forest (64% mortality) compared to the hedgerow (21% mortality). During the second year, the major source of mortality switched to physiological stress resulting from drought. Mortality due to drought stress was more noticeable in the hedgerow. By the end of the third year few seedlings remained alive (ca. 1% in forest, 10% in hedgerow). Over the 3-yr period, a small percentage of seedlings were lost due to other factors such as root grubbing, whole plant removal, and litterfall. Shading (50%), to emulate diffuse competition by overstory, was not found to affect survival to any significant extent in either habitat. Phytophagous insects did not result in any observable mortality but did remove 1-10% of the leaf area of the majority of seedlings in both habitats in each field season. I conclude that certain stages of recruitment may be significantly influenced by the presiding landscape element.
{"title":"Experimental studies of hickory recruitment in a wooded hedgerow and forest","authors":"B. Mccarthy","doi":"10.2307/2997179","DOIUrl":"https://doi.org/10.2307/2997179","url":null,"abstract":"recruitment patterns in contrasting landscape elements. To determine seed discovery efficiency by small vertebrates, I planted seeds of mockernut hickory (C. tomentosa (Poir.) Nutt.) with and without their aromatic husk in both forest and hedgerow. Regardless of diaspore type or habitat, seed discovery by herbivores was found to be 85-100% after only 5 days. Gray squirrels (Sciurus carolinensis), the principal predator-disperser, were determined to be equally abundant in both landscape elements. To assess the effects of diffuse competition and predation on seedling establishment and survival, I constructed split-plot shade/exclosure cages into which 576 seedlings were explanted and subsequently monitored (survival and mortality agent) for three years. Browsing by deer and rabbits resulted in considerable mortality after one year, particularly in the forest (64% mortality) compared to the hedgerow (21% mortality). During the second year, the major source of mortality switched to physiological stress resulting from drought. Mortality due to drought stress was more noticeable in the hedgerow. By the end of the third year few seedlings remained alive (ca. 1% in forest, 10% in hedgerow). Over the 3-yr period, a small percentage of seedlings were lost due to other factors such as root grubbing, whole plant removal, and litterfall. Shading (50%), to emulate diffuse competition by overstory, was not found to affect survival to any significant extent in either habitat. Phytophagous insects did not result in any observable mortality but did remove 1-10% of the leaf area of the majority of seedlings in both habitats in each field season. I conclude that certain stages of recruitment may be significantly influenced by the presiding landscape element.","PeriodicalId":9453,"journal":{"name":"Bulletin of the Torrey Botanical Club","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2307/2997179","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68415435","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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