G. McLeod, Joe Daigneau, J. Collins, Norma Swan, T. Allen
First Landing State Park is located on the southern shore of the mouth of the Chesapeake Bay. The park contains a prograding shoreline and dune complex that has been steadily growing northward. Accurate three dimensional mapping of the resident coastal dune features is challenging due to the dynamic nature of the dunescape. Precise mapping within First Landing was accomplished through careful planning, employ of advanced Global Positioning System ( GPS) technology, and intensive data analysis. Mapping ensued during a period of optimal satellite signal availability and strength. Data points were collected at manual intervals with a Leica GS50+ GPS receiver, utilizing real-time kinematic (R TK) corrections from ground control stations. Vertical data accuracies of less than 5cm were achieved. Horizontal accuracies were near 1 cm. The resultant data was interpolated to create realistic contour maps, triangulated irregular networks (TINS), and raster elevation models of the study area. The methods employed may be replicated at standard time intervals for the purpose of establishing a database to maintain an inventory of dune features within First Landing. Temporal changes in this inventory may be monitored to illustrate rates of change and illuminate conditions that may require management intervention. INTRODUCTION First Landing State Park is located on the southern shore of the mouth of the Chesapeake Bay. It was bought by the Commonwealth ofVirginia in 1933, dedicated to the citizens of the Commonwealth in 1936, and added to the National Register of Natural Landmarks in 1975. It is the most northern point on the United States East Coast where temperate and subtropical plants grow together. The park consists of cabin rentals, campgrounds, an environmental educational center, nature, hiking and biking trails. This park is one of Virginia's most popular and attracts tens of thousands of tourists per year. Virginia Journal of Science, Vol. 58, No. 1, 2007 http://digitalcommons.odu.edu/vjs/vol58/iss1 18 VIRGINIA JOURNAL OF SCIENCE Since the end of the last major glacial event, relative sea level has been rising. The term "relative" is used to indicate sea level when compared to land surface elevation. Land subsidence can result in increases in relative sea level that are much higher than the rate at which the sea itself is rising (Poag, 1999). The increase in relative sea level _has inundated and eroded a significant portion of the Virginia coast. However, eroded sediments do not vanish. They are transported and deposited elsewhere. The Cape Henry coast is essentially a left-handed spit built up from sediment eroded from the beaches further south by a process called longshore drift. This current of moving sand runs into the Chesapeake Bay and is disrupted by east-west trending tidal currents. These tidal currents then redistribute the sand onto the shoreline of the Chesapeake Bay and into shoals in the Bay mouth (Figure 1 ). This influx of sand builds up
{"title":"High Resolution Dune Complex Mapping for the Monitoring of Coastal Landform Change, First Landing State Park, Virginia","authors":"G. McLeod, Joe Daigneau, J. Collins, Norma Swan, T. Allen","doi":"10.25778/8GP6-WC66","DOIUrl":"https://doi.org/10.25778/8GP6-WC66","url":null,"abstract":"First Landing State Park is located on the southern shore of the mouth of the Chesapeake Bay. The park contains a prograding shoreline and dune complex that has been steadily growing northward. Accurate three dimensional mapping of the resident coastal dune features is challenging due to the dynamic nature of the dunescape. Precise mapping within First Landing was accomplished through careful planning, employ of advanced Global Positioning System ( GPS) technology, and intensive data analysis. Mapping ensued during a period of optimal satellite signal availability and strength. Data points were collected at manual intervals with a Leica GS50+ GPS receiver, utilizing real-time kinematic (R TK) corrections from ground control stations. Vertical data accuracies of less than 5cm were achieved. Horizontal accuracies were near 1 cm. The resultant data was interpolated to create realistic contour maps, triangulated irregular networks (TINS), and raster elevation models of the study area. The methods employed may be replicated at standard time intervals for the purpose of establishing a database to maintain an inventory of dune features within First Landing. Temporal changes in this inventory may be monitored to illustrate rates of change and illuminate conditions that may require management intervention. INTRODUCTION First Landing State Park is located on the southern shore of the mouth of the Chesapeake Bay. It was bought by the Commonwealth ofVirginia in 1933, dedicated to the citizens of the Commonwealth in 1936, and added to the National Register of Natural Landmarks in 1975. It is the most northern point on the United States East Coast where temperate and subtropical plants grow together. The park consists of cabin rentals, campgrounds, an environmental educational center, nature, hiking and biking trails. This park is one of Virginia's most popular and attracts tens of thousands of tourists per year. Virginia Journal of Science, Vol. 58, No. 1, 2007 http://digitalcommons.odu.edu/vjs/vol58/iss1 18 VIRGINIA JOURNAL OF SCIENCE Since the end of the last major glacial event, relative sea level has been rising. The term \"relative\" is used to indicate sea level when compared to land surface elevation. Land subsidence can result in increases in relative sea level that are much higher than the rate at which the sea itself is rising (Poag, 1999). The increase in relative sea level _has inundated and eroded a significant portion of the Virginia coast. However, eroded sediments do not vanish. They are transported and deposited elsewhere. The Cape Henry coast is essentially a left-handed spit built up from sediment eroded from the beaches further south by a process called longshore drift. This current of moving sand runs into the Chesapeake Bay and is disrupted by east-west trending tidal currents. These tidal currents then redistribute the sand onto the shoreline of the Chesapeake Bay and into shoals in the Bay mouth (Figure 1 ). This influx of sand builds up","PeriodicalId":23516,"journal":{"name":"Virginia journal of science","volume":"42 1","pages":"3"},"PeriodicalIF":0.0,"publicationDate":"2007-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90460116","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}
Since soybean (Glycine max [L.] Merr.) is low in saturated fat and active in reducing blood cholesterol, it is gaining interest as a healthy snack food. Direct consumption of vegetable soybeans is very popular in the Orient. However, the cultivars used in Asia are not adapted to U.S. production systems. The objectives of this study were to determine the efficiency of mechanical harvest and to identify vegetable soybean cultivars adapted for a mechanical harvest system. To implement the objectives, four vegetable soybean cultivars were planted in a randomized complete block design at Randolph Research Farm, Virginia State University. The cultivars were hand harvested and mechanically harvested at the green pod stage and evaluated for green pod yield (kg ha), one hundred pod weight (g), plant height ( cm), and pod dimensions oflength ( cm), width ( cm), and thickness ( cm). A significant difference (P < 0.01) was observed among the two methods of harvesting. The hand harvested beans yielded twice as many more pods as the mechanical harvested beans. However, the pods harvested mechanically were cleaner and required no further cleaning as compared to hand harvested pods. There was also significant cultivar x method harvest interaction. The common bean picker was effective in harvesting the vegetable soybean cultivars with plant height of 55 to 66 cm and pod size that ranged from 128 to 144 g 100pods This type of operation could be easily adapted by farmers using appropriate cultivars.
{"title":"Efficiency of Mechanical Harvest for Immature Vegetable Soybean Pods","authors":"T. Mebrahtu, C. Mullins","doi":"10.25778/QEJ4-5K62","DOIUrl":"https://doi.org/10.25778/QEJ4-5K62","url":null,"abstract":"Since soybean (Glycine max [L.] Merr.) is low in saturated fat and active in reducing blood cholesterol, it is gaining interest as a healthy snack food. Direct consumption of vegetable soybeans is very popular in the Orient. However, the cultivars used in Asia are not adapted to U.S. production systems. The objectives of this study were to determine the efficiency of mechanical harvest and to identify vegetable soybean cultivars adapted for a mechanical harvest system. To implement the objectives, four vegetable soybean cultivars were planted in a randomized complete block design at Randolph Research Farm, Virginia State University. The cultivars were hand harvested and mechanically harvested at the green pod stage and evaluated for green pod yield (kg ha), one hundred pod weight (g), plant height ( cm), and pod dimensions oflength ( cm), width ( cm), and thickness ( cm). A significant difference (P < 0.01) was observed among the two methods of harvesting. The hand harvested beans yielded twice as many more pods as the mechanical harvested beans. However, the pods harvested mechanically were cleaner and required no further cleaning as compared to hand harvested pods. There was also significant cultivar x method harvest interaction. The common bean picker was effective in harvesting the vegetable soybean cultivars with plant height of 55 to 66 cm and pod size that ranged from 128 to 144 g 100pods This type of operation could be easily adapted by farmers using appropriate cultivars.","PeriodicalId":23516,"journal":{"name":"Virginia journal of science","volume":"40 1","pages":"2"},"PeriodicalIF":0.0,"publicationDate":"2007-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81775327","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}
Loblolly pine (Pinus taeda L.) plantations of four different ages were examined to identify changes in the small mammal community in relation to changes in the vegetational community. Small mammals were evaluated during five seasons using two methods of trapping. Live traps accounted for 65% of captures and seven of nine species, whereas pitfall traps yielded eight species, of which two were not taken with live traps. For both trap types, catch rates averaged less than two per 100 trap-nights, very low even for pine forests. Both abundance and biomass of small mammals declined with increasing stand age, whereas species diversity increased with increasing stand age. The relative proportions of trophic groups changed after crown closure from mostly granivores and omnivores to mostly insectivores. However, after mechanical thinning of late-age stands, small mammals of forested habitats and of early successional habitats were found together. The numbers of trapped small mammals decreased progressively throughout the study. We speculate that weather events might have contributed to this pattern but the reasons are unknown. INTRODUCTION Small mammals of forests often show preferences for habitats differing in age and structure (Linzey and Linzey 1973, Kirkland and Griffin 1974, Dueser and Shugart 1978). Thus, the abundance and species of small mammals inhabiting recent clearcuts often differ greatly from those found in maturing forests. Furthermore, secondary succession sometimes is governed by attributes of the initial disturbance (Boring et al. 1981 ). For example, timber management practices such as site preparation and the use of herbicides, pesticides, fertilizers, and selective cutting can directly affect the composition of the plant community, and in tum indirectly affect small mammal communities. Much research has evaluated changes in small mammal communities in relation Present address: USATC, 1407 Washington Blvd, Fort Eustis, Virginia 23604, James.d.dolan@us.army.mil. Corresponding author: Dr. Robert K. Rose, Department of Biological Sciences, Old Dominion University, Norfolk, Virginia 23529-0266, Email : brose@odu.edu Virginia Journal of Science, Vol. 58, No. 3, 2007 http://di it commons.odu.edu/vjs/vol58/iss3 148 VIRGINIA JOURNAL OF SCIENCE to vegetation changes in hardwood forest systems in eastern North America (e.g. , Kirkland 1977, McComb and Rumsey 1982, Martell 1983, Buckner and Shure 1985). However, fewer studies have been conducted on small mammals in pine plantations in the Southeast. Atkeson and Johnson (1979) and Mengak et al. (1989) studied small mammals in pine plantations in the piedmont regions of Georgia and South Carolina, respectively, and Mitchell et al. (1995) studied small mammals in pine plantations on cleared pocosins in coastal North Carolina. In contrast, our study examined small mammal communities in managed loblolly pine plantations on upland sites in the coastal plain of Virginia, a region in which commercial st
以4个不同林龄的火炬松人工林为研究对象，探讨了植被群落变化与小型哺乳动物群落的关系。采用两种诱捕方法对5个季节的小型兽类进行了评估。活捕器捕获的种类占捕获总数的65%，9种中有7种，而陷阱捕获的种类为8种，其中2种不是用活捕器捕获的。对于这两种捕集器，每100个捕集器夜平均捕获率不到2个，即使在松林中也很低。小兽类的丰度和生物量随林龄的增加而下降，而物种多样性随林龄的增加而增加。冠合后各营养类群的相对比例由以花岗动物和杂食动物为主转变为以食虫动物为主。然而，经过后期林分的机械间伐后，森林生境和早期演替生境的小型哺乳动物同时出现。在整个研究过程中，被困小型哺乳动物的数量逐渐减少。我们推测天气事件可能促成了这种模式，但原因尚不清楚。森林中的小型哺乳动物往往表现出对不同年龄和结构的栖息地的偏好(Linzey and Linzey 1973, Kirkland and Griffin 1974, Dueser and Shugart 1978)。因此，居住在最近砍伐地区的小型哺乳动物的数量和种类往往与在成熟森林中发现的大不相同。此外，次生演替有时是由初始扰动的属性控制的(Boring et al. 1981)。例如，木材管理实践，如场地准备和使用除草剂、杀虫剂、肥料和选择性砍伐，可以直接影响植物群落的组成，反过来间接影响小型哺乳动物群落。许多研究已经评估了与之相关的小型哺乳动物群落的变化。现在的地址:USATC, 1407 Washington Blvd, Fort Eustis, Virginia 23604, James.d.dolan@us.army.mil。通讯作者:Robert K. Rose博士，Old Dominion University生物科学系，Norfolk, Virginia 23529-0266, Email: brose@odu.edu Virginia Journal of Science, Vol. 58, No. 3, 2007 http://di it commons.odu.edu/vjs/vol58/iss3 148 Virginia Journal of Science对北美东部阔叶林系统植被变化的研究(例如，Kirkland 1977, McComb and Rumsey 1982, Martell 1983, Buckner and Shure 1985)。然而，对东南部松林中的小型哺乳动物进行的研究较少。Atkeson and Johnson(1979)和Mengak et al.(1989)分别研究了佐治亚州和南卡罗来纳州山前地区松树林中的小型哺乳动物，Mitchell et al.(1995)研究了北卡罗来纳州沿海砍伐后的松林林中的小型哺乳动物。相比之下，我们的研究调查了弗吉尼亚沿海平原高地上有管理的火炬松人工林中的小型哺乳动物群落，在该地区，这种松树的商业林分通常占当地森林景观的大部分。为了了解小型哺乳动物群落与林龄的关系，我们选择了林龄为1、8、18和24年的松林。在弗吉尼亚州东部，大多数火炬松(Pinus taeda L.)种植园在大约30岁时收获。我们的目标是确定小型哺乳动物群落的相对丰度、生物量和物种多样性与管理松林林龄的关系，研究这些林分的小型哺乳动物群落的季节变化，并记录小型哺乳动物物种的存在或消失与松林林龄的关系。材料和方法研究地点选自联合营公司，位于弗吉尼亚州东南沿海平原地区的怀特岛县。在树桩和碎片被推入窗户后，使用机械播种机以1042-1482根/公顷的密度种植松树。我们在相对较近的地点(相距1-16公里)选择了四个年龄等级的松树种植园，以尽量减少当地天气条件变化的影响。我们无法控制对某些林分使用的除草剂、杀虫剂或间伐处理;我们寻找尽可能相似的复制站点。1岁和24岁林分有3个重复，8岁和18岁林分有2个重复。我们在五个季节期间捕获:(1)1995年6月12日7月26日，(2)1995年10月20日12月3日，(3)1996年1月19日3月3日，(4)1996年4月3日5月17日，(5)1996年7月9日8月22日。季节之间的间隔至少为30天。小型哺乳动物的有效调查需要两种诱捕方法，其中一种是清除诱捕(例如，Getz 1961;Wiener and Smith 1972)。因为松林支持大多数小型哺乳动物物种的低密度种群(Mengak et al. 1989; Mitchell et al. 1989)。
{"title":"Depauperate Small Mammal Communities in Managed Pine Plantations in Eastern Virginia","authors":"J. D. Dolan, R. K. Rose","doi":"10.25778/2MX5-Q917","DOIUrl":"https://doi.org/10.25778/2MX5-Q917","url":null,"abstract":"Loblolly pine (Pinus taeda L.) plantations of four different ages were examined to identify changes in the small mammal community in relation to changes in the vegetational community. Small mammals were evaluated during five seasons using two methods of trapping. Live traps accounted for 65% of captures and seven of nine species, whereas pitfall traps yielded eight species, of which two were not taken with live traps. For both trap types, catch rates averaged less than two per 100 trap-nights, very low even for pine forests. Both abundance and biomass of small mammals declined with increasing stand age, whereas species diversity increased with increasing stand age. The relative proportions of trophic groups changed after crown closure from mostly granivores and omnivores to mostly insectivores. However, after mechanical thinning of late-age stands, small mammals of forested habitats and of early successional habitats were found together. The numbers of trapped small mammals decreased progressively throughout the study. We speculate that weather events might have contributed to this pattern but the reasons are unknown. INTRODUCTION Small mammals of forests often show preferences for habitats differing in age and structure (Linzey and Linzey 1973, Kirkland and Griffin 1974, Dueser and Shugart 1978). Thus, the abundance and species of small mammals inhabiting recent clearcuts often differ greatly from those found in maturing forests. Furthermore, secondary succession sometimes is governed by attributes of the initial disturbance (Boring et al. 1981 ). For example, timber management practices such as site preparation and the use of herbicides, pesticides, fertilizers, and selective cutting can directly affect the composition of the plant community, and in tum indirectly affect small mammal communities. Much research has evaluated changes in small mammal communities in relation Present address: USATC, 1407 Washington Blvd, Fort Eustis, Virginia 23604, James.d.dolan@us.army.mil. Corresponding author: Dr. Robert K. Rose, Department of Biological Sciences, Old Dominion University, Norfolk, Virginia 23529-0266, Email : brose@odu.edu Virginia Journal of Science, Vol. 58, No. 3, 2007 http://di it commons.odu.edu/vjs/vol58/iss3 148 VIRGINIA JOURNAL OF SCIENCE to vegetation changes in hardwood forest systems in eastern North America (e.g. , Kirkland 1977, McComb and Rumsey 1982, Martell 1983, Buckner and Shure 1985). However, fewer studies have been conducted on small mammals in pine plantations in the Southeast. Atkeson and Johnson (1979) and Mengak et al. (1989) studied small mammals in pine plantations in the piedmont regions of Georgia and South Carolina, respectively, and Mitchell et al. (1995) studied small mammals in pine plantations on cleared pocosins in coastal North Carolina. In contrast, our study examined small mammal communities in managed loblolly pine plantations on upland sites in the coastal plain of Virginia, a region in which commercial st","PeriodicalId":23516,"journal":{"name":"Virginia journal of science","volume":"22 1","pages":"1"},"PeriodicalIF":0.0,"publicationDate":"2007-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80559846","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}
Knowledge of how density affects population growth is important for the harvest management of wild turkey. Unfortunately, available time-series are often too short for statistical detection of density dependence. The correlation between wild turkey recruitment and population size was assessed using data from 7 state wildlife agencies, circumventing the problem of short time-series by using multiple datasets. Correlation coefficients were calculated between surveyed poult:hen ratios and harvest-based population indices for 31 geographic or harvest management regions. Estimated correlation coefficients were tested for homogeneity to determine if an average correlation could be calculated. Correlation coefficients for the 29 regions ranged from -0.82 to 0.70. A Q-test for homogeneity indicated that correlation coefficients were similar enough to warrant averaging [Q=25.45, df = 28, P = 0.603]. The weighted average correlation coefficient (± standard error) was r = -0.30 ± 0.45. Population size accounted for little of the variation associated with production (r = 0.09). Graphical analysis indicated that a negative correlation between poult:hen ratios and population size tended to occur when the range of population sizes was large. Density dependence appears to have little effect on production. Density-independent models should have better success modeling wild turkey production, while density-dependent effects may have stronger influence on survival or immigration at low population sizes.
{"title":"Correlation of Eastern Wild Turkey Poult:hen Ratios with Population Indices to Detect Reproductive Density Dependence","authors":"J. D. McGhee, J. Berkson","doi":"10.25778/TFTZ-2W67","DOIUrl":"https://doi.org/10.25778/TFTZ-2W67","url":null,"abstract":"Knowledge of how density affects population growth is important for the harvest management of wild turkey. Unfortunately, available time-series are often too short for statistical detection of density dependence. The correlation between wild turkey recruitment and population size was assessed using data from 7 state wildlife agencies, circumventing the problem of short time-series by using multiple datasets. Correlation coefficients were calculated between surveyed poult:hen ratios and harvest-based population indices for 31 geographic or harvest management regions. Estimated correlation coefficients were tested for homogeneity to determine if an average correlation could be calculated. Correlation coefficients for the 29 regions ranged from -0.82 to 0.70. A Q-test for homogeneity indicated that correlation coefficients were similar enough to warrant averaging [Q=25.45, df = 28, P = 0.603]. The weighted average correlation coefficient (± standard error) was r = -0.30 ± 0.45. Population size accounted for little of the variation associated with production (r = 0.09). Graphical analysis indicated that a negative correlation between poult:hen ratios and population size tended to occur when the range of population sizes was large. Density dependence appears to have little effect on production. Density-independent models should have better success modeling wild turkey production, while density-dependent effects may have stronger influence on survival or immigration at low population sizes.","PeriodicalId":23516,"journal":{"name":"Virginia journal of science","volume":"88 1","pages":"3"},"PeriodicalIF":0.0,"publicationDate":"2007-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79716126","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}
Pub Date : 2007-01-01DOI: 10.25778/10.25778/9AQ6-CZ64
J. Kirwan, P. Wiseman, J. Seiler
Trees and saplings growing on K-12 school campuses were investigated in 105 school districts across Virginia. There were 2812 trees (>12.5 cm stem diameter at 1.4 m above ground level) inventoried across all campuses. The mean and median campus tree population was 27 and 18, respectively. Lob lolly pine (Pinus taeda L.) was the most abundant species, accounting for 11 % of all inventoried trees. Red maple (Acer rubrum L.) was the most frequently inventoried species, present on 44% of the campuses. Sapling (trees with 2.5-12.5 cm stem diameter at 1.4 m above ground level) populations were similar to tree populations. The mean and median campus sapling population was 23 and 13, respectively. Flowering dogwood (Cornus florid a L.) and red maple were the most abundant sapling species, each accounting for about 10% of all inventoried saplings. Flowering dogwood, red maple, Bradford pear (Pyrus calleryana Decne. 'Bradford'), willow oak (Quercus phellos L.), and ornamental cherry (Prunus spp.) were the most frequently inventoried sapling species, each present on more than 25% of the campuses. Across all campuses, species diversity was relatively low: less than 10 species accounted for over 50% of the inventoried trees and saplings. Prominent Virginia natives, in particular Carya and Quercus species, were under represented in the inventory. INTRODUCTION Urban forests are increasingly recognized for their ecological and societal benefits (Kane and Kirwan 2005). Trees in the urban forest improve air quality, protect watersheds, sequester carbon, and reduce energy consumption for heating and cooling buildings. In addition, properly designed and maintained urban vegetation has been linked to reduced crime (Kuo and Sullivan 2001), enhance cognitive development of children (Wells 2000), and job satisfaction (Kaplan et al. 1988). As the U.S. population grows and becomes more urbanized, urban forests will play an increasingly important role in environmental sustainability and quality of life. From 1910 to 2000, the urban segment of the U.S. population increased from 28% to 80% (Hobbs and Stoops 2002). By 2030, 87% of the U.S. population (projected to exceed 370 million) will live in urbanized areas (UNESA 2004) . The population of Virginia (currently about 7.5 million) is projected to reach 9.8 million by 2030 (U.S. Census Bureau 2005). In the Chesapeake Bay watershed alone, residential development is projected to consume 800,000 acres of land between 2003 and 2030 (Boesch and Greer 2003). This pattern and rate of population growth will place unprecedented strain on natural resources. Healthy, well-managed urban forests may be a key component of sustainable community growth. In 1998, the Virginia Tech Department of Forestry began an outreach program to teach dendrology, forest biology, and forest management concepts to K-12 students and Virginia Journal of Science, Vol. 58, No. 1, 2007 https://digitalcommons.odu.edu/vjs/vol58/iss1 4 VIRGINIA JOURNAL OF SCIENCE o
在弗吉尼亚州105个学区对K-12学校校园里生长的树木和树苗进行了调查。各校区共有2812棵树(树干直径大于12.5 cm，高于地面1.4 m)。校园树的平均和中位数分别为27和18。高山松(Pinus taeda L.)是最丰富的树种，占所有调查树种的11%。红枫(Acer rubrum L.)是最常被发现的树种，占校园的44%。苗木(茎径2.5 ~ 12.5 cm，距地面1.4 m)种群与乔木种群相似。校园树苗的平均树龄为23株，中位数为13株。开花茱萸(Cornus florid a L.)和红枫是最丰富的树苗种类，各占树苗总数的10%左右。开花茱萸，红枫，布拉德福梨(Pyrus calleryana Decne)。'Bradford')，柳树(Quercus phellos L.)和观赏樱桃(Prunus spp.)是最常见的树苗物种，每种树苗在超过25%的校园中存在。在所有校园中，物种多样性相对较低，不到10种的树木和树苗占清查树木和树苗的50%以上。突出的弗吉尼亚本地物种，特别是山核桃和栎属物种，在清单中代表性不足。城市森林因其生态和社会效益而日益得到认可(Kane and Kirwan 2005)。城市森林中的树木改善了空气质量，保护了流域，隔离了碳，减少了建筑供暖和制冷的能源消耗。此外，适当设计和维护的城市植被与减少犯罪(Kuo and Sullivan 2001)、促进儿童认知发展(Wells 2000)和工作满意度(Kaplan et al. 1988)有关。随着美国人口的增长和城市化程度的提高，城市森林将在环境可持续性和生活质量方面发挥越来越重要的作用。从1910年到2000年，美国的城市人口从28%增加到80% (Hobbs and Stoops 2002)。到2030年，87%的美国人口(预计超过3.7亿)将生活在城市化地区(UNESA 2004)。弗吉尼亚州的人口(目前约为750万)预计到2030年将达到980万(美国人口普查局2005年)。仅在切萨皮克湾流域，住宅开发预计将在2003年至2030年间消耗80万英亩土地(Boesch和Greer 2003)。这种人口增长模式和速度将对自然资源造成前所未有的压力。健康、管理良好的城市森林可能是可持续社区增长的关键组成部分。1998年，弗吉尼亚理工大学林业系开始了一项扩展计划，向K-12学生和《弗吉尼亚科学杂志》(2007年第58卷第1期)https://digitalcommons.odu.edu/vjs/vol58/iss1教授树木学、森林生物学和森林管理概念。该计划的启动是为了帮助解决全国中学生科学成绩下降的问题(Calsyn et al. 1999)，并帮助弗吉尼亚州的教师达到他们的学习标准(SOL)目标(教育委员会2003年)。该计划通过一个专门的网站(http://www.cnr.vt.edu/dendro/forsite /content .htm)、弗吉尼亚理工大学本科生的课堂演讲和K-12学生进行的基于互联网的科学调查来实施(Kirwan and Seiler 2005)。如今，这个拓展项目已经进入了第八个年头，横跨三个州，覆盖了83所学校和众多4-H俱乐部的近1.5万名K-12学生。作为推广计划的一部分，在学校校园进行了三次调查。根据这些清单，编制了学校树清单并将其放在项目网站上。由弗吉尼亚理工大学林业系开发的树木情况说明书和在线二分键与树木列表相连，以方便学生学习树木识别和森林生物学。在编制树木名单的过程中，我们获得了大量关于校园树木种群构成的信息。树木是校园里宝贵的资产。它们不仅提供了重要的环境效益，如遮阳和雨水减少，但也是一个宝贵的，但往往被忽视的资源，教导学生关于生态和管理。也许更重要的是，校园树木数量的构成反映了当地对公共财产树木的知识、态度和价值观。在大多数地区，影响校园树木保护和种植的生物、社会政治和经济力量同样影响着其他公共财产。由于这些原因，校园树木清单可以为弗吉尼亚的自然资源管理和教育工作提供洞察力。
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The Dismal Swamp subspecies of the southern bog lemming, Synaptomys cooperi helaletes, was named based on specimens collected during the 18951898 biological surveys conducted in the Dismal Swamp by the US Department of Agriculture. Unknown in the 20 th Century until re-discovered in 1980, this small boreal rodent was believed to be restricted to the Great Dismal Swamp ofV irginia and North Carolina where the cool damp conditions had permitted it to survive during the Holocene. However, field studies conducted since 1980 have revealed southern bog lemmings to be widespread throughout southeastern Virginia, with populations encompassing an area of more than 3300 km 2, including the cities of Virginia Beach, Chesapeake, and Suffolk, and Isle of Wight County. Lemmings were present on 38 of 165 (23%) pitfall-trapping sites; their frequency was much greater in prime habitats dominated by grasses and sedges on damp organic soils. Thus, southern bog lemmings are distributed widely in southeastern Virginia and, where present, they often are among the most numerous species of small mammal. INTRODUCTION The southern bog lemming, Synaptomys cooperi, distributed from Kansas and Nebraska northward through Minnesota and Manitoba, eastward through Canada, and southward into the Appalachian Mountains of North Carolina and Tennessee (Hall 1981 ), is one of the most enigmatic small mammals in North America. In some Midwestern states, highly trappable and high-density populations coexist with prairie voles in me sic or xeric grassland habitats (Kansas: Gaines et al. 1977; Illinois: Beasley and Getz 1986; Indiana: Krebs et al. 1969). In other permanently wet sites where herbivorous potential competitors often are absent, however, southern bog lemmings are difficult to trap. For example, isolated relic populations associated with permanently flowing springs (now incorporated into state-run fish hatcheries) are known from Meade County in southwestern Kansas and Dundy County in southwestern Nebraska. Other relic populations are believed to be restricted to the Pine Barrens of southern New Jersey and to the Dismal Swamp of southeastern Virginia and adjacent North Carolina. Thus, populations of this small stocky rodent with short tail and. tiny ears are highly patchy in both space and time. For example, in Douglas County in eastern Kansas, where generations of mammalogists have been trained at the University of Kansas since the 1920s, grassland populations existed for about four years starting in the middle 1920s (Lindale 1927, Burt 1928), then disappeared, reappeared in the middle 1940s, disappeared, and then reappeared in the mid-l 960s, since when they have persisted (Rose et al. 1977, Norman A. Slade, University of Kansas, pers. comm., October 2005). Understanding its ·spatial distribution is made difficult because 154 VIRGINIA JOURNAL OF SCIENCE Synaptomys cooperi often is reluctant to enter live traps. For example, Connor (1 959) caught only 38 bog lemmings during f
美国农业部根据1895 - 1898年在Dismal Swamp进行的生物调查中收集的标本命名了南部沼泽鼠的亚种Synaptomys cooperi helaletes。在20世纪不为人知，直到1980年才被重新发现，这种小型北方啮齿动物被认为仅限于弗吉尼亚州和北卡罗来纳州的大沼泽，那里凉爽潮湿的环境使它能够在全新世生存。然而，自1980年以来进行的实地研究表明，南部沼泽旅鼠广泛分布在弗吉尼亚州东南部，其种群覆盖面积超过3300平方公里，包括弗吉尼亚海滩、切萨皮克、萨福克和怀特郡等城市。165个陷阱点中有38个(23%)有旅鼠;在潮湿的有机土壤中，以禾草和莎草为主的原始生境中，它们的发生频率要高得多。因此，南部沼泽旅鼠广泛分布在弗吉尼亚州东南部，在那里，它们通常是数量最多的小型哺乳动物之一。南部的小狐猴(Synaptomys cooperi)分布于堪萨斯州和内布拉斯加州，向北穿过明尼苏达州和马尼托巴，向东穿过加拿大，向南进入北卡罗来纳州和田纳西州的阿巴拉契亚山脉(Hall 1981)，是北美最神秘的小型哺乳动物之一。在中西部的一些州，高度可捕获和高密度的种群与草原田鼠共存于湿润或干旱的草原栖息地(堪萨斯州:Gaines et al. 1977;伊利诺伊州:Beasley and Getz 1986;印第安纳州:克雷布斯等人1969)。然而，在其他永久潮湿的地方，食草动物的潜在竞争对手往往没有，南方沼泽旅鼠很难捕捉。例如，在堪萨斯州西南部的米德县和内布拉斯加州西南部的邓迪县，已知与永久流动的泉水(现在并入国营的鱼类孵化场)有关的孤立的遗迹种群。其他遗迹种群被认为局限于新泽西州南部的松树荒地和弗吉尼亚州东南部的凄凉沼泽以及邻近的北卡罗来纳州。因此，这种矮胖短尾啮齿类动物的种群。小耳朵在空间和时间上都是高度斑驳的。例如，在堪萨斯州东部的道格拉斯县，自20世纪20年代以来，几代哺乳动物学家在堪萨斯大学接受了培训，从20世纪20年代中期开始，草原种群存在了大约四年(Lindale 1927, Burt 1928)，然后消失，在20世纪40年代中期重新出现，消失，然后在60年代中期重新出现，从那时起它们一直存在(Rose et al. 1977, Norman A. Slade，堪萨斯大学，pers)。通讯，2005年10月)。了解它的空间分布是很困难的，因为Synaptomys cooperi通常不愿意进入活的陷阱。例如，康纳(1959)在新泽西松林的沼泽栖息地进行了四年的研究，只捕获了38只沼泽旅鼠。相比之下，其他种群很容易被捕获。在堪萨斯州东部潮湿和干燥的老田中，数百只库氏蝽被常规捕获在两种不同的活捕器中(Rose et al. 1977)，密度达到每公顷42-65只(Gaines et al. 1977, Gaines et al. 1979)。很明显，“沼泽游”这个名字是有误导性的，因为Synaptomys并不局限于沼泽，甚至不局限于潮湿的地方。据报道，在木本植被地区(Hamilton 1941, Coventry 1942, Connor 1959)，潮湿的草地地区(Howell 1927, Stewart 1943, Smyth 1946, Burt 1928, Getz 1961)，以及干燥的、朝南的草地，如堪萨斯州东部(Gaines et al. 1977, Rose et al. 1977, Gaines et al. 1979)，都发现了Synaptomys。第一次描述是在1888年，从新罕布什尔州杰克逊附近采集的标本中(Hall 1981)，之所以给这个通用名称，是因为Baird认为它是旅鼠(Lemmus)和真正的老鼠(= mys)之间的连接(=突触)。1895年，由a . K. Fisher领导的美国生物调查局的调查人员在弗吉尼亚州凄凉沼泽的德拉蒙德湖附近的藤条上收集了南部沼泽旅鼠，Merriam(1896)将其描述为一个新物种，Synaptomys helaletes。然而，Howell(1937)在对该属的修正中，将其降为S. cooperi he la Zetes亚种，这一决定被Wetzel(1955)在其对S. cooperi的分类研究中所接受。最近，Wilson和Ruff(1999)发现了7个亚种，包括在堪萨斯州、内布拉斯加州以及弗吉尼亚州和北卡罗来纳州的Dismal Swamp地区的孤立形式。直到1898年，费雪还从“凄凉沼泽”收集了其他的南方沼泽旅鼠，但此后，尽管包括查理二世在内的几位调查人员做出了努力，但没有一只被捕获。小汉德利，史密森尼哺乳动物博物馆馆长，他在1953年和其他年份和地方捕获了费舍尔的一些地点，但都没有成功。 Handley(1979)和其他人(Meanley 1973, Taylor 1974)推测，由于自1898年以来没有收集到任何标本，因此凄凉沼泽亚种可能已经灭绝。然而，Rose(1981)在大沼泽国家野生动物保护区(GDSNWR)西北角的电线下设置陷阱，于1980年在三个地点捕获了13个标本，打消了人们对其存在的怀疑。在20世纪80年代和90年代初，我和我的学生们在弗吉尼亚州东南部的100多个地点进行了诱捕调查，目的是捕捉阴郁沼泽东南鼩鼱(Sorex longirostris fisheri)，这是一种联邦政府列出的哺乳动物;这里报告的南方沼泽旅鼠也是在这些集合中捕获的。这些研究表明，Dismal Swamp亚种Synaptomys cooperi helaletes广泛分布于弗吉尼亚州东南部的适当栖息地，其种群至少延伸到Dismal Swamp以西的怀特郡。方法采用活诱捕法和陷阱诱捕法，其中陷阱诱捕法应用较多。在GDSNWR西北角40米宽输电线下的开放生境中进行了系统的活捕(Stankavich 1984)。Fitch活陷阱(Rose 1973)，在两个矩形网格(0.38和0.40公顷)中每隔7.6米设置一次，1980年10月至1982年2月每两周进行两天的护理。在接下来的二十年里，在整个地区的一系列栖息地进行的其他活体诱捕实验中，除了1987-1988年由L. J. Ford在萨福克郡进行的一项(未发表的)研究外，只发现了另一项使用活体诱捕器的Synaptomys。大多数关于分布和相对丰度的信息来自于在弗吉尼亚州东南部的一系列生境中设置在0.25公顷网格上的陷阱(Rose et al. 1990)。每个陷阱以12.5米的间隔放置在一个5 X 5的网格上，每个陷阱是一个10号锡罐，放置在与地面齐平的地面上，部分装满水。早期的研究(如French, 1980年)表明，东南鼩鼱(在较小程度上，南部沼泽旅鼠)很少被捕获，因此需要使用陷阱来收集这些物种的分布和状态信息。在最初的研究中，由濒危物种办公室(Rose 1983, Everton 1985)资助，在以GDSNWR为中心的一系列栖息地设置了37个陷阱网格。后来的一项研究(Padgett 1991)，由弗吉尼亚狩猎和内陆渔业局资助，增加了29个网格，大部分放置在离GDSNWR较远的地方，以努力了解凄凉沼泽东南鼩鼱的地理分布范围。在1986年至1995年期间进行的调查中，在该区域的不同地
{"title":"Distribution and Status of the Southern Bog Lemming, Synaptomys cooperi, in Southeastern Virginia","authors":"R. K. Rose","doi":"10.25778/BB6T-KM14","DOIUrl":"https://doi.org/10.25778/BB6T-KM14","url":null,"abstract":"The Dismal Swamp subspecies of the southern bog lemming, Synaptomys cooperi helaletes, was named based on specimens collected during the 18951898 biological surveys conducted in the Dismal Swamp by the US Department of Agriculture. Unknown in the 20 th Century until re-discovered in 1980, this small boreal rodent was believed to be restricted to the Great Dismal Swamp ofV irginia and North Carolina where the cool damp conditions had permitted it to survive during the Holocene. However, field studies conducted since 1980 have revealed southern bog lemmings to be widespread throughout southeastern Virginia, with populations encompassing an area of more than 3300 km 2, including the cities of Virginia Beach, Chesapeake, and Suffolk, and Isle of Wight County. Lemmings were present on 38 of 165 (23%) pitfall-trapping sites; their frequency was much greater in prime habitats dominated by grasses and sedges on damp organic soils. Thus, southern bog lemmings are distributed widely in southeastern Virginia and, where present, they often are among the most numerous species of small mammal. INTRODUCTION The southern bog lemming, Synaptomys cooperi, distributed from Kansas and Nebraska northward through Minnesota and Manitoba, eastward through Canada, and southward into the Appalachian Mountains of North Carolina and Tennessee (Hall 1981 ), is one of the most enigmatic small mammals in North America. In some Midwestern states, highly trappable and high-density populations coexist with prairie voles in me sic or xeric grassland habitats (Kansas: Gaines et al. 1977; Illinois: Beasley and Getz 1986; Indiana: Krebs et al. 1969). In other permanently wet sites where herbivorous potential competitors often are absent, however, southern bog lemmings are difficult to trap. For example, isolated relic populations associated with permanently flowing springs (now incorporated into state-run fish hatcheries) are known from Meade County in southwestern Kansas and Dundy County in southwestern Nebraska. Other relic populations are believed to be restricted to the Pine Barrens of southern New Jersey and to the Dismal Swamp of southeastern Virginia and adjacent North Carolina. Thus, populations of this small stocky rodent with short tail and. tiny ears are highly patchy in both space and time. For example, in Douglas County in eastern Kansas, where generations of mammalogists have been trained at the University of Kansas since the 1920s, grassland populations existed for about four years starting in the middle 1920s (Lindale 1927, Burt 1928), then disappeared, reappeared in the middle 1940s, disappeared, and then reappeared in the mid-l 960s, since when they have persisted (Rose et al. 1977, Norman A. Slade, University of Kansas, pers. comm., October 2005). Understanding its ·spatial distribution is made difficult because 154 VIRGINIA JOURNAL OF SCIENCE Synaptomys cooperi often is reluctant to enter live traps. For example, Connor (1 959) caught only 38 bog lemmings during f","PeriodicalId":23516,"journal":{"name":"Virginia journal of science","volume":"1 1","pages":"3"},"PeriodicalIF":0.0,"publicationDate":"2006-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84684423","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}
Between 2000 and 2003 there were an increased number of documented sea turtle mortalities related to hopper dredging in the channels of the Chesapeake Bay. A pilot study was undertaken to create a bathymetric surface and three-dimensional model of the Cape Henry Channel using Geographic Information Systems (GIS) as a visualization tool to examine sea turtle mortalities in relation to the dredging. In Fall 2003, the US Army Corps of Engineers dredged the Thimble Shoals Federal Navigation Channel, and a more refined model was developed using this data. This project examines the growing concerns over sea turtle mortality rates and dredging operations, as well as a description of the usage of GIS analysis, interpolation, and visualization methods as tools for examining turtle habitat and mortality issues. Future directions for incorporating G IS into attempts to reduce sea turtle mortality in dredging operations are then outlined. INTRODUCTION AND BACKGROUND The section of the Chesapeake Bay off the Virginia coast contains a series of Federal Navigation Channels that are periodically dredged by self-propelled hopper dredges. These dredges are suitable for all but hard materials and are, by far , the best suited dredges for offshore work (Herbich 2000). There are four main navigation channels in the lower Chesapeake Bay: York Spit, York River Entrance, Cape Henry Channel, and Thimble Shoals Channel. Cape Henry Channel and Thimble Shoals Channel mark the entrance to the Bay from the Atlantic Ocean. The Thimble Shoals and Cape Henry channels are congressionally authorized Federal projects located in the mouth of the Chesapeake Bay between Hampton Roads and the Atlantic Ocean. Thimble Shoals Channel is approximately 18288 meters long, 304.8 meters wide, with an original depth of 13.7 meters at mean low water (CENAO 1973) . The channel was constructed in 1914 and requires maintenance dredging once every 2-3 years. Cape Henry Channel is approximately 328 meters wide and 3.7 kilometers long, with an original depth of 12.8 meters at mean low water (CENAO 1980). Figure 1 shows the locations of the Thimble Shoals channel and a portion of the Cape Henry channel as they relate to the Chesapeake Bay coastline region. 1 Corresponding author, Department of Geography, 1 University Plaza, Youngstown State University, Youngstown, OH 44555. Phone: 330-941-3317. Fax: 330-941-1802. b.ashellito@ysu.edu 2 Phone: 757-201-7418 , keith.b.lockwood@usace.army.mil
{"title":"GIS and 3D Analysis Applied to Sea Turtle Mortalities and Navigation Channel Dredging","authors":"B. Shellito, Keith Lockwood","doi":"10.25778/HXQK-K674","DOIUrl":"https://doi.org/10.25778/HXQK-K674","url":null,"abstract":"Between 2000 and 2003 there were an increased number of documented sea turtle mortalities related to hopper dredging in the channels of the Chesapeake Bay. A pilot study was undertaken to create a bathymetric surface and three-dimensional model of the Cape Henry Channel using Geographic Information Systems (GIS) as a visualization tool to examine sea turtle mortalities in relation to the dredging. In Fall 2003, the US Army Corps of Engineers dredged the Thimble Shoals Federal Navigation Channel, and a more refined model was developed using this data. This project examines the growing concerns over sea turtle mortality rates and dredging operations, as well as a description of the usage of GIS analysis, interpolation, and visualization methods as tools for examining turtle habitat and mortality issues. Future directions for incorporating G IS into attempts to reduce sea turtle mortality in dredging operations are then outlined. INTRODUCTION AND BACKGROUND The section of the Chesapeake Bay off the Virginia coast contains a series of Federal Navigation Channels that are periodically dredged by self-propelled hopper dredges. These dredges are suitable for all but hard materials and are, by far , the best suited dredges for offshore work (Herbich 2000). There are four main navigation channels in the lower Chesapeake Bay: York Spit, York River Entrance, Cape Henry Channel, and Thimble Shoals Channel. Cape Henry Channel and Thimble Shoals Channel mark the entrance to the Bay from the Atlantic Ocean. The Thimble Shoals and Cape Henry channels are congressionally authorized Federal projects located in the mouth of the Chesapeake Bay between Hampton Roads and the Atlantic Ocean. Thimble Shoals Channel is approximately 18288 meters long, 304.8 meters wide, with an original depth of 13.7 meters at mean low water (CENAO 1973) . The channel was constructed in 1914 and requires maintenance dredging once every 2-3 years. Cape Henry Channel is approximately 328 meters wide and 3.7 kilometers long, with an original depth of 12.8 meters at mean low water (CENAO 1980). Figure 1 shows the locations of the Thimble Shoals channel and a portion of the Cape Henry channel as they relate to the Chesapeake Bay coastline region. 1 Corresponding author, Department of Geography, 1 University Plaza, Youngstown State University, Youngstown, OH 44555. Phone: 330-941-3317. Fax: 330-941-1802. b.ashellito@ysu.edu 2 Phone: 757-201-7418 , keith.b.lockwood@usace.army.mil","PeriodicalId":23516,"journal":{"name":"Virginia journal of science","volume":"55 1","pages":"4"},"PeriodicalIF":0.0,"publicationDate":"2006-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83314614","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}
The marsh rice rat, Oryzomys palustris, is the dominant semi-aquatic rodent living in tidal marshes of the Virginia coastal plain. Described as highly carnivorous, this species is known to consume a range of animal foods , including crustaceans, mollusks, fish, and arthropods, as well as some plant foods . Analysis of stomach contents from rice rats collected from Eastern Shore tidal marshes throughout an annual cycle revealed that all 103 stomachs contained di cots, 82 percent had monocots, 61 percent had crabs and insects, and 38 percent had snails. Thirty-eight percent of stomachs contained foods in all five categories, no stomach was empty or contained fish , and 84 percent of stomachs had amounts of hair, probably ingested during self-grooming. In sum, Virginia rice rats are carnivorous but consume greater amounts of plant foods compared to populations that have been studied in Georgia and Louisiana. INTRODUCTION The marsh rice rat, Oryzomys palustris, is a semi-aquatic rodent with its highest abundances in wet fields and marshes, mostly of the southeastern US (Wolfe 1982). Distributed along the eastern seaboard southward from coastal Pennsylvania to the tip of Florida and westward to Corpus Christi, Texas, its range extends northward along the Mississippi River basin into southern Missouri and Illinois. In Virginia, it is common in tidal marshes of the coast and Chesapeake Bay and is present in some grassland habitats as far west as the fall line (ca.Interstate Highway 95; Linzey 1998). The marsh rice rat readily takes to water to forage and escape from predators, and can be caught in floating live traps (personal observation, RKR). Its swimming ability has been studied by Esher et al. (1978) in Mississippi and Carter and Merritt (1981) in Virginia, and inter-island movements of marked rice rats have been documented for the Virginia barrier islands (Forys and Dueser 1993). Medium in size among rodents (up to 80 g), Oryzomys is considered to be highly carnivorous, second to North America's most carnivorous rodent, the grasshopper mouse, Onychomys, a desert grassland mouse of the western states. The meat-eating proclivities of marsh rice rats were observed by Schantz (1943), who reported them eating the bodies of trapped muskrats, a behavior also observed by RKR (unpublished) on trapped small mammals on Fisherman Island, Virginia. The natural history of the marsh rice rat is summarized in Wolfe (1982). 1 Corresponding author: Robert K. Rose, Department ofBiological Sciences, Old Dominion University, Norfolk, Virginia, Phone: 757-683-4202, Email: brose@odu.edu 116 VIRGINIA JOURNAL OF SCIENCE The objectives of our year-long study were to learn the kinds and proportions of foods eaten by marsh rice rats taken from tidal marshes of the Eastern Shore of Virginia and their seasonality of food selection. Oryzomys palustris is codominant in these tidal marshes with the meadow vole, Microtus pennsylvanicus (March 1995 Bloch and Rose 2005), with the la
沼泽稻鼠(Oryzomys palustris)是生活在弗吉尼亚海岸平原潮汐沼泽中的主要半水生啮齿动物。该物种被描述为高度肉食性动物，以各种动物性食物为食，包括甲壳类动物、软体动物、鱼类和节肢动物，以及一些植物性食物。对每年从东海岸潮汐沼泽收集的大鼠胃内容物进行分析后发现，103个胃中都有单胞菌，82%有单胞菌，61%有螃蟹和昆虫，38%有蜗牛。38%的胃里有这五种食物，没有空胃或鱼胃，84%的胃里有大量的毛发，可能是在自我梳理时摄入的。总之，弗吉尼亚稻鼠是肉食性的，但与在乔治亚州和路易斯安那州研究的种群相比，它们消耗更多的植物性食物。沼泽稻鼠(Oryzomys palustris)是一种半水生啮齿动物，在美国东南部的潮湿田地和沼泽中数量最多(Wolfe 1982)。沿东部沿海向南分布，从宾夕法尼亚州沿海到佛罗里达州的尖端，向西到德克萨斯州的科珀斯克里斯蒂，其范围沿密西西比河流域向北延伸，进入密苏里州南部和伊利诺伊州。在弗吉尼亚州，它在海岸和切萨皮克湾的潮汐沼泽中很常见，也出现在一些草原栖息地，远至西部的瀑布线(加利福尼亚州95号州际公路;林基1998)。沼泽稻鼠很容易到水里觅食和躲避捕食者，并可能被漂浮的活陷阱捕获(个人观察，RKR)。密西西比州的Esher等人(1978)和弗吉尼亚州的Carter和Merritt(1981)对其游泳能力进行了研究，并记录了弗吉尼亚堰洲岛有标记的稻鼠的岛屿间运动(Forys和Dueser 1993)。在啮齿类动物中，Oryzomys的体型中等(可达80克)，被认为是高度肉食性的，仅次于北美最肉食性的啮齿动物，蚱蜢鼠，Onychomys，一种西部各州的沙漠草原鼠。Schantz(1943)观察到沼泽稻鼠的食肉倾向，他报告说它们吃捕获的麝鼠的尸体，RKR(未发表)在弗吉尼亚州渔人岛捕获的小型哺乳动物身上也观察到这种行为。Wolfe(1982)总结了沼泽稻鼠的自然历史。1通讯作者:Robert K. Rose, Old Dominion University, Norfolk, Virginia，生物科学系，电话:757-683-4202,Email: brose@odu.edu 116 Virginia JOURNAL OF SCIENCE我们为期一年的研究的目的是了解沼泽稻鼠所吃食物的种类和比例，这些食物来自弗吉尼亚东海岸的潮汐沼泽，以及它们对食物选择的季节性。在这些潮汐沼泽中，Oryzomys palustris与草地田鼠Microtus pennsylvanicus共占优势(March 1995 Bloch and Rose 2005)，后者几乎完全是草食性的(Zimmerman 1965等)。在路易斯安那州(Negus et al.， 1961)、佛罗里达州(Pournelle, 1950)和佐治亚州(Sharp, 1967)对沼泽稻鼠的饮食进行了研究，发现稻鼠以不同比例消耗植物和动物材料。在我们的研究中，我们了解到弗吉尼亚稻鼠吃的植物比其他地理位置的高，加上不同数量的螃蟹、蜗牛和节肢动物(主要是昆虫)。材料与方法:本研究于1994年5月至1995年4月进行，为期一年。研究目标是每月从弗吉尼亚州北安普顿县的两个海滨地点收集多达15只动物的样本，一个位于牡蛎以南约300米，另一个位于汤森以东500米。10月，有机会检查附近堰洲岛(Myrtle, Ship Shoal, Smith和Mockhorn)沼泽中的动物，因此当月的样本量比其他月份要大得多。由于未知的原因，在6 - 8月的夏季，稻鼠很少，在此期间只收集到两只稻鼠(表1)，尽管与其他月份相比，这几个月的捕鼠工作有所增加。March(1995)在早期对东岸类似潮汐沼泽稻鼠种群动态的研究中也发现，6月和7月稻鼠密度很低或接近于零，Negus等(1961)在7月捕获了2145个陷阱夜，在另一年的6月捕获了3个陷阱夜，每200个陷阱夜均< 1只稻鼠，表明行为或其他变化降低了它们在夏季的可捕获性。两个研究地点都位于潮汐沼泽，后面是茂密的芦苇，芦苇。沼泽植物区系包括互花米草(米草)、盐草堆干草、惊慌草(Panicum sp.)、黑针草(Juncus roemeranius)、水杨草(Salicornia sp.)。 03) 2.3(0.03) 1.4(0.02) 62年3月。3 (0.07)30.1 (0.05)0.2
{"title":"Year-round Diet of the Marsh Rice Rat, Oryzomys palustris, in Virginia Tidal Marshes","authors":"R. K. Rose, S. Mcgurk","doi":"10.25778/4X69-4313","DOIUrl":"https://doi.org/10.25778/4X69-4313","url":null,"abstract":"The marsh rice rat, Oryzomys palustris, is the dominant semi-aquatic rodent living in tidal marshes of the Virginia coastal plain. Described as highly carnivorous, this species is known to consume a range of animal foods , including crustaceans, mollusks, fish, and arthropods, as well as some plant foods . Analysis of stomach contents from rice rats collected from Eastern Shore tidal marshes throughout an annual cycle revealed that all 103 stomachs contained di cots, 82 percent had monocots, 61 percent had crabs and insects, and 38 percent had snails. Thirty-eight percent of stomachs contained foods in all five categories, no stomach was empty or contained fish , and 84 percent of stomachs had amounts of hair, probably ingested during self-grooming. In sum, Virginia rice rats are carnivorous but consume greater amounts of plant foods compared to populations that have been studied in Georgia and Louisiana. INTRODUCTION The marsh rice rat, Oryzomys palustris, is a semi-aquatic rodent with its highest abundances in wet fields and marshes, mostly of the southeastern US (Wolfe 1982). Distributed along the eastern seaboard southward from coastal Pennsylvania to the tip of Florida and westward to Corpus Christi, Texas, its range extends northward along the Mississippi River basin into southern Missouri and Illinois. In Virginia, it is common in tidal marshes of the coast and Chesapeake Bay and is present in some grassland habitats as far west as the fall line (ca.Interstate Highway 95; Linzey 1998). The marsh rice rat readily takes to water to forage and escape from predators, and can be caught in floating live traps (personal observation, RKR). Its swimming ability has been studied by Esher et al. (1978) in Mississippi and Carter and Merritt (1981) in Virginia, and inter-island movements of marked rice rats have been documented for the Virginia barrier islands (Forys and Dueser 1993). Medium in size among rodents (up to 80 g), Oryzomys is considered to be highly carnivorous, second to North America's most carnivorous rodent, the grasshopper mouse, Onychomys, a desert grassland mouse of the western states. The meat-eating proclivities of marsh rice rats were observed by Schantz (1943), who reported them eating the bodies of trapped muskrats, a behavior also observed by RKR (unpublished) on trapped small mammals on Fisherman Island, Virginia. The natural history of the marsh rice rat is summarized in Wolfe (1982). 1 Corresponding author: Robert K. Rose, Department ofBiological Sciences, Old Dominion University, Norfolk, Virginia, Phone: 757-683-4202, Email: brose@odu.edu 116 VIRGINIA JOURNAL OF SCIENCE The objectives of our year-long study were to learn the kinds and proportions of foods eaten by marsh rice rats taken from tidal marshes of the Eastern Shore of Virginia and their seasonality of food selection. Oryzomys palustris is codominant in these tidal marshes with the meadow vole, Microtus pennsylvanicus (March 1995 Bloch and Rose 2005), with the la","PeriodicalId":23516,"journal":{"name":"Virginia journal of science","volume":"51 1","pages":"2"},"PeriodicalIF":0.0,"publicationDate":"2006-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84647608","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}
Kenaf (Hibiscus cannabinus L. ), a warm-season annual plant, has shown potential as an alternate source of fiber in the United States. Although preliminary research has indicated feasibility ofkenaf production in Virginia, production details are lacking. Field experiments were conducted during 1995 and 1996 to determine optimal row spacing and fertilizer needs, and to compare available kenaf cul ti vars. Although results indicated that differences in dry matter yields from four row spacings (30, 60, 90, and 120 cm) and four rates each ofN, P, and K fertilizers (50, 100, 150, and 200 kg·ha) were not statistically different, the yields were adequate ranging from 8.8 to 16.0 t·hawith an average yield of 12.5 t·ha-• Dry matter yields for narrow-leaf cultivars proved superior to broad-leaf, and the overall results demonstrate that kenaf can be easily produced in Virginia. INTRODUCTION Kenaf (Hibiscus cannabinus L. ), a relative of cotton ( Gossypium hirsutum L.) and okra (Abelmoschus esculentus L. ), is a warm-season annual plant that originated in northern Africa and has been used as a cordage crop for many years in India, Russia, and China (Dempsey, 1975). Kenafresearch in the USA began during World War II to supply cordage material for the war effort (Wilson et al, 1965). During the 1950s and early I 960s, it was determined that kenaf was an excellent cellulose fiber source for a large range of paper products ( newsprint, bond paper, corrugated liner board, etc.). It was also determined that pulping kenaf required less energy and chemical inputs for processing than standard wood sources (Nelson et al., 1962). More recent research and development work indicates that kenaf is also suitable for use in building materials (particle boards of various densities, thicknesses, with fire and insect resistance), absorbents, textiles, livestock feed, and fibers in new and recycled plastics (Webber and Bledsoe, 1993). These observations indicate that kenaf could be potentially grown in Virginia to diversify cropping systems, to provide alternative materials for paper mills, and to meet varied industrial needs. Virginia State University's New Crops Program, established in 1991, initiated a kenaf research project in 1992. The objectives of this project were 1 Contribution ofVirginia State University, Agricultural Research Station Journal Article Series No. 247. The use of trade names or vendors does not imply approval to the exclusion of other products or vendors that may also be suitable. 2 Corresponding Author, E-mail: hbhardwi @vsu.edu Virginia Journal of Science, Vol. 56, No. 3, 2005 http://digitalcommons.odu.edu/vjs/vol56/iss3 116 VIRGINIA JOURNAL OF SCIENCE to conduct preliminary production research and to determine the feasjbility of kenaf production in Virginia. Research conducted in Virginia during 1992-1994 indicated that kenaf has significant potential as an alternate crop in Virginia (Bhardwaj and Webber, 1994; Bhardwaj et al., 1995). However, informa
红麻(Hibiscus cannabinus L.)是一种暖季一年生植物，在美国已经显示出作为纤维替代来源的潜力。虽然初步研究表明在弗吉尼亚州生产红麻的可行性，但缺乏生产细节。1995年和1996年进行了田间试验，以确定最佳行距和肥料需求，并比较可用的红麻品种。结果表明，4种行距(30、60、90和120 cm)和4种施氮、磷肥和钾肥(50、100、150和200 kg·ha)的干物质产量差异无统计学意义，但产量在8.8 ~ 16.0 t·ha之间，平均产量为12.5 t·ha，窄叶品种的干物质产量优于阔叶品种，总体结果表明，弗吉尼亚州红麻很容易生产。红麻(Hibiscus cannabinus L.)是棉花(Gossypium hirsutum L.)和秋葵(Abelmoschus esculentus L.)的近亲，是一种原产于北非的暖季一年生植物，多年来在印度、俄罗斯和中国被用作绳索作物(Dempsey, 1975)。美国的Kenafresearch在第二次世界大战期间开始为战争提供绳索材料(Wilson et al, 1965)。在20世纪50年代和60年代初，人们确定红麻是一种优良的纤维素纤维来源，可用于各种纸制品(新闻纸、铜版纸、瓦楞衬里板等)。还确定，与标准木材相比，制浆红麻所需的能量和化学投入更少(Nelson et al.， 1962)。最近的研究和发展工作表明，红麻也适合用于建筑材料(各种密度、厚度、防火和防虫的刨花板)、吸收剂、纺织品、牲畜饲料和新塑料和再生塑料纤维(Webber和Bledsoe, 1993年)。这些观察结果表明，在弗吉尼亚州种植红麻可能会使种植系统多样化，为造纸厂提供替代材料，并满足各种工业需求。弗吉尼亚州立大学的新作物项目成立于1991年，1992年启动了红麻研究项目。本项目为弗吉尼亚州立大学农业研究站期刊第247期投稿。使用商品名称或供应商并不意味着批准排除其他可能合适的产品或供应商。2通讯作者，E-mail: hbhardwi @vsu.edu Virginia Journal of Science, Vol. 56, No. 3, 2005 http://digitalcommons.odu.edu/vjs/vol56/iss3 116 Virginia Journal of Science进行初步生产研究，确定在Virginia生产红麻的可行性。1992-1994年在弗吉尼亚州进行的研究表明，红麻作为弗吉尼亚州的一种替代作物具有巨大的潜力(Bhardwaj和Webber, 1994年;Bhardwaj et al.， 1995)。然而，关于理想的农艺实践的信息，如品种选择、肥力要求和植物密度，特别是弗吉尼亚没有。因此，进行了试验，以确定:(1)高产品种，(2)氮、磷、钾肥料的最佳水平，(3)理想行距。材料和方法1995年和1996年每年在弗吉尼亚州埃特里克(北纬37°14′，西经77°26′)的弗吉尼亚州立大学Randolph农场进行三个实验，海拔约为71 m。土壤类型为阿贝尔砂壤土(细壤土混合热水单倍体)，典型pH值为6.1 ~ 6.4。在第一个试验中，以“Everglades- 41”(宽叶红麻品种)和“Everglades-71”(窄叶红麻品种)2个红麻品种为研究对象，对4个行距(30、60、90和120 cm)进行了评价。分别于1995年5月22日和1996年5月20日进行了3个重复的分块设计，主样地设置品种，次样地设置行距。每个地块由三行组成，子地块之间间隔60厘米。在第二个试验中，以Everglades 41品种为研究对象，采用主区施氮、次区施磷、次区施钾4个重复，评价氮、磷、钾各施氮量(50、100、150和200 kg·ha)。每个地块由三行组成，行距为75厘米，地块之间留有一行空白。这些试验分别在1995年5月23日和1996年5月20日进行。试验3采用完全随机区组设计，分别于1995年5月23日和1996年5月21日种植21个红麻品种。每个地块由三行组成，行间间距为75厘米。这些地块各施氮、磷、钾100 kg·hm2。 每个品种在每3米长的行中种植约100颗种子。在每个试验中，种前施用1.5 l·ha1的氟乐灵除草剂来控制杂草。这些实验没有进行灌溉。在1月初的一场严重冰冻导致植物死亡后，从地面人工采集的样本中记录了干物质产量和植物高度的数据。1995年期间，每次试验从每个地块的中间行抽取1 m样本;1996年，采集了一个2米长的样本。在两个月的储藏期后，为了将水分含量稳定在恒定值并使物料干燥，对收获的物料进行测量，并以t·ha-•为单位计算产量。所有数据均使用SAS的一般线性模型程序(SAS, 1996)进行分析。行距:4种行距对两个品种干物质产量的平均影响不显著(表1)。然而，行距越近，产量越高，达到11.1 t·ha-。41号沼泽地的干物质产量(8.2 t·ha-)和71号沼泽地的干物质产量(8.6 t·ha-)也高于弗吉尼亚州的红麻产量117
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In a study conducted in mid-winter, pitfall traps were used to assess the small mammal communities on 14 grids set in open habitats in Isle of Wight County in eastern Virginia. In all, 136 shrews of three species and 103 rodents of five species were trapped. Least shrews (n= 110) comprised 46 percent of small mammals and 80 percent of shrews. Eastern harvest mice (n=62) were the most common rodents. Reproduction was detected only in pine voles and southern bog lemmings. The majority of small mammals of the region were trapped during this month-long study. INTRODUCTION As part of a study to determine the western extent of populations of the then federally threatened Dismal Swamp southeastern shrew, Sorex longirostris fisheri, I conducted a survey of small mammals in Isle of Wight County, located just west of the City of Suffolk and lying approximately 40 km west of the Great Dismal Swamp National Wildlife Refuge in eastern Virginia. Using a standard protocol to study the Dismal Swamp southeastern shrew, an assistant and I established 14 study grids at different locations throughout the county. Trapping between 6 January and 6 February 1992, we collected 239 small mammals of eight species. This report relates the details of the types of small mammals, and their associations, in a coastal plain county in eastern Virginia. MATERIALS AND METHODS The southeastern shrew, the species of particular interest, is known to achieve greatest numbers in early successional habitats, such as oldfields, recently clearcut forests, and sites that are infrequently mowed (Rose et al. 1990). Powerline rights of way provide excellent habitat for such small mammals because they are mowed at 3-5 year intervals to prevent excessive growth of shrubs and trees, thereby continually setting back biological succession and promoting the persistence of perennial grasses and other herbaceous plants. Furthermore, because powerlines cross roadways, these habitats are easily reached, an additional benefit. Several high-voltage powerlines form a network across Isle of Wight County (Figure 1 ), many radiating from the Surry Nuclear power plant located on the south side of the James River. Thus, wherever county roads crossed the 30 m wide powerlines, I examined the vegetative stage of the habitat and usually was able to establish one or two study grids nearby. The trapping grids were placed on sites with vegetation that is typical of early succession in the region. Grasses, mostly in the genera Andropogon, Panicum, and Uniola, dominated the vegetation of most grids, but sedges (Carex spp.) and even softrushes (Juncus spp.) were present on wetter places. Many grids had American cane (Arundinaria gigantea) and other woody elements, such as brambles (Rubus spp.), Jananese honevsuckle {f,onicera ianonicat and tree seedlings_ esneci::illvofsweet P-11m Virginia Journal of Science, Vol. 56, No. 2, 2005 http://digitalcommons.odu.edu/vjs/vol56/iss2 1111 84 VIRGINIA JOURNAL OF SCIENCE
{"title":"The Small Mammals of Isle of Wight County, Virginia, as Revealed by Pitfall Trapping","authors":"R. K. Rose","doi":"10.25778/rhxa-7277","DOIUrl":"https://doi.org/10.25778/rhxa-7277","url":null,"abstract":"In a study conducted in mid-winter, pitfall traps were used to assess the small mammal communities on 14 grids set in open habitats in Isle of Wight County in eastern Virginia. In all, 136 shrews of three species and 103 rodents of five species were trapped. Least shrews (n= 110) comprised 46 percent of small mammals and 80 percent of shrews. Eastern harvest mice (n=62) were the most common rodents. Reproduction was detected only in pine voles and southern bog lemmings. The majority of small mammals of the region were trapped during this month-long study. INTRODUCTION As part of a study to determine the western extent of populations of the then federally threatened Dismal Swamp southeastern shrew, Sorex longirostris fisheri, I conducted a survey of small mammals in Isle of Wight County, located just west of the City of Suffolk and lying approximately 40 km west of the Great Dismal Swamp National Wildlife Refuge in eastern Virginia. Using a standard protocol to study the Dismal Swamp southeastern shrew, an assistant and I established 14 study grids at different locations throughout the county. Trapping between 6 January and 6 February 1992, we collected 239 small mammals of eight species. This report relates the details of the types of small mammals, and their associations, in a coastal plain county in eastern Virginia. MATERIALS AND METHODS The southeastern shrew, the species of particular interest, is known to achieve greatest numbers in early successional habitats, such as oldfields, recently clearcut forests, and sites that are infrequently mowed (Rose et al. 1990). Powerline rights of way provide excellent habitat for such small mammals because they are mowed at 3-5 year intervals to prevent excessive growth of shrubs and trees, thereby continually setting back biological succession and promoting the persistence of perennial grasses and other herbaceous plants. Furthermore, because powerlines cross roadways, these habitats are easily reached, an additional benefit. Several high-voltage powerlines form a network across Isle of Wight County (Figure 1 ), many radiating from the Surry Nuclear power plant located on the south side of the James River. Thus, wherever county roads crossed the 30 m wide powerlines, I examined the vegetative stage of the habitat and usually was able to establish one or two study grids nearby. The trapping grids were placed on sites with vegetation that is typical of early succession in the region. Grasses, mostly in the genera Andropogon, Panicum, and Uniola, dominated the vegetation of most grids, but sedges (Carex spp.) and even softrushes (Juncus spp.) were present on wetter places. Many grids had American cane (Arundinaria gigantea) and other woody elements, such as brambles (Rubus spp.), Jananese honevsuckle {f,onicera ianonicat and tree seedlings_ esneci::illvofsweet P-11m Virginia Journal of Science, Vol. 56, No. 2, 2005 http://digitalcommons.odu.edu/vjs/vol56/iss2 1111 84 VIRGINIA JOURNAL OF SCIENCE","PeriodicalId":23516,"journal":{"name":"Virginia journal of science","volume":"76 1","pages":"2"},"PeriodicalIF":0.0,"publicationDate":"2005-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83834278","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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