Understanding the geographic range and growth of species is essential for effective land management in a landscape affected by anthropogenic activity and climate change. Climate change is expected to alter the distribution and growth of many tree species in eastern North America, including northern white cedar (Thuja occidentalis L.). This research examined the effects of climate on radial growth of T. occidentalis in disjunct populations south of its continuous range margin in eastern North America. A T. occidentalis tree-ring chronology was developed and examined for growth-climate interactions. Mean sensitivity of the T. occidentalis chronology was within the range of values reported for the species in northern portions of its range. Significant positive correlations existed between the T. occidentalis chronology and moisture variables late in the growing season of the previous year and current year. The relationship between the T. occidentalis chronology and temperature was more variable with significant positive and negative correlations throughout the previous year and current year. The Ordinary Least Squares (OLS) regression model suggested moisture conditions late in the growing season of the previous year and current year had a significant positive influence on the growth of T. occidentalis. In contrast, maximum temperature in March of the current year negatively influenced the growth of T. occidentalis. While the mean sensitivity of T. occidentalis appears similar throughout its range, there is geographic variability in the climate-growth response of T. occidentalis. More research is necessary to expand the scope of our knowledge concerning T. occidentalis growth throughout its range.
在受人为活动和气候变化影响的景观中，了解物种的地理范围和生长对有效的土地管理至关重要。气候变化预计将改变北美东部许多树种的分布和生长，包括北方白雪松(Thuja occidentalis L.)。本研究考察了气候对北美东部西部柽柳(T. occidentalis)连续分布范围以南的间断种群径向生长的影响。建立了西方柽柳年轮年表，并对其生长与气候的相互作用进行了研究。西部柽柳年代学的平均敏感性在其分布范围北部的报告值范围内。西洋槐年代学与当年和当年生长季后期的水分变量呈显著正相关。西部柽柳年代学与气温的关系变化较大，前年和当年均呈显著的正相关和负相关。普通最小二乘(OLS)回归模型表明，前一年和当年生长季后期的水分条件对西部柽柳的生长有显著的正影响。相反，当年3月的最高气温对西胸草的生长有不利影响。虽然在其整个生长范围内，西部柽柳的平均敏感性相似，但西部柽柳对气候-生长的响应存在地理差异。有必要进行更多的研究，以扩大我们对西方滴虫在其整个范围内生长的认识范围。
{"title":"The Effects of Climate on Radial Growth of Disjunct Northern White Cedar (Thuja occidentalis L.) in Virginia","authors":"J. A. Kincaid","doi":"10.25778/WGGY-JY81","DOIUrl":"https://doi.org/10.25778/WGGY-JY81","url":null,"abstract":"Understanding the geographic range and growth of species is essential for effective land management in a landscape affected by anthropogenic activity and climate change. Climate change is expected to alter the distribution and growth of many tree species in eastern North America, including northern white cedar (Thuja occidentalis L.). This research examined the effects of climate on radial growth of T. occidentalis in disjunct populations south of its continuous range margin in eastern North America. A T. occidentalis tree-ring chronology was developed and examined for growth-climate interactions. Mean sensitivity of the T. occidentalis chronology was within the range of values reported for the species in northern portions of its range. Significant positive correlations existed between the T. occidentalis chronology and moisture variables late in the growing season of the previous year and current year. The relationship between the T. occidentalis chronology and temperature was more variable with significant positive and negative correlations throughout the previous year and current year. The Ordinary Least Squares (OLS) regression model suggested moisture conditions late in the growing season of the previous year and current year had a significant positive influence on the growth of T. occidentalis. In contrast, maximum temperature in March of the current year negatively influenced the growth of T. occidentalis. While the mean sensitivity of T. occidentalis appears similar throughout its range, there is geographic variability in the climate-growth response of T. occidentalis. More research is necessary to expand the scope of our knowledge concerning T. occidentalis growth throughout its range.","PeriodicalId":23516,"journal":{"name":"Virginia journal of science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86317061","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 objectives of this research were twofold: test the infiltration rate of pervious concrete before and after vacuum cleaning, and assess infiltration variability over time. Infiltration tests were performed on a 558.2 m2 area of pervious concrete, divided into sixteen 0.35 m2 test areas in a parking area at the Science Museum of Virginia in Richmond, Virginia on five dates from November 4-December 30, 2013. Average infiltration rates (avg.= 22.8 and 36.3 L/m2/min) immediately after vacuuming were lower than those (avg.=30.7 and 41.3 L/m2/min) before vacuuming. We hypothesize that the vacuuming lifted materials towards the surface from deeper crevices of the lower profile of the pervious concrete, which clogged interstices in the upper portion of the pervious concrete, and impeded infiltration. Over time, however, average infiltration rates recovered, increasing significantly from 22.8 -44.1 L/m2/min (93% increase) from November 4 through December 30, 2013 (56 days). Ergo, over time, the infiltration capability of the pervious concrete increased as rains likely washed sediments to lower profiles and allow for increased infiltration rates, consistent with the findings of other studies. Infiltration rates on the leading edge of the pervious concrete area receiving runoff from adjacent impervious asphalt surfaces were significantly lower than those furthest away from the leading edge. In contrast to recommendations specifying that pervious concrete be regularly vacuumed monthly, we propose that annual or semiannual vacuuming of pervious concrete would allow adequate infiltration, and reduce costs significantly for pervious concrete areas located in the mid-Atlantic region.
{"title":"Effects of Vacuuming Pervious Concrete on Infiltration Rate","authors":"Demetrios E. Maurakis, E. Maurakis","doi":"10.25778/Q3H4-M763","DOIUrl":"https://doi.org/10.25778/Q3H4-M763","url":null,"abstract":"The objectives of this research were twofold: test the infiltration rate of pervious concrete before and after vacuum cleaning, and assess infiltration variability over time. Infiltration tests were performed on a 558.2 m2 area of pervious concrete, divided into sixteen 0.35 m2 test areas in a parking area at the Science Museum of Virginia in Richmond, Virginia on five dates from November 4-December 30, 2013. Average infiltration rates (avg.= 22.8 and 36.3 L/m2/min) immediately after vacuuming were lower than those (avg.=30.7 and 41.3 L/m2/min) before vacuuming. We hypothesize that the vacuuming lifted materials towards the surface from deeper crevices of the lower profile of the pervious concrete, which clogged interstices in the upper portion of the pervious concrete, and impeded infiltration. Over time, however, average infiltration rates recovered, increasing significantly from 22.8 -44.1 L/m2/min (93% increase) from November 4 through December 30, 2013 (56 days). Ergo, over time, the infiltration capability of the pervious concrete increased as rains likely washed sediments to lower profiles and allow for increased infiltration rates, consistent with the findings of other studies. Infiltration rates on the leading edge of the pervious concrete area receiving runoff from adjacent impervious asphalt surfaces were significantly lower than those furthest away from the leading edge. In contrast to recommendations specifying that pervious concrete be regularly vacuumed monthly, we propose that annual or semiannual vacuuming of pervious concrete would allow adequate infiltration, and reduce costs significantly for pervious concrete areas located in the mid-Atlantic region.","PeriodicalId":23516,"journal":{"name":"Virginia journal of science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82982452","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}
An adhesive organ is a prominent, protruding mucus secreting gland that is used by newly hatched tadpoles and larvae of some fishes to attach to aquatic vegetation. The objective of this research is to test the hypothesis that newly hatched cyprinid larvae of Hybognathus hankinsoni, Notemigonus crysoleucas, Cyprinus carpio and Gila atraria contain cephalic adhesive organs. Newly hatched larvae of Semotilus atromaculatus, which do not attach to submerged aquatic vegetation, were used as the control. SEM examination of newly hatched larvae indicate there were no adhesive organs on the control species (S. atromaculatus) or test species (H. hankinsoni, N. crysoleucas, C. carpio and G. atraria). Rather, newly hatched larvae of test species contain a localized highly modified epidermis (i.e., primarily on the ventral cephalic and anterioventral yolk sac surfaces of H. hankinsoni, N. crysoleucas, C. carpio, and G. atraria, and sometimes on dorsal cephalic epidermal cells of H. hankinsoni, C. carpio, and G. atraria). This modified epidermis is composed of epidermal cells with unculi-like projections, elevated microridges at peripheries of epidermal cells, and mucus from apical pores of goblet cells that probably are responsible for attachment of test species to substrates. We hypothesize that the unculi-like projections at centers of epidermal cells in newly hatched larval test cyprinids are true unculi. There is a need to define and clarify the meanings of words and phrases (i.e., cement gland, cement gland apparatus, cement gland-like structure, casquette, temporary adhesive glands, adhesive apparatus, adhesive gland, adhesive organ, attachment organ, and glue secretion and adhesion) for structures used by newly hatched larvae to attach to substrates. Definitions should be based on homologies, crucial in phylogenetic reconstructions of species relationships and in identifying developmental homologues of cells, tissues, glands, and organs that have been described as mechanisms for attachment by newly hatched larvae of various species to substrates. We proposed the phrase “attachment mechanism” as a broad definition for the ways in which newly hatched larvae attach and adhere to substrates during early development. This broad definition, however, should be modified to define specific methods of attachment (e.g. attachment mechanism of unculi, elevated epidermal microridges, and mucus) to assist in defining homologies.
粘附器官是一种突出的粘液分泌腺，新孵化的蝌蚪和一些鱼类的幼虫用它附着在水生植物上。本研究的目的是验证汉氏水蚤(Hybognathus hankinsoni)、crysoleucnotemigonus、carpio Cyprinus和atraria Gila新孵化的鲤科幼虫是否含有头黏附器官的假设。以新孵化的不附着于水下植被的半鹦鹉螺(Semotilus atromaculatus)幼虫为对照。新孵化幼虫的扫描电镜(SEM)检查表明，对照种(S. atromaculatus)和试验种(H. hankinsoni, N. crysoleucas, C. carpio和G. atraria)没有粘附器官。相反，新孵化的试验物种的幼虫含有一个局部的高度修饰的表皮(即，主要在汉氏蜱、crysoleucas、C. carpio和G. atraria的头腹侧和前腹侧卵黄囊表面，有时在汉氏蜱、C. carpio和G. atraria的头背表皮细胞上)。这种修饰过的表皮由具有unculil样突出物的表皮细胞、表皮细胞边缘隆起的微脊和杯状细胞顶端孔的粘液组成，杯状细胞可能负责被试物种与底物的附着。我们假设在新孵化的试验鲤幼虫表皮细胞中心的uncul样突起是真正的uncul。对于新孵化的幼虫附着在基质上的结构，有必要定义和澄清单词和短语的含义(即，水泥腺，水泥腺装置，水泥腺样结构，casquette，临时粘附腺，粘附装置，粘附腺，粘附器官，粘附器官，胶水分泌和粘附)。定义应基于同源性，这对于物种关系的系统发育重建和识别细胞、组织、腺体和器官的发育同源性至关重要，这些同源性已被描述为各种物种新孵化的幼虫附着于基质的机制。我们提出了“附着机制”一词作为新孵化的幼虫在早期发育过程中附着和粘附在基质上的方式的广义定义。然而，这个宽泛的定义应该加以修改，以定义特定的附着方法(例如，unculi的附着机制、表皮微脊的升高和粘液)，以帮助定义同源性。
{"title":"Microstructure of Attachment Mechanisms of Newly Hatched Larvae of Four Cyprinid Species with Comments on Terminology","authors":"George E. Maurakis, E. Maurakis","doi":"10.25778/XJT5-TR11","DOIUrl":"https://doi.org/10.25778/XJT5-TR11","url":null,"abstract":"An adhesive organ is a prominent, protruding mucus secreting gland that is used by newly hatched tadpoles and larvae of some fishes to attach to aquatic vegetation. The objective of this research is to test the hypothesis that newly hatched cyprinid larvae of Hybognathus hankinsoni, Notemigonus crysoleucas, Cyprinus carpio and Gila atraria contain cephalic adhesive organs. Newly hatched larvae of Semotilus atromaculatus, which do not attach to submerged aquatic vegetation, were used as the control. SEM examination of newly hatched larvae indicate there were no adhesive organs on the control species (S. atromaculatus) or test species (H. hankinsoni, N. crysoleucas, C. carpio and G. atraria). Rather, newly hatched larvae of test species contain a localized highly modified epidermis (i.e., primarily on the ventral cephalic and anterioventral yolk sac surfaces of H. hankinsoni, N. crysoleucas, C. carpio, and G. atraria, and sometimes on dorsal cephalic epidermal cells of H. hankinsoni, C. carpio, and G. atraria). This modified epidermis is composed of epidermal cells with unculi-like projections, elevated microridges at peripheries of epidermal cells, and mucus from apical pores of goblet cells that probably are responsible for attachment of test species to substrates. We hypothesize that the unculi-like projections at centers of epidermal cells in newly hatched larval test cyprinids are true unculi. There is a need to define and clarify the meanings of words and phrases (i.e., cement gland, cement gland apparatus, cement gland-like structure, casquette, temporary adhesive glands, adhesive apparatus, adhesive gland, adhesive organ, attachment organ, and glue secretion and adhesion) for structures used by newly hatched larvae to attach to substrates. Definitions should be based on homologies, crucial in phylogenetic reconstructions of species relationships and in identifying developmental homologues of cells, tissues, glands, and organs that have been described as mechanisms for attachment by newly hatched larvae of various species to substrates. We proposed the phrase “attachment mechanism” as a broad definition for the ways in which newly hatched larvae attach and adhere to substrates during early development. This broad definition, however, should be modified to define specific methods of attachment (e.g. attachment mechanism of unculi, elevated epidermal microridges, and mucus) to assist in defining homologies.","PeriodicalId":23516,"journal":{"name":"Virginia journal of science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73322676","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}
Eight different color polymorphisms of the Red-backed Salamander (Plethodon cinereus) have been described throughout its range. Among them, the erythristic phenotype is a mimetic morph with coloration patterns similar to that of toxic Eastern Newt efts (Notophthalmus viridescens). We describe an erythristic morph of P. cinereus collected at Mountain Lake Biological Station, Virginia. To our knowledge, there are no prior published records of this morph in Virginia.
{"title":"An Erythristic Morph of Red-Backed Salamander (Plethodon cinereus) Collected in Virginia","authors":"Trevor L Chapman, B. Gall, Kari L. Spivey","doi":"10.25778/VCC9-MM67","DOIUrl":"https://doi.org/10.25778/VCC9-MM67","url":null,"abstract":"Eight different color polymorphisms of the Red-backed Salamander (Plethodon cinereus) have been described throughout its range. Among them, the erythristic phenotype is a mimetic morph with coloration patterns similar to that of toxic Eastern Newt efts (Notophthalmus viridescens). We describe an erythristic morph of P. cinereus collected at Mountain Lake Biological Station, Virginia. To our knowledge, there are no prior published records of this morph in Virginia.","PeriodicalId":23516,"journal":{"name":"Virginia journal of science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79006110","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}
Jason V. Lombardi, M. T. Mengak, S. Castleberry, Vanessa C. K. Terrell, M. Fies
Though abundant throughout much of its range, the ecology and local geographic distribution of Mustela frenata (Long-tailed Weasel) is not wellknown, especially in the central Appalachian Mountains. In 2015, we conducted a camera study in rock outcrop habitats within Shenandoah National Park, Virginia. Our objective was to determine the presence of mammals considered uncommon in these habitats. After 2,016 trap nights, we report eleven photographic captures of Long-tailed Weasels at eight sites. Two of these sites represent the first record of this species in Rappahannock County, Virginia. These detections represent the first record of Long-tailed Weasels in Shenandoah National Park in 60 years and extend their known range within the Park.
{"title":"A New Long-tailed Weasel County Record in Shenandoah National Park","authors":"Jason V. Lombardi, M. T. Mengak, S. Castleberry, Vanessa C. K. Terrell, M. Fies","doi":"10.25778/QY29-TQ49","DOIUrl":"https://doi.org/10.25778/QY29-TQ49","url":null,"abstract":"Though abundant throughout much of its range, the ecology and local geographic distribution of Mustela frenata (Long-tailed Weasel) is not wellknown, especially in the central Appalachian Mountains. In 2015, we conducted a camera study in rock outcrop habitats within Shenandoah National Park, Virginia. Our objective was to determine the presence of mammals considered uncommon in these habitats. After 2,016 trap nights, we report eleven photographic captures of Long-tailed Weasels at eight sites. Two of these sites represent the first record of this species in Rappahannock County, Virginia. These detections represent the first record of Long-tailed Weasels in Shenandoah National Park in 60 years and extend their known range within the Park.","PeriodicalId":23516,"journal":{"name":"Virginia journal of science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72816677","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}
Problem: Several approaches to analyze seatbelt use have been proposed in the literature. Two methods that has not been explored are the use of unweighted and weighted logistic regression model and the use of item response theory (IRT) or the Rasch model. Since accurate methods to predict seatbelt use behavior based upon observed data must include a builtin design method and model, and overcome computation challenges, weighted and IRT method deem to be other options for an observational survey of seat belt use in the state of Virginia. Method: The observed data from 136 sites within the Commonwealth of Virginia over two years was collected in a two stage systematic stratified proportional to size sampling plan. The data is analyzed using a weighted Rasch model. Results: A relationship between seatbelt use of drivers weighted for county aggregate population size and length of the road segment observed and the factors of vehicle type and gender standardized using a standardized scale is confirmed using logistic regression model selection and AIC analysis. IRT model was considered and was found highly significant. Practical Application: The addition of socio-economic measures, measure of road and driving difficulty, and data from other states may allow the prediction of seatbelt use with a in a new methodology: the models provide tools for policy decision-making.
{"title":"Exploring New Models for Seatbelt Use in Survey Data","authors":"Mark K. Ledbetter, N. Diawara, B. E. Porter","doi":"10.25778/SETP-H375","DOIUrl":"https://doi.org/10.25778/SETP-H375","url":null,"abstract":"Problem: Several approaches to analyze seatbelt use have been proposed in the literature. Two methods that has not been explored are the use of unweighted and weighted logistic regression model and the use of item response theory (IRT) or the Rasch model. Since accurate methods to predict seatbelt use behavior based upon observed data must include a builtin design method and model, and overcome computation challenges, weighted and IRT method deem to be other options for an observational survey of seat belt use in the state of Virginia. Method: The observed data from 136 sites within the Commonwealth of Virginia over two years was collected in a two stage systematic stratified proportional to size sampling plan. The data is analyzed using a weighted Rasch model. Results: A relationship between seatbelt use of drivers weighted for county aggregate population size and length of the road segment observed and the factors of vehicle type and gender standardized using a standardized scale is confirmed using logistic regression model selection and AIC analysis. IRT model was considered and was found highly significant. Practical Application: The addition of socio-economic measures, measure of road and driving difficulty, and data from other states may allow the prediction of seatbelt use with a in a new methodology: the models provide tools for policy decision-making.","PeriodicalId":23516,"journal":{"name":"Virginia journal of science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78717721","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 use of social media has become an increasingly popular trend, and it is most favorite amongst teenagers. A major problem concerning teens using social media is that they are often unaware of the dangers involved when using these media. Also, teenagers are more inclined to misuse social media because they are often unaware of the privacy rights associated with the use of that particular media, or the rights of the other users. As a result, cyberbullying cases have a steady rise in recent years and have gone undiscovered, or are not discovered until serious harm has been caused to the victims. This study aims to create an effective algorithm that can be used to detect cyberbullying in social media using content mining. Bullies may not use only one social media to victimize other users. Therefore, the proposed algorithm must detect whether or not a user is victimizing someone through one or more social media accounts, then determine which social media accounts are being used to carry out the victimization. To achieve this goal, the algorithm will collect information from content shared by the users in all of their social media accounts, then will determine which content to extract based on a big data technology involving phrases or words that might be used by cyberbullies. Any extracted data will reveal some insight into whether or not cyberbullying is occurring and trigger appropriate approaches to handle it.
{"title":"Content Mining Techniques for Detecting Cyberbullying in Social Media","authors":"Shawniece L Parker, Y. Hu","doi":"10.25778/WHAA-RK11","DOIUrl":"https://doi.org/10.25778/WHAA-RK11","url":null,"abstract":"The use of social media has become an increasingly popular trend, and it is most favorite amongst teenagers. A major problem concerning teens using social media is that they are often unaware of the dangers involved when using these media. Also, teenagers are more inclined to misuse social media because they are often unaware of the privacy rights associated with the use of that particular media, or the rights of the other users. As a result, cyberbullying cases have a steady rise in recent years and have gone undiscovered, or are not discovered until serious harm has been caused to the victims. This study aims to create an effective algorithm that can be used to detect cyberbullying in social media using content mining. Bullies may not use only one social media to victimize other users. Therefore, the proposed algorithm must detect whether or not a user is victimizing someone through one or more social media accounts, then determine which social media accounts are being used to carry out the victimization. To achieve this goal, the algorithm will collect information from content shared by the users in all of their social media accounts, then will determine which content to extract based on a big data technology involving phrases or words that might be used by cyberbullies. Any extracted data will reveal some insight into whether or not cyberbullying is occurring and trigger appropriate approaches to handle it.","PeriodicalId":23516,"journal":{"name":"Virginia journal of science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81859947","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}
To meet the conservation needs of declining amphibian populations, there is a need to assess monitoring techniques in various habitat types and seasons. I assessed detection rates and proportion of area occupied via transect monitoring for red-backed salamanders at a site along the Virginia Fall Line in Doswell, Virginia. I established 24 transects in a 3.2-ha area in both riparian and upland habitats. Objects providing natural cover along these transects were sampled 3 times a week in fall and spring over a twoyear period. Models of occupancy and detection were developed and compared using Akaike’s Information Criterion. Based on 113 captures, model selection indicated a low fixed initial occupancy of transects with seasonal changes in colonization and extinction. Detection probability was uniformly low, possibly contributing to model uncertainty in determining the best explanatory variables. I infer that the increased colonization of transect cover objects during fall and increased emigration from cover objects during spring is a result of changing moisture conditions and feeding opportunities. It is likely that occupancy and detection will vary substantially for survey sites based on habitat, season, or even by transect placement, and thus managers will need to estimate these parameters for any population monitoring program of red-backed salamanders. INTRODUCTION In view of the worldwide decline of amphibian populations and the increased interest to conserve these populations, biologists have been highly interested in developing robust monitoring methods for specific populations, habitats, or sites of conservation interest (Dodd and Barichivich, 2007; Adams et al., 2013; Petitot et al., 2014). One problem in developing these methods is that, regardless of the sampling technique, there is a possibility that an observer will fail to detect an individual of the population of interest when they are present on the sampling site. Thus, the apparent absence of a taxon could mean that members of the population of interest are truly absent from the sampling site or that they are present but not detected. Because this problem has significant implications for whether management strategies are implemented, any robust monitoring method will require the estimation of detection probabilities, the probability (ranging between 0 – 1) that an individual will be detected by a survey procedure, given that is available to be found (Schmidt, 2003). Unfortunately, the detection probability is likely to vary extensively based on a suite of environmental Virginia Journal of Science, Vol. 67, No. 1, 2016 http://digitalcommons.odu.edu/vjs/vol67/iss1 doi: 10.25778/BHQ9-3R58 Virginia Journal of Science, Vol. 67, No. 1, 2016 https://digitalcommons.odu.edu/vjs/vol67/iss1 VIRGINIA JOURNAL OF SCIENCE 10 2 variables, species differences, population size differences, and even individual behavioral differences (Lancia et al., 1996; Dodd and Dorazio, 2004; Tanadini and Schmidt, 2
仅使用了红背蝾螈的检测，Virginia Journal of Science, Vol. 67, No. 1, 2016 http://digitalcommons.odu.edu/vjs/vol67/iss1 Virginia Journal
{"title":"Occupancy Rates and Detection Probabilities of Red-Backed Salamanders on the Virginia Fall Line","authors":"J. D. McGhee","doi":"10.25778/BHQ9-3R58","DOIUrl":"https://doi.org/10.25778/BHQ9-3R58","url":null,"abstract":"To meet the conservation needs of declining amphibian populations, there is a need to assess monitoring techniques in various habitat types and seasons. I assessed detection rates and proportion of area occupied via transect monitoring for red-backed salamanders at a site along the Virginia Fall Line in Doswell, Virginia. I established 24 transects in a 3.2-ha area in both riparian and upland habitats. Objects providing natural cover along these transects were sampled 3 times a week in fall and spring over a twoyear period. Models of occupancy and detection were developed and compared using Akaike’s Information Criterion. Based on 113 captures, model selection indicated a low fixed initial occupancy of transects with seasonal changes in colonization and extinction. Detection probability was uniformly low, possibly contributing to model uncertainty in determining the best explanatory variables. I infer that the increased colonization of transect cover objects during fall and increased emigration from cover objects during spring is a result of changing moisture conditions and feeding opportunities. It is likely that occupancy and detection will vary substantially for survey sites based on habitat, season, or even by transect placement, and thus managers will need to estimate these parameters for any population monitoring program of red-backed salamanders. INTRODUCTION In view of the worldwide decline of amphibian populations and the increased interest to conserve these populations, biologists have been highly interested in developing robust monitoring methods for specific populations, habitats, or sites of conservation interest (Dodd and Barichivich, 2007; Adams et al., 2013; Petitot et al., 2014). One problem in developing these methods is that, regardless of the sampling technique, there is a possibility that an observer will fail to detect an individual of the population of interest when they are present on the sampling site. Thus, the apparent absence of a taxon could mean that members of the population of interest are truly absent from the sampling site or that they are present but not detected. Because this problem has significant implications for whether management strategies are implemented, any robust monitoring method will require the estimation of detection probabilities, the probability (ranging between 0 – 1) that an individual will be detected by a survey procedure, given that is available to be found (Schmidt, 2003). Unfortunately, the detection probability is likely to vary extensively based on a suite of environmental Virginia Journal of Science, Vol. 67, No. 1, 2016 http://digitalcommons.odu.edu/vjs/vol67/iss1 doi: 10.25778/BHQ9-3R58 Virginia Journal of Science, Vol. 67, No. 1, 2016 https://digitalcommons.odu.edu/vjs/vol67/iss1 VIRGINIA JOURNAL OF SCIENCE 10 2 variables, species differences, population size differences, and even individual behavioral differences (Lancia et al., 1996; Dodd and Dorazio, 2004; Tanadini and Schmidt, 2","PeriodicalId":23516,"journal":{"name":"Virginia journal of science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75512062","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}
Virginia’s diverse environments support 84 amphibian species (anurans and caudates), making it the third highest state in terms of species richness. However, the Commonwealth matches the global trend in declining amphibian populations with over one-third of its amphibian species in conservation need. The Species of Greatest Conservation Need included in the most recent Virginia Wildlife Action Plan cut across amphibian families and ecoregions. It is challenging to ascertain the exact cause of most of the population declines. In one degree or another, all of the global threats to amphibians exist within Virginia’s borders. While an active research program on amphibians exists in the Commonwealth, there are an abundance of data deficient topics where research can help detect and inform the cause of these declines, as well as evaluate management efforts. On a positive note, there are a large number of existing conservation efforts being undertaken across Virginia that directly or indirectly benefit local amphibians. “These foal and loathsome animals are abhorrent because of their cold body, pale color, cartilaginous skeleton, filthy skin, fierce aspect, calculating eye, offensive smell, harsh voice, squalid habitation, and terrible venom; and so their Creator has not exerted his powers to make many of them.” Carolus Linnaeus 1758 INTRODUCTION Some people would likely still describe amphibians as Linnaeus once did, but today we know they are a diverse class of vertebrates, many in number and integral components of ecosystems (Hocking and Babbitt 2014). They are ecologically recognized for their energy efficiency and nutrient cycling. Amphibians serve as prey to many different organisms and as predators consuming vast numbers of insects, including those species that are vectors for diseases or cause agricultural damage. 1 Corresponding author: jennifer.sevin@gmail.com Virginia Journal of Science, Vol. 66, No. 3, 2015 https://digitalcommons.odu.edu/vjs/vol66/iss3 278 VIRGINIA JOURNAL OF SCIENCE People have, and continue, to use amphibians for a variety of purposes, including as food, pets and cultural icons. Additionally, the applications of amphibians for human health are wide ranging, including serving as important research subjects and for the treatment of all kinds of ailments (Burggren and Warburton 2007, O'Rourke 2007, Hocking and Babbitt 2014). Amphibians are the earliest terrestrial Tetrapods, first appearing during the late Devonian Period about 360 million years ago. Their physiological, biological, behavioral and ecological adaptations have enabled them to inhabit every continent except Antarctica. Over 7,400 species of amphibians have been described globally across three orders: Anura (frogs and toads), Caudata (salamanders and newts) and Gymnophiona (caecilians) (refer to www.amhibiaweb.org for the most up to date species list). Amphibians are ectothermic organisms mostly known for their permeable skin, complex life cycles, limited mobilit
弗吉尼亚多样化的环境支持着84种两栖动物(无尾类和尾类)，使其成为物种丰富度第三高的州。然而，英联邦与全球两栖动物数量下降的趋势一致，超过三分之一的两栖动物物种需要保护。在最近的弗吉尼亚野生动物行动计划中，最需要保护的物种跨越了两栖动物家族和生态区域。确定大多数人口下降的确切原因是具有挑战性的。在某种程度上，所有对两栖动物的全球性威胁都存在于弗吉尼亚境内。虽然英联邦存在一个积极的两栖动物研究项目，但有大量数据不足的主题，研究可以帮助发现和告知这些下降的原因，以及评估管理工作。积极的一面是，弗吉尼亚各地正在进行大量的保护工作，这些工作直接或间接地使当地的两栖动物受益。“这些小马驹和令人讨厌的动物令人憎恶，因为它们冰冷的身体、苍白的颜色、软骨状的骨骼、肮脏的皮肤、凶狠的外表、精明的眼睛、难闻的气味、刺耳的声音、肮脏的住所和可怕的毒液;所以造他们的主没有施展他的大能，使他们增多。”有些人可能仍然会像林奈曾经那样描述两栖动物，但今天我们知道它们是一种多样化的脊椎动物，数量众多，是生态系统的重要组成部分(Hocking and Babbitt 2014)。它们的能量效率和养分循环在生态学上是公认的。两栖动物是许多不同生物的猎物，也是大量昆虫的捕食者，包括那些传播疾病或造成农业破坏的物种。1通讯作者:jennifer.sevin@gmail.com Virginia Journal of Science, Vol. 66, No. 3, 2015 https://digitalcommons.odu.edu/vjs/vol66/iss3 278 Virginia Journal of Science人们已经并将继续将两栖动物用于各种目的，包括作为食物、宠物和文化标志。此外，两栖动物对人类健康的应用范围广泛，包括作为重要的研究对象和治疗各种疾病(Burggren和Warburton 2007, O'Rourke 2007, Hocking和Babbitt 2014)。两栖动物是最早的陆生四足动物，最早出现在大约3.6亿年前的泥盆纪晚期。它们的生理、生物、行为和生态适应能力使它们能够栖息在除南极洲以外的每个大陆。在全球范围内，有超过7400种两栖动物被描述为三个目:无尾目(青蛙和蟾蜍)，尾目目(蝾螈和蝾螈)和裸眼目(无尾目)(参见www.amhibiaweb.org获取最新的物种列表)。两栖动物是一种恒温生物，以其可渗透的皮肤、复杂的生命周期、有限的机动性和强大的地点保真度而闻名。它们有羊膜(果冻状)卵，有几十种生殖模式，从内部受精到外部受精，在陆地上有一小窝被保护的卵，在静水中有成千上万的卵。使两栖动物独一无二的那些特性，也正是使它们容易受环境变化影响的那些特性。由于这些原因，两栖动物被认为是生态系统健康的良好指示物种(Blaustein et al. 1994, Welsh and Droege 2001, Davic and Welsh 2004, Hopkins 2007)。然而，如果这些生物的反应确实反映了环境中正在发生的事情，那么就有充分的理由继续关注。在过去的几十年里，全球两栖动物数量经历了下降、局部灭绝和物种灭绝(Blaustein and Wake 1990, Gibbons et al. 2000, Stuart et al. 2004, Lannoo 2005, Bishop et al. 2012)。两栖动物现在被认为是全球最受威胁的生物群体之一，约有40%的物种受到威胁(Stuart et al. 2004, Bishop et al. 2012)。本文探讨了弗吉尼亚州两栖动物种群的现状，它们的潜在威胁，以及为保护它们所采取的行动。弗吉尼亚州的两栖动物以其响亮的叫声而闻名，弗吉尼亚州的青蛙的第一个印刷记录来自罗伯特·贝弗利1705年的《弗吉尼亚州的历史和现状》(米切尔2013)。然而，直到20世纪初，当Emmet Reid Dunn对弗吉尼亚州的两栖动物进行了开创性的研究时，真正的多样性才得以实现(Mitchell 2013)。即使在今天，使用基因技术的研究也在描述新物种(Tilley et al. 2008, Fienberg et al. 2014)。在弗吉尼亚联邦，目前有84种记录在案的无尾动物(在剩下的文章中被称为青蛙)和尾类动物(在剩下的文章中被称为蝾螈)。
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With 77 species, the mussel fauna of Virginia is one of the most diverse in the United States. Fifty-four species or ~70% of the state’s mussel fauna occurs in the rivers of the upper Tennessee River basin, especially in the Clinch and Powell rivers of southwestern Virginia. An additional 23 species reside in rivers of the Atlantic Slope, including the Potomac, Rappahannock, York, James and Chowan basins, and in the New River, a major tributary to the Ohio River. A total of 39 species or 51% of Virginia’s mussel fauna is listed as federally endangered, state endangered or state threatened. Excess sediment, nutrients and various types of pollutants entering streams from agriculture and industries are the main drivers of imperilment. Freshwater mussels reproduce in a specialized way, one that requires a fish to serve as a host to their larvae, called glochidia, allowing the larvae to metamorphose to the juvenile stage. This extra step in their life cycle uniquely defines mussels among bivalve mollusks worldwide, in freshwater or marine environments, and adds significant complexity to their reproductive biology. Further, they utilize “lures” that mimic prey of fishes to attract their host. Mussels rely on their fish host to provide them with long-distance dispersal and nutrition while they are glochidia, which are small (<0.5 mm) ecto-parasites that attach and encyst on the gills and fins of fishes, typically taking weeks to months to metamorphose, excyst and then drop-away as similar-sized juveniles to the stream bottom where they grow into adults. Adult mussels are mostly sedentary animals living in the benthos, i.e., the bottom of streams and lakes, typically in mixed substrates of sand, gravel and fine sediments. Mussels generally filter suspended organic particles <20 μm from the water column but can also filter deposited particles through the shell-gap when burrowed in the benthos. Further, the adults of most species are long-lived, regularly living 25-50 years or longer in freshwater environments throughout North America. Conservation of freshwater mussels in Virginia will require citizens, nongovernmental organizations, local, county, state and federal governments to apply their resources to five main areas: (1) water quality monitoring and Virginia Journal of Science, Vol. 66, No. 3, 2015 http://digitalcommons.odu.edu/vjs/vol66/iss3 310 VIRGINIA JOURNAL OF SCIENCE regulation enforcement, (2) restoration of stream habitat, (3) restoration of mussel populations, (4) educating the public about the importance and status of mussels, and (5) monitoring and research to understand why mussels are declining and what are the best ways to protect them. Sustained long-term efforts in these five areas offers the greatest potential to conserve freshwater mussels throughout Virginia. INTRODUCTION With 77 documented species, the mussel fauna of Virginia is one of the most diverse in the United States — only the states of Alabama (178 species), Tennessee (1
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