نتایج جستجو برای: urban transect

تعداد نتایج: 175005  

Journal: :Environmental science and pollution research international 2013
Jacob F Thomas Richard M Engeman Eric A Tillman Justin W Fischer Steve L Orzell Deborah H Glueck Rodney K Felix Michael L Avery

Ecological sampling can be labor intensive, and logistically impractical in certain environments. We optimize line intercept sampling and compare estimation methods for assessing feral swine damage within fragile wetland ecosystems in Florida. Sensitive wetland sites, and the swine damage within them, were mapped using GPS technology. Evenly spaced parallel transect lines were simulated across ...

2017
Xin Yao Min Zhao Francisco J. Escobedo

Studies have documented many biophysical factors that are correlated with urban forest carbon storage. This urban forest function is also increasingly being promoted as a nature-based solution for cities. While urbanization affects both the structure and function of urban forest ecosystems, quantitative analyses of specific casual drivers of carbon storage in urban versus peri-urban forests are...

Journal: :Conservation biology : the journal of the Society for Conservation Biology 2010
Ronald W Sutherland Phillip R Dunning Whit M Baker

Although amphibians have relatively high rates of road mortality in urban areas, the conditions under which traffic threatens the survival of local amphibian populations remain unclear. In the Sandhills region of North Carolina (U.S.A.), we counted living and dead amphibians along two transects (total length 165 km) established on roads in areas with varying degrees of urbanization. We found 26...

2015
Richard Glennie Stephen T. Buckland Len Thomas

Line transect sampling is a distance sampling method for estimating the abundance of wild animal populations. One key assumption of this method is that all animals are detected at their initial location. Animal movement independent of the transect and observer can thus cause substantial bias. We present an analytic expression for this bias when detection within the transect is certain (strip tr...

2017
François Bolduc David A. Fifield

Methods: We tested whether modeling of detection probabilities, and density estimates with their coefficients of variation obtained from the point-transect method provided more robust and precise results than the more commonly used line-transect method. We subdivided our data by species groups (alcids, and aerialist species), and into two behavior categories (flying vs. swimming). We also compu...

1996
Jeffrey L. Howard James E. Sova

Sequential extraction analysis was used to characterize the geochemical partitioning of Pb in roadside soils of the Detroit, MI area. Four soil profiles (10, 30, 60, and 100 m from road) were sampled at 15-cm intervals to a depth of 75 cm at each of five locations along an urban-rural transect. The observed concentrations increase with increasing traffic volume and proximity to the highway, ind...

Journal: :Planning Practice and Research 2021

This practice review examines some of the early evidence, and reporting, housing market change in England prompted by Covid-19 pandemic. Taking a transect from central London, through surrounding near-urban areas, to countryside beyond, it looks at possibility implications more dispersed choices what sorts challenges these may present local planning practice. The pandemic has potential accelera...

Journal: :Proceedings. Biological sciences 2014
Michael Z Levy Corentin M Barbu Ricardo Castillo-Neyra Victor R Quispe-Machaca Jenny Ancca-Juarez Patricia Escalante-Mejia Katty Borrini-Mayori Malwina Niemierko Tarub S Mabud Jere R Behrman Cesar Naquira-Velarde

Modern cities represent one of the fastest growing ecosystems on the planet. Urbanization occurs in stages; each stage characterized by a distinct habitat that may be more or less susceptible to the establishment of disease vector populations and the transmission of vector-borne pathogens. We performed longitudinal entomological and epidemiological surveys in households along a 1900 × 125 m tra...

Journal: :Ecology 2006
Solomon Z Dobrowski Shannon K Murphy

The variable area transect (VAT) is a plotless density estimator that has received little attention in the ecological literature despite having potentially robust estimation properties. VAT allows for density estimations without the lengthy search times associated with other plotless density estimators. In spite of this, little has been written about the effect of varying transect widths on its...

Journal: :Biometrics 2002
J H Pollard D Palka S T Buckland

Adaptive line transect sampling offers the potential of improved population density estimation efficiency over conventional line transect sampling when populations are spatially clustered. In adaptive sampling, survey effort is increased when areas of high animal density are located, thereby increasing the number of observations. Its disadvantage is that the survey effort required is not known ...

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