Transect


Transect

A transect is a path along which one records and counts occurrences of the phenomenon of study (e.g. plants noting each instance).

It requires an observer to move along a fixed path and to count occurrences along the path and, at the same time, obtain the distance of the object from the path. This results in an estimate of the area covered, an estimate of the way in which detectability increases from probability 0 to 1 as one approaches the path. Using these two figures one can arrive at an estimate of the actual density of objects.

The estimation of the abundance of biological populations (such as terrestrial mammal species) can be achieved using a number of different types of transect methods, such as strip transects, line transects, belt transects, point transects [Buckland, S.T., Anderson, D.R., Burnham, K.P and Laake, J.L. 1993. "Distance Sampling: Estimating Abundance of Biological Populations". London: Chapman and Hall. [http://www.colostate.edu/Dept/coopunit/download.html] ] and curved line transects. [Line Lex Hiby, M. B. Krishna 2001. Transect Sampling from a Curving Path. Biometrics. 57(3):727-731 [http://www.creem.st-and.ac.uk/tiago/webpages/pdfs/Hiby&Krishna2001.pdf] ]

New Urbanist town planners use the term transect to refer to the varieties of land use from an urban core to a rural boundary. [Transect applied to regional plans. September 2000. New Urban News. [http://www.newurbannews.com/transect.html] ] General New Urban transect classifications (from highest to lowest density) are: urban core, urban center, general urban, suburban, rural, and natural. [Transect. Duany Plater-Zyberk & Company (DPZ). Undated. [http://www.dpz.com/transect.aspx] ]

Transect for counting population

Transect is also a way of sampling populations. A transect line is used for measuring the changes between at least two areas, it can not measure the population, only the changes between two areas. A transect line is useful for things like: A scientist wants to see the impact of urban cities on the average intelligence of the humans. Or: A scientist wants to know the impact of a nuclear power station to a city.

For a transect line, you need two areas, you connect them with a line and then you measure the population of the species you want to count (e.g.: intestinal bacteria). For counting them, you distribute quadrats in regular intervals on the transect line, and you count the species in those quadrats.

References

ee also

*Census
*New Urbanism
*Mark and recapture
*MegaTransect
*Transect (urban)


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Look at other dictionaries:

  • transect — index dichotomize Burton s Legal Thesaurus. William C. Burton. 2006 …   Law dictionary

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  • transect — technical ► VERB ▪ cut across or make a transverse section in. ► NOUN ▪ a straight line or narrow cross section along which observations or measurements are made. DERIVATIVES transection noun. ORIGIN from TRANS (Cf. ↑trans ) + Latin secare divide …   English terms dictionary

  • transect — [tran sekt′] vt. [< TRANS + L sectus, pp. of secare, to cut: see SAW1] to cut across or divide by cutting transection n …   English World dictionary

  • Transect — Urbanísticamente el transect es un sistema analítico que conceptúa el mutuo refuerzo los elementos a fin de crear una serie de hábitats naturales específicos con ajustes urbanos a la forma de vida. El transect integra la metodología ambiental… …   Wikipedia Español

  • transect — 1) to divide by cutting transversely 2) a sample area in a long continuous strip. See also strip transect and visual transect …   Dictionary of ichthyology

  • Transect — Un transect est une ligne virtuelle ou physique que l on met en place pour étudier un phénomène où l on comptera les occurrences. Cet échantillonnage (systématique ou aléatoire) peut donner lieu à l utilisation de quadrats. En forêt Le transect… …   Wikipédia en Français

  • transect — I. transitive verb Etymology: trans + intersect Date: 1634 to cut transversely • transection noun II. noun Date: 1905 a sample area (as of vegetation) usually in the form of a long continuous strip …   New Collegiate Dictionary

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  • transect — transection, n. /tran sekt /, v.t. to cut across; dissect transversely. [1625 35; TRAN(S) + L sectus, ptp. of secare to cut, sever (see SECTION)] * * * …   Universalium