Isolation Transect 



An Exclosure (q. v.) which is divided into plots, one of 

 which is opened to grazing each year, and another plot which 

 has been grazed is added. 



Isonome 



A line drawn on a chart connecting areas of a community 

 that show equal Frequency indices of a species. 



Isophene 



A line drawn on a chart connecting areas where events 

 in the life history (e.g., egg-laying, flowering) of an organism 

 occur at the same time. cf. Aspection. 



Isopleth 



A line drawn on a map or chart connecting places having 

 the same value of a certain factor, cf. Isohyet, Isotherm. 



Isopod 



An animal in the order Isopoda, class Crustacea, e.g., 

 woodlice, pillbug. 



Isostasy 



The state of general equilibrium between the upland 

 and lowland areas of the earth, with indications that the 

 rock materials under the oceans are heavier than those under 

 continental protuberances, cf. Tectonic. 



Isotherm 



A line drawn on a map or chart connecting places with 

 the same temperature at a particular time or for a certain 

 period. 



Isotopes 



Forms or atoms of the same element that differ in atomic 

 weight and in the constitution of the atomic nucleus. Some 

 elements in nature such as radium and uranium have Radio 

 isotopes (q. v.). 



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