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Climatic variability and hemispheric differences in insect cold tolerance: support from southern Africa
Author(s) -
SINCLAIR B. J.,
CHOWN S. L.
Publication year - 2005
Publication title -
functional ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.272
H-Index - 154
eISSN - 1365-2435
pISSN - 0269-8463
DOI - 10.1111/j.1365-2435.2005.00962.x
Subject(s) - southern hemisphere , biology , temperate climate , ecology , habitat , latitude , cockroach , cold tolerance , botany , geography , geodesy
Summary1 Insects generally survive subzero temperatures by utilizing either freeze tolerance or freeze avoidance. Comparative analyses from a limited data set have indicated that freeze tolerance may be predominant among species at temperate latitudes in the southern hemisphere, while freeze avoidance dominates in the north. 2 We investigated the cold tolerance strategies of cockroaches and beetles from cold regions in southern Africa, including the Cederberg mountains, the Karoo desert and the Drakensberg mountains. 3 We found that 8 of 11 species are freeze tolerant. 4 Overall, 77% of species investigated in the southern hemisphere ( n = 27) were freeze tolerant, which is significantly different from the 29% ( n = 258) in the north ( P < 0·001). 5 There are regular, unpredictable subzero temperature events in the southern African habitats; such variability appears to be a general feature of many cold habitats in the southern hemisphere, which may lead to the observed interhemispheric discrepancies in cold‐tolerance strategies.