Studies on the Critical Thermal Maxima of Salamanders

Abstract

agers, long ago? I hope this question may be disturbing. Our preoccupation with. nomenclature has been at the root, perhaps, of that old jibe which defines ecology as "the painful elaboration of the obvious." I shan't say the accusation is completely warranted, but I think that if it were completely unwarranted, we should resent it less.Another criticism is that we are too concerned with old patterns. Too concerned, according to Bates, with static notions of the climax, or, as Stone suggests, subservient to belief in mysterious processes which man had better not try to change.Here we seem to have a clash of viewpoints-always refreshing and likely to be profitable-for Lutz explicitly states that knowledge of the climax and natural succession are basic to sound forest management, Costello refers to the principle of ecological balance as fundamental in range management, and he and Rickie indicate that the first essential of range and wildlife management is maintenance of harmony between animal populations and their environment.Speaking for myself, I doubt whether too much emphasis has been placed on the concept of balance. The question has particular import at this time because of the development of growing interest by the public at large in relations between man and nature. The ordinary citizen is becoming increasingly aware that, far from being a negligible term in the natural equation, man is a very important term indeed. Whether he has the wisdom and virtue to maintain the equational balance, he certainly has the power to unbalance the equation catastrophically.To me, balance in an ecological system is something that can be demonstrated, and it is not static.It is a condition in which orderly, constructive change can take place, in contrast to the chaotic sequences which follow imbalance, such as the development of overpopulations of livestock and wildlife on the western range, with consequent destruction of the plant cover and accelerated erosion. This dynamic balance, with orderly change, in contrast to the chaotic situation induced by man, is described very well by the medical term "homeostasis."As for future needs, several speakers have emphasized the need for more detailed autecological knowledge. This kind of knowledge will come, and surely it is on its way if only because synecological studies have raised questions regarding the why of observed natural phenomena that can only be pursued by controlled experiments. But we need not think we can write synecology off as some kind of outworn scaffolding useful in the past, of little future interest. Probably the really comprehensive concepts about the interrelations of organisms and environment are still to be developed.We are a long way, for example, from understanding man's place in nature. We cannot understand it until we can appreciate more adequately what we mean by our present, admittedly crude concept of a balance of nature. As one phase of the problem, where does normal geologic erosion leave off and accelerated man-caused erosion begin? As we review th...

Role of Temperature and Water in the Ecology of Lungless Salamanders

“…This conclusion is consistent with the results of numerous other studies on salamanders (Zweifel 1957, Hutchison 1961, Brattstrom and Regal 1965, Sealander and West 1969 and frogs (Brattstrom and Lawrence 1962, Brattstrom 1968, Dunlap 1968, Mahoney and Hutchison 1969. This conclusion is consistent with the results of numerous other studies on salamanders (Zweifel 1957, Hutchison 1961, Brattstrom and Regal 1965, Sealander and West 1969 and frogs (Brattstrom and Lawrence 1962, Brattstrom 1968, Dunlap 1968, Mahoney and Hutchison 1969.…”

Ecological separation in a polymorphic terrestrial salamander

“…Our data corroborate previous studies illustrating that the colour morphs of P. cinereus differ in their response to climate in their seasonal activity patterns (Greer 1973; Lotter & Scott 1977; Moreno 1989; Gibbs & Karraker 2006). Salamanders have an ecological thermal range that influences their activity (Zweifel 1957) and they can regulate the temperature to which they are exposed by moving vertically within the soil horizon. Animals move deeper into the soil during the winter to stay warm and during the summer to stay cool (Vernberg 1953).…”

Thermal behaviour of crustaceans

“…The thermal tolerance of animals measured using a variety of methods was reviewed by Cossins & Bowler (1987) and Kivivuori & Lahdes (1996). The concepts of critical thermal maximum (CT max ) and critical thermal minimum (CT min ) introduced in studies of thermal tolerance of reptiles (Cowles & Bogert, 1944;Lowe & Vance, 1955 ;Zweifel, 1957;Hutchison, 1961) were subsequently applied to crustaceans by Kivivuori (1977Kivivuori ( , 1980 and Claussen (1980).…”