DISTRIBUTION OF THE LICHEN CHONDROPSIS SEMIVIRIDIS IN RELATION TO ITS HEAT AND DROUGHT RESISTANCE

Abstract

SUMMARYThe distribution of Chondropsis semiviridis (FvM. ex Ny!.) Nyl. was mapped for Australia. Studies in gas exchange physiology demonstrated that length of drought is likely to limit distribution of the species. Similarly, it is shown that sensitivity to heat when wet is likely to prevent the species from establishing in arid areas with a summer rainfall seasons The surge of respiration upon wetting of lichen thalli noted by other workers was so short for C. semiviridis that it could not affect the limits of its distribution.

Austral lichenology: 1690–2008

“…Rod Rogers drew attention to lichens in biotic soil crusts in arid Australia (Rogers 1971(Rogers , 1972a(Rogers ,b, 1982b(Rogers , 2006Rogers & Lange 1971, typified James Stirton's Australian lichens (Rogers 1982a), and published on several lichen groups including Haematomma (Rogers 1982c(Rogers , 1985Rogers & Bartlett 1986;Rogers & Hafellner 1988), Pyxine (Rogers 1986a,b;see also Kalb 1994), Verrucaria (Rogers 1988), and Sagenidiopsis (Rogers & Hafellner 1987).…”

SEASONAL CHANGE IN THE PATTERN OF NET CO2 EXCHANGE IN UMBILICARIA LICHENS

“…They have argued that the lack of marked distinction among response curves means that the physiological response of the plant within its tolerance range plays a subordinate role to the response of the plant to stresses outside of the normal tolerance range. While there is no denying that factors related to the survival of the species within and outside of its tolerance limits must be examined together (Rogers, 1971), Kershaw (Kershaw, 1977;Kershaw and Smith, 1978) has failed in many recent studies to analyse his data except by visual inspection of the graphs despite his close involvement with Harris' modelling approach several years ago (Harris, 1972). The alternate approach involving the use of a model shows that while distinctions among response curves may seem small at first, they can make a significant impact on the carbon fixing potential of the plant in the field, even when the model used is a very simple one (Table 1).…”

Microbiotic soil crusts - a review of their roles in soil and ecological processes in the rangelands of Australia

“…The distribution of lichens is also strongly influenced by climatic patterns, particularly the amount and distribution of rainfall (Rogers 1971). In some areas where summer rains are not infrequent, the wet thalli of lichens may be damaged as a result of high temperatures.…”