DIFFERENTIAL RESPONSE TO CALCIUM WITHIN THE SPECIES FESTUCA OVINA L.

Abstract

With Plate 2 and 4 figures in the text) SUMMARY An investigation of population differentiation within the species Fcstuca ovina in relation to soil factors has shown that populations within this species differ greatly in their response to calcium in culture solution. Populations from acid, low calcium soils showed a weak response to calcium, whilst those from calcareous soils showed a strong response. All populations responded linearly to the logarithm of the calcium concentration at the low levels, but there was a decrease in yield of the acidic populations at higher calcium levels. The difference in response to calcium between the acidic and calcareous types of populations was as great as that previously shown to exist between extreme calcicole and calcifuge species. Such differences were found even between populations taken from areas only about i mile apart.Smaller scale variation was also shown to exist between individuals within single populations.Chemical analysis of the plants indicated that the differences in response between populations were due to differences in ability to absorb calcium from low solution concentrations, rather than to differences in ability to metabolize at low internal concentrations of calcium. The populations were also found to differ in ability to absorb other cations and in ability to root at low levels of calcium.The evolutionary significance of the results is discussed, and the importance of recognizing such variability, within apparently homogeneous species, in ecological and physiological studies is stressed.

Macro-element composition of tall-tussocks (Chionochloa) in the South Island, New Zealand, and their relationship with soil chemical properties

“…With widely dispersed populations, as in this study, there will certainly be much ecotypic variation within single species, similar to that described by Turesson (1922) and many later workers (Bradshaw et al 1958(Bradshaw et al , 1964Snaydon & Bradshaw 1961, 1962Clarkson 1966). Ecotypic variation may also develop over quite short distances, e.g., Anthoxanthum odoratum L. has evolved distinct races over 30 m in response to soil P status (Davies & Snaydon 1974).…”

POPULATION STUDIES ON LEAD-TOLERANT AGROSTIS TENUIS

“…A more likely reason for the comparative rarity of observations of edaphic ecotypes in the literature is the fact that special techniques of the kind described in this paper are required to detect and describe them. This is borne out by studies on Festuca ovina (Snaydon and Bradshaw, 1961) .…”

Plant growth and reproduction on a toxic alpine ultramafic soil: adaptation to nutrient limitation

“…It is true that tissue P concentrations doubled in tbe -I-NPK and -l-NPKCa treatments in this study; however this occurred with a large increase in growth and the disappearance of deficiency symptoms. In earlier studies such as those by Snaydon & Bradshaw (1961, 1969 and Crossley & Bradshaw (1968) it was suggested that the growth response differences to substrates with different nutrient availability had a genetic basis. Tbe Meikle Kilrannoch site has bad open vegetation for at least 200 yr (judging from early records of the open-habitat Lychnis alpina L. Smith, 1811), and probably much longer, and it is surprising that Cochlearia shows no evidence of adaptation to low nutrients of the sort found by the above authors.…”