ISSN:
1432-1254
Source:
Springer Online Journal Archives 1860-2000
Topics:
Geography
,
Physics
Notes:
Abstract The dune wintergreen (Pyrola rotundifolia ssp.maritima) is an evergreen perennial herb which has spread extensively in recent decades to, and on, various British dune systems including Braunton Burrows, N. Devon. Its multiplication is partly vegetative, by rhizomes bearing leaf rosettes. This study primarily concerns the relation between: (i) the growth of one particular invasive colony on Braunton Burrows, as shown by the numbers of living rosettes counted at midsummer from 1964–74 inclusive; and (ii) concurrent meteorological records made nearby. Monthly weather means were calculated on various quarterly bases. After de-trending thePyrola data statistically, correlations were sought between the growth in numbers achieved in each year and the local air temperature (three bases), rainfall and duration of bright sunshine. While the annual increase in net numbers appears to have been unaffected by sunshine hours, this increase does seem to have been much diminished by cold nights, particularly in early spring and, though less strongly so, by low rainfall in the latter part of the preceding summer. Taking account of the performance ofPyrola in other habitats on the Burrows, it is suggested that the rainfall correlation may reflect the influence of atmospheric humidity rather than water supply to the roots. Local meteorological records over a 51-year period show combined temperature and rainfall conditions consistently favourable toPyrola growth throughout a 5-year run to a degree which might be expected to occur in only three such runs out of every hundred. The favourable period (1957–61) occurred between the inferred first occurrence ofPyrola on the Burrows and its observed rapid spread.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02189207
