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Background to study The purpose of the study is to obtain information concerning the autecology of Aconitum anglicum with particular regard to its ability to survive competition from Oenanthe crocata. The study is located in alder coppice, last cut in 1976. It has been observed that althouth Aconitum anglicum is prominent within the reserve in Spring, by mid-Summer it is far less conspicuous and the dominant plant of the herbaceous layer appears to be Oenanthe crocata. In grazed areas close to the Reserve far fewer individuals of either species are found, but the Aconitum anglicum is more common, although occurring mainly where grazing Table 1 Weather Records (Cardiff) Rain Total accumulative Hours sun t min max °C 1982 Jan 38.2 38.2 40.1 -8.9 11.3 Feb 42.2 80.4 50.1 -3.1 14.2 March 59.6 140.0 157.7 -1.2 15.2 April 23.2 163.2 202.0 -0.9 17.5 May 31.5 194.7 223.8 -0.6 24.7 June 82.3 277.0 200.9 6.7 26.7 1983 Jan 155.9 155.9 38.9 -1.6 12.5 Feb 24.0 179.9 94.8 -3.4 10.7 March 53.8 233.7 87.8 -1.4 11.9 April 107.5 341.2 179.8 -1.8 15.6 May 154.1 495.3 130.3 4.8 18.0 June 47.5 542.8 186.4 6.2 23.3 1984 Jan 147.6 147.6 66.7 -4.0 11.4 Feb 69.1 206.7 61.0 -2.2 10.4 March 27.9 234.6 93.6 -1.1 12.9 April 10.5 245.1 252.5 -3.1 21.4 May 62.2 307.3 205.1 0.5 20.2 June 35.7 343.0 276.8 6.6 26.3 Area occupied 21 April (% of Quadrat) Pure Mixed Regeneration Aconitum Oenanthe Aconitum Oenanthe Aconitum Oenanthe 1982 38 13 19 47 36 1 1983 39 10 20 43 36 2 1984 55 3 25 21 39 3 Maximum Heights (in cms) Pure Mixed Regeneration Aconitum Oenanthe Aconitum Oenanthe Aconitum Oenanthe Ac 1982 155 138 133 148 32 42 125 1983 137 105 136 190 58 83 130 1984 179 149 148 168 100 153 102 *Clump of Aconitum adjacent to Regeneration quadrat. is likely to be less severe such as close to tree trunk; in shrub thickets, and on river banks. Of course, this location pattern might possibly be due less to the effects of grazing than of trampling. It would be somewhat ironic, however, if it were found that in protecting the reserve plants from deleterious effects of animals, they succumbed to aggressive competition by other plant species whose numbers might have been checked by light grazing. The Aconitum anglicum appears to be restricted to low lying ground subject to'flooding, but occurs on both sandy and peaty soils within this area. The experiment At first, two permanent quadrats each lmxlm were established to compare the progress of two in season