Welsh Journals

The growth in height of the tallest specimen of each species was recorded on a weekly basis. In addition to the heights of species within the permanent quadrats, the height of Aconitum anglicum in a clump adjacent to the Regeneration quadrat was also recorded. This was because this clump was almost certainly the origin of the Regeneration quadrat seedlings, and was precocious in its early growth compared with the clumps in the other quadrats. Notes on Results Coverage: It is apparent, from the Table, that the area occupied by the Aconitum has increased in all the quadrats during the period under study. Oenanthe has expanded in the Regeneration quadrat; elsewhere its area has decreased. Height: No clear overall trends can be detected in the case of height measurements in the quadrats over the study period. Nor is there any obvious link with weather phenomena. Conclusions Aconitum is expanding its cover in all the quadrats under investigation regardless of the relative heights of Aconitum anglicum and Oenanthe crocata. Oenanthe is only expanding in the Regeneration R. M. Baker, Department of Science, The Polytechnic of Wales, Pontypridd, Mid Glamorgan CF37 1DL Nestboxes in forest plantations in Mid Wales R. Bamford The large scale introduction of nestboxes can be expensive in both time and money; consequently few schemes are in operation outside a number of nature reserves in Wales. However, within the extensive recently established forests, there is scope for more nestbox studies and experimentation The present study has been continuing since 1979 when songbirds were censused at two sites using the standard Common Bird Census (CBC) procedure. During the following winter, tit type boxes were erected at both sites at a density of c25/hectare (Table 1). Songbird populations were assessed over Quadrat where the Aconitum is young and therefore not fully developed. It seems reasonable to suppose that Aconitum's success is at least partly due to its phenology. As shown in the Growth Graph, Aconitum main period of growth begins six weeks before that of Oenanthe, and even where Oenanthe eventually outgrows Aconitum, it is Aconitum which shades Oenanthe for the major part of the growing season. Thus Oenanthe appears to present no threat to the continued survival of Aconitum. The Future It would be useful to continue these readings to determine: (a) the longevity of the clumps, (b) whether Aconitum would continue to expand at the expense of Oenanthe as the overhead canopy is closing. This should be recorded, possibly by fish-eye lens photographs taken from the quadrat and facing vertically upwards. The occurrence and progress of Aconitum seedlings development should be recorded on a regular basis. There is scope here for experimental work to determine precisely the conditions necessary for the germination and successful development of Aconitum. subsequent seasons using CBC results together with information from nestbox usage. Previous work in upland thicket Spruce (Picea sp.) indicates a poor uptake of nestboxes by Coal tits (Parus ater). Greater success can be assured at lower levels and in more suitable crop types. Over 10 pairs/ha, Pied Flycatchers, have been attracted to plantation Oak (Quercus spp.). After four years of nestbox availability in Larch a density of 4.5 pairs/ha (Pied Flycatcher) has been reached (Table 2).