Conclusions (3) based on 6 years of experimental management and surveys, 1996

Conclusions (3) 1996 - 2001
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15.

Violets (Viola riviniana) were one of the most dominant species across the whole project site.

Violets (left) have consistently been the fifth most dominant species on the project site since 1999. They are most abundant in the annually cut sections.

They were less common in the more heath-like sections in the northern-most part of the project site and had been more or less eliminated from the control section by 2001.

Small Pearl-bordered Fritillary on gorse.

The Small Pearl-bordered Fritillary (left), a species which is of conservation concern, was recorded on the project site for the first time in 2001.

This was no accident as the caterpillars of this species feed on violets, including the Common Dog-violet (Viola riviniana), so abundant on the project site.

The female butterflies lay their eggs on or near the violets.

16.

Mosses have been a very significant component of the vegetation regenerating on the project site.

	The most common moss on the project site was Eurhynchium praelongum. This began to establish in 1997 and by 2001 was the third most dominant species on the project site. (Click on the image shown on the left to see the full size distribution chart for 2001.) This species is normally abundant in woods and hedgerows, but occurs across a wide range of habitats, including fields and marshes. It is a particularly shade tolerant species. This is an important feature which has allowed this moss to become dominant in the ground layer of the project site, despite being shaded by much taller vegetation for much of the year.
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	Other common mosses included Thuidium tamarascinum and Polytrichum formosum (left). Thuidium tamarascinum is more often found in woods and on hedgebanks, but it will also grow with other mosses amongst grass in open situations, as on the Heathland Restoration Project site. This moss and Eurhynchium praelongum, were the commonest moss species in section 5, the control strip. These two shade tolerant moss species thrived on the trunks and bases of the tall gorse bushes and young saplings in this section.
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	Polytrichum formosum (left) is primarily a woodland moss, although it also occurs on well drained heaths. On the Heathland Restoration Project site, this moss usually grows as thick carpets, often up to 10cm in height, in the more open areas. It is much less likely than the other mosses to be found intertwining among the grasses.
Other Polytrichum species such as P. piliferum and P. juniperum are more characteristic of heaths, being especially common as colonists on newly burnt sites. Distinguishing between individual species of Polytrichum in the field can often be difficult. Individual plants of the same species can vary widely in appearance and size depending on environmental conditions. Separating the species often requires microscopic examination and slide preparations to make certain of identification. Polytrichum piliferum and P. juniperum have not been recorded in the survey quadrats, but it is entirely possible that species of Polytrichum other than P.formosum are present on the project site. Time has simply not been available to individually examine every clump and stand of this widespread moss on the project site.
	Hypnum jutlandicum (left plus Polytrichum and Thuidium tamarascinum) is a very characteristic heathland moss. It was formerly classified as a variety of Hypnum cupressiforme (H.cupressiforme var.ericetorum) but is now considered sufficiently different to warrant specific status in its own right. It occurs on acid soils, especially on heaths and among Heather (Calluna). This moss has consistently increased across the site, most especially in the northern-most sections.

17.

Rhododendron ponticum is regenerating across the project site.

Rhododendron ponticum (left) has been recorded on the project site since 1997.

This highly invasive, non-native species formed the understorey in the original woodland covering the project site prior to clearance.

It is toxic to our native invertebrates, leading to the collapse of food chains in areas dominated by this species.

By 2001, it had re-appeared in 5 of the 9 sections.

In Britain, the normal climax stage of natural succession from heathland is woodland.

This natural succession can clearly be seen taking place in section 5, the control section which has had no management at all.

In this section, the tall gorse currently dominating, will eventually be shaded out by the developing trees. In time, the strip will become a miniature woodland. However, without intervention, this will not be the climax stage in the succession.

In the absence of any management or control, the re-invading rhododendron would form an understorey under the mature trees. Its extreme shading effect would prevent anything from growing underneath. When the mature trees eventually died, there would be no tree seedlings or pioneer species able to replace them and the rhododendron would take over completely.