INVERTEBRATES 1. Introduction This Appendix Reports
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RAYMOND BROWN EXTENSION TO BRICKWORTH QUARRY MINERALS AND RECYCLING LTD ECOLOGICAL ASSESSMENT _______________________________________________________________________________________________________________ APPENDIX 4: INVERTEBRATES 1. Introduction 1.1.1 This appendix reports the findings of an invertebrate survey carried out on the proposed extension areas to Brickworth Quarry. Survey was undertaken in 2015 by Dr Peter Kirby and Christopher Kirby Lambert MBiol. Both are experienced invertebrate surveyors. 1.1.2 The proposed extension includes two separate areas immediately adjacent to, and separated by, the active workings. These areas are Church and Lowdens Copse (Area A) to the east of the quarry area and Gooseye and Sandland Copse (Area B) to the west. Both areas consist of a complex of habitats including remnants of ancient woodland, rides and tracks, damp areas, conifer plantation, grass fields and other relatively open habitat. Whilst relatively diverse, all of the habitats present are greatly compromised by modification. The majority of the survey area consists of conifer plantation on land previously occupied by ancient woodland. The plantation areas have been variously managed and in places there are remnants of ancient broadleaved woodland, a habitat that would once have been predominant on the site. In addition to the more extensive areas of broadleaved remnant there are scattered broadleaved trees throughout the site as well as large hazel dominated hedgerows marking boundaries. As would be expected from a site dominated by conifer plantations most of the site was under closed canopy woodland or otherwise heavily shaded. 1.1.3 A system of rides and tracks criss-cross the site and provide somewhat more open habitats but these are generally still narrow, shaded and support species poor vegetation. The tracks exhibit a varying degree of wear, some being well vegetated and appearing barely used whilst others were heavily worn with areas of bare ground which in some cases was well compacted. 1.1.4 There were several areas within the site boundary that had been cleared of conifers which have created large, sunny, and relatively sheltered glades. Generally these seem to be subject to significant bracken and scrub invasion meaning any floral interest and diversity in the ground and herb layer is easily lost. The best areas within the glades are, despite being localised, of considerable potential when viewed simply in terms of habitat character and structure, with areas of bare, sometimes compacted, ground along and beside tracks, low open-structured grassy _______________________________________________________________________________________________________________ - 4.1 - WARD ASSOCIATES RAYMOND BROWN EXTENSION TO BRICKWORTH QUARRY MINERALS AND RECYCLING LTD ECOLOGICAL ASSESSMENT _______________________________________________________________________________________________________________ vegetation, varying degrees of scrub invasion providing a complex mosaic of structure, sheltered sunny conditions, a moderate amount of standing and fallen dead wood in varying degrees of sun-exposure and shade, and well-structured transitions to woodland. The quality of the invertebrate fauna on the site is a matter of how well any pre-existing fauna has survived, how many species have colonised newly available habitat, how much has been able to survive the rather dynamic conditions over recent decades, and how many species can survive in the sometimes small pockets of high-quality habitat suitable for specialist species. 2. Methodology 2.1.1 Terrestrial invertebrates were sampled using a small range of active methods, sweep-netting, beating, active search of key features of value for invertebrates as well as direct observation. Full details are given in Appendix 4.1. 2.12 The survey was taxonomically wide-ranging, but concentrated on those groups considered most likely to be informative as to conservation interest and habitat requirements. Since the survey was approached in as open-minded a way as possible, the default position was to identify any group which it was thought might hold interest. However, the selection of groups, and the relative extent of identification of the various groups, has been limited by expertise. The groups are identified in Appendix 4A 2.1.3 Names used predominantly follow readily available checklists, revisions, synopses and atlases (see Appendix 4A) 2.1.4 Each species mentioned in this report is assigned a status. For rarer species, these are the most recent published formal status, assigned by the Joint Nature Conservation Committee or their predecessor, the Nature Conservancy Council. Full details are given in Appendix 4B 3. Recording areas 3.1.1 The two extension areas were surveyed. They are separated by the existing quarry. These are shown on Figure 4.1and are identified as Area A, to the east and Area B to the west incorporating an old track, known as Sandland Drove, running close to the edge of the existing quarry workings. Records have been separately made and retained for these two major areas. In practice, though, as they are linked beyond the survey area boundary by further woodland, and for purposes of general assessment and analysis the survey area is regarded as a single unit. _______________________________________________________________________________________________________________ - 4.2 - WARD ASSOCIATES RAYMOND BROWN EXTENSION TO BRICKWORTH QUARRY MINERALS AND RECYCLING LTD ECOLOGICAL ASSESSMENT _______________________________________________________________________________________________________________ Within each large recording area, recording has been sub-divided largely according to the character of the recorded habitat rather than to map- defined areas, though the two to some extent coincide. 3.1.2 A grass field projecting to the north-east of Area A was also treated as a separate unit, but records from here are few: habitat character suggested very limited potential in the improved grassland, and this was borne out by initial sampling; boundary trees and hedges were not sampled; records from this field are mostly from the transitional fringe of herbaceous vegetation and low scrub around the grassland edges. Records from the remainder of Area A have been separated according to the level of tree cover. The most open-structured area, between the westernmost track and the woodland edge, together with the relatively unshaded path which adjoins it, was separately recorded; all the remainder, in which both woodland and enclosed tracks are under a closed canopy or at least heavily shaded for much of the day, are recorded as a single unit. Variation in character within this wood invites sub- division, but in practice the amount of variation in the recorded fauna, or at least in the level of interest of the recorded fauna, was not great enough to justify sub-division, the main effect of which would have been to squander field survey time in the repeated recording of common species. From a recording point of view, the most significant features within this woodland were trackside log piles, which formed a valuable focus for the recording of saproxylic species. The location of these piles is, however, entirely fortuitous. Note has been made in the detailed records of species recorded specifically from these piles, but they have not been treated as a separate recording unit for purposes of assessment and analysis. 3.1.3 The most clearly demarcated area in Area B is Sandland Drove. In the north of its length it is a shaded sunken track beneath the shade of hazels with substantial amounts of dead wood; to the south, the track is more open and sunny with abundant nectar flowers and is margined on the quarry side by what is effectively a mixed broadleaved hedge with trees, variably spreading into the grassy vegetation along the lane. This lane, with its remnant broadleaves, was recorded as a single unit. Elsewhere, as in Area A, the separation in records has been according to tree cover. There is a large area of relatively open habitat here, with scattered trees, significant scrub, and extensive bracken-domination, but also with very open areas and bare ground. Recording in the open habitat was concentrated along the tracks and the most open vegetation immediately bordering them, penetrating into denser areas to an extent sufficient to reach all scrub and tree species, standing dead wood, and the full range of _______________________________________________________________________________________________________________ - 4.3 - WARD ASSOCIATES RAYMOND BROWN EXTENSION TO BRICKWORTH QUARRY MINERALS AND RECYCLING LTD ECOLOGICAL ASSESSMENT _______________________________________________________________________________________________________________ habitat variation present. Little recording time was devoted to dense bracken. The remainder of the area, under closed or canopy cover or heavily shaded, was again treated as a single unit, though once again the variety of character would have enabled sub-division. In practice, recording effort was especially concentrated in the north-east. Habitat character here was most suggestive of the likelihood of invertebrate interest, since the woodland was relatively open-structured and contained substantial amounts of dead wood, some of significant size, and the area is contiguous with the old hazels of Sandland Drove, making it arguably the most likely area to have retained, or been colonised by, remnant ancient woodland fauna. Sampling was extended