Management – the original ideas

This preliminary set of ideas was put forward in early summer 2010, and will in due course be replaced by a more formal management plan

Suggestions for the management of Aston’s Eyot for peaceful recreation
and as a local nature reserve

by
Dr Anthony Cheke, former professional ecologist anthony.cheke@virginmedia.com
Author of Lost Land of the Dodo. An ecological history of Mauritius, Réunion & Rodrigues.
&
Dr Ruth Ashcroft, former professional ecologist ruth-ashcroft@ntlworld.com
Co-manager, SS Mary & John Churchyard Project

Preamble
Aston’s Eyot (henceforth ‘AE’) is currently a mosaic of habitats; some is woodland (both plantation & spontaneous) but the rest is open or scrub, both of which will gradually develop into woodland if not managed. On the assumption that maintaining the current diversity is preferred, and that the ideal is both nature conservation and quiet recreation, we offer some ideas on management. This note deliberately does not consider permission or funding issues, as these follow after an organisation is set up with vision for the area and a proposed management plan.

NB North is to the left of this map

AE-habitat-and-species-map

A: practical management

  1. Paths:The wide cinder path needs to be maintained, and other paths should be mown 6-8′ wide to keep them open when nettles and brambles take over in the summer. However we think it is open to debate whether any of the smaller paths should be surfaced in some way – our feeling is not to do that, thus keeping it more ‘natural’. The current network is probably about right, as one wants to leave fairly extensive blocks relatively undisturbed.
  2. The ‘orchard’:The area of self-sown apples near the bridge to the Kidneys is a most unusual feature, and also is a free fruit resource for local people in the autumn. Many of these seed-grown apples are fairly unpalatable raw, but a few have good flavour, and it would be interesting to get them identified and perhaps propagated. A new factor in 2010 has been apparently commercial collection of these apples by teams of people, for an unknown purpose – thus depriving locals of the resource. Elderly apple trees will, in due course, make excellent woodpecker nesting sites, and they attract lots of insects.
  3. The plantation:This is largely of ash, and is very dense and needs thinning and diversifying if it is to develop into good wildlife habitat. There is a significant amount of cherry and poplar in the mix, and occasional oaks. Birch and oak have high wildlife value, as does willow, though there is plenty of that elsewhere (see below). Some understorey of a shade-tolerant evergreen such as holly would help nesting birds. Some trees (notably cherries) are enshrouded in ivy – this provides excellent shelter and habitat, and should be left; in such dense woodland it is not a problem if some trees die, and in any case the cherries are already failing to compete against the faster-growing ash and poplars.
  4. The willow groves along the Cherwell & ditch north of the entrance gate:Crack willows look messy because they break and fall over, but this provides lots of interesting habitat for microfauna and the birds etc. that feed on them, so this ‘untidy’ area should be kept largely as it is, except that the trees along the Cherwell itself should be pollarded (as they once were) to stop them falling over and blocking the river, though perhaps leaving a longer trunk below the pollard than is usual would help woodpeckers etc. Some tidying up is needed along the ditch and to keep the path that goes along the ditch and the Cherwell open (though ducking under arches of branches adds interest, especially for children). Alders should be encouraged as they provide ample seed for resident and wintering finches (goldfinch, siskin, redpoll) and a good insect fauna.
  5. The Thames bank:the area between the cinder track and the river is scrub with open patches leading to the bank, which itself is lined with pollarded willows (clearly maintained as such) and alders. This seems to be a good mix, though some open areas could perhaps be included in the path mowing regime to promote grass rather than nettles.
  6. Open areas and scrub:One would normally expect open areas, especially if occasionally mown as they have been in recent years, to be kept open by rabbits, but there are rather few of them, probably because of large numbers of dogs being exercised and the high density of urban foxes. There are deer (muntjac, roe), but not enough to keep the weeds down. Increasing the width of the mowing along paths would perhaps be the simplest way to increase grassy areas, with perhaps some flailing of nettles in patches (but not wholesale). In SS Mary & John churchyard pulling nettles has proved useful in giving other species present a head-start, but can only be done over smallish areas. Artificial sowing of grassland flowers to restore patches of herb-rich grassland for butterflies etc. could be considered (see below under knotweed). The nettles and brambles provide cover for many animals in summer. Some birds (various warblers & finches especially) are very partial to scrub with open areas, and the grassy areas will support mice and voles which in turn will keep kestrels, stoats and weasels happy. So to maintain diversity it would be good to keep much of this in the successional stage of scrub, though allowing the occasional isolated tree (such as the young oak already present) would benefit birds of prey that like vantage points. Blackthorn is a favourite of various butterfly caterpillars – there is one very dense clump, and scattered bushes elsewhere. Another function of nettles and brambles is to protect fallen dead wood, excellent invertebrate habitat, from being carried off and burnt by rough sleepers.
  7. Knotweed:The invasion by Japanese Knotweed is most unfortunate, and controlling it mechanically as has been the recent policy is labour intensive and not fully effective. The announcement in early 2010 that a parasitic insect (a sap-sucking psyllid) has been cleared through careful research to be a safe method of biological control is much to be welcomed, and perhaps AE could be put forward as a volunteer site for early introduction of this insect. This is unlikely to be in the immediate future, so at present ‘old’ methods still apply. Although dug over by the council, the knotweed will re-sprout, and in any case there are large plants left under bushes etc. It may be worth considering treating the affected areas with glyphosate (‘Roundup’) as it sprouts. This would of course kill any surviving other plant species, but would give an opportunity to start from scratch seeding & spot-planting with a herb-rich grassland mix to create insect and butterfly-friendly habitat.
  8. The ditches:The ditch that runs from the Cherwell to the Thames via the Kidneys bridge is rather stagnant though there has been recent dredging work. We noticed water flowing inwards at the Thames exit in late March 2010, presumably due to levels in the river rising after rain. It probably should normally flow from the Cherwell towards the Thames, and if there was some gentle through-flow it would improve it as habitat for frogs and toads. In some years there have been huge numbers of amphibians there, but frogs have declined a lot and toads seem unpredictable – lots some years, few the next. There is likely to be contamination from the scrapyard, and it seems important to find out to what extent oil spillage etc is contained on that site and measures taken (if not in force) to contain pollution.
  9. The triangle south of the cinder track by the Kidneys bridge, bounded by the ditch down to the Thames and the river itself.There used to be a path that followed the ditch and river back round to the cinder track, but has become very overgrown. It might be a good place to have an undisturbed nature area, and keep it largely path-free – much of it is visible from the Kidneys so it could be watched from there without having to go in. Some management, preferably in winter, would be need to prevent it becoming purely woodland. It is the only part of the area with birch trees.
  10. Dead trees:There is a tall stump in the open area, and a tall dying tree nearby, both with woodpecker holes, loose bark and other good wildlife refuges. Such features are very important for diversity, but it might be wise to ‘ring-fence’ them with brambles to keep people at a distance and so reduce the risk of danger if they fell. The City Council have been very paranoid about dead or sick trees ever since one fell and killed someone in Gloucester Green a few years ago.
  11. General:In order to maintain diversity, different cutting/mowing regimes will be needed: regular/frequent mowing of paths, annual cuts to keep bramble reasonable and prevent scrub/tree growth in designated areas, occasional pruning of scrub to stop it becoming forest, and some areas left entirely alone as natural woodland.
  12. A comment on adjacent areas:

The Kidneys: This area belongs to and is managed by the City Council. It has large areas of mown rough grass so there is no need to attempt to duplicate that habitat in adjacent Aston’s Eyot. There is a ditch leading out of the Thames by the houseboats which has sometimes held large numbers or frogs and toads in spring.

The copse behind the boathouses: This is willow with alder & ash much like the patch in Aston’s Eyot just opposite it across the Cherwell, but wetter as it is at original floodplain level (not dumped on). A useful complementary plot which one hopes will remain undisturbed – it is not accessible to the public.

Long Meadow – the field between Aston’s & the University sports ground: This was likewise not dumped on, so is a residual bit of genuine floodplain pasture, which is sometimes grazed by cattle. There is winter pond there which dries up in summer. Access is restricted, but it would be interesting to re-survey it botanically.

B: Mapping, community involvement & wildlife recording

  1. A necessary starting point for a management plan is an accurate map; the aerial photo view on Google maps (and other similar websites), taken in summer, is so detailed that individual flowering elder bushes can be plotted, and several different tree species distinguished by subtle shades of canopy colour. The areas invaded by knotweed are also very clear. It would be easy to create an excellent working map from this source.
  2. Many locals people regularly note birds, bees, butterflies, plants etc seen – it would be good to have an online record and mechanism for pooling these observations and informing people of sightings of special interest.
  3. Elements of any management plan will involve work done by volunteers – i.e. all of us interested in the area. Work parties will have to be convened, but in addition if there was an agreed plan we could individually feel more confident doing small amount regularly, asuch as litter-picking & weeding. It would seem a less daunting task if each person knew that lots of other were also doing bits when time allowed.

snowy boathouse