Horseshoe pond

There's a pond in there somewhere.  Like many of our farmland ponds, Horseshoe pond was very overgrown, and in need of some TLC.  The only problem was where to begin!
September 2013 – There’s a pond in there somewhere. Like many of our farmland ponds, Horseshoe pond was very overgrown, and in need of some TLC. The only problem was where to begin!
Getting stuck in.  Once we started removing some of the willow, the sad remains of Horseshoe pond became visible.  With no light able to break through the trees, there were no water plants left, and very little water either.  The pond was choked with decaying leaves, making what remained of the water very low in oxygen.
September 2013 –  Getting stuck in. Once we started removing some of the willow, the sad remains of Horseshoe pond became visible. With no light able to break through the trees, there were no water plants left, and very little water either. The pond was choked with decaying leaves, making what remained of the water very low in oxygen.
A core was taken from what remained of the pond - this gives us a section through time, with deeper sections of the core coming from further back in the pond's history.  The preserved seeds and  plant & animal remains can then be taken from different depths in the core, and tell us what used to live in Horseshoe pond.
September 2013 –  A core was taken from what remained of Horseshoe pond – this gives us a section through time, with deeper sections of the core coming from further back in the pond’s history.  Preserved seeds, and plant & animal remains, can then be taken from different depths in the core, giving us information on what used to live in the pond.
Once most of the trees have been removed, Dom begins the task of removing decades worth of anoxic sludge.  This has built up over the years as the pond has terrestrialised, and is inhospitable to plants - not only is it anoxic, but it is very fluid, and plants cannot root in it.
September 2013 –  Once most of the trees have been removed, Dom begins the task of removing decades worth of anoxic sludge. This has built up over the years as the pond has terrestrialised, and is inhospitable to plants – not only is it anoxic, but it is very fluid, and plants cannot root in it.
Once the sludge has been removed, Dom sculpts the pond to create gently sloping sides, good for plants to root in.  Here you can see the white marl (clay) layer which provides a watertight lining to the pond.
September 2013 –  Once the sludge has been removed, Dom sculpts the pond to create gently sloping sides, good for plants to root in. Here you can see the white marl (clay) layer which provides a watertight lining to the pond.
Five weeks on - the water level is rising, although not as quickly as in Original pond on the other side of the field.  The slight green tinge to the water is due to algae, and also the return of some aquatic plants, which were not found before the restoration began.  So far these include two species of water crowfoot (Ranunculus).
October 2013 (five weeks on) – the water level is rising, although not as quickly as in Original pond on the other side of the field. The slight green tinge to the water is due to algae, and also the return of some aquatic plants, which were not found before the restoration began. So far these include two species of water crowfoot (Ranunculus).  At the moment, Horseshoe pond is in fact two small pools, which should flood together to form one large pond after more rainfall.
Seven weeks in - now the water in Horseshoe pond is crystal clear, and aquatic plants are growing well (considering it is November). Water level is rising slowly compared to Original pond, which is ow deeper but not as clear.
November 2013 (seven weeks in) – now the water in Horseshoe pond is crystal clear, and aquatic plants are growing well (considering it is November). Water level is rising slowly compared to Original pond, which is now deeper but not as clear.  The two small pools are getting closer to forming one pond, but at the moment I am monitoring each separately.  Both pools are teeming with invertebrate life; zooplankton, mayfly nymphs, water beetle larvae and water beetles are all abundant.
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January 2014 (week 18, 4 and a half months in) – Horseshoe pond has filled well after the heavy rain and storms, and is no longer two separate pools.  Water crowfoot (Ranunculus aquatilis) and celery-leaved buttercup (Ranunculus sceleratus) are developing extensive beds across the pond, while common water-plantain (Alisma plantago-aquatica) is also beginning to appear.
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January 2014 – extensive beds of bright green celery-leaved buttercup (Ranunculus sceleratus), are beginning to establish in Horseshoe pond. There is also good growth of water crowfoot (Ranunculus aquatilis), although this is not visible in this photo.
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February 2014 (5 months in)  – the continued heavy rain has led to Horseshoe pond becoming less of a horseshoe-shape, and more of a ring doughnut.  The beds of aquatic plants seem to be developing well, although gale-force winds and heavy rain during this visit made it difficult to see much!  There is still little in the way of marginal or emergent plants, but we expect this will begin to change come the Spring.
Jensen underwater copy
March 2014 (6 months in) – Above the surface, Horseshoe ponds is looking much the same as it did back in February.  However, spring is finally arriving, and aquatic plant growth has accelerated in all six ponds.  Marginal and emergent plants are still lagging behind.  Here the edge of a bed of celery-leaved buttercup (Ranunculus sceleratus), with plenty of filamentous green algae inter-dispersed, is visible in Horseshoe pond.  This species has established particularly well in this pond, growing right through from the margins to the deepest point.
Jensen frogspawn copy
March 2014 – and with the arrival of spring comes the arrival of the amphibians.  At the time of the last visit, frogs had been most active in spawning, with large masses of frogspawn in Horseshoe pond.  Several toads and smooth newts were also seen in and around the pond, but there was little amphibian activity in the near-by Original ghost.
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May 2014 – Horseshoe pond is beginning to look quite different.  The ‘island’ can still be seen poking out above the water (to prove it is the same pond!), but now aquatic plants are beginning to really become established.  Beds of Ranunculus aquatilis (water crowfoot) are beginning to cover the shallower areas of the pond, while under the surface Chara sp. is spreading across the sediment.
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May 2014 –  Although aquatic plant cover is starting to take off, there are still large bare areas of the pond where little but filamentous algae can be seen.  Hopefully  the aquatic plants will continue to spread, filling in these currently bare patches.
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June 2014 (9 months in) – Horseshoe pond is pretty much unrecognisable from its overgrown beginnings! There are now 11 aquatic / water-associated plant species, up from the 1 recorded before restoration.  Like Original ghost, Horseshoe pond is a hot-spot for dragonfly activity, while it’s faster development of aquatic vegetation, and location closer to a hedge, has attracted a range of amphibians.
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June 2014 – At the surface, Ranunculus aquatilis (water crowfoot) dominates, its white flowers covering the pond.  Underwater thick beds of Chara sp. have developed, visible through the clear water in the bottom left of the photo.  Other species, including Potamogeton crispus (curly-leaf pondweed), are starting to push up through the Chara, filling in the deeper water. NOTE: this picture was taken from the same spot as the one two above (May 2014) – you can see that the bare ground has indeed filled in well, mainly with Chara sp.
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June 2014 – Potamogeton crispus, pictured here growing in one of the covered microcosms, has also appeared in the main pond.  The germinations in the microcosm appeared a few weeks before the plant was first recorded in the pond, leading us to hope that a similar effect will occur in Original ghost.

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July 2014 – After a long dry period, the water level in Horseshoe pond has fallen, exposing ‘the island’ and stranding some of the fully aquatic species which were growing here.  Fortunately there are still plenty of deep water areas, where aquatic vegetation is thriving.  Much of the floating leaved vegetation (mainly Ranunculus), has now died-back, leaving Horseshoe pond looking a bit bare from a distance.

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July 2014 – Under the water’s surface, aquatic plants in Horseshoe pond are thriving.  Ranunculus aquatilis and Chara still dominate, but now the odd patch of Sparganium erectum is pushing its way to the surface.  There are still only two species of pondweed (P.crispus and P. natans).

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August 2014 – The water level in Horseshoe pond has remained fairly low, and is still a dark peaty colour.  Surface / floating leaved vegetation is fairly scarce, with most aquatic growth going on under the surface of the water.

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August 2014 –  Underwater, thick stands of Chara still dominate much of the pond, while Sparganium is becoming increasingly frequent.  The patches of P. crispus are spreading, and this species is now occurring right across the pond, as well as in three of the covered microcosms around the pond.

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September 2014 –  Horseshoe pond now supports 20 water-associated plant species, including 10 true-aquatics.  The water has remained a peaty-brown colour, unlike the crystal-clear Original ghost – presumably during restoration we did not remove as much organic sediment as in the other restored sites, leading to higher humic acid content.

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September 2014 –  Branched bur-reed (Sparganium erectum) continues to do well in Horseshoe pond, emerging through the dominant beds of chara.

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September 2014 –  A new species of aquatic plant appeared this month in Horseshoe pond – water dropwort (Oenanthe aquatica).  It was interesting to find four plants in the same area, which were definitely not present in August.

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November 2014 –  Horseshoe pond is looking rather bare in terms of vegetation.  Emergent plants are starting to die back, while aquatics with floating leaves are sinking down away from the water surface.

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     June 2015 –  Another spring, and Horseshoe pond is back to it’s full glory.  This spring we recorded 19 aquatic and water associated plant species, and abundant dragon and damselflies.  The pond is also proving popular with birds, especially swifts, swallows and warblers. In addition, amphibian populations are doing well, with breeding smooth newt, great crested newt, frogs and toads.

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June 2015 –  Ben Siggery (UCL), conducting an invertebrate survey at Horseshoe pond.

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June 2015 –  Charophytes are doing particularly well in Horseshoe pond, dominating both the shallow and deep water areas.

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June 2015 –  Broad leaved and curly leaved pondweed are both doing well in Horseshoe pond.

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