Orchids, water levels and Icelandic visitors
16th May 2023
The Icelandics are back tomorrow, so my main focus is upon preparing for that challenge. Leaky Dam building is very popular with them for a number of reasons a. It’s a good team building exercise, b. It is relevant to Icelandics since they are threatened by flash flooding (especially when a volcano melts large lumps of glacier ice), c. they get to use a range of tools such as axe, saw, long-handled loppers, spade, pick and lump hammer, d. they create something of lasting value to leave behind them.
The biggest challenge is sourcing the materials and tools, as well as finding a place to put a few more leaky dams in place. So I have to check-out a few suitable spots and determine where the building materials might come from (no good carrying sticks and logs halfway across the woodland). Leaky dam building is the epitome of good sustainability practice: you build something of value for the environment, using materials grown on-site, utilising the waste products of another activity (leftover logs from tree-felling and coppicing).
Satisfied that we have all of the above in place I can check some of then other projects I’m involved with on-site. The Leaky Dam Trail boards are surviving well, other than water ingress causing the laminated information sheets to run a little. I’m most impressed that no-one has as yet “vandalised” the plinths or the boards themselves (“vandalised” is too strong a word, as we rarely have visitors who want to destroy anything – usually it is just high spirits or carelessness). As with the leaky dams themselves, people notice and appreciate their value and respect them.
My project tour takes me down to the new ponds in the lower wood. The water level has dropped a little in the two lower ponds since they are not being recharged with fresh stream water, whilst the recent hot dry weather has increased their evaporation. I decide to let some stream water in, but 20 minutes later I have second thoughts. The ideal time to let water in is after heavy rains, when any nitrates and phosphates entering the stream from the reed bed pond is well diluted. Derived from human waste (number ones, number twos and perhaps washing detergent) the reed bed waste management system ensures no pathogenic bacteria can enter water courses, but it does not strip out the nitrates and phosphates. So I close the channel and make a mental note to open it again after the next rains.
The tadpoles don’t appear to be too put-out by the high levels of these chemicals and are busily growing rapidly, perhaps at the expense of their smaller brothers and sisters. Nature is red in tooth and claw, with the “survival of the fittest” meaning cannibalism can pay dividends!
The sound of the quad bike heralds the arrival of Dan and a surprise guest appearance by his son Frank. Frank has been in New Zealand and Thailand for 3 months, but is now back helping his dad with the milling and stacking of the timber planks for the new bridge. Dan tells me that his architect pals from Uni will be having a bridge-building weekend this summer to celebrate a 50th birthday among their numbers. I suspect this particular building enterprise will run on liquid fuel.
My stomach tells me that lunch approaches, so I head back up the valley by way of Bat Park. I am delighted that the deer fence that now encircles this area is doing its job. With the deer excluded from Bat Park, the hedge shrubs nibbled into oblivion in previous years are now pushing out fresh leaves. We might have another 100 metres of new hedge in the woods after all.
After lunch I decide to do an orchid count in Orchid Glade. We have lost a few individuals (perhaps 7) to slug or rabbits, but 21 Twayblade orchids and 8 Common-spotted orchids have survived, with 6 and 7 respectively bearing flower stalks. I decide to partially cover the Twayblades with dead twigs to deter rabbit predation. It appears that the tree thinning may yet pay dividends.
This time last year their numbers were 16 twayblades and 8 common spotteds, so we appear to have arrested their declining numbers. Orchids can be taken as a good indicator of the health of the woods and its management. If they survive then our conservation practice is working and the whole of the wood benefits.