I have just had a great weekend.
I used to work at Malham Tarn Field Centre in the limestone area of the Yorkshire Dales and I still live seven miles away from it. On alternate years they have a Seminar in November for people who have done research there or are interested in research.
On Saturday there were about 15 talks on topics: about caving and cave conservation; about diatoms in the tarn and sediments in the tarn; about dolines (pre-glacial solution hollows), the biggest ones being highest up. On "The Yellow Sedge" a plant which only grows in three places in England, including at Malham Tarn; about management of the Malham Tarn Estate; about the native white crayfish and efforts to conserve it as the American Signal Crayfish and the Crayfish Plague (brought in with the signal crayfish) have resulted in its disappeaing from most of our streams; about a national Banded Snail Survey that the Field Centre does with the sixth formers that go for courses there - and then the students can repeat the same project at home. http://www.evolutionmegalab.org/en_GB/
A talk was given about some records made in the 1350s of costs and receipts running a monastic sheep farm near Malham. He showed aerial photos of the monastic a sheep(milking) house on Malham Moor and
showed it was part of a bigger complex. The records had been copied by hand in Latin in in the 1540s. It showed the importance of records.
A lecturer from Bradford showed the results of pollen analysis made in a peat section on the bog next to the Tarn which tells us about the past 8000 years or so.
A fresh water ecologist showed me the graphs of how species increase and decrease in cycles in the Tarn of about 10 years.
He was concerned that records that had been made for a long period in the past about water nutrient content were no longer being made. We need long runs of data to monitor changes. For example there is more nitrogen chemicals in the water now due to pollution from the air
A lady from the National Trust chaired it very well, keeping people to time.
We had good food, including beef that (they thought) came from Darnbrook, a local farm.
On Sunday, those people that had stayed on had planned to go for short walks the morning. It was foul wet rainy weather with some sleet. One group went to see "The Yellow Sedge". One group went to Ha Mire to look for certain features of a bog area.
I wanted to do the OPAL lichen survey at Malham Tarn and the two tutors there were keen to try it out. So we downloaded and laminated the lichen picture key/chart (lamination valuable in the wet weather we were having). http://www.opalexplorenature.org/?q=AirSurvey
People have used lichens for over 40 years for looking at sulphur dioxide air pollution - The big bearded lichens only grow where there is pure air, and in very polluted areas you only get a green alga called Diplomacies (used to be Pleura). However sulphur dioxide pollution is much lower now since we closed many of the coal fired power stations, used methods of taking the SO2 out, nd exported our heavy industry to China and other countries, and closed down the textile industries which kept The Lancashire and Yorkshire Cotton Mill towns going 20 miles to the Se and SW So some of the sensitive lichens are coming back.
However this lichen survey looks at air pollution due to nitrogen oxides and possibly ammonia due to car exhausts and farm fertilizers. Some lichens will only grow where there is a very low concentration of these chemicals, other species will grow where there is a high concentration.
Anyway we went out, well wrapped up against the cold and wet and came back in and by the time we had entered our results in the national survey online we felt proud of ourselves.
In the afternoon I went for a walk (eventually by myself) following the Tarn Outflow Stream to see how far it was flowing beyond the normal sink hole. It was flowing about 1/4 mile to the next major sink hole, but not as far as the "dry waterfall" at Watlowes valley.. which was still dry in spite of the continuous heavy rain.
Do have a look at the OPAL website - It is very easy to do the Sycamore Tar Spot survey (now on leaves on the ground). The lichen survey is a little more detailed but very interesting and worth while trying. http://www.opalexplorenature.org/?q=AirSurvey
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