Saturday, 24 November 2012

Trip Report November 6 2012

TTHE LICHEN TRAIL - DURDHAM DOWN


6 Members attended  this meeting and gained an insight into the fascinating world of Lichens.
We followed the 1/2 mile Lichen Trail as set out on the leaflet produced for the trail.
Moving from tree to tree we were able to examine the various Lichens we encountered.
We managed to indentify a total of 15 different species of Lichens in total.Many thanks to Alan Rayner for his expert help with the id's.

Xanthoria parietina (click photo to enlarge

click photos to enlarge




Physcia tenella 


Lecidella elaeochroma


Evernia prunastri 





Physcia tenella


Lecanora chlarotera


Lecidella elaeochroma

Flavoparmelia caperata Click phototo enlarge

Ramalina fastigiata


Lecidella elaeochroma click photo to enlarge

Thanks Mark............................................

Wednesday, 21 November 2012

5,000 views


Thank you all for your support we have now had over five thousand views on this site with views from Russia,United States, Germany,Philippines,Ukraine,Vietnam,France,Indonesia,Canada.

All the best Steve

Wednesday, 14 November 2012

leaf miners

Click Photo to enlarge

The moth skills improvement group met at Elm Farm, Burnett on 29 October and at Brown’s Folly on 9 November to look at leaf miners. These are very small moths whose caterpillars feed within the thickness of a leaf but evidence of their feeding is left behind  . The mines which are created can be seen either as a blotch or a linear feature. In many cases the moths are host specific and can be identified by using a key based on a combination of the plant species and a description of the mine.


Probably the best (i.e less commonly recorded) moth was found on Bramble at Elm Farm. The picture shows the mine of the very common Stigmella aurella on the left and the much scarcer Stigmella splendididissimella on the right. The distinguishing feature is the line of frass (caterpillar poo) left behind as the larva progresses through the leaf. S. aurella leaves a thick line whereas S. splendididissimella leaves a thin line only occupying 1/3rd of the width of the mine.


Thanks to Mike Bailey

Tuesday, 13 November 2012

Members Photos


I am pleased to say that we now have over a thousand photos on the Bath nats Flickr site all taken by Bath nats members all of which are within our recording or on field trips, thank you all very much a few more contributors always welcome. Link to Bath Nats.flickr site

All the best Steve

Interesting bits from Paul


Birch Polypore

Piptoporus betulinus, commonly known as the birch polypore. Most often seen on dead Birch, however it often lies dormant in live trees and when the tree becomes 'stressed' through whatever means such as old age, disease or drought say the it causes 'brown rot' and the eventual death of the tree.
The fruiting bodies as shown in the photo were once used as razor strops. They are also the food plant for a number of beetle and insect larvae.
Click Photo to enlarge

Spindleberry

Spindle (Euonymus europaeus) this small tree or shrub is found in our older native hedgerows most commonly growing on a lime soil
At this time of year (November) it has unusual pink berries which were once ground in to a powder to eradicate head lice.
The wood was used to make such things as wooden skewers, pegs and knitting needles.
The Spindle can often be seen in the spring covered completely in silk webs and totally defoliated by the Spindle Ermine moth (Yponomeuta cagnagellus)
Click Photo to enlarge

Thank you Paul

Friday, 9 November 2012

Ivy Mining Bee (Colletes hederae)


The sighting of these bees has been reported to BWARS who are mapping the spread of this species.I understand a Bath Nats visit to Victoria Park saw another aggregation of these bees at the end of September. There were many hundreds over the bare ground on at least two allotments off Monksdale Road.






Click Photos to enlarge 











Thank you Geoff for the above


False Widow


False Widow - Steatoda grossa (Combe Down, Bath) 1-11-12

This is one of the species found in the UK with the common name of 'false widow'. It's also called the cupboard spider. They seem to be quite common in this area and I have found a number of these in the house. Their favourite prey being Woodlice. Apparently their bite is akin to that of a wasp so treat them with respect if you find one.
Click here to enlarge

Thank you Paul

Monday, 5 November 2012

Biodiversity SIG


“Birth of Biodiversity SIG - Prospecting for Woodland Lichens, Bryophytes and Fungi at Elm Farm” 30th  October 2012

Alan Feest and Alan Rayner have decided to start a new ‘Biodiversity Skills Improvement Group’, with the intention of helping Bath Nats members develop ecological understanding and survey skills in an enjoyable, focused and participatory way, which includes a lot ‘more than making a list’. To join the group, just send a note of your contact details to one or both Alans, and they will let you know when and if they have something planned and what it is.  

As a way of getting started, the two Alans met together with Marion Rayner, Philippa Paget and Ian Stapp on Tuesday 30th October 2012, to undertake a ‘structured survey’ of lichens, mosses, liverworts and macrofungi present in an area of 20-year-old deciduous woodland at Elm Farm. We recorded everything we could find and identify in a set of 20 8 metre diameter localities, approximately 20 metres apart. In this way we collected a ‘baseline’ list that will enable us to detect and measure any change that has taken place when we or somebody else repeats the exercise in months or years’ time when the trees will have grown and/or (in the case of ash, now threatened by die-back) died. We also had great fun and discovered, learned and – with the aid of Ian’s photography - recorded much that we wouldn’t have done without working together intensely, combining our different skills and interests. Philippa’s enthusiasm for digging in the dirt unearthed some tiny fungal fruit bodies, including Delicatula integrella, Clitopilus hobsonii, Microtyphula filiformis, Typhula erythropus and Clavulina rugosa, growing on twigs and soil, and Marasmius recubans and Mycena capillaris growing respectively on decaying beech leaf petioles/veins and laminae (see Ian’s photograph below).




Meanwhile, Alan Rayner’s focus on tree bark and branches revealed a surprisingly large variety of lichens, whose identification was not always made easier by parties of slugs and snails, which munched their way through some species (e.g. Arthonia radiata) more than others (e.g. Lecidella elaeochroma).




We were puzzled for a while by the sudden change in lichen cover evident on many trees about 1 metre above the ground. Then we came across a tree with its original protective shelter still partly in place. In the moisture underneath this, Marion was excited to encounter what later proved to be the liverwort Riccardia chamedryfolia, along with the ‘stringy moss’, Leptodictyum riparium, an inhabitant of water films sometimes grown in fish tanks, which she added to our smallish but significant list of bryophytes growing on the ground, around the base of trees and – in the case of Orthotrichum affine higher up trees in the wrinkled bark where branches emerged from the main trunk.

Assessment of the data showed that the biodiversity of bryophytes, lichens and macrofungi at Elm Farm was higher than for Primrose Hill which we had surveyed previously. We now have baseline data for both sites that we can compare in the future to detect biodiversity trends. Interestingly, despite the higher biodiversity at Elm
Farm both sites showed the effects of nitrogen, with Bryophyte Nitrogen
Indices of 5.67 at Elm Farm and 6.2 at Primrose Hill.  Anything above 4.0
indicates nitrogen influence. 

Thank you Alan Feest and Alan Rayner