Vegetation Monitoring at Penaran

MONITORING THE VEGETATION RESPONSE TO CONIFER REMOVAL, PONY GRAZING AND OTHER HABITAT RESTORATION ACTIVITIES WITHIN BLANKET BOG IN THE MIGNEINT-ARENIG-DDUALLT SAC, NE WALES.

Problem/Need

Relatively little high quality data on the impacts of conifer removal and the most appropriate stocking densities for the most effective management of blanket bog upon blanket bog vegetation are available.  Map 1 shows the areas of conifer removal and restoration work at Penaran. The project partners are committed to assessing the vegetation response to the conservation work at Penaran to a high standard acceptable for publication in the peer-reviewed literature.

Method and sequencing of conservation management

Conifers (Sitka Spruce) will be felled and the brash placed in the forest drain on-site. An area of 18 ha of Sitka plantation will be clear-felled, whilst 204 ha of blanket bog with scattered re-generating Sitka will be cleared of all non-native tree species. Alongside the tree removal work, a number of forestry drains will also be blocked using heather bales or peat dams. As part of this work, a series (c.25) of small bog pools will also be created. Once this work has been carried out, Welsh ponies will be introduced to the site. It is possible that small areas of dense heather will be mown in order to facilitate livestock movement around the site.

Tree removal will take place in autumn 2007, with the drain blocking and pool creation work forming part of the same contract. Fencing will take place in autumn 2007, and livestock will be introduced when completed.

Experimental design

Monitoring data, will in most cases, be collected before, and after restoration work.  LIFE projects allow monitoring after the funding period, and data in year 7 (2012) will be included out-with this contract as an additional before/after comparison, and provide longer-term responses to work carried out. 

Vegetation monitoring protocols

Vegetation monitoring will take place between 1 June and 30 September in years two and five of the LIFE project (2007 & 2010). Vegetation species composition, cover and structure will be measured in 1m² quadrats replicated within 100 quadrat clusters. Each quadrat cluster will consist of four 1m square quadrats- located 5 m apart at N, S, E and W, with the location of the cluster taken as the S corner of the S quadrat. This would be a total of 400 quadrats. Clusters will be distributed using a stratified random system across the areas highlighted in Map 1, with both treatment and non-treatment areas surveyed. Each cluster will be permanently marked 5m to the South of the S corner of the S quadrat and locations recorded with adequate accuracy  (e.g. potentially using differential GPS). 

Surveyors should (at least initially) use stringed quadrats to record cover values and check against each other to ensure consistency (for example by using fixed-point photography). 

For each quadrat record:

1. if heather is mowed,

2. if dam spoil is present

3. the cover of a) bare ground, b) surface water, c) each plant species including mosses and lichens.

4. peat depth to the nearest 5cms using a marked cane.

5. altitude, aspect and slope

6. presence of grazing damage

7. number of horse dropping clusters

8. number of sheep dropping clusters

9. presence/ cover of dead heather

10. distance to nearest Spruce

11. GPS location 

In the centre of each of the four quarters of the quadrat, use a 1.5m bamboo cane marked off at 5cm intervals and with 1cm thick, white tape at 0, 10, 20, 30 and 40cm from one end to record:

1.       The maximum height at which the quadrat strings are supported by vegetation when the quadrat is rested over the vegetation.

2.       The maximum height to the nearest 5cm class of vegetation within 5cm of the cane, rounding down for intermediate measures (i.e. 0 - 4cm record as 0, 5 - 9cm record as 5 etc).  Record separately the maximum height of dwarf shrubs, graminoid leaves, graminoid inflorescences, Juncus spp (i.e. the three common and taller  J. effusus, J. acutifloris, J. conglomeratus) and bracken. 

3.       Structure: Record whether white marks at 0, 10, 20, 30 and 40cm are obscured by vegetation, when holding the cane vertically, at arms length to the front (i.e. the same 4 positions at which height is measured).

A sample (5%?) of these quadrats will have digital photos taken, and these will be used to assess inter-observer variation in assessment of % cover. This is a widely accepted problem, and a standard way of dealing with it is the use of photo's. It would also tick the Bid box for fixed point photography.

The work will need to be done by two surveyors working together at all times for health and safety reasons.

Some flexibility in timing of visits to some areas may be required due to nesting birds. 

Data recording sheets, and the format of the electronic data files must be agreed with the LIFE Project Manager prior to fieldwork commencing.

A separate contract for data analysis will be established in Year 5 of the LIFE project.