(The following document is a diary that I completed on my own accord during completion of a 6 month practical diploma with BTCV. The info and pictures represent all my own experiences, views and knowledge gained during this time.)
As of January 2012 I have been completing a part time course: ‘Level Two Diploma in Work-Based Environmental Conservation’ run through BTCV. I am using this page as a place to write about what I have achieved each day and also to reflect on what I am learning during the course.
02-02-12: Vegetation Clearance (Rhododendron)
The first of two days of vegetation clearance at a site in Stalybridge Country Park.
Brief and why: The aim is to remove densely grown Rhododendron from a hillside that was historically moorland/ high altitude oak woodland. The latter is a particularly rare habitat type and as such local groups are keen to restore it to this specification. Rhododendron is a non-native fast growing shrub that out-competes other plant species and alters the pH of surrounding soils. Once felled Rhododendron can re-root from loose branches and so fallen vegetation was removed and chipped to prevent re-growth. Stumps are to be left in the ground to be sprayed with herbicides at a later date.
Site Hazards: The site consists of moorland covering steep hills meaning terrain is slippery and inconsistent. Cold weather had further resulted in icy patches which provided a further trip hazard as did stumps left from previous clearings. A chipper on site was a further hazard, working near the machine required ear cover and limited communication ability. We worked in close groups so had to be wary of falling vegetation and wear helmets. Chainsaw users were also felling larger shrubs/trees in the area.
Tools: Bow saw, Loppers, sharpening stone. PPE: Helmet, gloves, first aid kit, goggles, steel capped wellington boots.
Tasks: There were two main sub-task types to be completed on site, chopping down vegetation and removing it. By alternating tasks between group members throughout the day it was ensured people did not become too tired or lose concentration. To clear the site as efficiently and safely as possible, we formed a work chain stretching from the felling site to the chipper. Vegetation was passed down this line between team members and prevented the need of any one person to walk to far along treacherous ground.
09-09-12 Hedge Laying
Two days of hedge-laying, predominantly of hawthorn and blackthorn at a site that has undergone laying over the last 3 seasons.
Brief and why: The site we were at is an ex-dump turned nature reserve with areas designated to grazing farm animals. The brief was to finish laying hedge around one field housing cattle to complement and in time replace man-made fencing on site. Although it has fallen out of favour in recent years due to it being relatively time consuming to produce, hedge-laying provides a number of unique benefits to environments which other approaches do not. These ‘secondary’ benefits are primarily to the biodiversity hosted at the site. At many sites it will be the case that hedging will be provide the sole source of wood or shrub habitat. This dense shrub habitat is ideal for sheltering birds and small mammals that would naturally forage in open fields and furthermore it provides the latter with a safe channel to migrate long distances. The trees also benefit directly from hedge-laying as the practice, if repeated can extend the plants life-time indefinitely therefore increasing long-term habitat diversity at the site and providing a living barrier with a much greater life-span than conventional hedges or man-made fences.
Site Hazards: The site was sloped and icy therefore care needed to be taken when walking/ lifting timber . Many of the trees being laid were sharp and so gloves needed to be worn when manipulating branches for laying or removing deadwood. As usual gloves were also to be worn when using tools such as bow saws and sharpening stones but were not worn when using swinging tools such as the maul, axes and billhooks. As we were working with trees above head height helmets were also necessary to protect against falling branches.
Tools: Bow saw, loppers, heavy duty gauntlets, billhooks, pole saw, helmets, first aid kit, sharpening stones (canoe/cigar), rope, wooden stakes.
Tasks: Firstly it is important to identify what standing timber is best suited to a particular purpose. Along any stretch of hedge there will be some trunk that can be laid, some that should be left as standards (which act as support for the hedge and increase habitat diversity) and likely some that will just have to be removed. When the target trunks for laying are identified the next task is snedding to remove branches that will either prevent the tree from being laid or will prop up the trunk when it is lying on the ground. To lay the tree a horizontal cut is made near the base of the trunk with a bow saw, this should cut about 75% of the way through. Next an axe or bow saw is used to produce a sloping cut from above which connects to the edge of the horizontal cut in order to produce a hinge to allow the lay. When laid the remaining tree stumps should then be cut at an angle that complements the slope of the hinge as this prevents build up of water and debris inside the tree trunk that would cause additional stress to the tree. When a portion of hedge has been laid it is important to install posts at a regular basis on alternating sides of the hedge. This gives additional support to the hedge that is important for maintaining its shape in early stages when the hedging is still vulnerable.
16-02-12 Tree Felling
A day of tree felling at Prestwich Clough in Greater Manchester.
Brief and why: This particular site has historically consisted of acid grassland however the loss of grazing animals such as deer has resulted in ecological succession. Today the terrain on site consists of sparse oak woodland, and it is the joint decision of local conservation groups that the site should be gradually returned to its previous state. Our task was to further thin the tree coverage on the site by first felling target trees and then removing the stump and roots to prevent re-growth.
Site Hazards: The site is on a gentle slope with a generally flat ground surface that represents a low risk trip hazard. The site is popular with walkers and pet owners meaning care must be taken to inform the public that conservation work is ongoing at the site and if necessary to restrict access during the act of felling. The major inherent hazard for this activity is that of falling wood resulting from either dead branches in the canopy or the falling tree itself. The threat posed by this hazard can be largely mitigated by good work practices e.g. identifying and clearing a safe zone and escape route, not felling trees within a close proximity to other people and having a team member to communicate with passing walkers and other colleagues at work.
Tools: Bow saw, loppers, pole saw, wedge, mallet, axe, spades, mattock, felling lever, rope. PPE: Helmet, first aid kit, gloves, goggles.
Tasks: Working in groups of two it was the job of one team mate to complete the fell whilst the other keeps watch to maintain a safe parameter through which people can not pass, whilst offering advice on their colleagues progress if required. The first step in tree felling is to plan the direction in which the tree should be felled. Once this is established a safe zone can then be identified (directly behind the felling direction and 45 degrees to either side) and an escape route can also be planned. The next task is to remove branches or outgrowth around the target tree in order to allow a clean fall of the trunk and reduce the chances of a hang up. Once this has been completed it is time to saw the ‘gob’ or ‘bird-mouth’ which should cut around 25% of the way through the trunk. It is this that determines the direction the fall. A further cut should then be made directly behind and slightly above the ‘gob’ in order to connect at its hinge to complete the felling. As we also intended to remove the root and stump of the oaks, our gobs were cut about two feet of the ground to give additional leverage necessary for the removal. If this was not the case the ‘gob’ would be cut much lower in order to reduce the chances of kickback from the trunk and furthermore to remove the hazard that a high stump represents. To remove the stumps, mattocks and spades were generally used to remove soil and sever roots however for some bigger roots bow saws and axes were also employed. One difficulty for this part of the task is that oak trees posses a tap root which travels vertically downwards. This root has evolved as a means for the tree to find water under the grounds surface however as secondary characteristic it also provides additional support to the tree and is difficult to sever.
23-02-12 Tree Felling
Another day of tree felling and root removal at Prestwhich Clough. Having now done 3 days of this activity I feel confident completing the tree felling procedure and as such I targeted larger trees today. On one tree I had difficulty sawing out the bird-mouth due to the hard wooden core of the tree so I used an axe to chip the wedge out which was simple enough. These larger trees also had a much larger root complex and again I often used an axe to severe both lateral roots and the tap root.
24-02-12 Vegetation Clearance
A day of various types of vegetation clearance at Phillips Park, some of which was assessed in order to complete the first module of the course. Part of the day was spent thinning trees and removing dead branches and the rest was devoted to the clearance of bramble. Wood from the tree thinning was piled to form windbreaks, basically a continuous wood pile. Some interesting wildlife was found in previously established wood piles, including some red fungi (scarlet elf cup) and a well disguised frog. These findings are evidence of the importance of these alternative habitats to maintaining a diverse ecosystem.
01/03/2012 Hedge Laying
Spent the morning hedge laying at Phillips Park. The part of hedge I was laying was quite dense meaning there was little room for sawing into trunks. As such i used the axe almost exclusively to lay a number of the trunks. This was quite challenging and I definitely need to practice my accuracy with the tool, however I still laid all the hedge successfully if not leaving them slightly fragile. Later in the day I was using a mell to stake part of the hedge I had laid earlier and I somehow managed to catch my finger between the mell handle and the stake. This caused the end of my finger to pop and ripped my nail bed out. They reinserted the nail bed and stitched it back to my finger at A&E and hopefully it will heal sufficiently for me to start some tasks again next week.
8/9/15/16-03-12 Hedge Laying
Four days of hedge-laying, including a day of assessment to conclude 5 days of this activity at Phillips Park.
In this time we laid around 30m of hedge and the result is evidence a clear improvement in our groups ability. On the 8th and 9th my finger restricted me from using swinging tools with my right hand and instead I focused mainly on alternative tasks such as creating brash piles, weaving laid tree branches, tree ID, pointing stakes and using the pole saw to remove excess branches from trees to be felled. I also used this chance to observe my team mates and offer constructive criticism which I feel was a good way to improve my judgement when deciding what parts of hedge to lay.
On the later days of this task I could become fully involved again in all aspects of the hedge-lay. Again I tried to use the axe almost exclusively in order to improve my accuracy with the tool and produce a consistent finishing to the hedge. I was pretty happy with the results and feel I have greatly improved my ability with an axe over the last few weeks.
These days have concluded the hedge-laying module of this course, coinciding with the end of the hedge-laying season.
22-03-12 Revetment construction and fence removal
Today’s task was to remove a stretch of fence that was diverting a walkway along an eroded lake bank and secondly to construct a revetment to retain and reconstruct the damaged bank.
The fence in question consisted of wire mesh and deep set fence posts and its original purpose was to close off an eroded path. Having fallen into disrepair it was exacerbating erosion by diverting walkers closer to the bank-side. Bolt cutters were used to remove the wire meshing prior to digging out the fence posts with spades and mattocks. We decided to construct the majority of the revetment prior to inserting it into the bank. This decision was made as we felt that the fence posts may twist and become non-parallel if melled in separately. We measured the gap in the bank so we could construct the revetment accordingly and then used a mell to secure it in place. Some extra digging was required. Bricks and then gravel were used to fill the eroded pit behind the revetment, leaving a level, straight bank that could again be used as a footpath.
23/29/30-03-12 Tree Felling
Three days of tree felling at a site in Simister to conclude this practical module.
The site we worked in consisted largely of grassland and amenity woodland as well as a small wetland patch. The woodland itself is a relatively young, planted habitat in need of management for varying reasons. The local friends groups wanted the trees in the area to be crown lifted in order to improve visibility for the security of amenity users. The Woodland Trust wanted the wood to be thinned in order to allow remaining trees to have improved growing conditions. Most brash and deadwood was left in piles on site to be chipped at a later date but suitable trimmings were used to create stakes and a dead-hedge to enclose one end of a pond.
Within just one week of the dead hedge construction, evidence of its ecological value was apparent with various invertebrates and even amphibians were noted on site.
As the woodland was quite young, the majority of the trees could be felled easily, and there were not to many problems influencing the trees fall direction or with hang ups. Most of the trees were large enough to require an initial bird-mouth however a few could be felled with the two-cut procedure. We were briefed to leave the stumps around knee height on felled trees as contractors are to come through at a later date to reduce and score the stumps with chainsaws in order to prevent any regrowth.
Many of the trees on site, especially those with low forking trunks, had branches pruned to shoulder height in a process known as crown lifting. As mentioned the aim of this was primarily to increase visibility in the site, however the procedure is often beneficial to trees as it removes out-competed branches and weaker limbs that would be prone to splitting and rotting in the future.
12/13/19/20-04-2012 Dry Stone Walling
Four days of wall building, two of which with the aid of a Master Craftsmen.
Brief and why: We were tasked to restore a dilapidated, single skinned revetment wall which was slowly failing to withhold a raised bank bordering grassland. The reasoning behind this restoration was threefold. Primarily, it was necessary to restore the shape, strength and structure of the wall in order to contain the raised soil bank on site. Also of high importance was the maintenance of the localized habitat provided by the wall. Whilst dismantling the wall originally we found; newts, frogs, toads, mice (and nests), and countless invertebrates species. Whilst it felt a shame to destroy the habitat the semi-derelict wall provided, it is important to remember that a wall in this state would (relatively) quickly degrade to a point that it would no longer offer the range of micro-ecosystems that support the significant biodiversity found in functional dry stone walls. The final incentive to restore the wall was to improve site aesthetics, an important factor in a public park.
Site Hazards: The site was steeply sloped in some areas and marshy in others making the terrain hazardous and slippy. Other hazards represented by the site included the possibility of the weakened wall collapsing whilst work was being carried out and the presence of loose stones on the floor which represent trip risks. The task involved a high degree of manual handling, including lifting of awkward, heavy objects from varying heights. As such it was crucial to maintain a correct lifting posture at all times to prevent injury. Stone chippings produced from hammers and chisels posed a hazard to eyes and as such goggles were to be worn when using these tools.
Tools: Walling hammer, trench pins, string, Chisel/Bolster, buckets, spades, mattock.PPE: goggles, gloves, safety boots, helmet in some cases
Tasks: After assessing and clearing the work site the first task was to take down the remains of the old wall. The best practice procedure for completing this task is to organize or ‘grade’ the stones according to size as the wall is dismantled. The process of grading refers to to organizing stones in relation to size. The bigger the stones, the closer they should be to the wall. This is important as larger stones tend to be nearer the base of the wall and as such need to go on first. Moreover larger stones are obviously harder to carry and can pose a hazard to transport. This hazard is alleviated by grading. Once the wall has been dismantled and the foundation stones have been removed then it is necessary to make to wall base flat and level in order to provide an appropriate foundation upon which the wall can be built. The foundation stones are then laid, these should be large and should be laid with a flat level top upon which the rest of the wall can be constructed. From this stage onwards a dry stone wall should be built in courses, completing each course before beginning the next. Ideally, each course should be level as this makes it possible to build the next course so that its stones bridge the joints created in the course below. When building the wall there are a number of structural codes of practice that must be adhered to in order to maximize wall stability. Bridging joints between courses is one such condition that should be met. Other fundamental structural requirements include; laying stones lengthways into the wall, ensuring the stones face is level and sheds water away from the wall, ensuring wedge shaped stones have their thicker section inside the wall to prevent it being pushed out, ensuring that all stones are firmly settled and secured with ‘hearting’ (smaller stones and rubble) before the next stone is laid and ensure that after each course is laid, the packing is bought up to the same level. With all walls it is imperative for the base to be wide and taper into a thinner wall top. A rough guideline is that the base should be double the width of the tip.
As this wall was only a single skinned wall, packing was placed between the soil of the bank and the rear of the stone wall. Furthermore no top stones or coping stones were used on this wall. In other circumstances, e.g. walls with two skins, coping stones are used to provide additional support (acting as through stones) and for aesthetic improvement to the wall.
26/27-04-2012 and 4/10/11-05-2012 Dry Stone Walling.
A further few days of walling at a different site in Phillips Park.
The job specification for this task was to dismantle and rebuild an end section of a (mostly) free-standing, two skinned wall bordering a car-park at the site. The wall in question represented a barrier between 2 different ground levels and as such the lower section of the wall effectively had a retaining function. Due to the variation in ground level across the 2 sides of the wall, the approach to wall dismantling and reconstruction varied slightly from the conventional approach. Initially, stones removed from the wall were graded on their respective sides of the structure, this was the case until the freestanding section wall was dismantled. After this point, the remaining stone from both wall skins were removed and graded onto the lower ground level side only. Likewise, when rebuilding the wall, the lower, retaining part of the wall was built from the lower side only, whilst once the higher ground level was reached, building began from two sides.
We initially planned to dig the wall right down to its foundations as this would allow us to remove and reset the foundation stones to ensure the base of the wall was sturdy and level. However, after digging down over a foot into the soil (making the wall effectively above head height on one side) and still not finding the foundation, it was decided that we would have to begin building on top of the original wall. Although this decision was unavoidable when considering our time frame, it did result in problems further down the line.
A heavy nights rain after the first days building resulted in a bulge appearing in the wall. This required us to drop the slumped section (only one skin) back down to the stone layer at the base of the slump. From here we identified that the cause of the problem. A single stone, remaining from the original structure had a top surface that sloped down toward the front of the wall. When lubricated by wet weather, it resulted in the stones above it sliding forwards slightly, a problem that would have only become exacerbated over time.
When building the wall we decided to build a thick lower section due to the sections retaining function, only beginning to taper in the walls width once the higher ground level was reached. Unlike my previous wall building experience, this wall was built with 2 skins, and as such ‘through stones’ were used to enhance the walls structural stability. These we placed lengthways into the wall at regular intervals in order to bind the 2 skins together. Additionally we plan to finish this wall with coping stones during a final day on the wall later in the course.
17/18/24-05-2012 Path Construction.
The first three days of path construction at Gower Hey Wood in Greater Manchester.
Brief and Why: The job specification was to lay 50m of new path at the site which will connect two lengths of footpath currently separated by field, and furthermore improve another 80m of footpath by improving drainage and adding a new layer of top stone. The job specification requested an aggregate path, dug level with the surrounding terrain and constructed with local stone. In line with the local geology, gritstone was chosen to complete the path as this stone, having a similar pH to the surrounding environment, would not result in local acidity changes and subsequent variation in plant growth. The path wascreated with 3 stone layers; a sub-base, base and top layer consisting of finings. This will allow the path to withstand more wear and tear.
Tools: Mattock, spade/shovel, rake, measuring tape, wheelbarrow, spray paint, wacker plate. PPE: Safety boots, gloves, goggles, ear guards.
Site Hazards: The site itself is flat and even and presents few hazards. In wet weather some patches become boggy and can represent slip hazards or cause wheelbarrows to become stuck. The greatest risks associated with this specific task are related to manual handling, of which there is a large amount. Most sub-tasks required strenuous repetitive work such as wheeling loaded wheelbarrows, lifting turf and digging. The use of swinging tools also represented a significant hazard as did the use of the motorised ‘wacker’, employed to level the stone path.
Tasks: During the first few days of the path building, tasks focus was mainly on measuring and digging out the path trench, and applying the two few stone layers to the path. As such work involved a lot of material transportation e.g. removing excess soil and bringing in stone. We had to take care that we maintained neat path edges and a consistent depth (6 inches) when digging out the path trench as this allowed stone layers to be applied evenly across the paths length.
7/8/14/15-06-2012 Path Construction.
A further four days of footpath construction to complete the project at Gower Hey.
With the majority of the new path dug out and filled with the first 2 layers of stone, work on these days focused more on improving the 80m of original path. Maintenance of the existing path involved a number of subtasks. Firstly the drainage problems on the footpath were addressed in order to prevent and remove standing water on the pathway. To achieve this we first unblocked the pre-existing culvert however this had limited effect, partly because the culvert was not in line with the ground level at the path edge. To address this we filled up the sunken ground around the culvert using stones used in the base layer of the path. This raised the ground surface sufficiently to allow any collected water to flow straight through the culvert and solved the flooding in this section of the path. Digging trenches along the path edge and filling them with large base stones provided a soak away channel through which surface water at other path sections could percolate towards the culvert.
With drainage issues mitigated , the task remained to lay the top layer of stone and finish the surface to a suitable standard. The final layer, consisting of ‘finings’, was applied to the path and raked so as to produce an even, slightly sloped surface known as a camber. This angled surface promotes water runoff away from the path surface and was achieved by applying a slightly larger amount of stone to one side of the path and carefully raking the substrate to produce the angle. With all these tasks completed the final job was to compact the path surface using the wacker plate. This plate works by subjecting the stone path to intense vibrations, thus allowing stones to settle tightly together. For this path, the whole surface was flattened once, with uneven areas being re-raked or having more stone applied before a second turn with the plate.
21-06-2012 Dry Stone Wall
Today we spent an hour or two completing the wall and fitting large coping stones to the wall top. These stones probably weighed about 50-60kg and were really difficult to hoist onto the wall. We lifted some of them in pairs, wrapping them in straps to allow a greater grip. Thankfully my colleague Andy lifted the others onto the wall. Once in place the stones were easy to manoeuvre and secure with slate in order to perfect and secure their positioning.
The remainder of the day was spent completing theory and paper work required as the course nears completion.
22-06-2012 Grassland ID
Today represented my final practical day of the Diploma course. This was spent completing a grassland ID course at Phillips Park. As well as learning to identify a few common grassland species, the course identified surveying styles such as phase one surveys and NVQ ……