Woodland Management

This week has seen the start of my next MSc module on habitat management. After an introductory lecture, our first visit was to Anston Stones Wood near Rotherham where we looked at management practices in a mixed deciduous woodland in a limestone/calcareous area.

Coppicing was traditionally carried out in the woods for hundreds of years, with larger trees being taken for timber for buildings and ships. This ensured trees of different ages were present, and the clearings created during felling allowed ground flora to flourish. The difference in conditions in these  different pockets created small micro-climates and is one reason why there is such high biodiversity in woodlands. The area in the photo had a good assemblage of ferns and mosses, as it was largely damp and shaded.

Since the industrial revolution, woods have become largely redundant from an economic perspective and the lack of management has had an impact on woodland.  Offering no income, many woods were cleared to make way for more productive agricultural land. Many trees were also felled during the first and second world wars when timber could not be imported. This has left many woodlands that are uniformly around 100 years old and/or on steep slopes that made clearance difficult.

Today, woodlands do have to be managed to ensure a high level of diversity. Coppicing can take place - it is labour intensive but some groups do the work for free if they can take the products. Firewood, fence posts, charcoal, hurdles and beanpoles can all be harvested and sold for a profit. Remaining brash can be made into habitat piles (though the value of these was questioned) or chipped and used to line muddy paths. 

The site had some areas of grassland on the plateau. Scrub will always try and take over, though we learned that this needs cutting back to the point at which none of the grassland features are visible.  The meadow is cut once a year, and the arising are raked off, otherwise they would decay and smother new seedlings trying to come through. Grazing can work well, but consideration needs to be given to public interaction with livestock, and whether dogs could harm them. The cost of installing fencing can be prohibitive and may look unsightly.

An agricultural field had recently been converted to hay meadow, by ploughing it up and spreading the cut hay over it - this was not successful. Possibly due to high nutrients levels, all that appeared were weeds and thistles. When the area was sown with grass and then seeded, the result was more successful. I hope this doesn't mean that our hard work at Coronation Meadow last year will have been wasted.

Planting new trees does not make a woodland. A woodland is more than trees - it needs soil biota, mycorrhizal fungi, ground flora and invertebrates to establish a successful woodland community. It is better to expand an existing woodland, and these elements should then naturally move in and allow the woodland ecosystem to develop. However, this all takes time. One problem with modern woodland management is that it is too short term - plans need to be made that look decades ahead. One example of this is Toothwort (Lathraea squamaria) - a parasitic plant often growing near hazel that needs the interconnected relationships of the woodland to survive.

Unmanaged, wild woodland can be worse for wildlife as the denser shade leads to less ground flora and less cover for prey, though it is good to leave some areas unmanaged within a wider site. 

When planting trees, it's necessary to be wary of the spread of invasive species and disease, and there are problems for ash and larch in the UK at the moment. Even if seeds are gathered in the UK they can sometimes be sent to nurseries abroad to be grown on, so it's important to understand the provenance of saplings and source seeds locally where possible.

Damper, sheltered areas in valleys and gorges create good habitats for mosses and ferns, and leaving dead wood to rot (both standing and on the ground) is very good for invertebrates.

Finally, consideration needs to be given to other land users. There may be access routes through the site, and railways as much as roads needs a clear route with no overhanging vegetation. Clearance also needs to be maintained along power lines. Such work can be harsh on the environment but are necessary in our modern world. These considerations aside, remember that a woodland is a natural environment and should not be over-managed  so it becomes a landscape garden.