Flashcards in F215:03:09 Sustainable management Deck (24):
Give an example of a situation where there is a potential conflict between our need for resources and conservation
wood and timber production
What is coppicing
The traditional approach to obtaining a sustainable supply of wood
It involves cutting a tree trunk of a deciduous close enough to the ground to encourage new growth
How does coppicing work?
Once the tree has been cut, several new shoots grow from the cut surface and eventually mature into stems of quite narrow diameter
These can be cut again and used for fencing, firewood or furniture
Once cut the cycle begins again
What is the difference between coppicing and pollarding?
Pollarding cuts the trunk higher up
Coppicing cuts the trunk low to the ground
when is pollarding useful?
when the population size of deer is high, as they like to eat the emerging stems
Whereas if they are cut higher, the deer cant reach them
How is a continuous supply of wood provided?
woodland managers divide a wood into sections and cut one section each year until they've all been cut
What does the length of rotation depend on when managing a woodland
- How quickly the stems mature (depending on species)
and on the dimensions of the wood required
Are all trees coppiced in a woodland with coppicing as the sole purpose?
No, some trees are left to grow larger in each section, known as standards and then are used to eventually produce larger pieces of timber
What are the trees known as that are left when others are being coppiced?
Why is rotational coppicing good for biodiversity?
As if they were left unmanaged, woodland would go through a process of succession and would block all the light to the floor and therefore reduce the number of species that can grow there
It also provides different types of habitats
Give an example of a managed woodland
Bradfield Woods, managed since 1252
run of a 20-25 year cycle mainly on hazel and ash trees and oak trees are left as standards for timber
Explain what would happen to the biodiversity in Bradford Woods if the Suffolk Wildlife Trust stopped managing it
The wood would go through a process of succession, reaching a climax community in which biodiversity would be much lower than in the current case
Large is large scale timber production usually carried out?
clear-felling all trees in one area
Why is clear-felling so uncommon now in Br?
As it can destroy habitats on a large scale as it reduces soil mineral levels and leaves soil susceptible to erosion
The soil may also run off into water ways, thus polluting them
Why is clear-felling so damaging?
As trees usually:
- Remove water from the soil and stop it being washed away by the rain
- Maintain soil nutrient levels through the trees' role in the carbon and nitrogen cycles
What principles do modern sustainable forestry follow?
- Any tree which is harvested is replaced by another
- Even with extraction of timber, the forest as a whole must maintain its ecological function regarding biodiversity, climate and water cycles
- Local people should derive benefit from the forest
How do managers of large scale timber production ensure the habitats are broadly unaffected?
By using selective cutting and only removing the largest, most valuable trees
How do sustainable woodland managers ensure the balance between harvesting wood (for the forest to pay for itself) and conservation?
By trying to ensure the trees harvest as much wood as possible, as the more wood a tree supplies, the less trees have to be harvested.
How do foresters increase the efficiency of a woodland?
- control pests and pathogens
- only plant particular tree species where they know they will grow well
- position trees an optimal distance apart. (if too close, there will be competition and the trees will grow tall and thin, if too far, less trees can be planted)
What is meant by the phrase 'sustainable management of wood production'?
management techniques ensure that biodiversity is maintained, whilst providing a continuous and regular supply of wood
What are the similarities between small-scale and large scale production of wood?
- Selective cutting and growing standards are similar strategies used to gain high quality large timbers
What are the differences between small-scale and large scale production of wood
- Different sized timber is produced
- coppicing is used for small scale
- felling is used for large scale
- large scale is more damaging to habitat and can reduce soil quality
- Large scale requires need to plant new trees, small scale does not
When is felling used?
Large scale production