1) Tree planting history in Hong kong
Period 1870s to 1940s - aims : Health and aesthetic reasons.
Period 1950s to 1980s - aims : Soil erosion control, Water supplies improvement,
Fire Prevention and suppression and landscaping.
1980s onward - aims : Ecological restoration
Tree planting shortens the process of regenerating forest by skipping the status of grassland and shrubland in forest succession but start-jumping at secondary forest status by planting tree seedlings.
A wide range of native and exotic species has been tried but less than a dozen have been extensively planted with a high degree of success.
2) Pros and cons of planting exotic and native trees
Exotic tree species
The exotic tree species used in Hong Kong are fast growing and survive on very degraded sites. Some species, such as Acacia confusa, are fire tolerant and can be used to form a fire-break.
Most of the exotic species are monocultures. In some cases, monocultures of exotic trees can even suppress natural understorey regeneration and are often more susceptible to pest attack.
The invasion of native woody species, especially in young plantations, is significantly impaired by management practices such as weeding.
The mist is not so heavy. I can only see things within 50 meters. I did not take so many photos as I had to help them to dig holes for palnting seedling.
There are twelve students and two teachers to plant 50 seedlings in 1 hour and thirty minutes.
沒有留言:
張貼留言