Subject: Tree Management - Summer 2009 [Print This Page] Author: WWF Mai Po Time: 28/06/2009 12:19 Subject: Tree Management - Summer 2009
Over the summer period you will notice a number of trees being trimmed or managed around the Reserve by our staff.
Historically, trees have always been managed at Mai Po, a long time before WWF took over management responsibilities in the mid-1980s. In particular, the original gei wai operators kept bunds clear and open for access reasons, but encouraged wetland trees such as mangroves inside the gei wai. Old photographs show the 1970s Mai Po landscape was very different from todays with only a handful of terrestrial trees to be seen.
In the last 25 years under WWF’s management, a variety of trees have been allowed to establish around the Reserve. Also to add diversity, over 800 native trees/shrubs have been planted along paths since 2002. The trees/shrubs are most commonly used by cormorants, warblers, bulbuls, and birds of prey.
However trees need to be managed for a variety of conservation reasons. These reasons are purposeful in order to bring benefits to the wetland habitats and wildlife, and approved by the scientific committee overseeing Mai Po. These include:
- To ensure public safety near visitor access routes (i.e. near the Rotary shelter),
- To facilitate gei wai de-silting operations by creating locations on bunds for mud (i.e. gei wai #19 this summer),
- To prevent waterbirds from feeling too “enclosed” in the main high-tide roosts (currently gei wai #8, #11, #16/17, #21, and Ponds #20 and #24),
- To retain open areas of water needed by waterbirds (i.e. Pond #17b),
- To retain open views from bird watching hides for educational and research purposes,
- A need to gradually remove non-native species and replace with native ones.
Also the number of trees surrounding freshwater ponds has to be limited. This is to ensure enough water remains all year round inside the pond, otherwise the pond might be dry and empty by the end of the dry season in March (trees consume a lot of freshwater and our only source of freshwater is rain in the wet season!).
Please note that trees along the visitor paths will be encouraged to grow and we will plant many more medium sized trees/shrubs in the coming years to benefit birds. Our general tree policy is discussed in the Mai Po Management Plan (download here).
I would like to remind visitors that Mai Po is an internationally important wetland, and is therefore managed first-and-foremost for wetland wildlife, including waterbirds. This is our priority, but we do realise trees/shrubs bring added value to the Reserve in a number of different ways, hence a balance is required, and this is what we intend to achieve.
If you would like to discuss these points, please feel free to contact me at Mai Po. I am happy to carry out site visits to show and explain to people first hand our management if they like.
[ Last edited by WWF Mai Po at 28/06/2009 17:23 ] Author: wcaptain Time: 29/06/2009 09:11
In order to reduce the number of tree felling at Mai Po, WWF could consider crown reduction in some areas. Also, regular pruning can be done as well. Nevertheless, topping should be avoided.
On the other hand, WWF should stick to its tree management scheme (if any). You know in the Rhododendron management case at Ma On Shan by the govt. Some keen conservationists objected to any tree management in relation to the reduction of competition between Rhododendron and other vegetation. So, be careful.
Captain Author: ajohn Time: 29/06/2009 12:51
I think the situation at Ma On Shan (upland shrubland/woodland) would be very different from Mai Po. As Bena pointed out, Mai Po is managed primarily for the benefit of wetland wildlife which benefits from the presence of fewer trees. The tree species present are inevitably less diverse and support less fauna than in hillside shrubland.
At the moment, I think the policy at MP is just right - maintaining some trees on the landward side to enhance biodiversity but keeping the seaward side largely clear of trees for the benefit of waterbirds. I also agree with the policy of replacing exotic species with native shrubs.
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