Is scientific knowledge necessary for effective management of mangrove ecosystems?

[Chris Paterson]

Dear colleagues and friends,

Professor Gong has contacted me from the mangrove training course in Penang, Malaysia suggesting the following topic for discussion this month (May 2007):

Is there a need to understand science for the effective management of mangrove ecosystems?

The following is Prof. Gong's message:

We are about half way through the GEF/UNEP SCS training course on “Sustainable use management of mangrove ecosystems”. A few participants have asked why the course has had a number of lectures on the scientific aspects including identification of plant and animals, primary productivity, estuarine hydrodynamics, economic valuation and carrying capacity since they have been managing their mangrove ecosystems without any need of knowledge of the above.

A few participants have been really interested in some of these aspects e.g. one participant has been trying to get all the information we can provide on the measurement of primary productivity, while a few others have been keeping track of all the plant/animal species they have come across (and helped collect) during the field trips etc. The question I would like to pose (as our topic of discussion for this forum) is: Is there a need to understand science for the effective management of mangrove ecosystems?

Best regards,

Chris .

[Vu Tan Phuong]

Dear Prof. Goong and colleagues,

Yes, I do agree that science always underpine the development and management. In this course of the training, the basic understading on the mangrove ecosystems is very important. And of course, there will also be very important to know how to capture/apply scientific base into management.

Best regards
Vu Tan Phuong

[John Pernetta]

This is not strictly a reply to Gong's initial message, to which of course the answer is yes we do need sound scientific data and knowledge if we are to manage any set of human actions in the environment. When someone claims to have successfully managed mangroves without such data and information the chances are that they are wrong! It is likely that changes are occurring in the distribution and abundance of organisms that they simply have not noticed because they do not distinguish between the species concerned; or the trends in numbers are so slow as to be not immediately obvious from year to year.

My reason for posting is a news article from a Finnish newspaper that I encountered this morning which I am including herewith:

Stora Enso acquires land for mill site in China



The Finnish-Swedish pulp and paper manufacturer Stora Enso announced on April 28th that it has acquired a total of 250 hectares of industrial land in China for possible future use as a mill site.


The prospective site is in Beihai City in Guangxi, on the coast of the South China Sea, quite close to the Vietnam border, and its purchase price is about EUR 27 million. Stora Enso has been expanding its forest plantations in Guangxi, planning to establish a pulp and paper/board mill in the area.

Stora Enso stressed that no formal decision concerning the investment has been made as yet. A prerequisite for the investment decision is that the company is able to expand its present eucalyptus plantations in a way that will secure a sufficient fibre base.


Currently, Stora Enso has some 90,000 hectares of land for forest plantations, while the company’s goal is to expand its plantation area to 160,000 hectares.

Stora Enso reported further that the United Nations Development Programme (UNDP) has assessed the Guangxi plantations, finding no major environmental or social issues that could have an impact on Stora Enso’s plantation project in Guangxi.


Stora Enso already owns and operates a fine paper mill in China.

Why I have posted this is not because it will be of immediate interest to our colleagues in the Guangxi Mangrove Institute (although they probably are aware of this already) but because of the statement in the last paragraph that "UNDP has assessed the plantations finding no major environmental or social issues that could have an impact on.........."

Two questions arise from this:

1. Since when has UNDP been the Environmental arm of the United Nations?

2. What proof (i.e. scientific data and information) are available to support this assertion?

Perhaps Dr. Fan is aware of this UNDP study and can enlighten us, since I am very certain that the rate of transpiration of eucalyptus is considerably greater than the native vegetation, the root system penetrates deeper than native tress and hence a likely impact is a lowering of the water table. Does the UNDP study make any mention of this?

Regards
John

[Chris Paterson]

Sorry to interrupt the start of this discussion, but I thought some of you may enjoy the following photos from the recent RWG-Mangroves meeting in Koh Kong, Cambodia:


^The ferry crossing on the way from Phnom Penh to Koh Kong


^ The Regional Working Group on Mangroves


^ The deadly Koh Kong durian - Nyoto probably wishes to forget these .


^ By the way, can any of you remember what these are? (Don't forget about your commitment to finish the mangrove cookbook!)

Please visit the mangrove photo gallery for more. So far we have 281 photos online from your 8 mangrove meetings and demonstration sites - click here.

[John Pernetta]

The photograph is of Lingula, a brachiopod and sole surviving member of a once flourishing phylum, the so-called lamp shells. Found in muddy substrata in the tropics and sub-triopics often in association with sipunculid worms.

[Gong Wooi Khoon]

We are approaching the end of the GEF/UNEP SCS training course on mangroves and had a discussion this morning on the management system as practised in Matang. I think everyone agreed that there is a need for scientific (including economics and social sciences) knowledge for the effective management of mangroves. Also, whilst it is agreed that Matang has the best managed mangrove forest in the world, the group recognizes that there is room for improvement. I append herewith the gist of the discussion this morning:

Matang Mangrove Management – General Discussion 7 May, 2007
Led by: Ong Jin Eong
Rapporteur: Gong Wooi Khoon


1. Rotation
Rotation in Matang is 30 years.
How to determine rotation?
Go to forest and study GBH x age and MAI x age to pick when MAI is max.
Matang system – harvest is not at MAI (highest growth rate) which occurs around 15 years and not 30 years. But system good ecologically because animal populations & some other ecological aspects less disturbed with longer rotation.

2. Thinnings
Planting at planting density of 1.2x1.2m gives around 8000 trees/ha. British decided on certain ages of thinning to get some income instead of waiting till the end of the rotation. But at 15 years (1st thinning as practiced now), a lot of dead trees already. So what to do?
No. of trees vs time – get a reverse J curve. Refer to Gong et al paper on demography – around 12 years or so, many trees have died. So minimize wastage by thinning at earlier age. But is the size big enough for commercial use? At 20 years, also lots of dead trees earlier so maybe can thin earlier like at 18 years. No problem with size then. Looking at natural thinning, you can also determine what is a good number to remove.
Year 1 8000 trees
Year 15 7000 trees (some death)
Half removed so 3500 trees left.
Year 20 3000 trees (some death)
Half removed – around 1500 trees
Year 30 Around 1400 left

3. Ecology
3.1 Weeds
When Achrostichum grows in gaps created after harvest, it forms a dense clump so Rhizophora cannot regenerate. Formerly, the Achrostichum clumps were removed manually but now weedicides are used. What is the impact of this on the environment and on other flora and fauna?
3.2 Monoculture
Monoculture of Rhizophora in Matang. Associated problems of monoculture – decreased biodiversity, disease outbreak etc. But in a way, monoculture not so bad as mangroves grow in zones naturally most of the time so OK to have monoculture of Rhizophora in the Rhizophora zone. But in Matang, Rhizophora is grown in zones that naturally are not dominated by Rhizophora naturally. Perhaps this would affect the growth rate (economic consideration) and certainly decrease the biodiversity (and ecotourism).

4. VJR
The purpose of a VJR in many cases is to keep the biodiversity ( a baseline showing what was originally there) and also to act as a seed bank.
What about the VJR in Matang – is it even different from the planted forest? Participants observations/comments:
Cheerawat - Molluscs population higher in VJR,
Bert - Trees bigger and older.
Bert - No Nypa reserve (Answer: not the purpose of Matang – but Nypa can be commercially important so depends on each country)
Phuong - Important to know the aim of the VJR – the Matang VJR is too small for seed bank. (Answer: in Matang purpose is to keep a small area of the “natural” forest as is done in terrestrial forests, but in mangroves, naturally occurring species depends on zones so having just one VJR i.e. one zone then fewer species. Need to improve – perhaps having bigger VJRs or in different zones).
Bansok - Need to have reserves in different zones perhaps including mudflats.
Bansok - What is the maximum size of mangroves that can be converted to other use in any area? (Answer: cannot give a number. Depends on area. Have to monitor each area – use concepts like carrying capacity, limits of acceptable change etc. A manager needs to understand scientific, economics and social aspects (multi-sectorial) to write a proper management plan. Certain decisions may favour certain sectors e.g. fisheries over forestry – you have to make the decisions depending on the purpose of the management and explain your decisions and actions to the different stakeholders.
Suhaili - Matang VJR – is this conserving gene pool? Is the size too small? What is the minimum size? (Answer: minimum size varies depends on purpose and area).
Suhaili - How about having arboretums? (Answer: arboretums is also a terrestrial concept – no zones. Ok if the purpose is to put together many species in one small area for tourists but not for conservation of species – conservating of different zones is necessary then).

5. Economics
We know the price of cockles, some fish, dried prawns, charcoal, poles etc. Is charcoal underpriced? Why?
Participants’ comments:
Mai - Price for charcoal is low because of government subsidy. Externalities not taken into consideration. (Answer: the government pays for salaries for officers and workers for replanting and looking after the mangroves for 30 years, infrastructure etc. So, government should include this as part of the cost. The producers of charcoal should be charged more to cover government costs and they can maintain their profits if they sell charcoal at a higher price).
Mai - There is also environmental cost. (Answer: yes and the details are not worked out as yet. Market failure because of government subsidy? Government also provides social aspects like education of tourists and students. It is necessary to have an economist as well as scientists on the team working out management plans so that the plan is economically sound for the long term as well as reduce environmental costs).
Gate price of charcoal is RM800 per hectare. Someone wants to clear mangroves to make prawn ponds to sell prawns at RM20 per kg – much more revenue than charcoal. So why keep mangrove forests for charcoal instead of converting to other uses? It is therefore important to increase the price of charcoal so that economically, charcoal production compares better. Of course, we keeping the forest (for charcoal production has other uses (remember goods and services lecture). Also the government should provide equity.
Participants’ Comments;
Suhaili – as we saw during our field trip, many people use mangroves for education and ecotourism purposes. How much should the government charge for such services. (Answer: for ecotourism, the forestry department can work out the charges. But for education and also for the local population, the government should perhaps provide this free of charge).
Bert – yes, should charge eco-tourists e.g. chalets charges to be equal to hotel charges. (Answer: depends on individual governments and sites. Decide at a policy level what to do e.g. perhaps Matang will attract more tourists to Malaysia so indirect benefits already).

6. Is knowledge of science (including economics) needed for effective management of mangroves?
Yes, science is absolutely necessary for effective management as shown by the discussion over the last 2 weeks and also in today’s discussion. It is necessary for hard scientists, economists and social scientists to work together.
Participants comments
Phuong – yes, we need to fit in data into management and policy. (Answer: we need a multi-sectorial team for effective management. We need scientists, economists, forestry workers, fisheries workers, government officals etc to work together for effective management).

[Gong Wooi Khoon]

We are approaching the end of the GEF/UNEP SCS mangrove workshop and during the general discussion on the mangrove management system in Matang, it was agreed that scientific (including economics and social science) knowledge IS necessary for effective management. It was also agreed that whilst the Matang mangroves may be the best managed in the world, there is room for improvement and various suggestions were made. The gist of our discussion is appended below:
Matang Mangrove Management – General Discussion 7 May, 2007
Led by: Ong Jin Eong
Rapporteur: Gong Wooi Khoon


1. Rotation
Rotation in Matang is 30 years.
How to determine rotation?
Go to forest and study GBH x age and MAI x age to pick when MAI is max.
Matang system – harvest is not at MAI (highest growth rate) which occurs around 15 years and not 30 years. But system good ecologically because animal populations & some other ecological aspects less disturbed with longer rotation.


2. Thinnings
Planting at planting density of 1.2x1.2m gives around 8000 trees/ha. British decided on certain ages of thinning to get some income instead of waiting till the end of the rotation. But at 15 years (1st thinning as practiced now), a lot of dead trees already. So what to do?
No. of trees vs time – get a reverse J curve. Refer to Gong et al paper on demography – around 12 years or so, many trees have died. So minimize wastage by thinning at earlier age. But is the size big enough for commercial use? At 20 years, also lots of dead trees earlier so maybe can thin earlier like at 18 years. No problem with size then. Looking at natural thinning, you can also determine what is a good number to remove.
Year 1 8000 trees
Year 15 7000 trees (some death)
Half removed so 3500 trees left.
Year 20 3000 trees (some death)
Half removed – around 1500 trees
Year 30 Around 1400 left


3. Ecology
3.1 Weeds
When Achrostichum grows in gaps created after harvest, it forms a dense clump so Rhizophora cannot regenerate. Formerly, the Achrostichum clumps were removed manually but now weedicides are used. What is the impact of this on the environment and on other flora and fauna?
3.2 Monoculture
Monoculture of Rhizophora in Matang. Associated problems of monoculture – decreased biodiversity, disease outbreak etc. But in a way, monoculture not so bad as mangroves grow in zones naturally most of the time so OK to have monoculture of Rhizophora in the Rhizophora zone. But in Matang, Rhizophora is grown in zones that naturally are not dominated by Rhizophora naturally. Perhaps this would affect the growth rate (economic consideration) and certainly decrease the biodiversity (and ecotourism).

4. VJR
The purpose of a VJR in many cases is to keep the biodiversity ( a baseline showing what was originally there) and also to act as a seed bank.
What about the VJR in Matang – is it even different from the planted forest? Participants observations/comments:
Cheerawat - Molluscs population higher in VJR,
Bert - Trees bigger and older.
Bert - No Nypa reserve (Answer: not the purpose of Matang – but Nypa can be commercially important so depends on each country)
Phuong - Important to know the aim of the VJR – the Matang VJR is too small for seed bank. (Answer: in Matang purpose is to keep a small area of the “natural” forest as is done in terrestrial forests, but in mangroves, naturally occurring species depends on zones so having just one VJR i.e. one zone then fewer species. Need to improve – perhaps having bigger VJRs or in different zones).
Bansok - Need to have reserves in different zones perhaps including mudflats.
Bansok - What is the maximum size of mangroves that can be converted to other use in any area? (Answer: cannot give a number. Depends on area. Have to monitor each area – use concepts like carrying capacity, limits of acceptable change etc. A manager needs to understand scientific, economics and social aspects (multi-sectorial) to write a proper management plan. Certain decisions may favour certain sectors e.g. fisheries over forestry – you have to make the decisions depending on the purpose of the management and explain your decisions and actions to the different stakeholders.
Suhaili - Matang VJR – is this conserving gene pool? Is the size too small? What is the minimum size? (Answer: minimum size varies depends on purpose and area).
Suhaili - How about having arboretums? (Answer: arboretums is also a terrestrial concept – no zones. Ok if the purpose is to put together many species in one small area for tourists but not for conservation of species – conservating of different zones is necessary then).

5. Economics
We know the price of cockles, some fish, dried prawns, charcoal, poles etc. Is charcoal underpriced? Why?
Participants’ comments:
Mai - Price for charcoal is low because of government subsidy. Externalities not taken into consideration. (Answer: the government pays for salaries for officers and workers for replanting and looking after the mangroves for 30 years, infrastructure etc. So, government should include this as part of the cost. The producers of charcoal should be charged more to cover government costs and they can maintain their profits if they sell charcoal at a higher price).
Mai - There is also environmental cost. (Answer: yes and the details are not worked out as yet. Market failure because of government subsidy? Government also provides social aspects like education of tourists and students. It is necessary to have an economist as well as scientists on the team working out management plans so that the plan is economically sound for the long term as well as reduce environmental costs).
Gate price of charcoal is RM800 per hectare. Someone wants to clear mangroves to make prawn ponds to sell prawns at RM20 per kg – much more revenue than charcoal. So why keep mangrove forests for charcoal instead of converting to other uses? It is therefore important to increase the price of charcoal so that economically, charcoal production compares better. Of course, we keeping the forest (for charcoal production has other uses (remember goods and services lecture). Also the government should provide equity.
Participants’ Comments;
Suhaili – as we saw during our field trip, many people use mangroves for education and ecotourism purposes. How much should the government charge for such services. (Answer: for ecotourism, the forestry department can work out the charges. But for education and also for the local population, the government should perhaps provide this free of charge).
Bert – yes, should charge eco-tourists e.g. chalets charges to be equal to hotel charges. (Answer: depends on individual governments and sites. Decide at a policy level what to do e.g. perhaps Matang will attract more tourists to Malaysia so indirect benefits already).


6. Is knowledge of science (including economics) needed for effective management of mangroves?
Yes, science is absolutely necessary for effective management as shown by the discussion over the last 2 weeks and also in today’s discussion. It is necessary for hard scientists, economists and social scientists to work together.
Participants comments
Phuong – yes, we need to fit in data into management and policy. (Answer: we need a multi-sectorial team for effective management. We need scientists, economists, forestry workers, fisheries workers, government officals etc to work together for effective management).

[Tran Thi Kim Tinh]

Dear Prof. Gong and colleagues,

I agree with your opinion. Scientific knowledge is important and necessary for general management, expescially sustainable management of mangrove ecosystems. We are interest in concept of this trainning course, it help us to improve our scientific knowledge about mangrove ecosystem. We would like to thanks Prof and other "teachers" who provided for us these useful information.

I hope that this trainning course is successfully.

Best regards,

Mrs Kim Tinh

[Vener Corpuz Merana]

Dear Dr. Gong and colleagues

Yes, indeed. Scientific knowledge is deemed necessary for sustainable management of mangrove ecosystems. Without this basic knowledge/information in science appropriate approach/strategies can't be attained. Furthermore, scientific knowledge is a pre-requisite for effective management scheme.

Personally, i would like to thank you and the rest of the lecturers who provided us valuable information especially in the field of mangrove ecosystems plus scientific base technology during the heights of our lecture.

Best regards.

Vener Corpuz Merana

[Cheewarat Printrakoon]

Dear Prof Gong, Prof Ong and colleages

Yes of course, basically science is the tool to explain and answer in nature. In the case of mangrove ecosystem, science is the tool to drive a decision of mechanism management. We need a combination of scientific baseline information such as ecology, physiology information, including advance science economic and others for make the answer “how we manage our mangrove ecosystem in sustainable and effective way” . From the GEF/UNEP SCS training course on “Sustainable use management of mangrove ecosystems” we grain a lot of scientific knowledge and get the idea to manage mangrove ecosystems, base on science. Thank you very much

Best Regard
Cheewarat Printrakoon