ETFRN Newsletter no 45-46    2005       

(European Tropical Forest Research Newsletter)

Forest and water

Meine van Noordwijk

Issues on forest and water have hit the head­lines of the news in recent months.  “Down with Trees” became one of the slogans after the release of the DFID re­port  “From the Mountain to the Tap” and the FAO/CIFOR publication “Forests and Floods”. The excitement may come back to the simple observation s that trees use water and that heavy rainfall causes floods.

The balance of public perceptions is swinging for and back – from exaggera­ted expec­tations of what trees and refores­tation can achieve (actively promoted as part of a ‘conservation’ agenda) and from false attribution of any downstream pro­blem with water flows to the ‘defores­ta­tion’ activities of upland land users, we may go to the other extreme of ignoring the positive values of maintaining forested landscapes and well-buffered river sys­tems with riparian forests and wetlands. Beyond the probably necessary shock effect of ‘debunking myths’, we get valid concerns over not throwing away baby trees with the bathwater. In this newsletter the different positions in this public debate are reflected.

The ‘forest and water’ debate is full of valid observations that are used to make generalizations at the wrong level, ignoring the effects of scale on many of the ‘truths’. “Not seeing the forest for the trees it contains” is a well recognized pro­blem, but “not seeing the landscape for the forests it contains” is equally proble­matic: the water flows at landscape scale are in­fluenced by the patchwork of land cover plus the drainage system, in direct res­pon­se to the spatial and temporal pattern of rainfall and conditioned by geology, slo­pes and subsurface flow conditions.  Howe­ver, it is boring if flooding can only be blamed on heavy rainfall and not on logging or deforestation.

Paragraph 23 of the Millennium Declaration calls “To intensify our colle­ctive efforts for the management, conser­vation and sustainable development of all types of forests.” Because clean water is essential for meeting health-related Millenium Development Goals, and Goal 7 (‘Ensure environmental sustainability’) clearly links environment and poverty issues; the management of upper water catchments deserves full attention. Poverty in the more remote upper catchments can be substantial, and part of the poverty is linked to existing rules and perceptions about what land use is and what is not compatible with the environmental service functions. Equitable systems for capture and distribution of benefit (values) resulting from good upstream forest and land management need to start from an analysis of critical thresholds in the forest – agroforestry – agriculture continuum.

The articles in this newsletter are grouped under four headings:

1. Perception gaps around forest and water, and multistakeholder negotiations
2. Highlights in forest hydrology:
3. Livelihood issues and payments for environmental services
4. Case studies, including the special cases of peat swamp forests and riparian forests interacting with fish production

Section 1 starts with a summary of DFID’s synthesis ‘From the mountain to the tap’ by John Palmer and a ‘rebuttal’ by Nick Chappel, who lists the arguments for a re-valuation of what reforestation can achie­ve for water flows on the longer run. More nuance in the debate and distinctions be­tween areas where water demand exceeds the supply (and additional water use by trees is a problem) and wetter zones (where supply exceeds demand) is needed. For the wetter part of the world, however, the ‘floods’ issue is important. Thomas Enters and Patrick Durst summarize the evidence that changes in forest cover matter less than we’ve all been taught at school. Peter Walpole reflects on the issue from a Philippines perspective; Vu Tan Phuong reviews the evidence for Vietnam. Bruno Verbist and colleagues describe how the perception of ‘essential’ forests lead to conflicts in the past and how data on actual river flows help to negotiate agreements. David Thomas describes how measurement and evidence starts to play a role in basin management in northern Thai­­land, replacing a ‘forest’ centered dialogue.

The second group of articles pro­vides some highlights of current hydro­lo­gy: Nick Chappel reviews modelling ap­proaches, Kurniatun Hairiah and col­lea­gues describe the importance of the litter layer as primary control over water flows and Catherine Muthuri explains how the phenology of the tree determines the net effect on storm and base flows. Roland Koeck and colleagues describe the special importance of limestone soils and the in­fluence of tree cover on snowmelt that in­fluences ‘regularity of flow’. The ap­proach may be transferable to the tropics, the conclusions as such not… Water and nutrients interact in many ways: rainfall brings nutrients along, while water out­flows lead to transfers of nutrients down­stream. Tellez and colleagues provide fresh data on nutrient loading of rainfall in the Amazone, and its sources.

The third block of articles des­cri­bes current thinking and progress on va­rious forms of ‘payments for environ­men­tal services’ related to forests and water. Bob Hope reviews lessons from Costa Rica, Ivan Bond gives an overview of lessons learnt in the IIED network; Horst Weyerhauser relates the challenges faced by the ‘sloping land rehabilitation’ pro­gram in China, that was initiated after the Yangtse floods. Daniel Murdiyarso and Ulrik Ilstedt focus on the role of forests in the provision of drinking water. In a con­tribution from the RUPES program the emphasis is on the various steps that are needed to bridge the different perceptions, illustrated with the case of Lake Sing­ka ­rak. Brent Swallow describes the ‘forests, flowers or flamingo’ choices that are only now beginning to be understood in Kenya. Rowena Sorriaga reviews watershed governance in the Philippines and Bogliotti the re-focus on ‘demand’ issues in the Mediterranean region, as there isn’t much that can be done about ‘supply’.

The ‘case studies’ group, provide further local context for the issues. Gerrit­sen describes the Ayuquila watershed in Mexico; Eric E. Flores describes a case stu­dy of the Bulaba sub-basin and it impli­cations for the management of Panama­nian Watersheds.  Elke Verbeeten ana­ly­zes the situation in Burkina Faso, Olavi Luukkanen and Ping Zhou the Yangtse and Wim Douven the Mekong river in Yunnan close to its origin. Further down­stream, the Mekong river feeds the Tongle Sap in Cambodja, where the primary con­cern is, however, over the disappearance of floodplain forests and its effects on fisheries. Forest roles in sustaining fish is also the focus in Columbia. One step fur­ther into wetlands, three articles des­cribe the peat swamp forests as special case: Jack Riely provides an overview, Henk Wösten describes the situation in Berbak (Sumatra) and Jolanda van den Berg pro­vides a socio-economic context for the ap­proaches to conserve such wetland forests while enhancing livelihoods.

Throughout this newsletter pleas are made to get back to the collection and inter­pre­ta­tion of data. The public debate on forests and water in many countries is highly char­ged with expectations of public bene­fits of forests and attributions of blame to upland farmers using the landscape that are not based on analysis of facts and measurements. There is a need for ‘new hydrology’, but also for approaches that facilitate multi stakeholder negotiations of what combinations of restrictions and ‘re­wards’ will lead to the continued provision of water flows of desirable quality toget­her with land use that allows ‘uplanders’ to make a living. There will certainly be an important role for forests and trees in this respect, once we get the ‘myth-per­cep­tions’ sorted out.

Meine van Noordwijk

World Agroforestry Centre, ICRAF-SE Asia, Bogor, Indonesia

m.van-noordwijk@cgiar.org