Heringa (1) Heringa (1) Recent studies in Switzerland on forest - - PowerPoint PPT Presentation

Heringa (1) Heringa (1)

• Recent studies in Switzerland on forest and

water show us the way how to protect our economic interests:

• Forests act as a sponge: they absorb the

water during the rainy season and gradually release it during the dry season

• Dry season flows really depend on the

amount of forest we conserve

• Every catchment needs to have at least 30%
• f forest, otherwise it cannot provide enough

water for the irrigation of rice fields

Roessel (1) Roessel (1)

• Well, well, my dear colleague, Java is not

Switzerland.

• Infiltration all depends on the geology: in the

lime-stone areas water of Java will infiltrate deeply and emerge in springs after some months – this feeds the dry season flows, not the forest

• Because of that, there is no such thing as a

minimum forest cover

Heringa (2) Heringa (2)

• Java is becoming deforested, the results is

droughts and floods – the government should start a program of reforestation: it should acquire land from abandoned estates

• r farmers and plant trees!
• Planting trees will also provide direct

economic benefits to the government

Roessel (2) Roessel (2)

• You are jumping to conclusions here –

planting trees will not change the geology of the landscape, and will not help on dry season flows.

• To reduce erosion, other measures, such as

terracing, infiltration pits and soil cover have proved insufficient

• Reforestation should only be carried out if

certain soil types expose extreme susceptibility to erosion

Coster (1) Coster (1)

• Both of you are right, to a degree – but we

need to look at data from experiments. At the Forest Research Institute here at the Gunung Batu complex we have started a program of measurements.

• The vegetation determines the permeability
• f the soil.
• Discharge of springs depends on the amount
• f water that percolates into the soil minus

the loss of water because of evaporation.

Heringa (3) Heringa (3)

• Afforestation with fast growing timber trees

has the same hydrological effect as natural forest and is always better than agricultural estates – we need to plant trees to have water for the rice paddies

Coster (2) Coster (2)

• The effect of forests on water depends on

the elevation. Lysimeter measurements indicated that the evaporation of a free soil surface 1200, 900 and 600 mm per year at locations with an elevation of 250, 1500 and 1750 m a.s.l., respectively

Roessel (3) Roessel (3)

• In fact, forests without undergrowth and

without good humus formation are not

• helping. A soil cover with grass, dense

herbaceous or shrubby vegetation, however, will be much more effective – it’s not the trees, but the soil cover that matter

Coster (3) Coster (3)

• Measurements by the Forest Research

Institute showed that well maintained tea, coffee, rubber and kina plantations are from a hydrological point of view nearly the same as forests (planted or natural) – all are better than agricultural fields.

• Fires in the grass wilderness in the

mountains stimulate water run off and erosion.

Heringa (4) Heringa (4)

• In summary, your arguments don’t convince

me at all: the problems with ‘watershed functions’ are really urgent and they can be cured with reforestation, so let’s get started!

Coster (3) Coster (3)

• Afforestation in the low lands will decrease

the discharge (including that in the dry season), because of the high evaporation rate from the trees

• In the mountains, however, the loss by

transpiration is less and the rainfall is higher, so the net effect of trees is positive: the increased infiltration into the soil more than

• ffsets the increased water use by trees
• We need better data !

• r – what can we do to help people and institutions

adapt to the rapid changes in lives and landscapes

i n S o u t h E a s t A s i a

Bridging between local, policy and Bridging between local, policy and modellers modellers’ ’ perceptions of trees, forests perceptions of trees, forests and watershed functions and watershed functions

Meine van Noordwijk, Laxman Joshi, Ai Farida & Kevin Jeans ICRAF-SEA, Bogor, Indonesia

Local Ecological Knowledge Modellers’ Ecological Knowledge Public/Policy Ecological Knowledge

Based on ‘categories’ Based on ‘processes’ direct ‘observables’ includes balance sheets

Laws city Local govt National govt USLE engineers Guest Ecohydro- logist women men women men lowland upland

stem-flow through-fall rainfall cloud interception lateral

• utflow

percolation recharge infiltration surface evaporation transpiration canopy water evaporation uptake quick- flow base flow { surface run-on sub- surface lateral inflow surface run-off Stream:

the trees use water What matters most in AF:

Strategic landscape position of ‘filters’ can greatly reduce downstream effects Their litter protects soil & infiltration

Traditional image

• f Southeast Asia

Forest People

Agricultural lands

Conservation Protective Production

Forest

Upland crops Paddy rice Tree crops Plantations

Farming systems 1 = Lowland rice 2= Tree crops 3= Root & tuber 4= Upland intensive mixed 5= Highland mixed 7= Pastoral 8= Forest

:Source: ‘Farming Systems and Poverty: improving farmers’ livelihoods in a changing world’ by John Dixon, Aidan Gulliver and David Gibbon, 2001; FAO and World Bank

Fraction of Indonesia's population

Rice&Cities below UCM Root tuber Rice&Cities below forest UCM below tree crops Upland crop mosaic (UCM) Tree crops Tree crops below forest Forest below UCM Forest below tree crops Root tuber below forest Forest Tree crops below UCM UCM below forest Rice&Cities

5% 50% 25%

‘Forest’ Cover B C W

Forest

conservation protection production

Intensive agriculture

Tree plan- tations

Agrofor- estry/ eco- agriculture Agricultural lands

Conservation Protective Production

Forest

Upland crops Paddy rice Tree crops Plantations

Tree crops

Poverty

Strong links between watershed functions & biodiversity: every catchment needs 30% forest cover Clean water needed for biodiversity

Cause Solve INRM

Problem analysis Problem analysis

Four stages in developing ES reward mechanisms

Stage Providers, sellers of ES Interme- diaries Beneficies, buyers of ES Scoping Rapid As- sessment of Marketable ES Identifying partners Negotia- tions Monitoring agreement

II I III IV

RUPES = Rewarding Upland Poor for the Environmental Services they provide

10 steps in bridging perspectives & action 10 steps in bridging perspectives & action

• 1. Characterization & diagnosis
• f problems and issues
• 2. Landscape appraisal
• 3. Understanding the flows of

water

• 4. ASB-matrix characterization of

land use options from private/ social economic perspective and local/global ES impacts

• 5. Characterization of landscape

mosaic on segregate – inte- grate spectrum

• 6. Tradeoffs between relative

agronomic function (RAF) and relative environmental function (REF)

• 7. The landscape mosaic in

the context existing regulation and incentives at community scale

• 8. Patterns and land use practi-

ces from a multi-stakeholder (incl. gender and equity) perspective

• 9. Clearing misunderstandings

between local, policy and scientific knowledge

• 10. Negotiated agreements,

monitoring compliance

1. 1.Characterization (rainfall, population density, migration status, main agri- cultural enterprises) and diagnosis of main issues and problems related to watershed functions and livelihoods (incl. sources of drinking water Rainfall (mm/yr)

1,074

People/km2

54.6 (5,251/96.1)

Income/occupation

Field crop (Corn, Soybean) Vegetable (Cabbage, Shallot, Green Soybean,

Drinking water Rain and stream Problem

• Drought
• Accessibility

(infrastructure, market, etc.)

• Landslides/Erosion
• Conflict (landuse,

water,..etc.)

Mae Suk Watershed

Bekas Daerah Terkena Banjir dengan Kedalaman Profil Sungai Dangkal Kali Tundo (S Malang district, E Java) – recent landslides & banjir, Brawijaya investigates

Land use change in ‘coffee zone’ Sumber Jaya,

Lampung, Indonesia

Is there a problem with ‘watershed functions’?

A tale of two rivers

Way Besai (Indonesia), 2.5 m rainfall, 100 persons km-2 Mae Chaem (Thailand), 1.5 m rainfall, 10 persons km-2

20 40 60 80 100 120 50 100 150 200 250 300 350 Day of year River debit, m 3 s-1 20 40 60 80 100 120 140 160 180 100 200 300 Day of year Daily rainfall (station level), mm

10 20 30 40 50 60 70 80 90 100 200 300 Day of year Daily rainfall (station level), mm 100 200 300 400 500 600 50 100 150 200 250 300 350 Day of year River debit, m 3 s-1

River flow Rainfall

The hydro-electric dam wants as many days as possible with a debit of >= 25 m3/s

50 100 150 200 250 300 350 400 5 10 15 20 25 30 35 40 45 Target debit, m3/s #days target is met

1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1990 1991 1992 1993 1994 1995 1996 1997 1998 Average

and they are better off now than when the dam was designed, due to the land cover change.....

Water balance Sumberjaya (mm) Water balance Sumberjaya (mm)

Component 1975 1980 1985 1991 1995 Rain 2531 2797 2959 2459 2663 Evapo-transpiration 1162 1119 1166 741 662 Quick-flow 237 293 382 374 342 Base-flow 1132 1385 1411 1344 1659 %Quickflow 17 17 21 22 17

data PU dianalisa oleh Prof. Naik Sinukaban dan Dr. Tarigan, IPB

50% of catchment still forested Only 10% still forested

5 10 15 20 25 30 20 40 60 80 100 120 140 Rainfall, mm day-1 River flow, mm day -1

1975-1981 1982-1988 1990-1998 1st quarter 2nd quarter 3rd quarter 4th quarter

Way Besai Mae Chaem Wettest month in Mae Chaem is approaching Way Besai

Mae Kong Kha Watershed

Adapted from M.R. Smansnid Svasti

• 3. Understanding the flows of

water and consequences for lateral flows (entrainment, filtering) of soil, nutrients, pollutants etc.

1 4 2 3 5

WaNuLCAS model

Zone 1 Zone 2 Zone 3 Zone 4 Layer 1 Layer 2 Layer 4 Layer 3

Lateral inflows Vertical drainage Lateral

• utflows

Vertisols

0.1 0.2 0.3 0.4 0.5 0.6 0.7 Natural forest Agriculture Degraded

Mollisols 0.1 0.2 0.3 0.4 0.5 0.6 0.7 N a t u r a l f

• r

e s t A g r i c u l t u r e D e g r a d e d SoilQflow PlantAv Inacceess. Alfisols 0.1 0.2 0.3 0.4 0.5 0.6 0.7 N a t u r a l f

• r

e s t A g r i c u l t u r e D e g r a d e d Andisols 0.1 0.2 0.3 0.4 0.5 0.6 0.7 N a t u r a l f

• r

e s t A g r i c u l t u r e D e g r a d e d N a t u r a l f

• r

e s t A g r i c u l t u r e D e g r a d e d Inceptisols 0.1 0.2 0.3 0.4 0.5 0.6 0.7 N a t u r a l f

• r

e s t A g r i c u l t u r e D e g r a d e d Oxisols 0.1 0.2 0.3 0.4 0.5 0.6 0.7 N a t u r a l f

• r

e s t A g r i c u l t u r e D e g r a d e d Entisols 0.1 0.2 0.3 0.4 0.5 0.6 0.7 N a t u r a l f

• r

e s t A g r i c u l t u r e D e g r a d e d Aridisols 0.1 0.2 0.3 0.4 0.5 0.6 0.7 N a t u r a l f

• r

e s t A g r i c u l t u r e D e g r a d e d Ultisols 0.1 0.2 0.3 0.4 0.5 0.6 0.7 Spadosols 0.1 0.2 0.3 0.4 0.5 0.6 0.7 N a t u r a l f

• r

e s t A g r i c u l t u r e D e g r a d e d

Pedotransfer functions – assuming BD/BDref 0.7 , 1.0 , 1.3

Ultisols 0.1 0.2 0.3 0.4 0.5 0.6 0.7 N a t u r a l f

• r

e s t A g r i c u l t u r e D e g r a d e d

Loss of ‘soil- quickflow’ => more overland flow Loss of plant- available water

Visualizing macroporosity: Blue dye infiltration

Earthworms make macropores

• 4. Characteristics of land use systems as re-

gards yield/labour/cash input requirements/ profitability and impacts on water flows (eva- potranspiration, impacts on soil compaction, surface cover)

Forest Multistrata coffee Simple shade coffee Sun coffee Vegetables Ricefields

# pple supported m-2 Returns to labour (private) Returns to labour (social) Annual water use Effects

• n soil

BD

precipitation infiltration interception

Esoil + Eveg Einterc Qslow Qquick

Energy- limited evapo- transpiration potential Modification along river A B

Precipitation = P Evapotranspiration = E River flow = Q

Qquick Qslow Eveg Esoil Eirrig Einterc

Irrigation = I

Infiltration into the soil Green canopy Overland flow

Precipit at ion = P Evapot ranspirat ion = E River f low = Q

Qquick Qslow Eveg Esoil Eint erc Eirr

I nf ilt rat ion ~ soil st ruct ure Sprinkler irrigat ion ~ air humidit y Soil evaporat ion ~ soil cover (mulch) I nt ercept ion ~ leaf area index (Deep) wat er upt ake ~ phenology

• 1. Transmit water
• 2. Buffer peak rain events
• 3. Release gradually
• 4. Maintain quality
• 5. Reduce mass wasting
• Q/P=1-(E/P)
• ΣQabAvg/ΣPabAvg
• Qslow/P = (Pinf – ES+V)/P
• Qualout/Qualin
• ∆ risk

Scale dependent

GenRiver Overview

GenRiver – Generic River model on River Flow For homogeneous

• r Patchy rain…

• 3. Subsurface flow into

streams: ‘interflow’ or ‘soilquickflow’

• 1. Interception & evaporation

from wet surfaces

• 2. Overland flow into

streams: quickflow

1 2 3 Soil quickflow: drain towards ‘field capacity’ SoilQuickFlow: Max(0,Soil- FieldCap) Saturation Saturation GW store Percolation Fraction GW release Fraction Baseflow FC ‘Two-tank model’ RootZone store

• 5. Characterization of landscape mosaic on

segregate – integrate spectrum, and consequen-ces for the way productive and environmental functions are being met

Mae Kong Kha Mae Suk

v e g e t a t i v e f i l t e r s t r i p

Field runoff

Permanent forest

paddy rice: paddy rice: a major sediment filter a major sediment filter

field runoff

Forest fallow

Thailand

How much sediment really goes downstream??

Tools for understanding landscape Tools for understanding landscape-

• level functions

level functions

Innovation: Innovation: Nilam Nilam ( (Pogostemon Pogostemon) strips as ) strips as vegetative filters in coffee vegetative filters in coffee by HKM farmers, by HKM farmers, Sumberjaya 2004 Sumberjaya 2004

Relative agricultural function (RAF) Relative ecological function (REF)

A

Initial use

B

Degra- dation

C

Rehabilitation

E

Critical loss of ecological functions

D

Intensification by tech- nical substitution of ecological functions

6.Tradeoffs between relative agro- nomic function (RAF) and relative environmental function (REF)

c f

Litter layer

k1 t k2

Litter input

Decay of woody roots BD/BDref

Corg/Cref

Worm population

G-D

Land use practices

Root turnover Soil compaction by trampling & slaking quantity quality Soil tillage

Macropores SOM Inherent soil proper-ties (incl. texture)

• 7. Analyzing the existing patterns and land

use practices from a multi-stakeholder (incl. gender and equity) perspective

Volc.ash Volc.ash Tuff&Volc.lava Tuff+ lava+ ash Tuff+ lava+ ash Tuff Ranau Tuff&Ash Tuff&Volc.lava Granite Colv.ash+ Volc.tuff Basalt

Parent materials Parent materials

Low Medium High LU intensity Erosion rate

• 8. Understanding the existing problems and

conflicts at the level of local, policy and scientific knowledge: is there a shared perspective (but possibly different apprecia- tion of the various outcomes) or is there a need for ‘levelling off’ as first step in nego- tiations

LEK MEK PEK

Local Ecological Knowledge Public/Policy Ecological Knowledge Modellers’ Ecological Knowledge

Paningahan – Nagari with good gover- nance, forest protection, interest in rehabilitation Lake Singkarak

Can/should they get bigger share in hydroelectricity royalties as PES?

LEK Result on water source

Pine Needles leaf Fire Cutting Deep root Land coverage Soil evaporation Groundwater Water Source Used for fire wood and hut Tree density Banio, Surian, Bayua, Madang (Natural Forest) Big leaf Crop Grass Season Soil type

Ombilin river -> Indragiri (Riau) HEPP PLTA Singkarak

Scenarios for 3 scales

1 2 3 4 5 6 7 8

Natural Forest Current LU mix Sev.Degraded

mm day-1 HEPP water use River Outflow Lake Evaporation Transpiration Interception

GenRiver1.1 calculations for Lake Singkarak

Rehabilitasi Hutan Pengkayaan Vegetasi Kebun Lindung I I Kebun Lindung I

Kali Tundo case study Brawijaya team

STOP TAX PAY

Baseline of acceptable behaviour Regulation of unacceptable behaviour

• 10. Follow up to ne-

gotiated agree- ments, monitoring compliance and impact on environ- mental services and peoples’ livelihoods

10 steps in bridging knowledge 10 steps in bridging knowledge

• 1. Characterization & diagnosis
• f problems and issues
• 2. Landscape appraisal
• 3. Understanding the flows of

water

• 4. ASB-matrix characterization of

land use options from private/ social economic perspective and local/global ES impacts

• 5. Characterization of landscape

mosaic on segregate – inte- grate spectrum

• 6. Tradeoffs between relative

agronomic function (RAF) and relative environmental function (REF)

• 7. The landscape mosaic in

the context existing regulation and incentives at community scale

• 8. Patterns and land use practi-

ces from a multi-stakeholder (incl. gender and equity) perspective

• 9. Clearing misunderstandings

between local, policy and scientific knowledge

• 10. Negotiated agreements,

monitoring compliance

Kulekhani

Singkarak Sumberjaya Bungo

Kalahan

Manila

Bhakun

Act ion r esear ch sit es

Watershed functions Biodiversity Carbon stocks