38
INVESTMENT PLAN FOR WATER USE EFFICIENCY, ACCESS TO WATER RESOURCES AND BALANCED POLICY OUTCOMES MAY 2011 AUTHOR: PROFESSOR RODGER SANDS
INVESTMENT PLAN FOR WATER USE EFFICIENCY,
ACCESS TO WATER
RESOURCES AND BALANCED
POLICY OUTCOMES
MAY 2011
AUTHOR: PROFESSOR RODGER SANDS
CONTENTS
1. INTRODUCTION .................................................................................... 2
2. PREVIOUS FWPA SPONSORED RESEARCH .................................... 3
3. SWOT ANALYSIS ............................................................................... 10
4. CONTEXT ............................................................................................ 14
4.1 Plantations and water balance ..................................................... 14 4.2 Monitoring water use .................................................................... 15 4.3 Remote sensing ........................................................................... 16 4.4 Models of water use ..................................................................... 17 4.5 Environmental flows ..................................................................... 20 4.6 Water allocation ........................................................................... 21 4.7 Water use efficiency ..................................................................... 24 4.8 Economic and environmental benefit ........................................... 24 4.9 Plantations and salinity ................................................................. 25 4.10 Plantations and water quality (other than salinity) ...................... 25 4.11 Native forests ............................................................................. 26 4.12 Climate change and carbon ....................................................... 27
5. RECOMMENDATIONS ........................................................................ 29
6. RESEARCH PLAN .............................................................................. 33
7. ABBREVIATIONS ............................................................................... 34
8. REFERENCES..................................................................................... 35
9. APPENDIX 1: CONSULTAION ........................................................... 37
2
1. INTRODUCTION
Water and forests have reciprocal effects on each other. Water is
required for growth and can limit productivity when water is in short
supply, a common occurrence in many plantation areas in Australia.
Water management to increase productivity is best considered in the
FWPA silviculture and genetics research portfolios. This plan concerns
the reciprocal effect, the impact that forests have on water in the
wider environment. There are three main aspects to this. The first is
salinity. Tree removal over large areas of southern Australia brought
saline groundwater close to the surface and re-establishment of trees
may help reverse this. Plantations are unlikely to be profitable in areas
where salinity is a problem. The second is water quality (other than
salinity). Native forests and plantations, properly managed yield higher
quality water to catchments than do alternative land uses. The third is
the impact forests, both native and plantation, have on water yield to
streams and groundwater in conjunction with other land uses. This is an
important and sometimes controversial issue and will be the major
focus of this research plan. Native forests have the largest impact on
water because of their extent and their proximity to cities. However,
from the perspective of FWPA and its levy payers, the focus for
investment will be on plantations managed for high value wood
products.
3
2. PREVIOUS FWPA SPONSORED RESEARCH
Research over the period 2005-2010, completed or continuing, is
summarized in Table 1. FWPA contributed 28% of funding (Figure 1).
Government (Commonwealth and State) contributed 70% of total
funding and this was mainly due to the large Commonwealth
investment in PRC115-0809 (Table 1). Direct industry investment was
low at 2%.
PN04.4010: Regional scale, spatially explicit quantification of
plantation forest water use
Differences in canopy transpiration should be reflected in differences in
canopy temperature. The objective of this study was to determine
whether measuring canopy temperature with a hand held device
could quantify water use by Eucalyptus globulus plantations in the
Green Triangle region such that spatial and temporal differences in
transpiration could be determined and applied regionally. The
technique was unable to do so because the diurnal variation in
transpiration masked differences between locations. For a remote
sensing technique to be suitable it needs to get instantaneous
measurements across a region. Satellite or aircraft techniques are
required to meet this requirement and further investment in remote
sensing will be a recommendation in this plan.
PNC064-0607: Quantifying plantation water use in the Green Triangle
Water use in Eucalyptus globulus and Pinus radiata plantations was
measured over 3 years on sites in southwest Victoria of which the
hydrogeology contrasted with the extensive network of sites previously
monitored in the karst areas of southeast South Australia (Benyon and
Doody 2004). Current models produced unbiased predictions of
annual water use of plantations with closed canopies at sites where
tree roots do not access groundwater but with poor accuracy at sites
where roots take up groundwater. Significant reductions in run-off or
recharge were predicted to result from establishment of new
plantations in southwest Victoria.
Based on 22 closed-canopy sites across the whole Green Triangle
region, plantation water use was largely determined by rainfall except
at sites where groundwater was accessible (defined as <6m from the
surface) in which case it was determined by potential
evapotranspiration (see Benyon and Doody (2004) for more detail).
The extent and quality of the research in the Green Triangle is excellent
and pioneering. However, the results apply to defined situations and
assumptions. Water policy developers have scaled up this information
4
and applied it across the whole region and over areas the original
data did not represent and was not claimed to represent. This
highlights the importance of having extensive and detailed information
and being able to credibly present this at negotiations on allocation.
The researchers agree. The last sentence in the executive summary of
the final report on this project reads: 'with such large quantities of water
involved, potentially worth >$200 million, it is important to ensure
accuracy in estimates of plantation water use. The additional science
necessary to improve current estimates would cost a small fraction of
the potential value of the water involved.' This of course presupposes
that management changes as a result of the improved information.
PNC073-0708: Decision support for water use efficient plantation
management and wood production
This research examines the water use efficiency for wood production of
Pinus radiata, Eucalyptus globulus and Eucalyptus nitens plantations in
predominantly 'Mediterranean' type climates (hot dry summers and
cool wet winters) across southern Australia. It shows that both wood
production and the water use efficiency for wood production will be
increased by any means (breeding or management) that increases
the leaf area index during the early part of the growing season (winter
and spring). The implication is that increasing water use under these
circumstances (providing water and not carbon and nutrients are
growth limiting) will increase the water use efficiency of wood
production. It follows that the same volume of wood could be grown
using the same volume of water by planting a smaller area of higher
water availability.
The research also shows that promoting an increase in leaf area index
exposes the plantation to the risk of tree deaths during drought years
but that appropriate planting densities and thinning regimes can
control this.
PRC071-0708: The impact of plantations on water security
The objectives of this review can be summarized as
to identify regionally specific hydrological issues across Australia
relating to plantations and water interception, to analyse the
magnitude of the impacts of plantations on water flows and to
identify where research can inform policy.
to review forest management impacts on water use efficiency,
the impacts of other crops sharing catchments with plantations
and the role of native forests in water supply.
5
Consequently this review was valuable in informing this plan and
indeed some of the research recommendations of this review have
been carried forward into this plan. An important conclusion from this
review was that the impacts of plantations on water security at the
regional and national scale have been over-stated but that local-scale
impacts can be important in certain areas where the proportion of
plantation to other land use is high. The review emphasized that
plantations in predominantly groundwater systems are of more
concern than surface water catchments such as the Murray Darling
Basin. The report provides comprehensive information, state by state,
and as such is a valuable reference.
The review made recommendations for future research:
Consolidate national data sets. While this will not be a
recommendation in this plan, it is acknowledged as an important
requirement to assist future research and policy development.
Identify cost effective and practical methods to monitor
plantation water use and impacts. This will be a
recommendation in this plan through developing models at finer
scales of space and time and promoting research in remote
sensing.
Develop and apply methods to determine' significance' and
'thresholds'. This will not be a specific recommendation in this
plan. However, it may be incorporated in the model
development foreshadowed above.
Investigate and apply methods to assess the net benefits and
impacts of plantations on economic, environmental and social
values. There will be a recommendation in this plan framed
around this.
Investigate climate change and management impacts on
native forests and catchment water flows. This clearly is very
important but not a responsibility of FWPA. It will not be a
recommendation in this plan.
PNC061-0405: Predicting and managing the impacts of commercial
plantations on water balances
The objective of this research was to develop models to predict
transpiration and the hydrological consequences in existing or
proposed plantations in relation to their location and management. A
primary objective was to determine the impact of plantations in
catchments containing various land uses. A forest growth model 3PG+,
6
(Landsberg and Waring 1997, Morris 2003) was integrated with the
agricultural soil water balance model PERFECT within the Catchment
Analysis Tool (CAT) framework (Beverley et al. 2005). This framework
comprises a suite of farming system models.
The predictive value of the models was mixed, being able to predict
stream flow better in some catchments than others. This research is
certainly a valuable step in the right direction and a basis for further
research. It acknowledges the need to place forest models within
broader catchment models that incorporate other land uses. There is
a way to go however before such models can be used at appropriate
temporal and spatial scales that can partition water use between
various land uses.
PNC143-0809: Predicting Eucalyptus nitens plantation water use using
growth parameters
This research in progress uses a different approach to measuring
plantation water use and its impact on streamflow. The objective is to
develop empirical relationships between Eucalyptus nitens growth
parameters (e.g. basal area) and water use. These relationships could
then be integrated into forest estate models that could simultaneously predict water use and wood volume.
PRC115-0809: Methods to accurately assess water allocation impacts
of plantations
This is a large continuing research project where the dominant funders
are the National Water Commission (NWC) and CSIRO. FWPA
contributed 12% of the funding. This research has two parts. The first is
whole catchment scale modelling of the impacts of plantations on
water yields and flow durations using catchment scale models that use
average climate data and with limited capacity to analyse inter
seasonal flows and land uses other than forests compared with grass.
These are valuable but can only provide qualitative information at the
broadest level. More exciting is the second part, which like PNC061-
0405 attempts to account for all land uses in catchments, not just
plantations, and which attempts to do so at finer scales of space and
time. This research is ongoing and the final results currently are
unavailable. Preliminary reports suggest that, like PNC061-0405, this will
provide valuable leads for future research.
7
Table 1: Investment by FWPA in water projects 2005-2010
Completed
PROJECT TITLE FWPA COMMON-
WEALTH *
STATE GOVT INDUSTRY
(direct)
TOTAL %
FWPA
REGION SPECIES
PN04.4010 Regional scale,
spatially explicit
quantification of
plantation forest
water use
$39,254 $19,627 $9,814 $9,815 $78,510 50 Green
Triangle
E.globulus
P.radiata
PNC064-0607 Quantifying plantation
water use in the
Green Triangle
$187,222 $220,325 $347,000 $754,547 25 Green
Triangle
E.globulus
P.radiata
PNC073-0708 Decision support for
water use efficient
plantation
management and
wood production
$94,600 $40,500 $52,500 $187,600 50 Southern
Australia
Eucalypts
P. radiata
PRC071-0708 The impact of
plantations on water
security
$60,000 $30,000 $30,000 $120,000 50 National Native
and
plantation
PNC061-0405 Predicting and
managing the
impacts of
commercial
plantations on water
balances
$250,000 $79,800 $170,200 $500,000 50 Victoria
and
Tasmania
Eucalypts
and P.
radiata
8
Active
PROJECT TITLE FWPA COMMON-
WEALTH **
STATE GOVT INDUSTRY
(direct)
TOTAL %
FWPA
REGION SPECIES
PNC143-
0809
Predicting Eucalyptus
nitens plantation water
use using growth
parameters
$303,000 $525,270 $828,270 37 Tasmani
a
E. nitens
PRC115-
0809
Methods to accurately
assess water allocation
impacts of plantations
$200,000 $1,402,000 $1,602,000 12 National Native
and
plantation
Overview
Completed $631,076 $390,252 $527,014 $92,315 $1,640,657 38
Active $503,000 $1,402,000 $525,270 $2,430,270 21
Total $1,134,076 $1,792,252 $1,052,284 $92,315 $4,070,927 28
* Mainly CSIRO and NWC
9
Figure 1: Proportion of dollar investment in water projects from various donor agencies, 2005-2010.
10
3. SWOT ANALYSIS
Category Strengths Weaknesses Opportunities Threats
Monitoring Good information on
water flows in some
catchments
Lack of information on water
flows in some critical
catchments
Lack of commitment to
continue monitoring
Generally poor representation of
all the components of the water
balance
To continue monitoring
To establish a national database
Poor funding and lack of
commitment will result in
discontinuity or ceasing of
monitoring
Models Good (top down)
catchment scale
qualitative models for
average weather
comparing trees with grass
Good (bottom up) stand
scale growth models (3PG,
Cabala, Promod etc) for
plantation species
Models cannot account for
land-uses other than trees and
grass
Models at sub-catchment and
plot level are poor or non-
existent
Models for groundwater systems
are too general and potentially
misleading
Poor integration of top down
and bottom up approaches
Insufficient base data and lack
of integration and application
Develop better models to better
characterise those areas known
to have an impact, and at finer
scales
Incorporate the full range of land-
uses in predictive models
To consider the interactive effects
of drought and climate
uncertainty with the impact of
forests
Better integration of modelling
and monitoring for the
development of proactive
management strategies
Cost and complexity of
developing workable models
Fragmentation of existing
research capability
Lack of reliable data for
validation of modelling
approaches
11
Category Strengths Weaknesses Opportunities Threats
Remote sensing Potentially inexpensive
and effective method of
measuring
evapotranspiration at
regional scales
Does not measure all
components of the water
balance
Current techniques not largely
tested in Australia and not well
suited to Australia
Current techniques subject to
considerable error
Do not operate at finer temporal
scales
Difficulty in scaling single point to
daily values
To develop cost-effective remote
sensing technologies at finer
scales
Rotation length monitoring of
water resources
Potentially highly skilled and
difficult interpretation may
limit uptake by industry
players
Poor validation of existing
approaches in plantations
Allocation Good process based
understanding of the
controls on tree and
catchment water balance
Known and assumed water yield
reductions associated with
conversion of pasture to forest
Lack of knowledge on impact of
the range of agricultural
practices and the extent to
which they will be deployed
across large areas
To develop systems for
meaningful and fair interaction
with water policy developers to
ensure that forestry gets a fair
deal in water allocation
Ability to have water allocated on
the basis of quantity rather than
area of land to be planted
Proliferation of the
requirement for plantation
owners to obtain water
licences for new land
Uncertainty about whether
any retrospectivity will apply
for areas already planted (i.e.
not permitted to replant)
12
Category Strengths Weaknesses Opportunities Threats
Water use
efficiency (WUE)
Good silvicultural research
to optimise WUE
Poor interaction between forest
owners and water policy
developers
Models are not good enough to
provide the best information at
the required scales
Proven silviculture not being
practiced
Allocation procedures not suited
to allocation of water by
amount
Confusion over use of the term
water use efficiency at the
scales from leaf to catchment
To make best use of a given
amount of water allocated
To improve plantation productivity
and therefore profitability
To provide security of the
plantation estate
Unreasonable expectations
of other land users
Care need to make sure that
practices do not make trees
more vulnerable to drought-
induced mortality
Triple bottom line
(environment,
economics and
society)
Plantations provide a
product of high national
importance
Plantations provide
environmental benefits
that competing land-uses
cannot
Plantations viewed by many as
less important than other
agricultural land uses such as for
food production
Environmental benefits of
plantations not widely accepted
in the broader community
To ensure that water policy
developers understand the full
value of plantations
Improve value of forest products
to match or exceed that of
alternative land uses
Forestry does not get a fair
deal from negotiations
Value of the forest products
may be less than competing
land uses
13
Category Strengths Weaknesses Opportunities Threats
Salinity
Water quality
other than salinity
Trees planted in recharge
areas can rehabilitate
saline sub-catchments
Both native forests and
plantations, properly
managed, yield high
quality water
Plantations have less of a
'human face' than does
agriculture
Plantations established for wood
alone are non-commercial in
saline areas
Native forest to plantation forest
impacts poorly understood
To provide good quality drinking
water to urban populations and
to agriculture
To establish mechanisms to give
the full value for rehabilitation
plantings that include the value of
the water
Commercial tree planting in
stream management zones (with
appropriate safeguards)
Agriculture not releasing
targeted recharge areas for
tree planting
Wildfire
Poor practice, especially
roading
Native forest Dominates the supply of
quality water to urban
areas
Regrowth management
Fire control
Wildfire and inappropriate
prescribed burning
Climate uncertainty
Fragmentation of research
Climate change
and carbon
Forests sequester carbon
Construction in wood
emits less carbon-dioxide
than competitors
Any increase in WUE will
increase productivity for
the same amount of water
(BUT see weaknesses)
Any increase in ET will result in
decreased water yield to
streams and/or groundwater
Poor (but improving)
understanding of the effect of
elevated carbon-dioxide
concentrations and increased
temperatures on WUE and ET at
catchment scales
Poor community understanding
of the benefits of forestry in
ameliorating climate change
and providing an
environmentally superior
building material
To incorporate regional
predictions of climate change,
and the impacts of these on
plantation health and
productivity, in models
Uncertainty about climate
trends at regional level?
Drier climates in some regions
Changed growing
environments
Competition with agriculture
Increases in pests and
disease
Increased wildfire
Tree mortality
14
4. CONTEXT
4.1 Plantations and water balance
When rain falls on a catchment some is held up and evaporated
directly from leaves while the rest falls to the ground and adds to soil
water storage if there is capacity to do so or else runs off to streams or
adds to ground water. Counteracting this is evapotranspiration (ET),
which is the sum of water evaporated directly from the leaves, water
transpired through leaves and water evaporated from soil and free
water surfaces. Apart from rainfall, ET is usually the largest component
of this water balance and particularly in forested catchments. ET from
forests usually is greater than from grassland because of a combination
of (a) more rain evaporated directly from forest canopies, (b) forest
canopies having higher water conductances from canopy to
atmosphere and (c) forest trees having deeper root systems, allowing
them to access water unavailable to more shallow rooted species,
particularly in the dry season.
Consequently, plantations generally use (evapotranspire) more water
than rain-fed agriculture. The extent to which this occurs is often
overstated because (a) most plantations in Australia have been
established on cleared native forest where the differences are not as
marked, (b) most comparisons have been made between plantation
and grass without reference to other more consumptive agricultural
land uses and (c) the area of plantation in most catchments is small.
Nevertheless, in areas where the proportion of plantation cover is high
there may be legitimate concern about the extent of water use by
plantations. (There are hydrological implications of multiple rotation
forestry. The observed declines in second rotation productivity in the
hardwood sector seem to be related to decreased soil water
availability as a result of the first rotation. Inter-rotation management
may have significant role to play in the management of the
hydrological impacts of plantation forestry).
Climate drives the system. Water flows in a catchment are mainly
determined by the amount, intensity and distribution (spatial and
temporal) of rainfall. Water flows will be less in low rainfall areas and in
areas experiencing drought. The proportion of rainfall (not amount) ET
contributes in plantations usually increases as rainfall decreases and
consequently the relative impact of plantations will be greater in areas
experiencing low rainfall. Water flows may be low or absent in dry
years.
For convenience, catchments can be divided into surface water
15
catchments where water flows are mainly directed towards streams
and groundwater catchments where water flows are mainly directed
towards groundwater. In the groundwater catchments of the Green
Triangle (SE South Australia and SW Victoria) and in the Gnangara
mound close to Perth, the potential for excessive water use by
plantations in situations where they may be directly accessing
groundwater is a concern to water resource managers.
O'Loughlin and Nambiar (2001) discuss the range of issues concerning
plantations and water.
4.2 Monitoring water use
There is an important need for cost effective methods of monitoring
water use over the long term. Clearly the best way to monitor runoff to
streams and groundwater levels is to measure them directly by
gauging streams and measuring changes in groundwater levels. Many
catchments containing plantations and native forests have been
monitored and some for long periods. However, direct monitoring is
expensive to maintain and there is reluctance by some authorities to
continue measurements when they can see no obvious financial
benefit in doing so. The financial implications of not doing so could be
significant.
There is widespread agreement amongst industry and amongst
research providers that there is a real need for a comprehensive
national database sharing all available information. There is a range of
databases either contemplated or in early phase of operation. The
National Water Initiative (NWI) requires government agencies to report
hydrological data from some forested catchments. Currently this data
is not freely available and presented in a form useful to all researchers.
Also private entities and research organizations are not required to
submit their data and this is needed in order for this to be a nationally
relevant database. The Water Information Research and
Development Alliance (WIRADA) is a partnership between CSIRO and
the Bureau of Meteorology that has the aim, amongst other things, to
'hold and manage all of Australia's water data'. Their website
(www.csiro.au/partnerships/WIRADA.html) says 'Water resources
information is currently collected and held by hundreds of
organisations across Australia, making it difficult to monitor the status
and use of Australia's water resources and to accurately forecast water
availability. The Bureau of Meteorology’s role has expanded to include
transforming Australia’s water resources information by improving its
accessibility, integration and use. These improvements will be
achieved through substantial innovation and will yield huge benefits
through more informed policy and infrastructure decisions'. However,
16
this information is not yet accessible to the broader research
community. Donohue et al. (2010) discuss the numerous Australian
spatiotemporal datasets that have been generated for analysing rates
and trends in hydroclimatological conditions, particularly in
evaporative demand.
Researchers interviewed were unanimous in their plea for a
consolidation of national data sets. This was also a key
recommendation of the FWPA sponsored PRC071-0708 (page 2).
Comprehensive national information is needed to adequately develop
and validate predictive models for use by water resource managers
and policy developers. Researchers who need this data are confused
about the current stage of development, freedom of access, extent of
information and applicability to their particular requirements of
national databases either under construction or contemplated. There
is a need to rationalize this to provide a database that actually works
for the benefit of all interested parties. It is easy to be pessimistic about
this. Past experience in other areas show that such enterprises may
start with collective enthusiasm but end with indifference. The key is to
have clear and accountable procedures that all parties accept and
agree to. The initial challenge is to work out how to do this and to
maintain it. This would involve evaluating the role, accessibility and
applicability of existing datasets. The objective might be to identify an
already existing database and provide recommendations on how this
may be further supported to become complete and available to all
researchers. This is not a research project and therefore not
appropriate for FWPA investment. Rather it is a service required by and
requested by researchers. Funding and motivation should come from
elsewhere.
4.3 Remote sensing
The cost of monitoring by direct on-the-ground measurement is high.
Remote sensing of ET is a cost-effective possibility. After rainfall, ET is the
dominant variable in the water balance. The advantage remote
sensing offers is the potential ability to get virtually instantaneous
estimates of ET over extensive regions at a resolution at which
differences in land uses can be partitioned at the scale at which
management decisions are made. There have been several studies
using remote sensing techniques such as Advanced Very High
Resolution Radiometer (AVHRR), the Surface Energy Algorithm for Land
(SEBAL), and Mapping Evapotranspiration at high Resolution with
Internalized Calibration (METRIC). MODIS (Moderate Resolution Imaging
Spectroradiometer) can remotely estimate Leaf Area Index (LAI),
which is related to evapotranspiration. These systems have not been
comprehensively tested in Australia and their accuracy in Australia is
17
questionable. Australia has a limited number of flux towers and none in
a plantation setting. More towers are needed to improve the
accuracy of these remote sensing systems in the Australian
environment. Flux towers are expensive to construct and maintain. The
NWC recently funded studies into remote sensing that aim to partition
ET between different land use types (e.g. plantation forestry, cropping,
dryland pasture, irrigated agriculture, wetlands, floodplains and native
forest) at the catchment scale. One of these used SEBAL to look at
water use in the green triangle (SKM 2010). The resolution in this study
was 30 metres, possibly fine enough for the purpose. They compared
the on-ground sap-flow measurements of Benyon and Doody (2004,
2005) with SEBAL ET data and found a good match at 3 of the 7 sites
and that on average SEBAL ET was 15% lower than field-based ET. They
considered the differences to be 'a result of the different processes and
errors associated with comparing point-based measurements with
area-based measurements.' Herein lies the dilemma. The detailed
data of Benyon and Doody are based on individual tree
measurements that need to be scaled up to represent the variability
that occurs over the whole region. The area-based measurements of
SEBAL need to be scaled down to meet the precision of the single-tree
data of Benyon and Doody. Even although there is more data on tree
water use in the Green Triangle than in any other plantation region in
Australia, there is still insufficient ground data to provide
comprehensive and reliable data on which to base water policy for
the region.
SEBAL is subject to error arising from 'self calibration' routines the
algorithm uses to scale estimates of sensible heat and the temporal
scaling of the image snapshot. There is still a long way to go before
accurate estimates of ET can be derived routinely via remote sensing
approaches. While remote sensing of ET is important, integration with
and estimation of the other components of the water balance will be
critical to resolving regional water balance issues.
The forest research community is enthusiastic about the possibility of
using remote sensing at appropriate scale but vague about the current
state of knowledge and applicability. This plan will recommend further
research in remote sensing.
4.4 Models of water use
Simple surface water models such as Forest Cover Flow Change (FCFC,
Brown et al. 2006) represent an average condition at the whole of
catchment scale. They give flow duration curves i.e. the shape of the
flow. They compare forest with non-forest using average annual
climate. They do not account for land uses other than trees, they do
18
not consider the distribution/position of land use within the catchment
and they do not cope with climate variability. They provide predictions
only of long term mean annual flow. As such they are valuable models
in determining whether or not plantations are likely to have an impact
at the catchment/basin scale but should not be expected to provide
more detailed information than this. These models confirm that in
surface water catchments in Australia, plantations most often have no
impact because they occupy such a small area of the catchment.
However, impacts may be significant at the sub-catchment or plot
scale where plantations occupy a significant proportion of the area or
would be if new plantations were to be established. For example, the
impact of plantations in the Murray Darling Basin (MDB) is almost
invisible at the whole of catchment level but plantations have
significant impacts in the sub-catchments of Tarcutta Creek, Gilmore
Creek, Adjungbilly Creek and Adelong Creek. PRC071-0708 (page 4)
reports estimates that establishing a hypothetical 30,000ha of
plantation in the Adelong Creek sub-catchment would result in a 23%
reduction in stream flow. Large-scale plantation expansion in areas of
low rainfall is likely to reduce local stream flow significantly. However,
currently plantations are established as a mosaic with other land uses
rather than the “wall to wall” plantations of the past and as such have
a lesser impact on water availability.
Similarly, models developed for groundwater have been valuable for
providing general information but have considerable scope for
redefining. Models have poor accuracy where trees are using
groundwater. They do not adequately account for the low water use
during the fallow periods between rotations and the low water use
during the early stages of growth prior to canopy closure. They do not
account for the effect of thinning and spacing and differences in soil
properties. Most investigations have been at plot scale, which is
difficult to extrapolate to regional scale. Also investigations have been
over short time periods, which provide limited information on temporal
variability (O'Grady et al. 2010). The information on which far-reaching
decisions about water allocation and licencing of forest plantations
using groundwater has been on very limited data that mostly over-
estimate water use by plantations.
Current catchment scale models can determine whether plantations
have a significant impact or not on water use (although there is no
robust definition of what is significant and what the thresholds are).
Research and modelling should be focussed in areas where the
impacts of plantation development on the water resource are high.
Water use by plantations can be very variable and site specific. Scale
is an important consideration. Ideally models and decision support
systems should account for all of the variables that determine water
use. Ideally models should be:
19
nationally applicable but locally relevant
simple enough to be applied in practice
flexible enough to account for local circumstances
scientifically sound, and accepted as such
applicable at a scale used in the implementation of policies
able to compare, spatially and temporally, all interceptors in the
catchment (vegetation type and management, irrigated
agriculture, farm dams, groundwater bores, dryland farming,
expansion of perennial pastures)
able to account for differences in extent of different land uses
(eg perennial pastures versus plantation forestry)
able to account for seasonal and inter-annual flows
able to separate the effect of climate change and changing
land use
able to account for the impact of site quality (soil, aspect, slope),
the impact of silviculture (fertiliser, weed control) and tree
(species/genotype)
able to deal with patchiness and mosaics in both hydrological
properties and land use
able to be incorporated into forest management plans
precise enough to locate appropriate places in a catchment to
maximise wood production per unit of water used, which will also
increase water use efficiency)
able to apply over extended time periods
This is a formidable list and it is unlikely and indeed impracticable that
all of these can be accounted for in a universal model. Realistically,
those variables that have the most significant impact on water use and
informing policy for individual circumstances should be identified and
targeted. The effect of location within a catchment can have large
effects on water use. Models are required at a range of scales. The
appropriate scale will be that at which water allocations are made
and at which management decisions are made. Point models do not
show what happens in a catchment farther away and later in time.
Often a catchment will delay and dilute impacts. Trees are penalized
at point scale rather than catchment scale. Long time periods are
involved. Models need to allow for differences in space and in time.
A step in the right direction is the combination model developed in
PNC061-0405 (page 5). Also, PRC115-0809 (page 6) is developing a
combination model that has a forest growth model (3PG) combined
with an agricultural model (PERFECT) each delivering water to a
hydrological model (2CSalt). This acknowledges that land uses other
20
than trees and grass need to be considered. All interceptors in a
catchment need to be included in models. The current trend towards
replacing annual with perennial pastures may well have an effect on
reducing stream flow of the same order of magnitude as plantations.
Sinclair Knight Merz (SKM) and the Victorian Department of Primary
Industry recently looked at modeling the impacts of various land uses in
Victorian catchments. CSIRO and Queensland DPI have developed
the Agricultural Production Systems Simulator (APSIM, www.apsim.info),
which is a modular framework that grows a range of crops, pastures
and plantation forests and details their carbon, water and nutrient
balances. It can compare agricultural and forestry systems at point
scale. The challenge would be to place APSIM within a hydrological
model that delivers water to streams and groundwater. Perhaps APSIM
could be used as an appropriate framework on which to focus future
modeling research. Current models are not sophisticated enough to
account for the range of land uses. Benyon et al. (2007) agree.
There are some very good process-based growth models for Australian
plantation species. The problem is that they have not been
adequately integrated with models for other land-uses, which together
are placed into a hydrological model that delivers water to streams
and/or groundwater at appropriate scale. Validation of such
approaches is difficult as the required ground truthing is often absent.
In most situations the scenarios modelled are unconstrained.
Appropriate models may already exist. The challenge is for better
integration and application of these biophysical models. Most of the
models are validated against the residual term, streamflow, but very
few validate the estimates of ET, which is one of the largest terms of the
water balance. Better testing, validating and improved capacity to
downscale the predictions should be a high research priority.
Improved estimates of water use could cost a small fraction of the
potential value of the water involved.
4.5 Environmental flows
Adequate environmental flows of surface water are necessary to
maintain downstream ecosystem health. Currently the Murray Darling
Basin Authority is calling for increased environmental flows at the
expense of irrigation diversions. There may well be more calls for
greater environmental flows in other surface water catchments across
Australia. Plantations are seen as significant interceptors and may be
asked to make sacrifices to contribute their share. Modelling could
provide a framework for increasing environmental flows by positioning
new plantations within catchments to minimise stream flow impacts
and maximise productivity.
21
4.6 Water allocation
Water intercepting activities, including plantation water use, can
become an issue in catchments where water is near, at, or over
allocated.
Perth extracts groundwater from the Gnangara mound. The amount
Perth extracts from the mound has fallen from about 50% to 25% of its
consumption and falling. A desalination plant providing water at a
much greater cost and at a considerable energy cost has made up
the shortfall. Water availability from the mound has fallen because of
(a) continued extraction of urban water, (b) 22,000 ha of un-thinned
Pinus pinaster plantations and (c) an extended drought period.
Recent research has shown the major reason for the decline to be the
current 35-year drought, but there is no recharge under the Pinus
pinaster, which is in poor condition and subject to serious risk of drought
related mortality. It was suggested that the Pinus pinaster should be
removed over a couple of decades and replaced by Banksia
woodland. This was estimated to provide 100mm groundwater
recharge per year. The establishment of this woodland would be very
expensive ($10,000 per hectare) but there are other options. Thinning is
one option (but there is no market for the thinnings). Another option is
low-density ‘checkerboard’ plantations to allow recharge and provide
effective firebreaks. The State Government has commissioned a study
looking at these options. From a forestry perspective, modification of
the existing plantation estate is preferable to clearing it.
Pinus radiata and Eucalyptus globulus currently occupy 14% of the
area in the South Australian part of the Green Triangle but are
allocated 30% of the water use from the regional consumptive pool.
Much of the existing softwood estate was converted from native forest
and has never contributed to the pasture recharge used to calculate
this pool. In the Lower Limestone Coast Water Allocation Plan,
deemed rates of plantation water use are used for
accounting purposes. On average Pinus radiata intercepts 83% of
annual aquifer recharge and Eucalyptus globulus intercepts 78%. In
areas where groundwater is close to the surface (< 6m), trees are
deemed to use more than annual rainfall due to direct extraction from
groundwater. The current extraction models use rotation length
averages of 1.66 ML/ha/yr for softwood and 1.82 ML/yr for hardwood.
Currently there is a 'free' licence for existing plantations to recognize
prior rights for interception and extraction but a licence has to be
purchased for new plantations to cover deemed extraction and also
for interception in specified fully allocated water management areas.
In cases where the volumetric value of the licence is reduced it is
proposed that the loss should be met across the existing or future
estate. This could mean that some areas may not be able to be
22
replanted. These precedents concern plantation owners in other
states. Current estimates of direct extraction by plantations in the
Green Triangle are highly precautionary (based on a partial
hydrological model) and lead to major over-allocation issues when
coupled with conservative estimates of groundwater recharge. Recent
bore observations indicate declining water tables during drought and
development of a cone of depression under Eucalyptus globulus
plantations. However, the underlying behaviour of the water table is
not fully understood given visual observations of poor tree growth and
recent higher rainfall. The crucial problem of scaling up point water
use estimates from plot studies or observation wells to regional
estimates must be addressed to gain wider industry support.
Improved community confidence would also be achieved if these
results match alternative estimates from remote sensing studies,
hydrologic models or regional plantation productivity.
A water licence for new areas is an up-front cost to be factored into
any decisions about purchasing land and establishing new areas of
plantations, whether for wood production or carbon credits. The NWI
says there should be no retrospectivity – that existing plantations can
remain in over allocated catchments. However, the NWI also says that
over allocated catchments should be brought back to full allocation.
This is confusing and plantation owners have a right to be nervous.
Plantation owners need to acquire the best quality information to
present to the developers of water policy, including the relative impact
of other water users and intercepting activities on total water budgets.
There is the need to consider where plantations have been established,
where they are likely to be established in the future, areas of surface or
groundwater management that are over-allocated or approaching full
allocation, where these overlap and the extent to which plantations
may significantly reduce water flows. Most plantations in Australia
have been established on prior native forest sites. From this perspective
it might be argued that native forest and not pasture should be used as
a default. However, in most allocation situations the relevant question
is how much water would be released if the plantation forest were
converted to pasture. Also new plantations are being established on
pasture rather than native forest sites. Even so, there is a case that
native forest should be included in research comparing water use by
the range of land uses in catchments. All interceptors should be
identified and considered. Past experience demonstrates that where
information is of general rather than specific nature, the impact of
plantations is likely to be over-estimated by the policy makers. There
needs to be well defined and agreed mechanisms by which plantation
owners communicate with developers of water policy and with water
resource managers. Plantation owners also should ensure that their
management plans include potential water impacts. Frequently the
23
approval process for plantation establishment and water allocation are
not linked.
The recent guide to the Murray Darling Basin plan (Murray–Darling Basin
Authority, 2010) says that the basin receives a long term average (1895-
2009) of 500,000 GL/y rainfall of which 31,781 GL/y is average surface
water inflow and approximately 26,500 GL/y is groundwater recharge.
They calculate the consumptive use of surface water as 13,677 GL/y
made up as 'surface water diversions' for irrigation and urban supplies
(10,942 GL/y), 'interception' by farm dams (2,394 GL/y) and
'interception' by forest plantations (341 Gl/y). Thus, plantations
comprise just 2.5% of consumptive use on average but with
considerable variation between regions. Other evapotranspirers
(annual and perennial pastures, native forest and any other rain-fed
vegetation) have not been included as 'interceptions.' The area of
perennial pastures in the Murray Darling Basin has increased to about
70% of the area of the basin whereas the area of plantations is less
than 0.03% (NAFI 2011). Clearly the impact of perennial pastures on
water use will be greater than that of plantations but these have not
been considered as interceptors in the plan. It is proposed that the
'surface water diversion' allocations should be reduced across the
basin to ensure adequate environmental flows but no reduction in
allocations have been foreshadowed for 'interceptions' in any regions.
CSIRO (2011) criticized the implication in the plan that current
interceptions should be considered against low water-use pasture as
the appropriate baseline rather than the historical baseline of prior to
clearing for pasture. They considered that only future interception in a
fully allocated region should be of concern. The guide to the plan
acknowledges the paucity of reliable information on the contribution
of plantations. There is some irony in that forest plantations are not
being considered for cuts in allocation at this stage because the
quality of the available information is not good enough and plantation
water use in the basin currently is largely unregulated. This however
must not be used as an excuse to do nothing in the vain hope that it
will all go away. The need for high quality information on water
intercepting activities that is regionally relevant and at appropriate
scale is inescapable.
Recent droughts have highlighted concern about environmental water
provisions, particularly in the Murray Darling Basin, and measurements
of wetland water use are also required for equitable allocations
among all water users. Surface - groundwater connectivity and water
quality issues must also be considered in a complete water balance
framework, rather than one solely based on quantity estimates of
recharge or streamflow. Continuous improvement of information and
hydrologic understanding should be the basis for better decision
making and adaptive management of water resources.
24
4.7 Water use efficiency
Water use efficiency (WUE) can be considered at a range of scales: at
the foliar gas exchange level, at the canopy level, at the whole plant
level, at the stand level and at the catchment level. Here WUE is
defined as the amount (weight, volume) of harvestable product per
unit of water used. PNC073-0708 (page 4) demonstrated that for
plantations in Mediterranean type climates such as over much of
southern Australia, both WUE and overall wood production increase
with tree water use when water and not nutrition is the growth-limiting
factor. Under these circumstances in order to produce a given
amount of wood it would be better to plant trees in areas where they
will use more water rather than less. This presupposes that competing
weeds are controlled, that evaporation of water from soil is minimised
and that nutrients are not growth limiting. Taking this one step further,
WUE would be increased by encouraging rather than discouraging the
use of shallow groundwater and irrigation would also increase WUE.
However, both of these would be controversial and not worth arguing
the case.
Consequently it makes more sense for policy makers to allocate to
plantation managers an amount of water to be used rather than an
area to be planted in order to produce a given amount of wood. This
would give the silviculturalist maximum flexibility and managers long-
term security of the plantation estate. Generally the best silviculture to
improve productivity will increase water use efficiency. Currently
methods of water allocation to plantations are not suited to allocation
on a water used basis and it would require a significant shift in thinking
by both policy makers and plantation managers to achieve this. Even
so, it is a worthwhile objective.
There is the risk that trees well supplied with water will be at greater risk
of mortality in times of drought. This can be controlled to some extent
by thinning and spacing.
4.8 Economic and environmental benefit
Water policy should be directed towards optimizing the value of
allocated water across the range of uses within a water allocation
zone (e.g. irrigated and rain-fed agriculture, plantations, drinking water,
environmental flows, etc). The objective should be to maximize value
by analyzing trade-offs between alternate land uses. Inevitably
differences of opinion and expressions of self-interest will arise. It is
important that the full value of both plantations and native forests are
recognized in negotiations. Water use efficiency of plantations could
be further defined as economic benefit per unit of water used.
25
Economic benefit here is not simply defined as company profitability
but as overall national benefit. Also, plantations bring biodiversity and
water quality benefits. This, however, needs to be balanced against
potential negative effects on downstream ecosystems resulting from
reduced stream flows.
In this context there is scope for research analyzing the economic and
environmental benefit of plantation forestry compared with alternative
land uses within water allocation zones.
4.9 Plantations and salinity
Tree clearing in the past over large areas of southern Australia resulted
in an increase in groundwater recharge which mobilized salts deeper
in the soil and brought them close to, even breaching, the surface.
Planting with trees can reverse this effect. Tree planting in saline areas
has the potential to improve the quality of otherwise non-potable
water to that fit for human consumption and agricultural use. This
could occur over time periods as little as one decade. However,
salinity reduces tree productivity and wood quality. FWPA 's main focus
is promoting high value wood production and as such should not invest
in salinity related research.
4.10 Plantations and water quality (other than salinity)
Native forests appropriately managed and in the absence of wildfire,
provide higher quality water than land cleared for agriculture. This is
also the case for plantations although the public at large generally
does not appreciate this. Providing current codes of practice are
adhered to (roading, harvesting, fertilizing, buffers, pesticides),
plantations will yield better quality water than most agricultural pursuits
where management interventions are usually more intense and more
frequent. Codes of Forest Practice usually preclude clearing of
vegetation near streams and require the preservation of buffers to
arrest the movement of sediment into streams. However, in other parts
of the world planting stream management zones (SMZs) with perennial
vegetation, including trees, is seen as a way to protect water quality
against agricultural activities that encroach on streams. Neary et al.
(2010) suggest that, properly managed, commercial tree plantings
could be carried out in SMZs in Australia. This could be an opportunity
for commercial forestry but would need considerable background
research to ensure that it is 'safe' and of course the impacts on water
quantity would need to be taken into consideration. There is no
suggestion here that the requirement for buffer strips in plantation
establishment should be relaxed in any way. Rather the idea is that
26
commercial tree planting could help to rehabilitate SMZs where
agricultural activity has fouled the streams. FWPA should not invest in
research in this area at the moment but should keep a watching brief.
Wildfires can cause immediate and extreme deterioration in water
quality.
4.11 Native forests
The role of native forests in affecting water quality and quantity is
orders of magnitude more important than that of plantations. The area
of native forests is much larger than that of plantations. Also native
forests are very important in supplying drinking water to urban
populations and in ensuring environmental flows. Even so, there are
many catchments where agricultural activities lay alongside or
downstream from large areas of native forest.
All native forest is vulnerable to wildfires of varying intensities from mild
to catastrophic. Wildfire can greatly and quickly reduce water quality.
The Canberra fire of 2003 is a good example of this. Prescribed burning
may assist in reducing the occurrence and intensity of wild fires but in
itself, unless properly managed, can be a source of deterioration in
water quality. Usually the areas of prescribed burning are small
enough for there to be no significant effect on water quality but the
impact of greatly increasing the annual area to be burnt, as
recommended in the 2010 Royal Commission in Victoria, is not known.
There is need for further research of fire effects on water quality in
native forests.
A very small percentage of native forests in Australia are available for
harvesting and consequently any harvesting effects on water issues will
be correspondingly small overall. However, there may be significant
local effects on both water quantity and water quality if not properly
managed. This is of particular concern in catchments that supply
drinking water. Areas in Australia that are selectively logged (e.g.
coastal forests north of Sydney) and the Jarrah forests of Western
Australia are mainly water positive, i.e. logging increases water yield.
Natural regeneration in these areas is usually not vigorous enough to
cause any problem. Jarrah forests are heavily thinned to increase
water yield but this results in large wastage of biomass. In areas where
clear felling or island harvesting regimes are practiced (e.g. eastern
Victoria and Tasmania), vigorous regrowth can reduce water yield.
Much has been made of the Kuczera curves. This relationship was
developed from rainfall and runoff data collected from predominantly
Eucalyptus regnans catchments that were completely or partially burnt
by the 1939 fires. The Kuczera curves predict a sudden but short-lived
27
increase in water yield following a large scale clearing event (fire or
clear-felling) followed by a decline in water yield to a minimum at
about 20 to 30 years, followed by a gradual rise back to 'old growth'
levels at about 100 years of age (see Vertessy et al. 2001). However,
these classic and often quoted curves are based on large-scale
clearing (near 100%) of Eucalyptus regnans by wildfire. This does not
represent current harvesting practices in Australia's native forests.
Almost all significant areas of Eucalyptus regnans in Victoria are
reserved in the Melbourne water catchments and unavailable for
harvesting. More research is needed on the water release curves of
forest types actually being harvested and under the harvesting regimes
that are practiced. Current research is looking at the effects of fire,
regrowth management and thinning on water yield.
Native forests exert overwhelming control over drinking water and
environmental flows. At the national scale native forests exert far more
control on water supplies than do plantations. There have been
significant reductions in harvesting in native forests over the past few
decades and currently plantations provide approximately 70% of
Australia's wood harvest and increasing. Consequently agencies other
than FWPA should have the major responsibility for research in native
forests. FWPA should focus its investment on plantations.
4.12 Climate change and carbon
The effect of increased carbon-dioxide concentrations in the
atmosphere together with slightly increased temperatures will
accelerate photosynthesis and therefore plant productivity up to the
point that water and/or nutrients become limiting. Also, increases in
rainfall are predicted at the global scale. Consequently increased
global productivity overall has been predicted as a result of global
warming. However, in regions where decreases in rainfall are
predicted, productivity of forests, including plantations, will be reduced
and the relative impact of forests on reducing water yield in
catchments will be greater. Predictions of climate change at the large
scale are rough and predictions at the regional scale are even
rougher. The safest way of looking at future climate is that it will be
uncertain and forward planning should be about climate uncertainty.
There may be increased frequency and intensity of wildfires. There
may be increased pestilence. Both of these will reduce forest
productivity but can be managed in plantation forests.
Increased concentrations of carbon dioxide will increase WUE, which
may be expressed as increased productivity, reduced ET or a
combination of both. Increased temperatures will increase vapour
pressure deficit (VPD) and therefore ET if relative humidity (RH) remains
28
unchanged or decreases. The impact that these interactions will have
on ET is uncertain. Research is required but this is not appropriate for
FWPA investment.
The effect of the recent long drought period in southern Australia has
confounded the interpretation of the effect of increasing plantation
areas on water availability. It is a great challenge to the modellers to
unravel this. It is likely there are cases where reduced water availability
has been wrongly blamed on plantation establishment when it has
largely been caused by drought.
Much has been made about the potential of planting trees in low
rainfall areas to gain carbon and biodiversity credits. Plantations in
these areas would hardly provide a commercial timber crop and as
such is not relevant to FWPA.
29
5. RECOMMENDATIONS
FWPA has limited funds to invest and must be strategic in order to meet
its goal of improving profitability and reducing risk to levy payers. The
following recommendations are based on interviews with key industry
players and with those research providers who have developed a
relationship with industry. Regrettably there are important areas of
research that miss out. The recommendations are essentially risk
mitigation strategies. However, it is clear that failure to address these
issues would almost certainly reduce profitability. It will impact on
whether or not new areas can be planted and even whether current
plantation areas can be replanted.
There was a strong consensus that the collection, continuity,
consolidation and security of data are of paramount importance and
that all parties should have unencumbered access to a
comprehensive and well-maintained national database of
hydrological data from forested catchments. This is not a research
issue and there will be no specific research recommendation on it.
However, it is of such fundamental importance that FWPA should keep
a watching brief to see whether there are any ways it can assist.
Perhaps a scoping study would be appropriate. Also FWPA might act
as an agent to bring appropriate parties together for discussion.
Models
Current models are inadequate to represent forest water use when
developing water policy and allocating water to competing land uses.
Recommendation 1: FWPA will invest in the development of models
that account for all interceptors at finer scales of space and time.
It is difficult to put a price on this but the consequences of not having
and applying good models will mean that plantation enterprises will
not have the information available for them to get a fair deal when
allocations are being negotiated. Past experience has shown that if
plantation managers do not have good information, their water use is
likely to be overestimated. If a water licence is an initial start up cost
that has to be carried with interest over the rotation, then this may
make all the difference between success and failure, or indeed
whether it is worth acquiring the land in the first place. Even if the
licence comes only at a nominal cost it still pegs the amount of new
land available for plantation establishment. Also, the possibility of
retrospectivity is a worry. Priority should be given to groundwater
systems.
30
PRC071-0708 (page 4) agrees with his. Better testing, integrating and
validating should be a high research priority.
It follows from the above that the impact of pre-harvest water for Life
Cycle Analysis (LCA) of timber is based on generalisations that over-
emphasize water use. Better models will provide better information for
Life Cycle Inventory (LCI) and LCA.
FWPA is looking for comprehensive objective data that is accepted
across the range of land users. Consequently the ideal arrangement
would be for research to be carried out within teams that represent the
range of primary producers co-existing within key catchments where
plantation forestry is considered to have an impact. This will have two
benefits. Firstly, agreement at the research stage will assist with
reaching agreement at the policy stage. Secondly it provides the
opportunity for co-funding from other primary producing interests (e.g.
GRDC). A good investment would be to encourage the use of APSIM
in meeting the modelling recommendation.
Plantation impacts are more significant in ground water systems than
surface water systems and research should be focussed on these
where possible.
Remote sensing
Remote sensing is a promising cost-effective option for measuring forest
water use.
Recommendation 2: FWPA will invest in research into remote sensing at
appropriate scale to measure water use of the range of land uses in
catchments containing plantations.
The outcome will be less expensive monitoring and model
development. Currently the most relevant remote sensing expertise
resides with CSIRO, the Commonwealth Department of Meteorology,
the University of Melbourne, the University of NSW, various state water
agencies and DPIs, and SKM. The NWC retains an overarching interest.
Some agencies, e.g. CSIRO, are concerned with improving accuracy.
This necessitates constructing more flux towers and improving
algorithms. Arguably the nearest to best of the most recent research of
direct relevance to FWPA is the NWC sponsored project carried out by
SKM looking at remote sensing of water use in the Green Triangle (SKM
2010, and page 14). This research did not deliver a completely
satisfactory outcome because of insufficient ground-based data over
long enough time periods for calibration. Also there are concerns
about the accuracy of SEBAL in this environment. However, further
research investment in the Green Triangle is justified to produce a
31
better result. The Green Triangle is the area with the most water use
data, an area of great economic importance for plantation forestry
and also the area in which water allocation problems are evident.
Alternatively, additionally or coincidentally FWPA could focus remote
sensing research in those catchment(s) where investment will be made
in further model development. Ideally investment could be made in
remote sensing research carried out in parallel with an APSIM based
modelling project in a catchment where plantations are considered to
have a significant impact. This may or may not be the Green Triangle
but a good case can be presented that it should.
Allocation
Ultimately the objective should be for forestry to get a fair deal in
negotiation with water policy developers and for the agricultural
community to understand and accept that plantation forestry is a
legitimate land use within the broader primary industry community
concerned with fair and equitable access to water.
Recommendation 3: FWPA will invest in research to analyse trade-offs
between plantations and alternate land-uses in optimising economic,
environmental and social benefits and to have these recognised and
accepted by the developers of water policy and by the community at
large. Implicit in this is the need for plantations to have a 'licence to
operate' within the broader primary industries community competing
for access to water.
The need is to undertake appropriate sociological research to
understand and manage the potential conflicts involved. This involves
understanding the social dynamics in collective decisions made about
water allocation. The forest industry (growers and processors) needs to
be proactive rather than reactive in negotiation. This necessitates
understanding the various players and processes in order to make best
use of the reliable information gained from improved models. This
should include research into how the decisions are made, how much
information is required to make defensible decisions and how dynamic
are the policy settings to ensure security of future investment in the
industry.
Proposals for funding should as a priority address specific
catchments/ground water systems where water is at, near or over
allocated and where plantations cover an area large or consolidated
enough for them to have a known or suspected impact. Ideally they
would cover the same catchments/ground water systems as those
used in recommendations 1 and 2, although quality proposals from
other areas may also be considered. A state government committee is
handling the research and policy surrounding the role of plantations on
32
the Gnangara mound and FWPA need not be involved. Water
allocation policy and practice in the South Australian part of the Green
Triangle has already been set to some extent but should not be
immune from careful scrutiny. It is ironical that, arguably, the best
research information on water use in any plantation area in Australia is
in the Green Triangle and yet the information is too site specific and
limited to provide enough information for rational and fair decisions on
water allocation. FWPA should support any initiative that critically
analyses the pathway that set current water policy in the South
Australian part of the Green Triangle with the objective of learning how
plantation forestry might have been better involved in policy setting
and how plantation forestry may yet be partners in a reconsidered
policy. Such research should benefit plantation forestry as a whole.
FWPA could also support a project that looks at water policy setting in
a surface catchment where plantation expansion would have an
impact.
Ideally a successful proposal will have the major competing land users
involved. This will be challenging because agricultural interests may
judge they have nothing to gain and potentially something to lose by
entering into research partnerships. It would be essential however that
water policy makers and regulators are involved as research partners
rather than as uninvolved parties or worse as combatants.
33
6. RESEARCH PLAN
Research on the impact of plantations on water mostly has past the
pre-competitive stage. It is more significant in some regions than
others. Clearly research should be focussed on areas with significant
impacts, particularly in catchments that are fully allocated. From this
perspective significant direct regional industry co-investment is
expected. Ideally, research teams should not be confined to forestry
interests but should cover the broad spectrum of competitive land
uses. FWPA could achieve this cost-effectively by co-investing with
larger funders (e.g. NWC) to incorporate FWPA's particular interests.
PRC115-0809 (page 7) is a good example.
FWPA will allocate $1,250,000 over the period 2011 to 2015 as follows.
The direct industry investment in water research over the period 2005-
2010 (Table 1) was a low 2% of total funding. The expectation is that
industry will directly invest more than in the past. Preference will be
given to projects with significant direct industry investment.
Table 2: Proposed investment by FWPA over the period 2011-2015.
Recommendation 2011 2012 2013 2014 2015 Total
Models $100,000 $150,000 $150,000 $150,000 $50,000 $600,000
Remote sensing $50,000 $100,000 $100,000 $100,000 $50,000 $400,000
Allocation $50,000 $50,000 $50,000 $50,000 $50,000 $250,000
Total $200,000 $300,000 $300,000 $300,000 $150,000 $1,250,000
34
7. ABBREVIATIONS
AFPA Australian Forest Products Association
APSIM Agricultural Production Systems Simulator
ASDI Australian Spatial Data Infrastructure
AVHRR Advanced Very High Resolution Radiometer
CAT Catchment Analysis Tool
CSIRO Commonwealth Scientific and Industrial Research
Organisation
FWPA Forests and Wood Products Australia
ET Evapotranspiration
DPI Department of Primary Industry
FCFC Forest Cover Flow Change
GRDC Grains Research and Development Corporation
LAI Leaf Area Index
LCA Life Cycle Analysis
LCI Life Cycle Inventory
METRIC Mapping Evapotranspiration at High Resolution with
Internalized Calibration
MDB Murray Darling Basin
MODIS Moderate Resolution Imaging Spectroradiometer
NAFI National Association of Forest Industries
SEBAL Surface Energy Algorithm for Land
NWC National Water Commission
NWI National Water Initiative
RH Relative Humidity
SKM Sinclair Knight Merz
SMZ Stream Management Zone
VPD Vapour Pressure Deficit
WUE Water Use Efficiency
35
8. REFERENCES
Benyon, R.G. and Doody, T.M. (2004). Water use by tree plantations in
southeast South Australia. CSIRO Forestry and Forest Products
Technical Report No. 148. CSIRO Mt Gambier SA.
Benyon, R.G. and Doody, T.M. (2005). Regional scale, spatially explicit
quantification of plantation forest water use. CSIRO final report to
FWPA Project PN04.4010.
Benyon, R., England, J., Eastham, J., Polglase, P. and White, D. (2007).
Tree water use in forestry compared to other dry-land agricultural crops
in the Victorian context. Report to the Victorian Department of Primary
Industries. Ensis, Canberra, 83pp.
Beverly, C., Bari, M., Christy, B., Hocking, M. and Smetton, K. (2005).
Salinity impacts from land use change; comparison between a rapid
assessment approach and a detailed modeling framework. Australian
Journal of Experimental Agriculture 45: 1453-1469.
Brown, A.E., McMahon, T.A., Podger, G.M. and Zhang, L. (2006). A
methodology to predict the impact of change in forest cover on flow
duration curves. Science Report 8/06. CSIRO Land and Water,
Canberra.
CSIRO. (2011). CSIRO Technical Comments on the Guide to the
Proposed Basin Plan. CSIRO, 18pp.
Donohue, R.J., McVicar, T.R., Lingtao, L. and Roderick, M.L. (2010). A
data resource for analysing dynamics in Australian ecohydrological
conditions. Austral Ecology 35: 593-594.
Landsberg, J.J and Waring, R.H. (1997). A generalized model of forest
productivity using simplified concepts of radiation-use efficiency,
carbon balance and partitioning. Forest Ecology and Management
95:209-228.
Morris, J.D. (2003). Predicting the environmental interactions of
eucalypt plantations using a process-based forest model. Pages 185-
192 in J.W. Turnbull (ed). ACIAR Proceedings on Eucalypts in Asia, No
111, Zhanjiang, Peoples Republic of China, 7-11 April 2003.
Murray–Darling Basin Authority (2010). Guide to the proposed basin
plan: overview. Murray–Darling Basin Authority, Canberra.
NAFI. (2011). Opening Statement by the National Association of Forest
36
Industries to the House of Representatives Standing Committee on
Regional Australia Inquiry into the Impact of the Murray-Darling Basin
Plan in Regional Australia. NAFI 3pp.
Neary, D.G., Smethurst, P.J., Baillie, B.R., Petrone, K.C., Cotching, W.E.
and Baillie, C.C. (2010). Does tree harvesting in streamside
management zones adversely affect stream turbidity? - preliminary
observations from an Australian case study. J. Soil Sediments 10: 652-
670.
O'Grady, A.P., Carter, J. and Holland, K. (2010). Review of Australian
groundwater discharge studies of terrestrial systems. CSIRO Water for a
Healthy Country, Canberra, pp 56.
O'Loughlin, E. and Nambiar, E.K.S. (2001). Plantations, farm forestry
and water – a discussion paper. Water and Salinity Issues in
Agroforestry No. 8, RIRDC Publication No. 01/37.
SNK. (2010). Assessment of plantation water use in south-west Victoria
and south-east South Australia using SEBAL remote sensing technology.
National Water Commission funded project on application of remotely
sensed evapotranspiration to improve water accounting and
management.
Vertessy, R.A. Watson, F.G.R. and O’Sullivan, S.K. (2001). Factors
determining relations between stand age and catchment water
balance in mountain ash forests. Forest Ecology and Management 143:
13-26.
37
9. APPENDIX 1: CONSULTAION
AFPA Richard Stanton
Mick Stephens
CRC Forestry Gordon Duff
CSIRO Auro Almeida
Mat Gilfedder
Anthony O'Grady
Philip Polglase
Tivi Theiveyanathan
Don White
Lu Zhang
Forests NSW Ashley Webb
Forestry Plantations Queensland Ken Bubb
Forest Products Commission (WA) Stuart Crombie
John McGrath
Forestry SA Jim O'Hehir
Don McGuire
Forestry Tasmania Sandra Roberts
Gunns Ian Ravenwood
SA Water Board Graham Allison
SKM Robert Molloy
University of Melbourne Richard Benyon
Patrick Lane
VicForests Michael Long
