UNEFM, Ingeniería Agronómica, Modelización Producción Agrícola, Predicting Plant Growth

1. Trevor H. Booth
Predicting Plant Growth:
Where will it grow? How well will it grow?
Three recent projects have developed and enhanced generic methods to evaluate the
suitability of particular plants for general regions and specific sites. All three projects have
concentrated on forestry in developing countries, but the methods are suitable for other
regions and for plants other than trees. Two of the projects have emphasized the
development and application of cheap easy-to-use PC-based programs, whilst the third has
shown how a simple PC-based model can also be applied as part of a multi-million dollar
land evaluation study using the ARC/INFO GIS on Sun workstations. Four methods used in
the projects are outlined here, including the development of climatic interpolation
relationships, the development of climatic mapping programs, the application of the
Plantgro simulation model and the development of simulation mapping programs. Though
more work is needed to validate and calibrate these programs for the hundreds of tree
species important in tropical and sub-tropical areas it is concluded that they already provide
a useful basis for selecting species and provenances for planting in different regions.
Introduction
The world's rapidly rising population requires most countries to make the best
possible use of their land resources for agriculture, horticulture, forestry and
conservation. Being able to predict where and how well particular plants are likely
to grow in different regions is vital for land use planning. Linking GIS and models
can help to answer these questions, but decision makers and researchers in
developing countries have limited access to these technologies. This paper
outlines on-going efforts to provide improved access to databases, mapping
programs and simple simulation models to assist land evaluation. The work
described relates mainly to forestry projects in developing countries, including work
for the Australian Centre for International Agricultural Research (ACIAR) project
9127 "Predicting Tree Growth for General Regions and Specific Sites in China,
Thailand and Australia" and the Australian Agency for International Development

2. (AusAID) project on "Improving Tree Productivity in Southeast Asia". However, the
methods could also be applied in other areas and with plants other than trees.
Four methods are outlined. First, the development of climatic interpolation
relationships which allow mean climatic conditions to be estimated reliably for any
location within a particular country. Second, the development of climatic mapping
programs which use interpolated data to indicate where particular trees can be
grown. Third, the use of the Plantgro model, which uses detailed soil and climate
information to estimate how well a particular tree is likely to grow on a specific site.
Fourth, the use of simulation mapping programs, which use a simplified version of
the Plantgro model, to predict how well a particular tree might grow at thousands of
locations across a country or continent. The purpose of this paper is to provide a
brief introduction to the methods. More details are available in the proceedings of
an international workshop entitled "Matching Trees and Sites" (Booth 1996a).
Climatic interpolation
Climate has an important influence on plant growth. It is particularly useful as a
means to predict where particular plants will grow, as mean climatic conditions can
now be reliably estimated for most locations around the world. For example, Dr
Michael Hutchinson (Centre for Resource and Environmental Studies, Australian
National University) has developed a package known as ANUSPLIN, which uses
Laplacian smoothing splines to interpolate spatially between data recorded at
meteorological stations (Hutchinson 1989, 1992). As part of ACIAR project 9127
mean monthly data were collated from meteorological stations in a single area
including China, Thailand, Vietnam, Laos, Cambodia and Peninsula Malaysia (Zuo
et al. 1996). Monthly mean data for 1222, 1117, 3832, 898 and 903 stations were
collated for maximum temperature, minimum temperature, precipitation, solar
radiation and evaporation respectively. Interpolation relationships were developed
relating these monthly mean values to latitude, longitude and elevation.
Latitude and longitude are easily estimated for any location, but elevation must
also be provided to interrogate the interpolated climatic relationships. A digital

3. elevation model was prepared by Zuo et al. (1996) and monthly mean values for all
five climatic factors were estimated for a 1/20th of a degree grid (5km approx) of
approximately 400 000 points across China and mainland Southeast Asia.
Example colour maps showing mean annual values of these five factors across
China and mainland South East Asia are included in the ACIAR proceedings
(Booth 1996a). Climatic interpolation analyses for Indonesia (Jovanovic and Booth
1996a) and the Philippines (Jovanovic and Booth 1996b), which were developed
as part of work for the AusAID, are also described in the ACIAR proceedings.
Details of the interpolation methods used, sample outputs and references to
studies in other areas are provided by Hutchinson et al. as well as Kesteven and
Hutchinson (both papers in these proceedings).
Climatic mapping programs
Very large climatic databases are impressive, but they are of little help for decision-
making in developing countries if potential users cannot access them. In countries
where average incomes may be no more than a couple of hundred dollars a year,
few individuals or institutions have access to sophisticated GIS programs or
powerful computers. Even if low-cost PC-based GIS programs, such as IDRISI
(Eastman 1993), are available they may seem complex to many first time users.
Climatic mapping programs were developed to provide very easy access to
interpolated climatic information (Booth 1996b). Simple descriptions of ranges of
climatic conditions are entered and the climatic mapping programs show which
areas, if any, satisfy those sets of conditions. As climatic mapping programs were
mainly developed for forestry studies the following set of six climatic factors were
used initially:
a) mean annual precipitation (mm)
b) rainfall seasonality (uniform/bimodal, summer, winter)
c) dry season length (months)
d) mean maximum temperature of the hottest month (oC)
e) mean minimum temperature of the coldest month (oC)

4. f) mean annual temperature (oC)
These factors had proved to be useful as part of an expert system developed to
assist selection of tree species for tropical and sub-tropical plantations (Webb et al.
1980). In the second edition of their system, Webb et al. (1984) described the
climatic requirements of 175 species in terms of ranges of these six climatic
factors. Any one of these descriptions can be input into a climatic mapping
program. Areas which satisfy the requirements are shown on the microcomputer
screen in green, whilst locations which do not satisfy the description are shown in
red. The user can move a marker over any location and check the detailed climatic
conditions at a particular location.
Descriptions of the requirements of particular trees (or other plants and also
animals) can be developed from bioclimatic analyses of natural distributions. For
example, the BIOCLIM program accepts geocoded information describing natural
distributions and uses climatic interpolation relationships to determine the range of
climatic conditions where a particular plant or animal is found (Booth 1985, Nix
1986, Busby 1991). This type of analysis can provide a first indication of a
particular tree's climatic requirements. However, many trees can grow successfully
in conditions which are somewhat different from those they experience within their
natural range. Information from trials and large scale plantations outside the natural
range can be used to improve descriptions of requirements.
Climatic mapping programs, like more sophisticated GIS packages, allow users to
visualise the implications of particular descriptions. For example, the Webb et al.
(1980, 1984) description of the requirements of Pinus radiata implied that New
Zealand was climatically unsuitable when it was plotted using a climatic mapping
program for the whole world. As there are over 1.2 million hectares of Pinus radiata
plantations in New Zealand something was obviously wrong with the description.
Using the program's moveable marker it was easy to check conditions at sites in
New Zealand and correct the errors in the description (Booth 1990). Working with
individuals who have experience with growing trees in particular regions, climatic
mapping programs can be used to quickly check and improve existing descriptions
of trees' requirements (e.g. Booth and Pryor 1991).

5. As part of ACIAR Project 9127 climatic mapping programs were prepared at the
CSIRO Division of Forestry for China (100 000 grid points), Thailand (40 000 grid
points), South East Asia (10 000 grid points) and Latin America (66 000 grid points
- interpolated climatic data kindly supplied by Dr Peter Jones, CIAT, Colombia).
Most of the programs have been developed for the MS-DOS environment, which is
the most common operating system on PCs used in the developing world.
However, a version of the THAI program has recently also been developed for the
Windows environment. Windows allows multitasking, which makes it easy to
compare maps produced by different descriptions on the computer's screen, as
well as providing built-in support for hundreds of different printers. Figure 1 shows
the areas of Thailand which are climatically suitable for provenances of Acacia
auriculiformis from Papua New Guinea.
As part of an AusAID-supported project climatic mapping programs were
developed for Indonesia (26 000 grid points), Vietnam (16 000 grid points) and the
Philippines (13 000 grid points). Papers describing the development of these

6. programs are all included in the ACIAR proceedings. Whilst a climatic mapping
program satisfies a simple definition of a GIS as "a computer system capable of
holding and using data describing places on the earth's surface" (ESRI 1992) many
people would consider them too simple to be called a GIS. Whether they are a GIS
or not they certainly provide a useful and appropriate means of delivering
environmental information to users in developing countries. Users who have both
the equipment and skills necessary to operate more elaborate systems find it easy
to incorporate the interpolated climatic databases used by climatic mapping
programs into GISs.
Plantgro
Being able to identify where particular trees (or other plants) will grow is useful, but
many people need to know how well they will grow on particular sites. Generally
they do not require highly precise predictions of yield, but they do need to know
whether growth will be good, fair, poor or useless. Detailed process-based models
are available for the dozen or so major crop plants, such as wheat and rice, which
dominate world agricultural production (e.g. Godwin et al. 1989, Singh et al. 1993).
These simulate complex processes such as light interception, photosynthesis and
translocation and in many cases provide quite reliable estimates of yield. A few
process-based models have been developed for trees (e.g. McMurtrie et al. 1989),
but there is no prospect of such detailed models being developed for the hundreds
of tree species which are important in forestry around the world. Dr Clive Hackett
faced a similar problem in 1984 when he was asked to take part in a study of
village-based subsistence agriculture and small-holder cash cropping in Papua
New Guinea (Hackett 1988). There were numerous plant species involved and
relatively little was known about their environmental requirements.
Hackett devised a new and simple method for providing coarse predictions of the
growth of lesser-known plants. To assess the suitability of particular climatic or soil
factors he used 'notional relationships', which are simply two-dimensional graphs
made up of linear segments indicating conditions which are most suitable for

7. growth and those which are less suitable. These are used along with more
complex calculations of the effects of light, temperature and moisture. To combine
the effects of all factors he used Liebig's Law of the Minimum (Liebig 1885), which
was originally devised to describe the effects of available plant nutrients on plant
performance. In simple terms this states that the most limiting factor determines
plant performance (i.e. favourable levels of other factors do not compensate for the
unfavourable level of the limiting factor). Overall conditions were evaluated
according to limitation ratings on a 0-9 scale where 0 indicates ideal conditions (i.e.
no limitations) and 9 indicates the greatest possible limitations.
The PC-based Plantgro program (Hackett 1991) evaluates 11 soil factors including
phosphorus, potassium, nitrogen, slope and drainage. Climatic data used include
maximum temperature, minimum temperature, precipitation, evaporation and solar
radiation. Monthly mean data are usually used for trees, but the program can also
evaluate ten-day or weekly data. The program evaluates the effects of temperature
on development as well as carrying out simple water balance calculations. To run
the program a plant file, soil file and climate file are required. The program provides
summary predictions of likely growth patterns as well as detailed evaluations of
limitations due to light, temperature, moisture and important soil factors.
Figure 2 shows an example of the summary output produced by Plantgro for a
northern provenance of Eucalyptus camaldulensis growing at a trial site near
Bangkok in Thailand. Growth is steady for much of the year, but is limited in the
period from December to March. Inspection of Plantgro's detailed output would
indicate that the growth limitations in the December to March period are mainly due
to moisture stress because of the dry period, whilst growth during the rest of the
year is limited at this particular site by soil depth. The '77.0's at the foot of the

8. figure indicate that a perennial plant is being evaluated.
The Plantgro program has recently been used as part of a multi-million dollar
project developing a 'National Masterplan for Forest Plantations' (NMFP) in
Indonesia. This work was carried out by the DHV consultancy company and some
of the work is outlined in the ACIAR proceedings. For example, Davidson (1996)
describes how Plantgro plant files were developed for about 50 tree species. For
the better-known species, such as Tectona grandis (teak) and Acacia mangium
numerous trial results provided a good basis for the development of the notional
relationships which described the trees' responses to environmental conditions. For
the lesser-known trees the notional relationships were more educated guesses.
Though the exact form of a response may not be known, there is usually some
evidence for a species general preferences, for example, its need for acidic,
neutral and/or alkaline soil conditions. Pawitan (1996) describes how a batch file

9. version of Plantgro was developed, Plantgro limitation ratings were related to
standard growth curves for different species to predict potential yield, yield
predictions were used to evaluate the economic viability of particular projects and
recommended land uses were plotted using the ARC/INFO and Arc/View GIS
packages.
Plantgro was also used in ACIAR project 9127 and Hackett (1996) describes the
use of foresters' expert opinions to develop Plantgro plant files. The development
of a database of 244 Plantgro soil and climate files for Thailand is also described
(Taweesak et al. 1996). The soil files were developed from detailed soil chemical
and physical analyses, which had been carried out for four horizons at sites
representing the major soil types of Thailand. The climate files were prepared
using the interpolation relationships for Thailand (Zuo et al. 1996). Using the tree
files developed for the NMFP project it would be possible to estimate the potential
productivity of 50 tree species for all these 244 sites. As part of ACIAR project
9127 tree growth, soil and climate measurements were also collected from over
200 tree trial plots in Thailand and China (Sirirat et al. 1996, Yan Hong 1996).
Simulation mapping programs
The Plantgro program is generally used to predict growth at individual locations or
small numbers of sites. However, it is useful to be able to see the suitability for
particular species and provenances over wide areas both to check descriptions of
requirements and to make recommendations of trees for particular regions. PC-
based simulation mapping programs allow a simplified version of the Plantgro
model to be run for thousands of grid points. They use interpolated monthly mean
climatic data to carry out the same light, non-linear heat sum and water balance
calculations as Plantgro, but use information from maps to carry out a simplified
assessment of soil limitations.
The ACIAR proceedings includes a description of simulation mapping programs
developed for Africa, Australia, Thailand and China containing data for 10 187, 11
299, 6 242 and 15 789 grid points respectively (Booth 1996c). The programs

10. output three maps showing limitations for soils, climate and the two factors
combined. For example, Figure 3 shows the suitability of 15 789 sites across China
for the Petford provenance of Eucalyptus camaldulensis. In the example shown the
model was run for all 15 789 grid points, a process which takes about 85 seconds
on a 90mhz Pentium PC. It is possible to speed the operation of the program by
restricting the analysis to areas satisfying a description of climatic requirements
similar to those used by climatic mapping programs. This description is shown
below the maps.
A marker can be moved over any location and a summary of the month-by-month
limitations is shown for that particular location (see Figure 4).

11. In Figure 4 the Ge73-2/3a soil type was assessed as having a level 4 limitation
rating, which remains unchanged for all the months of the year. In January
limitations for solar radiation, temperature and moisture were 3, 8 and 4
respectively. Applying Liebig's Law of the Minimum the greatest limitation in
January is due to temperature and is rated as 8 (i.e. a major limitation). In contrast
the greatest limitation in July is due to soil factors and is a moderate rating of 4.
The colours shown for this single location on each of the three maps in Figure 3
simply indicate the mean limitations for soil, climate and overall conditions.
Discussion
The need for effective integration of GIS and environmental modelling is probably
greater in developing countries than in the rest of the world, as environmental
systems in many areas are already under great strain. At the same time the
support available for sophisticated technologies is a fraction of that available in
wealthy nations. Appropriate technologies need to be quick, simple and cheap.
Reliable climatic data are essential for predicting plant growth and modern
interpolation methods can provide this information economically for any location on

12. earth. Climatic mapping programs provide an effective means of delivering this
information to users with minimal computing facilities and GIS skills. The Plantgro
model provides a simple means of providing estimates of the potential growth of
lesser-known plants. It was originally designed to work if necessary on text-only
microcomputers, but the National Masterplan for Forest Plantations project has
shown that it can also play a vital part in a multi-million dollar GIS analysis.
Simulation mapping programs provide broadscale Plantgro-based analyses on PC-
based systems.
Preparing appropriate tools and making them available either free or at minimal
cost is only part of the process of ensuring the uptake of environmental
assessment methods in developing countries. Training has been an important part
of the work described here. In the last three years courses have been given in
Thailand (2), China (2), Vietnam, Indonesia and the Philippines. Generally, one
week training courses have been provided. The first day has been an open
seminar, which could be attended not only by the main group of trainees, but also
by senior decision-makers and students (see, for example, Murdiyarso and Booth
1994). In the following three or four days a much smaller group of 12-16 trainees
have been given "hands-on" training in the use of the climatic mapping, simulation
mapping and Plantgro programs, usually operating two to a computer.
A course in Vietnam was successfully given in 1994 using microcomputers with
286-type processors. These modest machines were not only capable of running
the programs described here, but were also used to show an animated fly-by of a
digital elevation model of Vietnam (Booth 1995). Animations are useful in providing
a quick appreciation of the effects of topography on climate. A good example of the
effective uptake of the training provided in Vietnam was the use of a climatic
mapping program by one of these trainees after the course to develop descriptions
of the climatic requirements of nine native and nine exotic tree species important
for plantations in Vietnam (Nghia 1996). Maps generated using climatic mapping
programs are also beginning to appear in reference texts, such as "Growing Exotic
Trees in China" (Pan and You 1994) and "Trees for Saltland" (Marcar et al. 1995).

13. Validation is a major problem with developing and applying models such as
Plantgro. Some brief reports of validation work are included in the ACIAR
proceedings (Booth 1996). However, more validation work needs to be done
particularly with large datasets (i.e. >50 sites). Unfortunately, few datasets include
information in sufficient detail or from a large enough number of sites to provide a
really effective basis for validation (e.g. Schonau 1969, Hunter and Gibson 1984).
Even where such large datasets exist, access may be restricted for commercial
reasons. The large datasets which do exist tend to be from single countries and
therefore usually do not explore the full range of conditions under which a species
may be grown. Opportunities to develop large datasets by combining information
from several countries are severely restricted because of the lack of an
internationally agreed minimum dataset for recording results from forestry trials.
Forestry trials are expense to establish and maintain, so it is unfortunate that
greater efforts are not made to encourage the sharing of information. There is a
great need for organisations such as the Center for International Forestry
Research (CIFOR) to establish standards which would facilitate the exchange of
data between countries.
The programs described here are of great help in assisting species introductions.
However, the decision to introduce new species to an area should not be taken
lightly and ecological as well as socio-economic impacts need to be carefully
considered. Small scale trials should always be undertaken before large scale
plantation establishment is attempted. Attention should also be given to
establishing plantations which are ecologically sustainable (Nambiar and Brown
1996).
More information about the methods described here is included in ACIAR
Proceedings no. 63 'Matching Trees and Sites' which is available from Bibliotech,
GPO Box 4, Canberra, ACT 2601, Australia (fax +61 6 257 5088). Persons and
institutions working in relevant areas in developing countries who may be eligible
for a free copy should write to Publications, ACIAR, GPO Box 1571 Canberra, ACT
2601, Australia.

14. Acknowledgements
I am grateful to the Australian Centre for International Agricultural Research
(ACIAR) and the Australian Agency for international Development (AusAID) for
their financial support of the work described in this paper. I am also grateful to
numerous collaborators in Australia, China, Thailand, Vietnam, Indonesia, the
Philippines, Laos, Costa Rica, Colombia, Kenya and many other countries. Full
acknowledgements are given in several papers included in the 'Matching Trees
and Sites' publication (Booth 1996).
References
Booth, T.H. (1985) A new method for assisting species selection. Commonwealth
Forestry Review 64: 241-250.
Booth, T.H. (1990) Mapping regions climatically suitable for particular tree species
at the global scale. Forest Ecology and Management 36: 47-60.
Booth, T.H. (1995) Flying around the world. GIS User 14: 18-20.
Booth, T.H. ed. (1996a) Matching Trees and Sites. Proceedings of an international
workshop held at Bangkok, Thailand, 27-30 March 1995. ACIAR Proceedings No.
63.
Booth, T.H. (1996b) The development of climatic mapping programs and climatic
mapping in Australia. In Booth, T.H. ed. Matching Trees and Sites, ACIAR
Proceedings No. 63.
Booth, T.H. (1996c) Simulation mapping programs for Africa, China, Thailand and
Australia. In Booth, T.H. ed. Matching Trees and Sites, ACIAR Proceedings No.
63.
Booth, T.H. and Pryor, L.D. (1991) Climatic requirements of some commercially
important eucalypt species. Forest Ecology and Management 43: 47-60.
Busby, J.R. (1991) BIOCLIM - a bioclimatic analysis and prediction system. In
Margules, C.R. and Austin, M.P. eds. Nature Conservation: cost effective biological
surveys and data analysis. Melbourne: CSIRO, pp. 64-68.

15. Davidson, J. (1996) Developing Plantgro plant files for forest trees. In Booth, T.H.
(ed.) Matching Trees and Sites, ACIAR Proceedings No. 63.
Eastman, J.R. (1993) IDRISI version 4.1. Clark University, Graduate School of
Geography, Worcester, Massachusetts, 209 pp.
ESRI (1992) ArcView User's Guide. Environmental Systems Research Institute,
Redlands, 164 p.
Fryer, J. (1996) Site sampling and growth prediction in Central America. In Booth,
T.H. (ed.) Matching Trees and Sites, ACIAR Proceedings No. 63.
Godwin, D.C., Ritchie, J.T., Singh, U. and Hunt, L. (1989) A User's Guide to
CERES-Wheat v 2.10. Muscle Shoals, Alabama 35662, USA: International
Fertilizer Development Center, 86 pp.
Hackett, C. (1988) Matching Plants and Land: Development of a broadscale
system from a crop project for Papua New Guinea. CSIRO Division of Water and
Land Resources. Natural Resources Series no. 11, Melbourne, 82 pp.
Hackett, C. (1991) Plantgro : a software package for the coarse prediction of plant
growth. Melbourne: CSIRO
Hackett, C. (1996) A study of forest scientists perceptions of trees' environmental
relationships : implications for predicting growth. In Booth, T.H. (ed.) Matching
Trees and Sites, ACIAR Proceedings No. 63.
Hutchinson, M.F. (1989). A new objective method for spatial interpolation of
meteorological variables from irregular networks applied to the estimation of
monthly mean solar radiation, temperature, precipitation and windrun. CSIRO
Division of Water and Land Resources, Tech. Memo. 89/5, Canberra: CSIRO, 10
p.
Hutchinson, M.F. (1992) Documentation for SPLINA and SPLINB - two programs in
the ANUSPLIN software package. Canberra: CRES, Australian National University.
Hunter, I.R. and Gibson, A. R. (1984) Predicting Pinus radiata site index from
environmental variables. N.Z. Journal of Forestry Science 14: 53-64.
Jovanovic, T. and Booth, T.H. (1996a) The development of interpolated
temperature and precipitation relationships for the Indonesian Archipelago. In
Booth, T.H. (ed.) Matching Trees and Sites, ACIAR Proceedings No. 63.

16. Jovanovic, T. and Booth, T.H. (1996b) The development of climatic interpolation
relationships for the Philippines. In Booth, T.H. (ed.) Matching Trees and Sites,
ACIAR Proceedings No. 63.
Liebig, J. (1855) Die Grundsatze der Agriculurchemie mit Rucksicht die in England
angestellten Untersuchungen. Braunschweig: F. Vieweg und Sohn,
McMurtrie, R.E., Landsberg, J.J. and Linder, S. (1989) Research priorities in filed
experiments on fast-growing tree plantations: implications of a mathematical
production model. In Pereira, J.S. and Landsberg, J.J. (eds.) Biomass Production
by Fast-growing Trees. London: Dortrecht, pp. 187-207.
Marcar, N., Crawford, D., Leppert, P., Jovanovic, T., Floyd, R. and Farrow, R.
(1995) Trees for Saltland : a guide to selecting native trees for Australia East
Melbourne: CSIRO.
Murdiyarso, D. and Booth, T.H. (1994) Evaluation of Climatic and Soil Data for
Agriculture, Forestry and Conservation. Proceedings of a Seminar and Workshop.
Bogor Agricultural University , 113 pp.
Nambiar, E.K.S. and Brown, A.G. (1996) Management of Soils, Nutrients and
Water in Tropical Plantations. Canberra: Australian Centre for International
Agricultural Research.
Nghia, Nguyen Hoang (1996) Climatic requirements of some of the main tree
plantation species in Vietnam. In Booth, T.H. (ed.) Matching Trees and Sites,
ACIAR Proceedings No. 63.
Nix, H.A. (1986) A biogeographic analysis of Australian elapid snakes. In
Longmore, R. ed. Atlas of Australian Elapid Snakes. Bureau of Flora and Fauna,
Canberra, ACT, 4-15.
Pan Zhigang and You Yintian ed. (1994) Growing Exotic Trees in China. Beijing:
Beijing Sci. and Tech. Press, 756 p.
Pawitan, H. (1996) The use of Plantgro in forest plantation planning in Indonesia.
In Booth, T.H. (ed.) Matching Trees and Sites, ACIAR Proceedings No. 63.
Schonau, A.P.G. (1969) A site evaluation study in black wattle (Acacia mearnsii De
Wild.) Annale Universiteit van Stellenbosch 44: 79-214.

17. Singh, U., Ritchie, J.T., and Godwin, D.C. (1993) A User's Guide to CERES-Rice v
2.10 Muscle Shoals, Alabama 35662, USA: International Fertilizer Development
Center, 130 pp.
Sirirat Janmahasatien, Chingchai Viriyabuncha and Snowdon, P. (1996) Soil
sampling and growth prediction in Thailand. In Booth, T.H. (ed.) Matching Trees
and Sites, ACIAR Proceedings No. 63.
Taweesak Vearasilp, Jovanovic, T. and Booth, T.H. (1996) Plantgro soil and
climate database for Thailand. In Booth, T.H. (ed.) Matching Trees and Sites,
ACIAR Proceedings No. 63.
Webb, D.B, Wood, P.J, and Smith, J.P. (1980) A guide to species selection for
tropical and sub-tropical plantations. Oxford: Commonw. For. Inst. Oxford, Trop.
For. Pap. 15, 342 pp.
Webb, D.B, Wood, P.J, Smith, J.P. and Henman, G.S. (1984) A guide to species
selection for tropical and sub-tropical plantations. Oxford: Commonw. For. Inst.
Oxford, Trop. For. Pap. 15, 256 pp.
Yan Hong (1996) Site/genotype matching and growth prediction for Australian
trees in China. In Booth, T.H. (ed.) Matching Trees and Sites, ACIAR Proceedings
No. 63.
Zuo, H., Hutchinson, M.F., McMahon, J.P. and Nix, H.A. 1996. Developing a mean
monthly climatic database for China and Southeast Asia. In Booth, T.H. (ed.)
Matching Trees and Sites, ACIAR Proceedings No. 63.
Trevor H. Booth
CSIRO Division of Forestry
PO Box 4008
Queen Victoria Terrace
Canberra
ACT 2600
Australia
Telephone : +616 281 8259
Fax : +616 281 8312
email : Trevor.Booth@cbr.for.csiro.au

18. From Third International Conference/Workshop on Integrating GIS and
Environmental Modelling, Santa Fe, New Mexico, 21-25 January 1995,
Proceedings published on WWW and CDROM by National Center for Geographic
Information and Analysis, Santa Barbara.