Agriculture, Ecosystems and Environment 82 2000 303–319
Estimating vulnerability under global change: modular modelling of pests
R.W. Sutherst
∗
, G.F. Maywald, Beth L. Russell
CSIRO Entomology, 120 Meiers Rd., Indooroopilly, Qld 4068, Australia
Abstract
Global change research and decision-making are conducted in an environment where there are many stakeholders, numerous targets and few resources. This calls for global collaboration and sharing of information on a scale that has not been attempted
before. It demands a parsimonious approach to research, with the aim of enabling robust decisions to be made with the minimum of new information. Our approach to these problems has been to develop generic analytical tools, which in turn are used to foster
collaboration through joint model development, testing and application. This collaboration is achieved through a workshop and networking process to establish ‘CLIMEX’- or ‘DYMEX’-Modelling Networks, and to extend the information to the wider com-
munity using the world wide web WWW http:www.ento.csiro.auresearchpestmgmtIPMModellingNetworkindex.htm. In this paper we outline key features of these modelling approaches and illustrate a ‘hypothesis-driven’ approach to climate-
matching, using CLIMEX http:www.ento.csiro.auresearchpestmgmtclimexclimex.htm that contrasts with the usual, statistically based, pattern-matching of meteorological data without consideration of possible mechanisms that limit the geo-
graphical distribution. We illustrate the nature of a generic and modular simulation model built using DYMEX http:www.ento. csiro.auresearchpestmgmtdymexdymexfr.htm, but emphasize the urgency for the scientific community to collect the data
necessary to build reliable population models. We summarize results and conclusions from a global change workshop based on the use of both these software tools. They illustrate the advantages of the proposed approach as a means of building col-
laborative international research communities, which are able to avoid repetition by contributing their modules into a library of functions for sharing with other users. © 2000 Elsevier Science B.V. All rights reserved.
Keywords: CLIMEX; Risk assessment; Multi-trophic impacts; DYMEX; Modelling workshops; Collaborative networks; Climate change
1. Introduction
There are major gaps between the actual and at- tainable yields of crops, attributable largely to pests,
diseases and weeds Oerke et al., 1994. In global change research, estimates of crop yields using simu-
lation models also suffer from major gaps between the observed and predicted yields Landau et al., 1998.
Furthermore, invertebrates, plant pathogens and weeds referred to collectively here as ‘pests’ are highly
∗
Corresponding author.
adapted to change and so are prime targets for risk assessments in global change research.
The Intergovernmental Panel on Climate Change IPCC has developed a process for estimating the
vulnerability to climate change of regions and indus- tries Parry and Carter, 1998. Vulnerability is de-
termined by the sensitivity of the system to impacts, taking adaptation options into account. This approach
recognises that mankind will inevitably implement management responses to change wherever possible,
so assessment of risks in the absence of consideration of adaptation is not realistic for a managed system, at
least.
0167-880900 – see front matter © 2000 Elsevier Science B.V. All rights reserved. PII: S 0 1 6 7 - 8 8 0 9 0 0 0 0 2 3 4 - 6
304 R.W. Sutherst et al. Agriculture, Ecosystems and Environment 82 2000 303–319
Vulnerability = Sensitivity 1 − Adaptive management where ‘Sensitivity’ is the impacts in the absence of
adaptation and ‘Adaptive management’ the response options as determined by the sustainability and ro-
bustness of available and putative management tools Sutherst et al., 1998.
The process described above has proved to be very appropriate for use on pests, diseases and weeds.
Sutherst 2000 described a conceptual framework for studying the effects of invasive species under
global change. This framework incorporates ap- proaches from the IPCC, and the quarantine pest risk
International Plant Protection Convention, IPPC and plant pathology communities. Sutherst et al.
2000 applied the IPCC approach in an assessment of the vulnerability to climate change of differ-
ent horticultural industries and growing regions in Australia.
The research issues facing global change research- ers, policymakers and managers of pests were
reviewed by Sutherst et al. 1996a. In summary, there is less support available for climate change research
than is allocated to the solution of problems of im- mediate concern. This is despite the initial need for
global change research to understand current prob- lems better. Such research will provide a true baseline
as well as an understanding with which to enhance risk assessments and the design of both current and
future management options. Other research issues are that risk assessments often involve multiple in-
teracting drivers of change, which degrade the value of isolated assessments. Furthermore, outputs relate
mostly to the policy-level, which means regional, national or global scales involving industries or re-
gions. Policy questions focus on defining impacts and vulnerability, via a combination of regionalindustry
scale sensitivity analysis and evaluation of adaptation options. Results of risk assessments have to be trans-
lated into socio-economic measures in order to be meaningful for policymakers. These demands are not
matched by available resources and therefore need a degree of pragmatism if they are to be addressed in
the foreseeable future.
The scientific community involved in biological research needs some common data sets, analytical
tools and languages to facilitate collaboration. The uncertainty of future global change scenarios and
our inability to conduct large-scale experiments on impacts of global change have forced reliance on
models to explore possible impacts. Global research networks are also needed to gain leverage through
collaboration and information sharing. The Global Change and Terrestrial Ecosystems Program GCTE
of the International Geosphere Biosphere Program IGBP has a number of crop and soil networks
Ingram et al., 1999 and is developing a pest and disease network Sutherst et al., 1996b; Scherm et al.,
1999. The crop modelling community has already made progress in developing international collabora-
tive research groups, which run model comparison exercises in a push to improve the models for use
in global change research Landau et al., 1998; In- gram et al., 1999. The partnership has been assisted
by the previous collaborative network built around the use of the DSSAT model http:agrss.sherman.
hawaii.edudssatindex.htm. In contrast the pest re- search community faces different challenges with its
large number of pest communities that vary greatly in composition in different regions and on different
crops, making it less appropriate to focus collabora- tion on particular species. Thus GCTE has focussed
effort initially on developing generic approaches to the assessment of risks under global change Sutherst
et al., 1996a; Scherm et al., 1999, while recognising the need to increase effort in experimentation and
monitoring activities.
Two modelling tools are discussed here, namely CLIMEX Sutherst et al., 1999, a tool for modelling
species’ responses to climate, and DYMEX May- wald et al., 1997, 1999, a generic and modular mod-
elling toolkit designed for biologists. Both CLIMEX and DYMEX offer the advantage that the models or
modules that they create can be readily shared with other users to avoid the need for wasteful repetition of
effort.
2. A biological toolkit for global change
