22
Mark Burgman et al.
that after a taxon has been formally circumscribed and published, and thus
brought to the attention of the wider community, collections of it may increase.
Some of the constraints affecting collection patterns include time, money, seasonal conditions, and land tenure changes.
The collections of the Western Australian Herbarium may not be entirely representative of collections elsewhere because CALM has a structured process for
monitoring taxa of conservation concern. The process includes legislation to
declare and then protect plant taxa, state government processes to maintain a
conservation list of both declared and undeclared taxa, and formal survey and
monitoring protocols. The interplay of these factors may affect collection patterns
and confound the application of the methods described above. For example, once
a plant species is declared rare, it is protected by legislation and almost all casual,
opportunistic, and scientific collections will cease unless special authority is given
by the state. However, immediately prior to being protected, the same taxon is
likely to be relatively heavily collected because departmental protocols require
that the range and abundance of the declared rare flora taxon be established
through extensive surveys. A rash of collections followed by a dearth of collections could be expected for declared rare flora, a pattern independent of any
change in conservation status. Other factors affect collecting patterns in an unpredictable way. The observations in Appendix I reveal that the following processes
play a part in determining unusual collection patterns in Western Australia’s
Acacia conservation taxa:
• geographic location
• taxonomic uncertainty
• taxonomic interest
• legislative controls
• establishment of monitoring programs
• survey attention (priority list taxa are more likely to be surveyed than unlisted
taxa)
• timing of district surveys
• particular interests of individual collectors
• herbarium curatorial procedures (e.g., “uninformative” specimens such as collections from a single location made at different times may be excluded)
Conclusions
Type II errors are made in setting conservation priorities when a conclusion is
reached that a taxon is not threatened, when, in fact, it is. The frequency with
which type II errors are made depends in part on the quality of the data. Any tool
that makes better use of existing information will improve the quality of decision
making in setting conservation priorities. The methods applied here are one such
tool that provide better tests of the dynamic properties of populations than are
currently available.
The best strategy is to use many different methods together. If one uses a set of
complementary tests, there is less chance of missing significant changes simply
Mark Burgman et al.
that after a taxon has been formally circumscribed and published, and thus
brought to the attention of the wider community, collections of it may increase.
Some of the constraints affecting collection patterns include time, money, seasonal conditions, and land tenure changes.
The collections of the Western Australian Herbarium may not be entirely representative of collections elsewhere because CALM has a structured process for
monitoring taxa of conservation concern. The process includes legislation to
declare and then protect plant taxa, state government processes to maintain a
conservation list of both declared and undeclared taxa, and formal survey and
monitoring protocols. The interplay of these factors may affect collection patterns
and confound the application of the methods described above. For example, once
a plant species is declared rare, it is protected by legislation and almost all casual,
opportunistic, and scientific collections will cease unless special authority is given
by the state. However, immediately prior to being protected, the same taxon is
likely to be relatively heavily collected because departmental protocols require
that the range and abundance of the declared rare flora taxon be established
through extensive surveys. A rash of collections followed by a dearth of collections could be expected for declared rare flora, a pattern independent of any
change in conservation status. Other factors affect collecting patterns in an unpredictable way. The observations in Appendix I reveal that the following processes
play a part in determining unusual collection patterns in Western Australia’s
Acacia conservation taxa:
• geographic location
• taxonomic uncertainty
• taxonomic interest
• legislative controls
• establishment of monitoring programs
• survey attention (priority list taxa are more likely to be surveyed than unlisted
taxa)
• timing of district surveys
• particular interests of individual collectors
• herbarium curatorial procedures (e.g., “uninformative” specimens such as collections from a single location made at different times may be excluded)
Conclusions
Type II errors are made in setting conservation priorities when a conclusion is
reached that a taxon is not threatened, when, in fact, it is. The frequency with
which type II errors are made depends in part on the quality of the data. Any tool
that makes better use of existing information will improve the quality of decision
making in setting conservation priorities. The methods applied here are one such
tool that provide better tests of the dynamic properties of populations than are
currently available.
The best strategy is to use many different methods together. If one uses a set of
complementary tests, there is less chance of missing significant changes simply