# dots on maps

[Jim Croft]

> Should it be by dots, and if so what
> size should the dots be?  The Flora of Australia has 15 distribution maps to
> a page and the size of the dots used in recent editions of the Flora has the
> standard dot equivalent to about 100 kms diam.  Any smaller may be more
> accurate but less effective as a means of showing the distribution.  Some
> maps in earlier volumes showed distribution in the form of blocked areas and
> at the scale being used is perhaps just as meaningful as dot maps.

Ah, dots on maps - the curse of the printed flora - neither fish, nor
fowl - neither a point in space and time, nor a meaningful biogeographic
statement.  But people seem to like them, believing that they contain
more information that a list of specimens examined.  The Flora of
Australia maps are a case in point - next to useless, they do not tell
you where a plant has been found nor where it might be expected to be
found based on climatic, edaphic or even historic profiles - it really
is debatable whether they justify the intellectual and editorial angst
that goes into their production.  But people like them and like to look
at them (and more importantly your treatment will not get published
without them).

> Ideally it would be nice if mapping programs (such as MapInfo) could use the
> same flora distribution data to zoom in on distributions as the scale became
> smaller. Theoretically it could then be possible to fine-tune the
> distribution patterns of individual collections within the area of a 100 km
> wide dot.  This geographic and spatial data could then presumably be
> able to link up with on-line interactive identification and information
> retrieval programs.

This is the guts of the matter.  Focussing on a dot on a map, and
printing it on paper (or on a frozen PDF file for that matter) locks you
into one vizualization of many for any biological occurrence.  Focussing
on the particular point in space (and time if you like) gives you a real
datum that can be visualized in any number of ways, at any number of
scales, any number of times, at negligible incremental costs.

An accurately georeferenced specimen (or record, for those who are not
too hung up on vouchers) visible to the web is a very potent beast.  And
we are sitting on millions of the little blighters.

If editors insisted of files of georeferenced specimens rather than
dotted maps, what an incredible tool and information base we would be
building...

-- jim