[Taxacom] Panbiogeography and biosecurity

John Grehan calabar.john at gmail.com
Tue May 30 09:47:21 CDT 2017


I realize that quite a few of my postings on the politics of
panbiogeography are are on the negative side and likely that elicits an
automatic negative response, so it is with some pleasure that I can make
note of a more positive circumstance. In a paper by Nigel Clark
titled Mobile Life: Biosecurity Practices and Insect Globalization
published in Science as Culture,  (2013)  22:1, 16-37 the author makes some
very positive reference to panbiogeographic insights with respect to
understanding the evolution of New Zealand's biota and the importance of
conceptualizing New Zealand's natural structure for assessing biosecurity.
Also, it is readily apparent that he 'gets it'.

It just goes to show that should one live so long it is possible to be
surprised. Perhaps not so surprising is that the author is not from a New
Zealand biosecurity or conservation institutions, but from the Lancaster
Environment Centre of Lancaster University. Anyone interested in the
article can access it at
https://www.researchgate.net/publication/271822613_Mobile_Life_Biosecurity_Practices_and_Insect_Globalization

A couple of excerpts below:


"While a certain `nationalist’ inflection of New Zealand naturalism has
repeatedly fallen back on the idea that the islands constitute  a once
unique and unsullied relic of the ancient continent of Gondwana (Craw,
1990),  the challenge of deciding which organisms belong where is helping
push the issue of geological origins in rather different directions. And
this, I want to argue, has potentially important implications for thinking
about both the `bio’ in biopolitics, and the `geo’ in geopolitics."

The question as to why there are similar biotic assemblages ranging across
the widely separated landmasses of the southern hemisphere is an important
one - and more complex and contested than it may first appear. The short
answer derives from the study of plate tectonics, which shows that the
landmasses in question were formerly part of the great southern continent
of Gondwana – and that they have drifted apart, carrying related floristic
and faunal assemblages with them as they have moved.  With regards to the
landform now known as New Zealand or Aotearoa, however, there is a more
complicated – and by no means universally accepted answer. By looking
closely at both the geological composition and the biotic assemblages of
the island arc, some life and earth scientists argue that Aotearoa New
Zealand is made up of heterogeneous terranes – or crustal fragments -
mostly from sources other than Gondwana. Like many other landmasses, it is
claimed,  these islands have no single origin: they are a conglomerate of
 varied geological processes ,  including  orogenic forces (uplifting  and
 downlifting) erosions and accretions, and the drifting and suturing
together  of terranes arriving from several different directions (see Craw,
1985)  As entomologist and biogeographer Robin Craw puts it:
Aotearoa was formed by convergent forces radiating out from at least three
oceanic spreading centers. This triple plate junction is a complex mosaic
of numerous terrains of disparate origin, formed in widely spaced settings,
and then welded together and metamorphosized by immense tectonic forces.
New Zealand is a biogeographic/geological composite or hybrid area, an
orogenic collage of fragments...’ (Craw and Hubbard, 1993: p.32).

By this reading, the isolation which Elton and so many others have
foregrounded, while significant, may not as definitive as most life
scientists and many cultural commentators have tended to assume.  As Craw
and a handful of other biogeographers have proposed, there may be no good
reason to treat `New Zealand’ as a coherent unit or natural biogeographic
entity at all. Rather, New Zealand’s biological community appears to be
profoundly differentiated, reflecting the multiple origins of the islands’
geological components.  And in this way, more so than it shows the effect
of isolation, the characteristics of the country’s various biotic
assemblages reveals pronounced  affiliations with the  biota of the regions
to which each fragment once belonged (Craw, 1985;  Cooper, 1989;  see also
Clark, 2012)


More information about the Taxacom mailing list