BASICPRINCIPLES – MAKING THEMOST OF THECLUES 31
and Fungi imperfecti. In most cases, deterioration by
soft rot fungi is confined to the cellulose of the wood
cell wall while the lignin is often not degraded. Obser-
vations of soft rot in waterlogged wood suggest that the
responsible fungi are able to attack wood at levels of
oxygen lower even than those required by wood-
degrading Basidiomycetes.
Bacteria are ubiquitous in nature and can survive in
environments with or without oxygen; some are even
capable of living in both types of environment. Although
many different bacteria can be found on wood, not all
species possess the necessary enzymes to degrade the
wood. Those that can cause deterioration may degrade
only certain pit membranes within the wood, while
others have the capacity to degrade lignin and cellulose
within the cell wall. Bacteria that can degrade woody
cell walls produce specific degradation patterns and have
been separated into three forms: cavitation, tunnelling and
erosion. Cavitation bacteria form cavities that often
develop perpendicular to the long axis of the cell wall.
Tunnelling bacteria penetrate the secondary wall and
form minute tunnels. Erosion bacteria are characterized
by erosion of the cell wall from the lumen toward the
middle lamellae. Very little is known about the influence
of environmental factors on bacterial decay and the
occurrence of bacterial degradation of wood under com-
pletely anaerobic conditions has not been unequivocally
demonstrated. The occurrence of bacterial attack on
wood in waterlogged conditions that could be character-
ized as near anaerobic (e.g. buried within sediments)
suggests that erosion bacteria are the main bacterial
cause of deterioration and are capable of degrading
wood in situations where fungi are completely excluded
because of the limited oxygen content. Fortunately, these
bacteria are only able to attack the cellulose within the
cell wall of the wood and leave the lignin in the middle
lamella behind.
From a conservator’s perspective, waterlogged archae-
ological wood is generally considered to be poorly pre-
served. It is often only the water that has replaced the
degraded cellulose that provides the shape of the surviv-
ing wood and the wood cell is only held together by
the skeleton of lignin remaining in the middle lamella.
However, from an archaeological perspective, the fact
that the wood has been deposited within an environ-
ment that limits biological attack leaves us with the
chance of finding well-preserved archaeological clues
about our past.
Although this section has only dealt with wood, it
demonstrates how important it is to understand the type
of archaeological material being studied and what factors
will affect its deterioration. Only by understanding this
will it be possible to understand the effects the under-
water environment will have on preserving archaeo-
logical clues about the past.CULTURE AND SITE-FORMATION PROCESSES
As well as the physical environment, it is important to
consider how cultural aspects affect site formation. It
would be far too simplistic to suggest that an understand-
ing of the environment leads to an understanding of
humankind. One is not the only factor determining the
behaviour of the other. It could be said that people do not
react to the environment but rather they react to their
view of the environment. Levels of technology will shape
the response to environmental challenges. Factors such as
religion will shape attitudes (e.g. to issues like the eating
of meat or birth control). A consideration of all the
motives and actions that go together to make up ‘human
nature’ clarifies just how complex the problem of under-
standing cultural influences on the archaeological record
can be.
How does an object go from being used to being
recorded as part of an archaeological site? The idea of
throwing out rubbish or trash is a familiar one. Archae-
ologists are often experienced in painstakingly investigat-
ing the equivalent of ancient dustbins. A great deal of
archaeological material was buried through being discarded,
thrown into pits or left in abandoned buildings that col-
lapsed around them. Items are regularly lost by accident- coins, wallets, car keys. Sometimes they are found while
on other occasions they may lie where they fell for
many years. The same has been true since before people
first had holes in their pockets. Isolated, accidental losses - sometimes traumatic, such as during a fire or battle –
are therefore responsible for much material entering the
archaeological record.
Deliberate burial of groups of associated material is much
less common. There are examples of material buried for
posterity like the ‘time capsules’ buried by schoolchildren.
Graves may seem a more common example of burial
for posterity, but in many circumstances this could be
seen as another example of rubbish disposal. Hoards of
coins or other valuables are sometimes deliberately
buried for safekeeping. However, it could also be said that
those that are found are examples of ‘accident’ since the
owner was not able to reclaim them once the trouble
had passed.
There is considerable evidence of ritual activity
around lakes and rivers (Bradley, 1990). The superstitious
nature of fishermen and sailors is also well attested
and is often considered to be a cultural response to the
uncertainties of the environment in which they operate.
The carrying of talismans for good luck, or the deliberate