Man On Coastal Margins

In a world without roads coastlines provide convenient migration routes as well as access to the resources of the land and the sea. The early Mesolithic and later Neolithic coastal settlements that are found from the extreme north of Norway to the Atlantic islands of the Hebrides are a clear testimony to an early exploitation of the advantages of northern oceanic environments. The maritime conditions caused by the ameliorating influence of the North Atlantic Drift on Europe's north-western littoral allow pastoral and arable farming to be pursued at higher latitudes than would otherwise be the case. In particular, the cultivation of winter crops and the outdoor overwintering of animals have supported relatively large human populations as already referred to in relation to Neolithic Orkney (Section 11.2). The long history of human settlement in these regions has in turn produced marked changes in the landscape through human impact on vegetation.

Island woody vegetation appears to be particularly vulnerable to human disturbance both in the Atlantic and Pacific Oceans. Easter Island with its monumental statuary has now been found to have been settled later (c. AD 1200) and deforested more rapidly than previously thought (Hunt & Lipo, 2006). The islands of Macaronesia (the Canary Islands, Madeira and the Azores) all had their tree cover rapidly altered by human settlement. In contrast to the Canary Islands, Madeira and the Azores had no autochthonous human populations and were first settled with the arrival of Europeans in the early fifteenth century. The immediate effect of the human settlement was the large-scale removal of forest. In Madeira there is evidence that much of the forest was removed by devastating fires (Sziemer, 2000). Iceland also suffered serious loss of tree cover in the centuries after its settlement c. AD 870 (see below).

In oceanic territories such as Orkney and Shetland (Bunting, 1996) western Norway (Kaland, 1986) and the Hebrides (Tipping, 1994), the advent of Neolithic farming was marked by the rapid and extensive replacement of trees by heathlands to an extent that did not take place in more continental areas. The relative importance of climate and human disturbance in the formation of modern heaths has been the subject of extensive discussion for many years. The existence of moorlands in western Europe can be traced to pre-Pleistocene times (Stevenson & Birks, 1995) and there is also evidence for the initial replacement of trees by moorlands and mires in a number of oceanic habitats even before the arrival of the first farmers. In Unst (Shetland), some opening of the tree canopy is detectable before the arrival of the first Neolithic settlers (Bennett et al., 1992). The new Holocene heath-lands in north-west Europe differ from those of earlier times in having a pronounced dominance of Calluna vulgaris. However, it was with the arrival of Neolithic farmers that heathland development became much more extensive along the European Atlantic seaboard. In Orkney most of the tree cover appears to have been removed within 500 years of the arrival of the first Neolithic farmers (Bunting, 1996).

The length of time that the more oceanic areas of Scotland have been without any substantial tree cover has sometimes been assumed to mean that these peripheral and exposed islands of the Outer Hebrides, Orkney, and Shetland were always treeless. Early accounts (McVean & Ratcliffe, 1962) depicted many of the western islands of Scotland as naturally treeless. However, subsequent research has shown that these hyperoceanic regions once supported extensive areas of birch woodland with Corylus avellana (Fig. 11.13),

Fig. 11.13 Monoecious flowers on hazel (Corylus avellana). The male flowers are in the pendent catkins while the female flowers with conspicuous red styles are borne separately in clusters. Hazelnuts have been found in large numbers in Mesolithic sites and would have made a valuable contribution to the protein content of the winter diet of early settlers throughout Europe.

Fig. 11.13 Monoecious flowers on hazel (Corylus avellana). The male flowers are in the pendent catkins while the female flowers with conspicuous red styles are borne separately in clusters. Hazelnuts have been found in large numbers in Mesolithic sites and would have made a valuable contribution to the protein content of the winter diet of early settlers throughout Europe.

Salix spp., Populus spp., and Sorbus aucuparia even near their coastal fringes, while more central and eastern parts of the islands may have had stands with more warmth-demanding species (Tipping, 1994). The warmer conditions that existed in Mesolithic times are shown by the substantial remains of hazelnuts found on archaeological excavations in the Hebrides. Remains of over 100000 nuts were found on a Mesolithic site on Colonsay (Inner Hebrides) which were dated to around 6700 BC. Pollen sampling from a nearby loch also showed an almost complete collapse of the woodland just after the intense hazelnut harvests had taken place (Mithen, 2003). Hazel is particularly sensitive to climatic factors for flowering and fruiting (Tallantire, 2002) and crops best when the hazel bushes form the forest canopy. At present hazel does not produce commercially harvestable quantities of nuts in Scotland. This may be due to the fact that in present-day forests hazel is mainly found as an under-storey component, which can reduce flowering and fruiting. The copious remains of hazelnuts found in Mesolithic sites may therefore reflect the more dominant status of hazel in woodlands before the Atlantic oak woods became dominant, as well as the warmer climate of this period. The abundance of hazelnuts would have been especially advantageous nutritionally as they are rich in protein and easily conserved for winter use.

In the Outer Hebrides blanket peat began to appear between 9000 and 8000 BP (Fossitt, 1996). A marked climatic deterioration (Klitgaard-Kristensen et al, 1998), commonly termed 'the 8200 BP event' (probably due to freshwater fluxes in the final deglaciation of the Laurentide ice sheet), appears to have been accompanied by some reduction in tree cover throughout western Europe. In western Lewis (Outer Hebrides), there was a progressive replacement of trees by blanket peat which began about 7900 BP and continued with a further reduction of tree cover between 5200 and 4000 BP (Fig. 11.14). This later forest decline was associated with early Neolithic settlements (Fossitt, 1996).

In evaluating the relative roles of climate and human interference in removing tree cover, the late Norse settlement of Iceland (c. AD 870) provides a useful comparison with the longer settled regions ofthe North Atlantic. Studies of pollen and plant macro-fossils show that dense birch forest was present in Iceland from 6900 BP onwards (Rundgren, 1998).

Accurate association of vegetation changes immediately before and just after the time of the landnam (agricultural settlement) has now been possible with dating of the landnam tephra to AD 875 from the GRIP ice core (Pilcher et al., 2005). Differences in the pollen record below and above the tephra layer show that the decline of birch was greatly accelerated after the settlement and was accompanied by an expansion of waterlogged soils and mires (Hallsdottir, 1987). The pollen record therefore shows that Iceland, despite exposure to the hyperoceanic conditions of the North Atlantic, retained much of its tree cover throughout most of the Holocene, and it was only after the Norse settlement that forest disappeared with great rapidity.

Ari 'the Learned', writing in AD 1120-30, states in the Islendingabok that, 'at that time [the time of the settlement] Iceland was covered by woodland from the mountains to the coast'. It is unlikely that the treeline in Iceland ever exceeded 300-400 m (Hallsdottir, 1987),

Fig. 11.14 Paludification accelerated by human settlement in Harris (Outer Hebrides, UK) as seen at the head of Loch Maaruig in 1966. Harris and Lewis were once tree-covered and are now largely bog and moorland. The continued retreat of agriculture and the advance of heathland can be seen on the far hillside where abandoned lazy beds are now covered in heather.

yet Ari's description nevertheless indicates that there had been a marked change by the twelfth century from that at the settlement in the nineth century. The Landnamabok also records that the early settlers had to clear trees to make it suitable for farming (Palsson & Edwards, 1972). Icelandic land-claim laws contained in the Gragas Lawbook (as recorded in codexes from about 1270) pertaining certainly to the twelfth century and probably also the eleventh (P. Foote, pers. com.) define very precise rules governing forest utilization for fuel and building. Careful distinctions are made as to whether wood is to be taken by cutting or pulling and whether or not meadow is allowed to replace woodland. Conservation was also an issue as there are regulations concerning joint owners of woodland who may have had disputes with regard to woodlands being overused. There are even penalties for hacking notches in a tree or causing scrapes that result in damage. Similarly, the penalties for browsing another man's trees are greater than those exacted for encroaching on his grassland. There are also precise laws governing the exploitation of new growth from old trees (Dennis et al., 1980). The detail of these laws tells us that by the twelfth century woodland was regarded as a very important asset and not something which farmers had an automatic right to remove.

In England similar strictures conserving trees also appear in King Alfred's law code, clause 12: 'If one man burns or fells the tree of another, without permission, he shall pay five shillings for each big tree, and five pence for each of the rest, however many there may be; and 30 shillings as a fine' (King Alfred, AD 849-899).

0 0

Post a comment