9.2 Environmental Evidence

By the medieval period, the woodland cover had been much reduced in most areas of the Highlands. For example, at Sangobeg, northwest Sutherland (MHG29877; Brady et al 2007) and Freswick, Caithness (Morris et al 1995; Case Study Freswick Links) the pollen suggested very low tree levels, though there was enough variety to suggest scrub woodland. At Lairg, the final woodland clearance dated to the medieval period (Tipping 1994, 25).

The picture in the west in the areas controlled by the Norse and the Lords of the Isles needs to be brought together and the gaps noted. Here, there is abundant sculptural evidence for ship-building across the 12th to 16th centuries but, apart from ship fragments from Rubh’ an Dùnain in south-western Skye (MHG4895; Case Study Rubha an Dunain), no surviving physical evidence of the ships themselves exists. The documentary record for ship-building in the Highlands, mainly in the Argyll and Lochaber districts, has been explored by McWhannell in various publications (Campbell and McWhannell 1995; McWhannell 2000; 2013). Although management of woodlands for ship construction has been argued for Scandinavian settlement in Ross and southeastern Sutherland (Crawford and Taylor 2003), there is only a single reference to a vessel being built at Inverness in the Middle Ages. To gain a better understanding of the management of woodland, especially oak, for use in the construction of the galley fleets that are known to have been operated by Highland potentates, researchers need to consider the dating of the Atlantic oakwoods that extended up the Argyll coast from Morvern along with evidence for their management (Sansum 2009).   

On the other hand, archaeologists know from evidence of industrial and domestic hearths and charcoal burning platforms that wood resources including oak still survived in many parts of the Highlands in the medieval period (see 9.5). Documentary evidence of shipbuilding suggests managed woodland survived in some areas. The Scottish Ancient Woodland Survey, although mainly focused on the post-medieval period, would also provide a good starting point for the integration of this data into the archaeological record.

Charcoal assemblages can also provide evidence about woodland cover that would complement pollen analysis, including insights into woodland management. Recent work on charcoal inclusions in mortar at Castle Camus (Knock Castle) on Skye (MHG45401) provided dated contexts for wood used as fuel when creating the mortar. Birch, and to a lesser extent, oak and pine were used, and this evidence shows the local survival of species not common elsewhere on Skye. These results were compared to a pollen core taken less than two miles away from the castle several decades earlier, and to some documentary references and post-medieval maps. It is noteworthy that the pollen work only picked up hints of pine, but the charcoal analysis clearly shows its use (Thacker 2020). This work shows the potential for similar investigations elsewhere.

Aerial view of Castle Camus
Aerial view of Castle Camus (Knock Castle), Skye. ©HES

Wood was important as a building material and as fuel. Scottish kings and elites controlled forests which were valued more for their hunting than their trees. It is worth remembering that it is only in modern usage that the term forest necessarily means a large area of closed canopy woodland. Medieval forests might have few – if any – trees and the label would have related to their jurisdictional status as zones managed by forest law, with hunting and controlled grazing as the central function (Oram forthcoming b). In the Highlands, deer in the hunting forests would have been reserved for the Crown (eg Inverness) or for barons and ecclesiastical leaders who were granted ‘rights of free forest’ such as Rothiemurchus (Gilbert 1979).

Legal documents for Scotland as a whole show concerns about protecting woodland in the medieval period, first as a property right for hunting, but later with increasing concern about the theft of the wood. Only towards the end of the medieval period do legislation and leases elsewhere in Scotland become concerned with replanting (Oram forthcoming b). Documentary sources indicate woodland management was taking place in Scotland (Gilbert 2016), though more work needs to be done for the Highlands. In Scotland as a whole, wood for building was so depleted by the 15th century that foreign imports were the norm, first for oak, then for pine (Mills and Crone 2012, 30). It still remains to be tested however, whether this applies for much of the Highlands. Dendrochronology on oak and pine as well as charcoal analysis on other timbers holds some potential to test this.

The information for the Highlands needs to be pulled together to map areas of woodland for the entire region to determine where gaps in the evidence exist and if this general picture for Scotland holds true in the Highlands woodlands.

At Geodha Smoo Caves in northwest Sutherland a large amount of charcoal was recovered, with the identified wood types covering a range of habitats. Some, like spruce and Scots pine, may have been gathered as driftwood, or even imported. Birch was the most common wood for charcoal (Alldritt 2005; Case Study Geodha Smoo Cave complex). Nearby at Sangobeg (MHG29877) the record was dominated by turf and heather including as fuel (Brady et al 2007, 71).  Again, further studies in the area are needed to identify if the wood is local or imported.

Cave entrance visible in the rock
The Geodha Smoo cave complex, Sutherland. ©Helen Spencer

A number of bloomery sites have been dated to the medieval period (see 9.5). These required large amounts of charcoal, and it is thought that the industry moved around to areas of good woodland. In some cases, oak is clearly in use. The evidence of localised woodland cover, together with industrial evidence, especially from charcoal studies, could be expanded. However, peat was also used as fuel in some cases.

As with other periods, the environmental evidence for this period in the Highlands remains to be integrated. A number of excavated sites have included environmental investigations, notably Portmahomack (Carver et al 2016) and Cromarty (MHG51786). When the results from the excavations at Cromarty are published, these two sites together will provide useful insights into the environmental data for Easter Ross. The information from the plethora of excavations which have taken place over the past decades also would provide useful context when consolidated.

In Caithness, the investigations at Freswick also have provided useful data; this data is linked to a dated pollen core nearby (Huntley 1995; Morris et al 1995; Dickson and Dickson 2000, 146–150; Case Study Freswick Links). This can be combined with information about plants from nearby Brotchie’s Steading, a well stratified site with occupation over multiple centuries (MHG46260; Holden et al 2008; Case Study Brotchies Steading).

Brotchie’s Steading during excavation. Tim Holden ©Headland Archaeology (UK) Ltd

There are gaps in much of the knowledge for other areas of the Highlands. Analysis of environmental samples from the Whitefriars Priory in Kingussie, Badenoch should provide much-needed information for this area of the Highlands when published (MHG4413; Birch 2018b; 2020). Further work for Lochaber and Skye is also needed.

Oram (2014c, 233–234) has argued that the arable practices in the medieval period accelerated erosion, including where turf from dunes was stripped and then used to enrich plough soils. This is shown elsewhere by archaeological evidence of fields beneath wind-blown sand. In the Highlands, there is evidence of windblown sand over occupation and cultivation layers at Freswick, Caithness (Morris et al 1995, 32; Case Study Freswick Links), but it is not possible to attribute this to human activity. Data from other coastal sites would potentially shed light on this aspect of the medieval as well. At and around Fearn Abbey, Easter Ross there is evidence for soils being introduced to the site ; this activity has been identified and assigned to the medieval period (Barber 1981, 359). The areas concerned are extensive and warrant further environmental analysis to identify their purpose of soil introduction.

Bog iron was exploited in the medieval period (see below 9.5). This forms in a process dependent on organic and mineral iron salts in solution, in areas where increased podsolisation occurs in areas of high rainfall (Wordsworth 1993b).

For Scotland and elsewhere in Europe, the climate was warmer and milder at the beginning of the medieval period, but in the later 13th century documentary and environmental evidence shows a worsening. Subsequent harvest failures and famine continuing into the 14th century when there were episodes of plunging temperatures. This has come to be known as the first part of the ‘Little Ice Age’. Records elsewhere suggest this change in temperature was episodic. Combined with war, animal diseases, and then the Black Death epidemics, it was a difficult time for a wide section of the population (Oram and Adderley 2008; Oram 2014c, 224ff; forthcoming a).

There have been attempts to link the sparse historical records with climatic evidence in Scotland (Ross 2011; Oram 2014c), but the ways forward will depend on palaeoenvironmental research and dendrochronology, with a need for a focus on local conditions (Wilson et al 2017; Oram forthcoming a). The impact of climate changes in the Highlands remains to be teased out, hampered by poorer documentary records. Detailed work from Loch Sunart, Lochaber (Cage and Austin 2010) and Tralligil basin, northwest Sutherland (Charman et al 2001) provide some subtly nuanced local evidence for the types of impact to be expected from the later 1250s onward (Oram forthcoming a).

Dendrochronology also has great potential in providing climate information. While most work in this field relates to post-medieval or prehistoric material, medieval samples have been obtained from Strathspey, with the local chronology now continuous from the late 10th century. Further sampling is planned on sub-fossil trees to provide more medieval data (Wilson et al 2011; pers comm).

Oram has argued that the adverse, cooler climate affected all social levels in the north and west of Scotland, rural as well as urban. Less biomass production for grazing would have had an impact on cattle, and on deteriorating soil conditions (Oram and Adderley 2008; Oram 2014c, 231–2). The climatic change affected the sea as well as the land. The effects on fishing can be demonstrated elsewhere (Oram 2014c, 231–2), and should be looked at for Highland areas where fishing was important, such as Cromarty on the Black Isle and Freswick, Caithness where detailed analyses of fish bones were undertaken (Morris et al 1995; Case Study Freswick Links).  Studies using oxygen and carbon stable isotope analysis of deposits in Loch Sunart, a sea loch in Lochaber, demonstrated colder temperatures (Cage and Austin 2010), which in turn would have affected types of fish available in the waters. Targeted proxy studies, combined with consolidation of existing information would provide useful data for different areas of the Highlands. As Oram (forthcoming a) remarks, environmental data exists or is being gathered, and now requires archaeologists and historians to document the human impact of these difficult years.


Case Study: Freswick Links

Case Study: Rubha an Dunain

Case Study: Brotchies Steading

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