3.2 Environmental Evidence

Environmental studies can shed light on both human activity and the natural environment in which people operated. Some studies focus on individual periods and will be discussed in the chronological chapters. But much of the environmental work spans multiple periods, and/or the individual results need to be considered in the larger context. Environmental studies should be integrated with historical evidence where available to provide insights into how people reacted to environmental changes (Oram forthcoming a).

Issues of climate change and other environmental factors were summarised in National ScARF (Palaeolithic and Mesolithic section 3; Chalcolithic and Bronze Age section 3.2). Environmental studies pre 2000 from Caithness and northern Sutherland were summarised in Huntley 2000. The comprehensive discussion of environmental history by Richard Tipping (2017) in the Regional Archaeological Research Framework for Argyll (RARFA) is a model of the detailed research which can be undertaken, with potential for similar for the Highlands as a whole. His area of focus overlaps in places with southwest Highland region, but in any case is a pertinent and useful overview of sources and environmental factors as well as a plea for interdisciplinary working. He identified 22 research questions, and the non-site specific questions could usefully be applied to the Highlands where indeed key sites in the Highlands could be substituted (RARFA section 4.8).

The National ScARF Science section also covered a range of scientific techniques which aid environmental reconstruction, including geoarchaeology, archaeobotany, archaeozoology, archaeoentomology, pollen analysis, geomorphology and sedimentology and palaeoclimatology, with an overview of what these disciplines can offer and current developments up to 2012. This is currently being updated. The Highland Regional ScARF symposium talk by Scott Timpany also covers many of these topics, with a focus on some Highland sites.

This chapter will not repeat these overviews but will instead signpost to some of the work in the Highlands including areas needing further work. It is fair to say that there has been a great deal of work in the past, but little of this has been brought together for the Highlands; integrating studies done with different techniques, dating and foci is also an issue (Charman et al 2006). Most developer-led projects, and many research projects have carried out some environmental sampling, usually pollen analysis, but finding this information and pulling it together for local and regional areas is needed.

The general trends of climatic changes are known and increasingly are better dated (Tipping et al 2012). However, this does not mean these changes had the same impact on every place in the Highlands. Studies from Skye for example have shown that the variation in degree of exposure to prevailing winds, location in relation to mountain ranges or issues of altitude affected contemporary regional and local vegetation (Walker and Lowe 1990; Selby 2004). The northern Highlands is a climatically sensitive region, which means that it is impossible to generalise within relatively small areas, much less the entire Highland region. For example, even pollen diagrams from Loch Sionascaig, Wester Ross and a small island within the loch had differences (Birks 1993). The human response to conditions is also not uniform, which will be discussed below.

As increasingly the evidence shows local, micro-climatic evidence existed, the running of multiple studies in areas is needed if regional trends can be suggested (Langon and Barber 2005; Charman et al 2006). It is also notable that many of the studies mentioned in Table 4.4 involving cores that cover a long period are found in areas with little evidence of human settlement. Exceptions include Freswick, Caithness (Morris et al 1995); Rowens, near Camster Cairns, Caithness (Sybenga 2020); a number of Sutherland sites including the Garbh Allt catchment area near Rogart (Tipping et al 2008a; 2008b), Lairg (McCullagh and Tipping 1998), Strath of Kildonan (Charman et al 1995; Gillie 2003) and Upper Suisgill (Andrews et al 1985); Inver Aulavaig, Talisker Bay and Peinchorran on Skye (Selby 2004); Dail na Caraidh, Lochaber (Barrett and Bourlay 1999) and the Arisaig area of Lochaber (Carter et al 2005). Work in progress at several sites, for example by Hannah Genders Boyd in Wester Ross and Scott Timpany at Balvattie, Easter Ross, will help fill some gaps in evidence.

More interdisciplinary projects are needed such as the one at Lairg (McCullagh and Tipping 1998; Smith 1998), with archaeologists and scientists collaborating from the start. This investigation also showed the necessity of taking multiple cores through showing that change and human activity can sometimes be picked up from one core and missing from another.

A wealth of techniques is available, which can be deployed depending on the research questions:

Area to investigateMajor potential sources to explore
Vegetational changePollen, non-pollen palynomorphs, plant macrofossils, insects, microscopic charcoal
Agricultural activityPollen, charred plant remains, animal bone, human bone
Woodland managementWaterlogged wood, charcoal, pollen
Animal grazingPollen, non-pollen palynomorphs, insects, animal bone (and dentition)
PalaeoclimateInsects, plant macrofossils (sphagnum), non-pollen palynomorphs (testates), pollen, dendrochronology, chironomids

Many of these techniques are discussed in Chapter 2 and in the National ScARF Science section. Until the late 1980’s pollen studies were generally focused on vegetational change rather than archaeology. As a result, research questions were focussed on the immigration of trees and changing woodland patterns rather than directly looking for the interactions between people and landscapes. Early studies did not always record charcoal, and charcoal analysis is still not common. It was not until the late 90’s that analysts started to look at non-pollen palynomorphs so evidence for dung etc was not standard. This still applies today to some extent. More multi-proxy studies should be undertaken, using a range of techniques to build the full picture, see Timpany et al (2020) for a good example of such a study in Orkney).

Dating is key to all of these studies. Many of the dated cores in early investigations only had a limited number of radiocarbon dates, and those obtained often needed bulk sampling, thus providing large dating margins. Analysis of volcanic tephra has allowed more precise linking of cores though there remains issues of whether the tephra shards were buried immediately or had been subject to exposure before eventual deposit (eg Landon and Barber 2005; Tipping et al 2008b). The goal to define dating to generational spans remains (Tipping et al 2012).

3.2.1 Climatic Change

3.2.2 Vegetation and Woodland

3.2.3 Sea Levels

3.2.4 Ways Forward