9.2.8 Post Medieval

The apparent invisibility of first millennium AD and medieval rural, non-elite, settlement is being addressed (eg Atkinson 2016; Strachan et al 2019). The palaeoecology of the medieval and postmedieval has much to contribute to the archaeological and environmental history of the document-aided period. Three clusters of studies indicate the potential to connect high-resolution palaeoecology with documentary, archaeological, land management and conservation records. These include studies of the environmental history around Loch Tay (Hamilton et al 2009; Tipping et al 2009a) and Loch Awe (Sansum 2005; Davies and Watson 2007) over the last 400–1000 years as well as the  palaeolimnology of Loch Leven over the last 200 years (Salgado et al 2010; Bennion et al 2012).

The value and meanings of trees and woodlands are recurring themes in prehistory, palaeoecology and contemporary science, management and policy (Smout et al 2005; Noble 2017; Bastin et al 2019). Palaeoecological studies commonly document extensive millennial-scale reductions, in which humans often played a significant role (Tipping 1994). Studies from western Perth and Kinross and neighbouring Argyll that combine detailed pollen studies with historical archives offer more nuanced insights into the tensions over tree management and the management legacies that shape the distribution and composition of surviving ‘ancient’ woodlands.

Loch Tay ©️ Phillip Capper (CC BY-SA)

The work of Sansum (1995) demonstrates that ‘core’ woodland areas survived last millennium against a wider process of loss, but not without significant change. During the late medieval period, old-growth woods were possibly transformed into more open stands used for pasture and domestic wood supply. This regime prevented trees from maturing and may have depleted more browsing-sensitive species, raising questions over the longer-term sustainability of these uses. In closer proximity to farm townships, pre-industrial woods were certainly a source of tension between landlords and tenants. Trees were owned by the estate, but used for small timber and as sheltered grazing by tenants, for whom animals were often the main source of income and rent (Davies and Watson 2007). Pollen sequences from small infield and shieling sites on Loch Tay offer a closer insight into how these dynamics played out. Around AD 1400, a birchwood developed around the upper head dyke on the township of Leadour, reaching its maximum extent around AD 1560–1600 (Hamilton et al 2009). Grazing and cultivation continued throughout, suggesting that the trees were deliberately protected, in accordance with estate policy. Court records leave little room for doubt that the estate strongly objected to the destruction of this wood between AD 1614–1620. Grazing records, albeit fragmentary, suggest that from at least the mid-17th century, the farmer was investing in cattle, possibly to supply the growing trade with England. Intensified grazing is recorded on the shieling grounds belonging to this farm, as well as those on the north side of Loch Tay (Tipping et al 2016) and in Glenorchy (Davies and Watson 2007), over the course of the 17th century. It may be testament to a shift in farmer, as opposed to landlord, values. Both economics and climate may have played a role in the types and longevity of land use at higher altitudes on Ben Lawers (Tipping et al 2009a).

Woods were not the only resource whose history demonstrates economically-driven management impacts. Hanley et al (2008) show a strong correlation between rising market prices for livestock and the loss of diversity over the last 400 years in pastures and shielings/hill grazing across multiple estates, including Breadalbane lands on Loch Tay and in Glenorchy. If viewed simplistically, this fits into a narrative of grazing-led ‘degradation’ of the uplands. However, there was certainly no universal or synchronous trend in plant diversity, indicating complex interactions between local ecological conditions, management choices and economic incentives, within which grazing continues to have an important role.

The period from 1700 benefits from the availability of good and relatively cheap chronological controls in the form of spheroidal carbonaceous particles (SCP) derived from combustion of fossil fuels, and radionuclides from natural (e.g. lead 210Pb) and anthropogenic sources (eg americium 241Am and caesium 137Cs from nuclear weapons testing and the Chernobyl explosion), which jointly span the last 70–250 years. Tree pollen from afforestation and landscape design with non-native and non-local species can also be used to provide approximate dating controls where there are good records of planting dates and species.

Commercial interests also became the dominant factor in the Breadalbane woodlands around AD 1700–1900, with the establishment of an intensive harvest rotation to meet strong economic incentives for a valuable double crop: charcoal for iron smelting and bark for tanning (Sansum 1995). In some woods, oak may have been deliberately selected and lower value competitor trees removed. The intensive woodland management during the 18th and 19th centuries contrasts with limited use, except for grazing, in the last 100 years, when the currently dominant oaks have matured. This overtopping process led to the exclusion of shorter-lived and less shade-tolerant species, and generated large and often gnarled oaks that are erroneously considered to be an ancient characteristic in contemporary conservation.

Breadalbane woods, Glen Lochay ©️ Steve Garvie (CC BY-SA)

Taking an interdisciplinary approach to environmental history allows palaeoecology to test for potential biases or blind spots in documents written (on the whole) by estate managers and ‘improvers’. For instance, palaeoecology and some farm-level vignettes from written sources show that farmers were very much involved in and potentially leading efforts to improve productivity and economic returns from farms around Loch Tay during the later 18th and 19th centuries. These contrast with descriptions of later 18th century agriculture as backward and in need of ‘improvement’ (Hamilton et al 2009; Tipping et al 2009a).

Palaeoecology also contributes to conservation concerns in lowland Kinross. Loch Leven is the largest shallow nutrient-rich freshwater lake in Scotland. While palaeolimnological studies from this site focus on changes in plant, algal, nutrient and sediment conditions within the water, they highlight the sensitivity of the lake ecosystem to management in the surrounding catchment (Salgado et al 2010; Bennion et al 2012). The data cover around the last 200 years in order compare modern monitoring with a pre-industrial reference state which is used as to define ‘good ecological status’ in the EU Water Framework Directive. The lake sediment results from Loch Leven can be combined effectively with accounts from naturalists, which survive from the 1820s onwards, to document compositional changes and species losses. These result from the combined effects of lake level change from the natural, gradual erosion of outflow channels and abrupt lowering to reclaim land for agriculture in the 1830s, and nutrient enrichment from agriculture, sewerage and industry, beginning around 1850 and accelerating in the 1950s. Management efforts since the 1980s have only partially reversed these impacts, highlighting the imprint of Anthropocene legacies in this apparently serene rural setting.