A big house in the country: Assessing the biodiversity and ecosystem service values of trees and their management trade-offs in the Harewood Estate parkland

Wood-pasture and parkland estates are managed landscapes which represent an important part of UK conservation and cultural heritage. The landscapes have historically been multifunctional, yet their values in meeting 21st century societal needs, such as tackling ecosystem degradation and biodiversity loss, have been overlooked. This thesis aims to value the Harewood Estate parkland to determine its biodiversity and ecosystem service (ES) benefits, identify the characteristics that influence these values, and identify trade-offs between these values to support management decisions. Values were generated using the Tree related Microhabitats (TreMs) methodology, i-Tree Eco software and CAVAT tool and statistically modelled to determine the main tree and landscape drivers of these values. This thesis found the historic parkland estate is a complex landscape which is valuable due to its dominance of veteran and ancient trees. Despite relatively low levels of diversity within the tree communities themselves, TreM diversity was higher in parkland trees than trees found in broadleaf European forests. Parkland trees currently provide 1,224,030 kg of carbon storage, 14,522 kg/year of gross carbon sequestration, 693 m³/year avoided stormwater runoff and 412 kg/year air pollution removal regulating ES values and £28,117,919 in cultural amenity ES value. The consistent dominant driver of these values was tree size and age, agreeing with the previous literature that it is the largest and oldest trees that contribute disproportionately to biodiversity and ES. Biodiversity, regulating ES and cultural ES were overwhelmingly synergistic when trade-off analysis was carried out, suggesting the Harewood Estate parkland is a successfully multifunctional landscape. A parkland tree management plan should be created, with future management initially focused on maintaining and retaining veteran and ancient trees, as these trees provide greater benefits the larger and older they become. Wood-pasture and parkland estates have an important part to play in meeting 21st century societal challenges and under the correct sustainable management regime they can help achieve this.