Most of the models in the Integrated Modelling Platform have a long-standing history of use in environmental contexts. Alternatively, the Land Allocation Model (LAM) has been custom-developed with the Welsh Government to best reflect on-farm decision-making in Wales. In broad terms, the LAM simulates how land managers might respond to the various options for land use and land management provided by the forestry and agricultural models. It then passes this information to the biodiversity and ecosystem service models to simulate the consequences of these changes in land use and land management on the wider environment.
The LAM is a rule-based model, which aims to predict future farm types (and their associated land use and livestock selections) and forest areas across Wales using outputs from the farm and forest models (SFARMOD and ESC-CARBINE). It is applied to all full-time (≥1FTE) holdings across Wales.
The LAM is provided with the optimised SFARMOD farm solutions (crop types / areas, grassland types / areas, stocking types / numbers, fertilisation, etc.) under a given scenario. These include the optimised solution for a holding’s current farm type (e.g. dairy), but also for all alternative farm types (e.g. mixed livestock, specialist sheep, etc.). The LAM modifies the simulated long-term net farm profit outputs of each to account for unsimulated income (e.g. non-agricultural sources of farm income and expenditure (unpaid labour, rent and finance, etc.), using data from each farm type within the Welsh Farm Business Survey.
The LAM then asks four questions for each simulated farm holding under the given scenario settings to determine the projected changes in future land use and management:
- Is the current farm type, with its cropping / livestock management optimised to the given scenario settings, economically viable in the long-term?
- Are there alternative farm types that may be sufficiently more profitable to merit conversion?
- If there are no farm types that are viable with the given scenario setting, is afforestation viable and permitted?
- If there are no viable farm types and afforestation is not viable or permitted, will land undergo natural regeneration to woodland or short vegetation?
The sensitivity of the LAM to the assumptions regarding economic viability, farm type conversion and unsimulated costs/incomes have been assessed through sensitivity testing and in discussion with a Welsh Government Expert Group.
Schematic representation of decisions and rules within the Land Allocation Module (LAM)
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