To install follow these steps:
This version of SCUAF only runs on Windows-based machines and requires Microsoft Excel® to be available.
This file contains the SCUAF program. Double-clicking on the icon will run the model.
This is an Excel spreadsheet containing a template with all the inputs required to run SCUAF.This file must be in the same folder as the program SCUAF5.exe for the model to run. It can also be kept within its own folder within the SCUAF folder.
This is an Excel spreadsheet containing a template for outputs. A copy of this file will be used to write the outputs when SCUAF simulations are run.This file must be in the same folder as the program SCUAF5.exe for the model to run. It can also be kept within its own folder within the SCUAF folder.
This folder contains help files, organised into web pages, which are accessed by clicking the 'Help' button on the main SCUAF screen.
This folder is initially empty, but it needs to be there, because SCUAF will save new files to this directory.
This folder contains example input files for different systems (input file names in brackets):
Rainforest (Ex-Rainforest.xls)
Trees only in a lowland humid environment, with a high initial biomass – i.e. mature rainforest. Note that as the forest is mature there is no net increase in biomass, so ‘retained as growth’ is zero (and one has to say falsely that all roots are fine roots, since coarse ones are necessarily retained).
Monocropping Ex-Monocropping.xls
Subhumid zone, and everything default
except that the only plants are crops. As expected, soil carbon (especially
labile carbon) and crop yield decline.
Contour Hedgerows (Ex-ContourHedgerows.xls)
Illustrates the effects of contour-aligned hedgerows on a steep slope, subhumid climate. With crops only, erosion is 15t/ha in Year 1, rising to 83t in Year 30; by Year 30, soil depth has fallen from 100 cm to 28 cm, and crop yield from 1202kg/ha in Year 1 to 222kg in Year 30 (the plot would be abandoned before then). Adding 10% contour hedgerows (=Trees) is assumed (on experimental evidence) to lower the Crop Cover Factor from 0.4 to 0.1. Erosion is reduced to 4t/ha in Year 1 rising to 7t/ha in Year 30. The space taken by the hedgerows reduces crop yield by 10% in Year 1, but it becomes more sustainable, in Year 30 571 kg/ha, plus a harvest (e.g. pigeon pea) from the hedgerows. ( Under a humid climate, steep slope, and crop only, by Year 28 erosion reaches 400t and soil depth is reduced to zero.).
Shifting Cultivation - Short Fallow (Ex-ShiftCultShort.xls)
Lowland humid climate, and steep slope, as is common for this land use system. Assumed a poor crop variety, initial NPP lowered to 3000, hence fruit=harvest 1000 kg/ha. In this situation the forest is not mature, it is growing rapidly, so much of the wood (as in default) is retained as growth. 5 years of forest (last year is a cut year) followed by 4 years of cropping.
Shifting Cultivation - Long Fallow (Ex-ShiftCultLong.xls)
Lowland humid climate, and steep slope, as is common for this land use system. Assumed a poor crop variety, initial NPP lowered to 3000, hence fruit=harvest 1000 kg/ha. In this situation the forest is not mature, it is growing rapidly, so much of the wood (as in default) is retained as growth. 10 years of forest (last year is a cut year) followed by 4 years of cropping.
Carbon Sequestration (Ex-CarbonSequestration.xls)
This model demonstrates a degraded (low fertility) soil reclaimed by afforestation, with the objective of carbon sequestration. The trees are felled and harvested, on a 20-year rotation. A 100-year run shows that over each rotation, 170-190 t/ha carbon accumulates in the standing biomass. Soil carbon, and hence total carbon, increases by 8-16 t/ha (rising) over each rotation (see graphs of Total C and Soil C).