Impact model: BASFOR

Sector
Forests
Region
local

BASFOR is a BASic FORest model, with simple representation of forest biogeochemistry. Despite this, the aim is wide model applicability by simulating the impacts of a range of environmental drivers.



BASFOR simulates soil-plant-atmosphere processes of deciduous and coniferous forest stands. Interactions with the atmospheric and soil environment are simulated in some detail, as are the impacts of management: thinning and pruning. Three biogeochemical cycles are simulated: carbon, nitrogen and water. BASFOR is a one-dimensional model, so no horizontal heterogeneity of the forest is captured. BASFOR does not simulate wood quality or pests and diseases.



BASFOR has 17 state variables. Nine of those variables quantify the state of the trees and eight variables represent the soil. The tree variables are tree density, carbon pools (stems, branches, leaves, roots, reserves), foliar nitrogen and phenological state (accumulated chill days, thermal time). The soil variables are carbon and nitrogen in litter and two classes of organic matter, mineral N, water.



Inputs to the model include atmospheric CO2 concentration and time series of radiation, air temperature, precipitation, wind speed, humidity. Also required is a calendar indicating days at which the stand is thinned or pruned.



Outputs from the model include, in the default set-up, 36 different output variables: the 17 state variables plus biogeochemical fluxes (including those of greenhouse gases to and from trees and soil) and forest productivity variables (stem diameter, volume, height). This selection of output variables can be altered by the model user.

Information for the model BASFOR is provided for the simulation rounds shown in the tabs below. Click on the appropriate tab to get the information for the simulation round you are interested in.

Person responsible for model simulations in this simulation round
David Cameron: dcam@ceh.ac.uk, Centre for Ecology & Hydrology (UK)
Additional persons involved: Marcel van Oijen
Output Data
Experiments: I, Ia, II, IIa, IIb, IIc, III, IIIa, IIIb (Hyytiälä, Peitz, Solling beech, Solling spruce, Sorø, Collelongo)
Climate Drivers: None
Date: 2018-08-06
Basic information
Model Version: https://github.com/davcam/BASFOR/tree/ISIMIP
Model Homepage: https://soil-modeling.org/resources-links/model-portal/basfor
Simulation Round Specific Description: * Data in embargo period, not yet publicly available
Reference Paper: Other References:
  • Van Oijen, M., Rougier, J. & Smith, R. et al. Bayesian calibration of process-based forest models: bridging the gap between models and data.Tree Physiology ,25,915-927.,2005
Resolution
Spatial aggregation: forest stand
Temporal resolution of input data: climate variables: daily
Temporal resolution of input data: co2: annual
Temporal resolution of input data: soil: constant
Input data
Simulated atmospheric climate data sets used: MIROC5 (rcp45), IPSL-CM5A-LR, GFDL-ESM2M
Emissions data sets used: Atmospheric CO2 concentration
Other human influences data sets used: Nitrogen deposition (ISIMIP2)
Spin-up
Was a spin-up performed?: Yes
Spin-up design: The model was run from planting year for each site using the information provided in the PROFOUND database.
Management & Adaptation Measures
Management: Management was as prescribed in the forest section of the protocol. For years before stand density data was available the forests at each site were thinned at regular intervals from planting density until achieving the density found in the profound database. For precise details please refer to the code at https://github.com/COST-FP1304-PROFOUND/ISI-MIP/tree/BASFOR/BASFOR/management
Model set-up specifications
How did you initialize your model, e.g. using individual tree dbh and height or stand basal area? how do you initialize soil conditions?: BASFOR was run from planting. Both initial aboveground and belowground C and N pools were initialised with preexisting parameter values and then the model was run until present day at each site. Soil water values (wilting point and field capacity) were taken from the PROFOUND DB "SOIL".
How is management implemented? e.g. do you harvest biomass/basal area proportions or by tree numbers or dimensions (target dbh)?: Management (thinning and harvesting) is implemented as the fraction of biomass removed.
When is harvesting simulated by your model (start/middle/end of the year, i.e., before or after the growing season)?: All thinnings and harvestings were made in January each year.
How do you regenerate? do you plant seedlings one year after harvest or several years of gap and then plant larger saplings?: Regrowth is from the fraction of biomass remaining after harvesting.
How are the unmanaged simulations designed? is there some kind of regrowth/regeneration or are the existing trees just growing older and older?: In the unmanaged simulations growth continues so effectively the trees become older and older.
How are models implementing the noco2 scenario? please confirm that co2 is follwing the historical trend (based on profund db) until 2000 (for isimipft) or 2005 (for isimip2b) and then fixed at 2000 or 2005 value respectively?: The noco2 runs had fixed co2 after 2000 and 2005 respectively for ISIMIPFT and ISIMIP2b.
Does your model consider leap-years or a 365 calendar only? or any other calendar?: The model followed the data availability of the weather variables in the PROFOUND DB for historical and climate scenario runs.
In hyytiälä and kroof, how did you simulate the "minor tree species"? e.g. in hyytiälä did you simulate only pine trees and removed the spruce trees or did you interpret spruce basal area as being pine basal area?: For Hyytiälä the model was run from planting assuming only pine trees.
What is the soil depth you assumed for each site and how many soil layers (including their depths) do you assume in each site? please upload a list of the soil depth and soil layers your model assumes for each site as an attachment (section 7).: BASFOR has a single soil layer. Soil depth which in BASFOR is also the rooting depth was taken from PROFOUND DB "SOIL" for each site.
Is there any stochastic element in your model (e.g. in the management or mortality submodel) that will lead to slightly different results if the model is re-run, even though all drivers etc. remain the same?: No BASFOR is fully determinisitic.
What is the minimum diameter at which a „tree is considered a tree“? and is there a similar threshold for the minimum harvestable diameter?: N/A
Has your model been "historically calibrated" to any of the sites you simulated? e.g. has the site been used for model testing during model development?: No calibration of BASFOR was made for these runs. Previous parameter values were available for some sites from a previous project (NItroEurope).
Key model processes
Nitrogen limitation: Yes. Potential growth without N limitation is first estimated. Then using an N/C ratio the N demand required to achieve that growth is found. The ratio of available N supply over N demand is calculated and used to limit growth.
Causes of mortality in vegetation models
Age/senescence: No.
Fire: No.
Drought: Yes. There is implicit drought stress which can limit primary productivity. With sufficient stress growth is less senescence and the trees start to die back.
Insects: No.
Storm: No.
Stochastic random disturbance: No.
NBP components
Fire: No.
Land-use change: No.
Harvest: Yes. Tree stems are removed. Branches and leaves are added to the litter pool. Roots are added to the fast soil organic matter pool.
Species / Plant Functional Types (PFTs)
List of species / pfts: Pinus sylvestris (pisy), Fagus sylvatica (fasy), Picea abies (piab)
Model output specifications
Do you provide the initial state in your simulation outputs (i.e., at year 0; before the simulation starts)?: No although the runs were all from planting the outputs were only from the initial date where weather data was provided in the PROFOUND DB for each site.
Output per pft?: No
When you report a variable as "xxx-total" does it equal the (sum of) "xxx-species" value(s)? or are there confounding factors such as ground/herbaceous vegetation contributing to the "total" in your model?: N/A
Did you report any output per dbh-class? if yes, which variables?: No
Additional Forest Information
Forest sites simulated: Peitz, Soro, Hyytiala, Solling (Beech) and Solling (Spruce)
Person responsible for model simulations in this simulation round
David Cameron: dcam@ceh.ac.uk, Centre for Ecology & Hydrology (UK)
Additional persons involved: David Cameron dcam@ceh.ac.uk
Output Data
Experiments: historical (Hyytiälä, Peitz, Solling beech, Solling spruce, Sorø)
Climate Drivers: None
Date: 2018-07-17
Basic information
Model Output License: CC0
Person responsible for model simulations in this simulation round
David Cameron: dcam@ceh.ac.uk, Centre for Ecology & Hydrology (UK)
Additional persons involved: David Cameron dcam@ceh.ac.uk