AWC See available water holder capacity.
Available water holding capacity The volume of plant-available water a soil can hold via capillary tension.
BBS The plant functional type boreal broadleaved summergreen tree.
BINE The plant functional type boreal needleleaved evergreen shade-intolerant tree.
Biomass The amount of functional tissue of living organisms in an ecosystem, expressed as the mass of constituent carbon per unit ground area. In LPJ-GUESS only the biomass of vegetation is considered, divided into the compartments leaves, fine roots, sapwood and heartwood.
Biomass burning See wildfire disturbance.
BNE The plant functional type boreal needleleaved evergreen tree.
BNS The plant functional type boreal needleleaved summergreen tree.
Cohort mode Vegetation mode in which each average individual represents an age class (cohort) of a PFT in a patch. Multiple patches are simulated to accomodate stochastic variation in plant growth, mortality and disturbances. A sample instruction file for cohort mode accompanies LPJ-GUESS Education.
C3G The plant functional type cool (C3) grass.
C4G The plant functional type warm (C4) grass.
DGVM Dynamic Global Vegetation Model, established term for an ecosystem model combining process-based biogeochemistry with vegetation distributional and structural dynamics that may be applied to any global region without recalibration. LPJ-GUESS is an example.
Disturbance Exogenous process that destroys biomass and causes mortality, e.g. wildfire, storm damage, human deforestation. In cohort mode, generic, patch-destroying disturbances with a specified expected return interval may be implemented. Wildfire disturbance is also simulated. More information is available here.
Environmental driver file A plain-text file containing monthly temperature, precipitation, sunshine (complement of percentage cloud cover) and rainday data and atmospheric carbon dioxide (CO2) concentration for every year of an intended simulation with LPJ-GUESS. The file thus contains environmental driver data both for the initialisation and scenario phase of the simulation. The file may be opened and viewed as a tab-delimited text file in spreadsheet software such as Excel. An environmental driver file reflecting climate conditions anywhere on Earth can be generated using GetClim.
Evapotranspiration The total loss of water from an ecosystem due to transpiration from plant surfaces, evaporation from the soil surface, and evaporation of rainfall intercepted by the vegetation canopy.
Fire return time See wildfire disturbance.
Future scenario mode Option in GetClim in which the environmental driver file contains modern-day climate and atmospheric CO2 concentrations for the initialisation phase of the simulation, and anomalies (changes) relative to modern conditions are applied linearly throughout the scenario phase. More information is available here.
GetClim Software module for creating the environmental driver file that contains environmental input data and defines the protocol for a simulation with LPJ-GUESS Education. GetClim can be accessed within the LPJ-GUESS Windows Shell on the Simulation Settings form or the File menu. It is also available in the LPJ-GUESS Education program group in the Windows Start menu.
GPP Gross primary production, the annually-accrued photosynthesis of an ecosystem.
Heterotrophic respiration The annual loss of carbon from an ecosystem associated with decomposition of litter and soil organic matter.
IBS The plant functional type boreal/temperate shade-intolerant broadleaved summergreen tree.
Initialisation Initial phase of a model simulation required to build up vegetation and soil carbon and nitrogen pools in an approximate steady state with climate and atmospheric CO2 conditions at the start of the subsequent scenario phase. In cohort mode, the initialisation should normally be at least five times the expected disturbance interval but not longer than 1000 years. Synonymous with static phase.
Instruction file A text file containing settings for a simulation with LPJ-GUESS, such as the vegetation mode, disturbance interval, whether to simulate wildfire disturbance or not, and parameters defining the characteristics of the PFTs that will be simulated. LPJ-GUESS Education comes with two sample instruction files, one for cohort mode, and one for the more simplified population mode.
Interception Evaporation of water intercepted as rainfall by the canopy of a vegetation stand. A component of evapotranspiration.
LAI Leaf area index, projective leaf (or needle) area divided by the area of ground covered.
NBE Net biome exchange, the annual change in carbon storage of an ecosystem due to the balance between NPP, annually-accrued heterotrophic respiration and carbon emissions due to wildfire disturbance. Synonymous with NEE in LPJ-GUESS.
NECB Net ecosystem carbon balance, the annual change in carbon storage of an ecosystem due to the balance between NPP, annually-accrued heterotrophic respiration and carbon emissions due to wildfire disturbance. Synonymous with NEE in LPJ-GUESS.
NEE Net ecosystem exchange [of carbon], in LPJ-GUESS representing the balance between NPP, annually-accrued heterotrophic respiration and carbon emissions due to wildfire disturbance. Alternative terms for NEE, in the above sense, are net biome exchange (NBE) or net ecosystem carbon balance (NECB). A stricter, alternative definition of NEE widespread in the literature is the balance between photosynthesis and ecosystem respiration (ignoring emissions due to fire).
NPP Net primary production, the balance between GPP and annually-accrued autotrophic (plant) respiration. It corresponds to the amount of carbon available to plants each year for allocation to new biomass.
Palaeo mode Option in GetClim in which data for the initialisation phase of the simulation are derived by applying user-specified anomalies (changes) relative to modern-day climate and atmospheric CO2 concentrations. If a scenario phase is included, anomalies are reduced proportionately for each year of the scenario phase so that modern climate and CO2 are reached in the last year of the simulation. More information is available here.
Patch Sample of the vegetation of a modelled area corresponding in size to the approximate area of influence of one large adult tree on its neighbours. In cohort mode, a number (typically 100) of replicate patches, normally 0.1 ha in area, are simulated to account for heterogeneity resulting from stochastic plant establishment, mortality and disturbances. The simulated patches have no defined spatial relationships to one another.
PFT See Plant functional type.
Population mode Vegetation mode in which each PFT is described by a single average individual, representing the average state of all individuals of this PFT over a larger area. Population mode is faster but more simplified and less accurate than the alternative cohort mode. A sample instruction file for population mode accompanies LPJ-GUESS Education.
Plant functional type (PFT) A set of functional and structural characteristics pertaining to some subset of the vegetation simulated at a particular location. A single PFT may represent from one up to a large number of species with relatively similar growth form, phenology, physiology, allometry, bioclimatic affinity and life history. In population mode, each PFT is represented by a single average individual for each modelled location. In cohort mode, individuals from multiple age classes and patches may belong to the same PFT. The PFTs defined in the default instruction files that accompany LPJ-GUESS Education are listed here.
Raingreen Drought deciduous.
Scenario Phase of the model simulation in which climate and/or atmospheric CO2 concentrations are changing relative to the trend-free conditions of the initialisation phase. Synonymous with transient phase.
Simulation protocol Arrangement in simulation time of environmental driver data provided as input to a simulation with LPJ-GUESS. Defined by the user as part of the process of creating an environmental driver file using GetClim. More information is available here.
Simulation Settings form Form for launching a simulation with LPJ-GUESS. The workspace folder, instruction file and environmental driver file for the simulation may be chosen, or a new environmental driver file created with GetClim. The form appears when the item Run is chosen on the Model menu in the LPJ-GUESS Windows Shell.
SLA See Specific leaf area.
Spatial mass effect In cohort mode, implies that establishment rate of a PFT in a given patch is positively influenced by current abundance of the PFT in other simulated patches.
Specific leaf area Surface area (1-sided) to carbon mass ratio for plant leaves.
Spin up See Initialisation.
Static phase See initialisation.
Summergreen Winter deciduous.
TeBE The plant functional type temperate broadleaved evergreen tree.
TeBS The plant functional type temperate (shade-tolerant) broadleaved summergreen tree.
TeNE The plant functional type temperate needleleaved evergreen tree.
Transient phase See scenario.
Transpiration Evaporation of water from plant surfaces, particularly via stomata (pores) on the surfaces of leaves. A component of evapotranspiration.
TrBE The plant functional type tropical broadleaved evergreen tree.
TrIBE The plant functional type tropical broadleaved evergreen shade-intolerant tree.
TrBR The plant functional type tropical broadleaved raingreen tree.
Vegetation mode Configuration of LPJ-GUESS in terms of the internal representation of vegetation structure and the processes controlling vegetation dynamics. Two modes are available: cohort mode and the more simplified population mode. LPJ-GUESS Education comes with two sample instruction files, one for cohort mode and one for population mode. More information about these vegetation modes is available here.
Wildfire disturbance Simulated disturbance type in LPJ-GUESS that results in vegetation mortality and emission of carbon from combusted biomass and litter. The mean expected return time of fire disturbance at any point on the landscape is calculated annually based on climate conditions and accumulated fuel in the form of vegetation litter.
Workspace A common default location for the instruction files, environmental driver files and output files from simulations with LPJ-GUESS. Users are prompted to create or choose a workspace folder the first time they start the LPJ-GUESS Windows Shell. A new workspace may be chosen by choosing Change workspace ... in the File menu of the Windows Shell. Fresh copies of the default instruction files for cohort and population mode are copied to a new workspace when it is first created.