Tool Tree Growth Season
The 'Tree Growth Season' tool estimates the potential number of days suitable for tree growth as well as the average temperature for these days. The estimation needs monthly data of mean, minimum, and maximum temperature and precipitation. Internally a soil water balance model is run on a daily basis. Using the given thresholds a relative tree line height can optionally be estimated.
References
- Karger, D.N., Kessler, M., Conrad, O., Weigelt, P., Kreft, H., König, C., Zimmermann, N.E. (2019): Why tree lines are lower on islands - Climatic and biogeographic effects hold the answer. Global Ecol. Biogeogr., 00:1–12, doi:10.1111/geb.12897. online.
- Paulsen, J. / Körner, C. (2014): A climate-based model to predict potential treeline position around the globe. Alpine Botany, 124:1, 1–12. doi:10.1007/s00035-014-0124-0. online.
- Author: O.Conrad, L.Landschreiber (c) 2016
- Menu: Climate|Bioclimatology
Parameters
| | Name | Type | Identifier | Description | Constraints |
|---|
| Input | Mean Temperature | Grid list, input | T | - | - |
| Minimum Temperature | Grid list, input | TMIN | - | - |
| Maximum Temperature | Grid list, input | TMAX | - | - |
| Precipitation | Grid list, input | P | - | - |
| Soil Water Capacity of Profile (*) | Grid, input, optional | SWC | Total soil water capacity (mm H2O). | - |
| Output | Mean Temperature | Grid, output | SMT | Mean temperature of the growing season. | - |
| Precipitation Sum (*) | Grid, output, optional | SMP | Precipitation sum of the growing season. | - |
| Length | Grid, output | LGS | Number of days of the growing season. | - |
| First Growing Day (*) | Grid, output, optional | FIRST | First growing day of the year (1-365). | - |
| Last Growing Day (*) | Grid, output, optional | LAST | Last degree day of the year (1-365). | - |
| Tree Line Height (*) | Grid, output, optional | TLH | Estimated relative tree line height. | - |
| Options | Grid System | Grid system | PARAMETERS_GRID_SYSTEM | - | - |
| Default | Floating point | SWC.Default | default value if no grid has been selected | Minimum: 0.000000
Default: 220.000000 |
| Top Soil Water Capacity | Floating point | SWC_SURFACE | - | Minimum: 0.000000
Default: 30.000000 |
| Transpiration Resistance | Floating point | SW1_RESIST | - | Minimum: 0.010000
Default: 0.500000 |
| Default Latitude | Floating point | LAT_DEF | - | Minimum: -90.000000
Maximum: 90.000000
Default: 0.000000 |
| Threshold Temperature | Floating point | DT_MIN | Threshold temperature (C) that constrains the growing season. | Default: 0.900000 |
| Minimum Soil Water Content (Percent) | Floating point | SW_MIN | - | Minimum: 0.000000
Default: 2.000000 |
| Minimum Length | Integer | LGS_MIN | Minimum length (days) of the growing season. | Minimum: 1
Default: 94 |
| Minimum Mean Temperature | Floating point | SMT_MIN | Minimum mean temperature (Celsius) for all days of the growing season. | Default: 6.400000 |
| Maximum Tree Line Height Difference | Floating point | TLH_MAX_DIFF | - | Minimum: 0.000000
Default: 3000.000000 |
| (*) optional |
Command-line
Usage: saga_cmd climate_tools 11 [-T <str>] [-TMIN <str>] [-TMAX <str>] [-P <str>] [-SWC <str>] [-SWC.Default <double>] [-SWC_SURFACE <double>] [-SW1_RESIST <double>] [-LAT_DEF <double>] [-SMT <str>] [-SMP <str>] [-LGS <str>] [-FIRST <str>] [-LAST <str>] [-TLH <str>] [-DT_MIN <double>] [-SW_MIN <double>] [-LGS_MIN <num>] [-SMT_MIN <double>] [-TLH_MAX_DIFF <double>]
-T:<str> Mean Temperature
Grid list, input
-TMIN:<str> Minimum Temperature
Grid list, input
-TMAX:<str> Maximum Temperature
Grid list, input
-P:<str> Precipitation
Grid list, input
-SWC:<str> Soil Water Capacity of Profile
Grid, input, optional
-SWC.Default:<double> Default
Floating point
Minimum: 0.000000
Default: 220.000000
-SWC_SURFACE:<double> Top Soil Water Capacity
Floating point
Minimum: 0.000000
Default: 30.000000
-SW1_RESIST:<double> Transpiration Resistance
Floating point
Minimum: 0.010000
Default: 0.500000
-LAT_DEF:<double> Default Latitude
Floating point
Minimum: -90.000000
Maximum: 90.000000
Default: 0.000000
-SMT:<str> Mean Temperature
Grid, output
-SMP:<str> Precipitation Sum
Grid, output, optional
-LGS:<str> Length
Grid, output
-FIRST:<str> First Growing Day
Grid, output, optional
-LAST:<str> Last Growing Day
Grid, output, optional
-TLH:<str> Tree Line Height
Grid, output, optional
-DT_MIN:<double> Threshold Temperature
Floating point
Default: 0.900000
-SW_MIN:<double> Minimum Soil Water Content (Percent)
Floating point
Minimum: 0.000000
Default: 2.000000
-LGS_MIN:<num> Minimum Length
Integer
Minimum: 1
Default: 94
-SMT_MIN:<double> Minimum Mean Temperature
Floating point
Default: 6.400000
-TLH_MAX_DIFF:<double> Maximum Tree Line Height Difference
Floating point
Minimum: 0.000000
Default: 3000.000000