Tree Growth Season

Author(s)	O.Conrad, L.Landschreiber (c) 2016
Library ID	climate_tools
Tool ID	11
Version	1.0
Menu	Climate and Weather \| Bioclimatology

Description

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

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

Parameters

	Name	Type	Identifier	Description	Constraints
Input	Mean Temperature	grid list, input	`T`	Monthly averages of daily mean temperature (12 grids, January to December) [°C]	-
	Minimum Temperature	grid list, input	`TMIN`	Monthly averages of daily minimum temperature (12 grids, January to December) [°C]	-
	Maximum Temperature	grid list, input	`TMAX`	Monthly averages of daily maximum temperature (12 grids, January to December) [°C]	-
	Precipitation	grid list, input	`P`	Monthly sums of precipitation (12 grids, January to December) [mm / m²]	-
	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 number	`SWC_DEFAULT`	default value if no grid has been selected	Minimum: 0.000000 Default: 220.000000
	Top Soil Water Capacity	floating point number	`SWC_SURFACE`	-	Minimum: 0.000000 Default: 10.000000
	Transpiration Resistance	floating point number	`SW1_RESIST`	-	Minimum: 0.010000 Default: 1.000000
	Default Latitude	floating point number	`LAT_DEF`	-	Minimum: -90.000000 Maximum: 90.000000 Default: 0.000000
	Threshold Temperature	floating point number	`DT_MIN`	Threshold temperature (C) that constrains the growing season.	Default: 0.900000
	Minimum Soil Water Content (Percent)	floating point number	`SW_MIN`	-	Minimum: 0.000000 Default: 2.000000
	Minimum Length	integer number	`LGS_MIN`	Minimum length (days) of the growing season.	Minimum: 1 Default: 94
	Minimum Mean Temperature	floating point number	`SMT_MIN`	Minimum mean temperature (Celsius) for all days of the growing season.	Default: 6.400000
	Maximum Tree Line Height Difference	floating point number	`TLH_MAX_DIFF`	-	Minimum: 0.000000 Default: 3000.000000

Command Line


Usage: saga_cmd climate_tools 11 [-T ] [-TMIN ] [-TMAX ] [-P ] [-SWC ] [-SWC_DEFAULT ] [-SWC_SURFACE ] [-SW1_RESIST ] [-LAT_DEF ] [-SMT ] [-SMP ] [-LGS ] [-FIRST ] [-LAST ] [-TLH ] [-DT_MIN ] [-SW_MIN ] [-LGS_MIN ] [-SMT_MIN ] [-TLH_MAX_DIFF ]
  -T:                 Mean Temperature
	grid list, input
  -TMIN:              Minimum Temperature
	grid list, input
  -TMAX:              Maximum Temperature
	grid list, input
  -P:                 Precipitation
	grid list, input
  -SWC:               Soil Water Capacity of Profile
	grid, input, optional
  -SWC_DEFAULT:    Default
	floating point number
	Minimum: 0.000000
	Default: 220.000000
  -SWC_SURFACE:    Top Soil Water Capacity
	floating point number
	Minimum: 0.000000
	Default: 10.000000
  -SW1_RESIST:     Transpiration Resistance
	floating point number
	Minimum: 0.010000
	Default: 1.000000
  -LAT_DEF:
                           Default Latitude
                           	floating point number
                           	Minimum: -90.000000
                           	Maximum: 90.000000
                           	Default: 0.000000
  -SMT:               Mean Temperature
	grid, output
  -SMP:               Precipitation Sum
	grid, output, optional
  -LGS:               Length
	grid, output
  -FIRST:             First Growing Day
	grid, output, optional
  -LAST:              Last Growing Day
	grid, output, optional
  -TLH:               Tree Line Height
	grid, output, optional
  -DT_MIN:         Threshold Temperature
	floating point number
	Default: 0.900000
  -SW_MIN:
                           Minimum Soil Water Content (Percent)
                           	floating point number
                           	Minimum: 0.000000
                           	Default: 2.000000
  -LGS_MIN:           Minimum Length
	integer number
	Minimum: 1
	Default: 94
  -SMT_MIN:        Minimum Mean Temperature
	floating point number
	Default: 6.400000
  -TLH_MAX_DIFF:
                           Maximum Tree Line Height Difference
                           	floating point number
                           	Minimum: 0.000000
                           	Default: 3000.000000