Biomass production from grassland - Supply

<font 14.0pt/inherit;;black;;inherit>General description:</font>

<font 12.0pt/inherit;;inherit;;inherit>The approach presented here is comprised of two main parts. The first part (steps 1 and 2) assesses the optimal yield (ES potential) according to the length of the growing season, the respective growth functions and the specific land use types. The second part refines the biomass productivity according to region-specific precipitation patterns (steps 3 to 7) and local small-scale topographic conditions (steps 8 to 10), in order to provide more reliable local yield estimates (ES status).</font><font 12.0pt/inherit;;inherit;;inherit>Figure</font> <font 12.0pt/inherit;;inherit;;inherit>1</font><font 12.0pt/inherit;;inherit;;inherit>describes</font><font 12.0pt/inherit;;inherit;;inherit>in</font><font 12.0pt/inherit;;inherit;;inherit>detail</font><font 12.0pt/inherit;;inherit;;inherit>the</font><font 12.0pt/inherit;;inherit;;inherit>calculation</font><font 12.0pt/inherit;;inherit;;inherit>procedure</font><font 12.0pt/inherit;;inherit;;inherit>to</font><font 12.0pt/inherit;;inherit;;inherit>derive the Supply (DM kg/ha) for each local administrative units (LAU2) of the Alpine Space.</font>

<font 12.0pt/inherit;;inherit;;inherit>Input data:</font>

• <font 12.0pt/inherit;;inherit;;inherit>DEM (slope, aspect)</font>* <font 12.0pt/inherit;;inherit;;inherit>Precipitation (in mm)</font>* <font 12.0pt/inherit;;inherit;;inherit>Climate Data (number of Vegetation days, start of growing season)</font>* <font 12.0pt/inherit;;inherit;;inherit>Land use types (intensively used, moderately used and extensively used grassland, Natural Grassland (CLC)…</font>

<font 12.0pt/inherit;;inherit;;inherit>Calculation processes:</font>

<font 12.0pt/inherit;;inherit;;inherit>(1) Calculate Vegetation Days</font><font 12.0pt/inherit;;inherit;;inherit>(</font><font 12.0pt/inherit;;inherit;;inherit>days</font><font 12.0pt/inherit;;inherit;;inherit>with</font><font 12.0pt/inherit;;black;;inherit>T</font> _{<font 12.0pt/inherit;;black;;inherit>mean</font>}<font 12.0pt/inherit;;black;;inherit>≥ 5 C)</font>

<font 12.0pt/inherit;;inherit;;inherit>The approach is based on the assumption that biomass production does not start if the daily average temperature is below 5°C, hence the year is divided into a growing season and a dormant season.</font>

<font 12.0pt/inherit;;inherit;;inherit>(2) Calculate Optimal Yield</font>

<font 12.0pt/inherit;;inherit;;inherit>This</font><font 12.0pt/inherit;;inherit;;inherit>is</font><font 12.0pt/inherit;;inherit;;inherit>done</font><font 12.0pt/inherit;;inherit;;inherit>according</font><font 12.0pt/inherit;;inherit;;inherit>to</font><font 12.0pt/inherit;;inherit;;inherit>the</font><font 12.0pt/inherit;;inherit;;inherit>productivity</font><font 12.0pt/inherit;;inherit;;inherit>type</font><font 12.0pt/inherit;;inherit;;inherit>of</font><font 12.0pt/inherit;;inherit;;inherit>the</font><font 12.0pt/inherit;;inherit;;inherit>grassland types of your study area. In the table below you find the factors we used for the Alpine-wide approach according to the dataset we had at our disposal.</font>

<font 12.0pt/inherit;;inherit;;inherit>The optimal yield is then derived using the following functions, where x is the number of vegetation days.</font>

<font 9.0pt/inherit;;inherit;;inherit>(Figure 1: Yield calculations Source: Egger, G., et al.</font> <font 9.0pt/inherit;;inherit;;inherit>(2004). GIS-gestützte Ertragsmodellierung zur Optimierung des Weidemanagements auf Almweiden.</font> <font 9.0pt/inherit;;inherit;;inherit>Irdning, Irdning: BAL. Modified by Jaeger and Tasser)</font>

<font 12.0pt/inherit;;inherit;;inherit>(5) Indicate Growing</font> <font 12.0pt/inherit;;inherit;;inherit>Season</font><font 12.0pt/inherit;;inherit;;inherit>Start</font><font 12.0pt/inherit;;inherit;;inherit> and End in days of the year (DOY)</font>

<font 12.0pt/inherit;;inherit;;inherit>If no specific data is available for your test region, you can use a DEM-based method (i.e. Krautzer et. al. 2012) to approximate the start of the growing-season.</font>

• <font 12.0pt/inherit;;inherit;;inherit>(3) Calculate start of growing season based on DEM</font><font 12.0pt/inherit;;inherit;;inherit>(DOY)</font> * <font 12.0pt/inherit;;inherit;;inherit>Here the example function we used for the entire Alpine space: (0.0689*DEM)+0.4444</font>
• <font 12.0pt/inherit;;inherit;;inherit>(4) Calculate end of growing season</font>
  • <font 12.0pt/inherit;;inherit;;inherit>Start of Growing Season + Vegetation Days (in DOY).</font>