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Table of Contents
Biomass production from grassland - Supply
General description:
<font 14px/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). Figure 1 describes in detail the calculation procedure to derive the Supply (DM kg/ha) for each local administrative units (LAU2) of the Alpine Space.</font>
Input data:
- <font 14px/inherit;;inherit;;inherit>DEM (slope, aspect)</font> * <font 14px/inherit;;inherit;;inherit>Precipitation (in mm)</font> * <font 14px/inherit;;inherit;;inherit>Climate Data (number of Vegetation days, start of growing season)</font> * <font 14px/inherit;;inherit;;inherit>Land use types (intensively used, moderately used and extensively used grassland, Natural Grassland (CLC)…)</font>
Calculation processes:
<font 14px/inherit;;black;;inherit>(1) Calculate Vegetation Days (days with T</font> <font inherit/inherit;;black;;inherit>mean</font><font inherit/inherit;;black;;inherit>≥ 5 C)</font>
<font 14px/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 14px/inherit;;inherit;;inherit>(2) Calculate Optimal Yield</font>
<font 14px/inherit;;inherit;;inherit>This is done according to the productivity type of the 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 14px/inherit;;inherit;;inherit>Land use type</font> | <font 14px/inherit;;inherit;;inherit>Productivity type</font> |
| <font 14px/inherit;;inherit;;inherit>Permanent Grassland</font> | <font 14px/inherit;;inherit;;inherit>4</font> |
| <font 14px/inherit;;inherit;;inherit>Natural Grassland (CLC)</font> | <font 14px/inherit;;inherit;;inherit>3</font> |
| <font 14px/inherit;;inherit;;inherit>Natural Grassland (HRL)</font> | <font 14px/inherit;;inherit;;inherit>3</font> |
| <font 14px/inherit;;inherit;;inherit>Bogs</font> | <font 14px/inherit;;inherit;;inherit>2</font> |
| <font 14px/inherit;;inherit;;inherit>Dwarf bushes</font> | <font 14px/inherit;;inherit;;inherit>2</font> |
| <font 14px/inherit;;inherit;;inherit>Larch meadows</font> | <font 14px/inherit;;inherit;;inherit>1</font> |
| <font 14px/inherit;;inherit;;inherit>Alpine grasses</font> | <font 14px/inherit;;inherit;;inherit>1</font> |
<font 14px/inherit;;inherit;;inherit>The optimal yield is then derived using the following functions, where x is the number of vegetation days.</font>
| <font 14px/inherit;;inherit;;inherit>Forage type</font> | <font 14px/inherit;;inherit;;inherit>Yield function (dt/ha)</font> |
| <font 14px/inherit;;inherit;;inherit>4</font> | <font 14px/inherit;;inherit;;inherit>y=(0.0021*(x²))-(0.419*x)+93.774</font> |
| <font 14px/inherit;;inherit;;inherit>3</font> | <font 14px/inherit;;inherit;;inherit>y=(0.0007*(x²))-(0.1513*x)+26.585</font> |
| <font 14px/inherit;;inherit;;inherit>2</font> | <font 14px/inherit;;inherit;;inherit>y=(0.0006*(x²))-(0.1613*x)+25.321</font> |
| <font 14px/inherit;;inherit;;inherit>1</font> | <font 14px/inherit;;inherit;;inherit>y=(-0.00007*(x²))+(0.1084*x)-4.7726</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>