What is biomass?

The quantity of biomass refers to the amount of vegetation, expressed in kilograms per hectare of dry matter (kg/ha). Dry matter is used to describe any form of vegetation above the ground, excluding its water content. In the context of pastoral situation analysis, dry matter serves as an effective measure to assess the availability of forage resources.

Why use the quantity of dry matter as a pastoral indicator?

All vegetation varieties consist of both water and dry matter, but at varying rates. For instance, the percentage of dry matter in hay is much higher than in green grass. Additionally, the nutrients essential for livestock are found in the dry portion of forage, such as energy, proteins, and minerals. This is why the nutritional requirements of livestock are typically calculated based on the quantity of dry matter per unit of time.

What are the limitations?

Data on quantities of dry matter produced do not provide information on the quality of vegetation. Indeed, the nature of the pasture and its palatability are crucial in determining the carrying capacity of livestock in an area, i.e., the number of animals that can graze there. Moreover, not all forages are equivalent and may contain different levels of energy, proteins, and minerals.

To address these limitations, the system relies on an analysis of biomass production anomalies, involving the assessment of deviations from the average situation considered as normal.

Where do the data come from?

The European Copernicus Global Land Service provides the public with products derived from satellite data acquired by the European Space Agency (ESA). One of these products, the Dry Matter Productivity (DMP), informs about dry matter production in kilograms per hectare per day (kg/ha/day), with a spatial resolution of 1×1 km and a ten-day update frequency. The final processing of this product is carried out using a tool developed by ACF called BioGenerator.

What are the generated maps?

Three types of maps related to biomass production are generated, focusing on pastoral and agro-pastoral areas.

The production map provides information on the total annual biomass production during the last rainy season. Production is expressed in kilograms of dry matter per hectare (kg/ha).

Factsheet on the Biomass

The anomaly production analysis maps compare the total production of the current year to the average calculated over the period 1999 to the current year. This anomaly can be represented as a percentage of the average value or as the number of standard deviations from the average value (normalized anomaly). Areas with negative anomaly deficits are depicted in red, while areas with positive anomaly excesses are in green. The anomaly maps compare the current biomass situation to the historical average, allowing the determination of abnormal deficits or surpluses in specific areas. However, these maps alone do not provide information on the quantity of biomass.

Factsheet on the Biomass
Factsheet on the Biomass

The Vulnerability Index map is developed to overcome a simple anomaly-based analysis, which compares the current year with all previous years without considering the sequence of anomalies. This map is produced using a recursive analysis that assigns higher weights to recent years: the current year represents 50% of the index, the preceding year 25%, the year before that 12.5%, and so on.

Factsheet on the Biomass

For more information

Factsheet on biomass

Description of the DMP product from the Copernicus Global Land Service

Informations on the dry matter and the animal nutrition

Informations on the BioGenerator