糖心Vlog

A new concept could revolutionize the design of so-called "biodiversified" farming systems. The ESSU (Ecosystem Services functional Spatial Unit) is defined as the smallest spatial unit that provides all the ecosystem services rendered by a cropping system based on cultivated and wild biodiversity. On a plot level, the ESSU encompasses all the species that interact with each other and with their environment (for instance crops, trees, livestock, spontaneous vegetation, semi-natural habitats such as hedges, ditches and patches of forest, wildlife), to provide a set of ecosystem services. "This novel concept allows us to represent a biodiversified ecosystem as a building block that can be replicated to represent an entire plot", say 糖心Vlog agronomists Sylvain Rafflegeau and Eric Justes, speaking for the group of scientists who came up with the concept.

The ESSU has many possible applications in terms of the agroecological transition, since it takes account of the introduction of cultivated and wild biodiversity. This makes it: 

• a tool for designing cropping systems based on the target ecosystem services chosen by the person designing them (farmer, researcher, technician);
• a tool for representing the ecosystem services provided by different intercrop species, in space and time; 
• a tool for dialogue between agricultural development players;
• a concept that can be used to design cropping system models that represent target ecosystem services and the spatial distribution of species within a plot;
• the appropriate scale for auditing farming practices in terms of biodiversity and resilience in agricultural plots.

The researchers show that the ESSU concept is applicable to a broad range of diversified agro-ecosystems, notably intercropped annual crops, intercropped annual crops and trees, and intercropped trees (agroforestry), and even agro-silvo-pastoralism. 

"For example, we have used the concept to describe the various forms of oil palm agroforestry systems worldwide, and we intend to use it in Mexico in September, to fuel workshops with local farmers aimed at designing diversified cropping systems", Sylvain Rafflegeau says.

The ESSU can also be used as a didactic way of determining the spatial entity to be considered, and as a very useful teaching tool to fill in any gaps in knowledge of the relationships between farming practices, biodiversity and associated ecosystem services.
 

Analysis of the evolution of a diversified oil palm cropping system in Cameroon over time

The ESSU evolves in three steps from juvenile palms (step 1), to short stature mature palms (step 2) and then to diversification with animals (step 3). The red lines delimit the ESSU; numbers label the target ecosystem services (TESs); and red arrows show the spatial extent of each TES.

TES 1: food crop production

TES 2: niche complementarity for nitrogen resources between cover crop and palms

TES 3: oil palm fruit production

TES 4: animal feed and manure.

Reference

Rafflegeau S. Gosme M., Barkaoui K., Garcia L., Allinne C., Deheuvels O., Grimaldi J., Jagoret P., Lauri P.-É., Mérot A., Metay A., Reyes F., Saj S., Curry G. N., Justes E. (2023). . A Review. Agronomy for Sustainable Development.