The nursery

 

In 2017, thanks to the expertise and advice of SOLICAZ, SMSE decided to build a new nursery on the Saint-Elie site. It enjoys better climatic conditions than the old nursery shaded by a large Clitoria fairchildiana that provides us with seeds, In addition, this new nursery has benefited from the construction of an automated and programmable irrigation system to manage precisely the water resource available for young trees. This new nursery facilitates the nursery’s work and makes it possible to obtain more robust plants. In 2019 a greenhouse was also built nearby to serve as both a drying area for seed bombs and a covered storage area for inputs.

 
 

It was through the supervision and guidance of SOLICAZ that SMSE understood the importance of selecting the right plant species for long-term results:

- Pioneering species: These are high-growth species (several metres/year) adapted to the difficult climatic conditions found on a mining site (poor soil, strong sunshine, high heat, limited water resources, etc.). These species will suffer little from difficult conditions and will therefore establish with a high success rate (>90%), their rapid growth will allow them to quickly create a cover for the fauna and flora requiring more shade and freshness.

 

 

- Nitrogen fixing species: these are species capable of creating a symbiosis with a bacterium (Rhizobium) by forming nodosities (small white balls) at the level of its roots, this bacterium has the interesting ability to fix atmospheric nitrogen and share it with the plant, then at the death of the plant, the nitrogen is returned to the soil. These species will gradually enrich the soil with nitrogen, which is essential for the growth of trees and therefore for soil fertility.

 
 

- Fruit species: These are species that will produce a quantity of fruit, which will attract wildlife. Fauna is the most important vector in the natural recolonization of open and degraded surfaces thanks to the droppings of birds and bats or the transport of seeds attached to the fur of small animals. They will allow wildlife to be integrated into the forming ecosystem and accelerate its implementation, while increasing the density and diversity of trees present on site.

 

 

Since its first revegetation work in 2013, SMSE has been able to observe and compare its results with those obtained by natural revegetation on the edge of the forest. We then realized that nature was using a very wide variety of species whose potential was not exploited by SMSE because it was too little known. Based on this observation, we have, with the help of a botanist, located, sampled, identified and finally compiled in a herbarium many pioneering species present in young forests (<20 years) having settled on former mining areas. We then started many tests of germination and use of these new species to enrich our catalog and thus enjoy a greater diversity of species to implant.

Screen Pépi

Ingas 1 an après plantation (Louise 2018)


171222 nodosité inga de 2 mois (6)

181125_Face_Village (12)


WhatsApp Image 2018-10-01 at 19.17.52

 

 

The construction of the nursery required the use of a hydraulic shovel for one day and 8 people (shovel driver, mine manager, workers..). All spread over July and August of the year 2017.
The purchase of the various materials and materials necessary for the nursery’s activity was purchased from local Guyanese companies.

The irrigation system and its installation were provided by Concept Eau.

Compilation of costs related to the construction of the nursery
Elément Coût
Workers 7 700
Machines 300
Building material 4 200
Watering 2 300
Operating material 6 800
TOTAL 21 300

Watering

 

The nursery is irrigated with sprinklers placed on 3 axes and spaced 3 meters each to allow irrigation distributed over the entire nursery. The watering is programmed using an automaton, at the rate of 4 times 20 min watering per day in the dry season.

During the rainy season, a sensor can determine the rainy periods and thus stop the watering program depending on the rainfall.

 

Schéma irrigation pépinière

 

The multiplication of species

Germination

Cajou (pépinière de St-Elie 2017)

In Saint-Elie, the majority of the plants are multiplied thanks to the natural germination of the seeds.
The recovered seeds are put in small pots made of a mixture of topsoil, compost, sawdust and sand. Ashes are sometimes added to the mixture.
They are then placed under the nursery, where they can germinate and grow. This technique allows genetic mixing and thus creates additional diversity.

Cuttings

Boutures de clitorias (pépinière de St-Elie 2017)

Cutting, in addition to germination, is used for Clitorias (Clitoria fairchildiana) because it has a very high success rate (90%).
Branches of about 30 cm are cut on mature Clitorias, and are then put into the ground. From the reserves present in the 30 cm section, the cutting will be able to reconstitute its roots and thus give life to a new plant of Clitorias, clone of the tree generating the cutting.

Layering

Vetiver à la pépinière de St-Elie (2017)

Layering is used for only one species, Vetiver (Chrysopogon zizanioides). Indeed this plant has the particularity to produce new plants from its roots. Thus, when a Vetiver plant is planted in a pot, a tuft develops rapidly consisting of several clone plants. It is then enough to separate these different plants and replant them individually. The operation can be repeated as many times as necessary.

Vegetative development

 

The plants will grow for 3 to 6 months in the nursery, in order to reach a size sufficient to withstand the shock associated with their implantation on the poor soil of the mine site. The development time of the plants is limited to 6 months to facilitate their transport on site, indeed the older they are the more difficult it is to transport and handle them.

The company SOLICAZ offers rehabilitation services, but also support services for the creation of nurseries and the learning of revegetation techniques.