SIRAS Pacifique
Pioneering technology for sustainable revegetation in New Caledonia
Sustainable solutions for the preservation of our ecosystem
In order to better meet our clients’ expectations, we consider improving knowledge and techniques as essential for SIRAS Pacifique. This is why numerous trials have been conducted every year since 2004. The company regularly works in partnership with various research institutes in the region, particularly on themes such as:
- The establishment of seed production fields and promoting seed production from endemic plants,
- Improving the germination of endemic species more or less commonly used in mine revegetation,
- Enhancing the growth of species used in revegetation by associating them with endomycorrhizae,
- The developing of propagation techniques for rare and endangered species.
Context
For over 20 years, SIRAS Pacifique teams have been working on rare and endangered species (R&E species). Thanks to the different missions entrusted to them, our teams havelearned to identify these species, monitor their phenology, harvest them, and produce them for future reintroduction.
Methodology and Process
A conservation operation for an R&E species generally follows several steps:
These missions may be initiated specifically to search species suspected to be present in an area or are carried out opportunistically when an R&E species is detected during another mission.
If immature fruits are found on a fruit-bearing tree, the technique of bagging is used to protect the fruits until they ripen and can be collected.
These missions are triggered, as required by regulations, before any vegetation clearing to determine if R&E species are present within the parcel to be cleared. In such cases, protocols are implemented to “scan” the vegetation as thoroughly as possible. This involves performing transects at regular intervals and observation plots whenever an R&E species is spotted. In each plot, a count of the R&E species is conducted to estimate the number of individuals within the plot.
When an R&E species is found in in an area that is destined for clearing, or likely to be degraded, a collection of all specimens is usually triggered. These samples can take various forms: they may be fruits (preferably), cuttings or seedlings. If time allows before clearing, plants may also be air-layered.
The collected plant material is then processed by either our Seeds sector or the Nursery, depending on its nature. Particular attention is given to traceability, under the supervision of the team’s engineers. In the case of seed collection, once the seeds are sorted and cleaned, they are sent to the Nursery for propagation.
In most cases, the propagation methods for R&E species are not well understood. Therefore, propagation trials must be set up. Depending on the amount and type of material collected, several tests can be conducted by varying parameters such as:
- Pretreatments (chemical, thermal, scarification, etc.) to break dormancy or sowing methods if seeds are used.
- Size, hormones, humidity levels or cutting substrate for cuttings.
- Potting substrate, watering frequency for seedlings, etc.
The goal is to determine the most suitable propagation protocol for each species.
If propagation trials are successful and produce sufficiently robust R&E plants, in-situ reintroduction operations are organized. Appropriate planting zones are selected in agreement with the client.
Reintroduced plants are marked and geolocated at the time of planting. At intervals agreed upon with the client, these plants are monitored, and their condition (growth, survival rate, general appearance) is analyzed to continue gathering data on the species and, if necessary, apply corrective treatments.
Ongoing programs involving technological monitoring
Propagation trials for the Tontouta valley mines R&E species
Many sensitive species, due to their limited distribution in the Tontouta Valley, are found on mining sites (SMGM, SMT, and SLN) in the region. To mitigate the impacts of their activities on these species, our mining partners (SMT and SMGM) have commissioned us to conduct propagation trials. The previously described steps are currently being applied to species such as Cloezia artensis var. riparia, Cupaniopsis tontoutensis, Hibbertia emarginata, Hibbertia heterotricha, Hibbertia tontoutensis, Homalium betulifolium, Pycnandra intermedia, Scaevola coccinea, Styphelia enervia, and Uromyrtus thymifolia.
Contexte
Conventional revegetation techniques (hydroseeding, dry seeding, planting), described in the WORKS section, are sometimes unsuitable for treating some inaccessible sites. Helicopter work can be considered in such cases, but it results in high additional costs and requires large quantities of inputs and seeds (refer to the hydroseeding and dry seeding page).
SSC are produced using equipment that ensures rapid and precise fabrication. Seeds are preselected according to their purity and germination rate. Each SSC contains one to 4 or 5 seeds (depending on their size), is enriched with organic matter and includes slow-release fertilizer. The fertilizer gradually dissolves, providing seedlings with the necessary nutrients for their growth.
Advantages of SiraSeedCaps
The method enables the reach of remote and difficult-to-access sites where traditional revegetation machinery and techniques cannot be used. Indeed, the low weight and volume of SSCs allow for their manual spreading (after hiking to the target area if necessary) or their distribution using drones.
These small units significantly reduce implementation costs compared to traditional revegetation methods.
The process requires minimal resources and technical expertise to be deployed in the field, facilitating its use in various environments.
Thanks to the organic matter enrichment and slow-release fertilizers contained in each capsule, the SSC provide a suitable environment for the development of young plants, promoting optimal growth, even in difficult conditions.
Ongoing tests
Currently, tests have been launched on more than 20 New Caledonian endemic or pioneering species, and in two types of biomes: dry forest and mining scrub.
Initial results in semi-controlled conditions show variable outcomes depending on the species and the composition of the SSC. Furthermore, some germination anomalies, such as inverted geotropism, have been observed and require further analysis.
Future outlook
To determine the most suitable composition combinations for each species, further trials will need to be conducted based on the different already obtained and/or the upcoming results.
Currently, 40 to 50 species are successfully used in scrubland or dry forest restoration through seeding or planting techniques. Our goal is to test all these species using SSC, in order to eventually apply the method in various environmental conditions.
Finally, since the ultimate goal of SSC is to treat inaccessible areas, drone dispersal trials will also be conducted.
Contexte
Traditional revegetation methods, such as hydroseeding, dry seeding or planting, while effective in many situations, show limitations when it comes to restoring large, inaccessible areas which cannot be reached on foot or by 4WD vehicles. These limitations require the exploration of alternative methods. Among them, helicopter-aided seeding and fertilization present a particularly interesting solution. By using a helicopter, this technique allows for intervention over large areas in a short amount of time, although it can involve additional costs due to the use of specialized equipment and the need to transport large quantities of seeds and inputs.
Method
The technique of helicopter-aided seeding and fertilization is carried out using a specially equipped tank designed to be transported by helicopter, ensuring even distribution of seeds and fertilizers. The pilot follows a predetermined GPS path to spread the material over the target areas.
Advantages of Helicopter-Aided Seeding and Fertilization
This method allows for the treatment of areas that would otherwise be inaccessible, such as mountainous regions, deep valleys, or remote sites. The use of helicopters enables access to areas without terrestrial infrastructure.
The capacity of helicopters to cover large areas in a short time allows for the rapid treatment of degraded and inaccessible surfaces, which would otherwise remain untouched if this technique were not implemented.
Helicopter-aided seeding and fertilization projects have been carried out on two critical sites in New Caledonia, affected by fires, severe erosion, and mining activities:
- 1 fire-impacted site (Montagne des Sources, Mont-Dore),
- 1 anciant mine (in the municipality of Népoui).
Future Outlook
In an effort to improve the effectiveness of helicopter-aided seeding and fertilization, new trials are planned to adapt the types of seeds, the fertilizers, and other inputs. Additionally, determining whether the environmental conditions of the sites affect the success of these operations is also a key focus.
