Biodiversity Protection and Conservation Strategies of Native Vanilla spp. (Orchidaceae) in the Amazon forest of Peru
Project location: PERU, Madre de Dios
Project start date: December 2017 - Project end date: May 2019
Project number: 2017-038
Beneficiary: ArBio - Asociacion para la resiliencia del Bosque a la inter-oceanica
The project goals were:
1) testing the connectivity level within and among populations of native species through the reproductive biology;
2) investigating the ecology of pollinators involved in order to understand in detail the reproductive strategies adopted by Vanilla pompona;
3) identification of strategies to improve the connection within and between populations and favor the spread of native Vanilla in the local area
4) selection of the most suitable species to be propagated in and agro-ecological model system promoted by Arbio Perù (AP).
1) Samples of Vanilla were collected from five populations of Vanilla pompona (Annex, Table 1). Additionally, samples of other Vanilla species were collected for determining genetic identities (Annex, Table 2). Before sending the biological material to ZooPlant Lab in Italy, replicas of the material was deposited at National Herbarium in Lima, Universitad Agraria La Molina. Transport guidelines CITES have been followed for delivering the samples to Italy.
Due to the degradation of the material arrived to destination and the nature of Vanilla succulent leaves, very difficult to dry especially in tropical habitat, it wasn't possible to genetically assess the degree of connection among populations of Vanilla pompona. However, for three species AP assessed the genetic identities: Vanilla pompona, V. palmarum, V. hostmanii (Annex, Table 3).
For testing the degree of connection among populations of Vanilla pompona AP selected the secondary methodology based on their spatial distribution. Coordinates of Vanilla pompona were taken from dataset available on http://atrium.andesamazon.org/. Most of the populations (3/4) resulted not connected as distant more than 20 Km, which is the maximum spatial distance run by the bees observed to act as pollinators (Eulaema species) for Vanilla pompona. Except from the wetland La Cachuela, that over exceeds 20 km of extension, the connection within wetlands is potentially ensured by distance that pollinators can support.
AP therefore concluded that actions are required for ensuring the connection between populations and contrasting the habitat fragmentation of the original habitat (wetlands with Mauritia flexuosa).
2) Investigation on the pollination ecology of the species Vanilla pompona revealed the pollination strategy adopted by the species. Observation were carried out in 15 days in two sites (Kapievi and Baltimori, in proximity to Rio Tambopata) from 2nd September 2018 until 19th September 2018, time ranging from 5 am to 3 pm. Only Eulaema cingulata was observed to enter in the orchid labellum and therefore to act as pollinator for Vanilla pompona. The range of temperature in which E. cingulata was observed to approach Vanilla flowers varied from 20°C to 29° C. A total of seven insects approaching the flowers were caught for identification and were identified at Museum of Entomology - Universitad National Agraria La Molina. On a total of 68 insects approaching the flowers 56 were Eulaema, 10 Trigonini bees, 2 Euglossa sp. All the insects caught and identified approaching the flowers were males.
Behavioural tests were performed in the same sites (Kapievi and Baltimori) in order to test the attraction of insects to Vanillina fragrance.
AP set up experiments for five days from 6.00 am to 10.00 am, during the optimum of bee activity, at the base of a plant of Vanilla pompona, creating baits containing Vanillina for attracting insects. The experiments showed that the bees attracted by the baits were males of Trigonini bees and two species of Euglossa bees. A total of 58 insects were recorded during the test. The test revealed that the Eulaema was attracted by the fragrance but didn't manifested any probing behaviour to the baits. Instead, both Trigonini and Euglossa species displayed several attempts of probing on the surface of the baits and they spent fro1 to 20 minutes on the baits. Alternatively, Eulaema showed an attraction to the baits, but approached the baits only for few seconds, from 2 sec to 15 sec.
Self-reproduction experiments of the species, using organza bags to avoid pollinator contact, revealed that Vanilla pompona needs pollinators for being reproduced.
Concluding, Eulaema cingulata was the pollinator of Vanilla pompona in Madre de Dios. The attraction to Vanilla flowers is based on a likely oil collecting behaviour operated by males in order to invite the females for the mating ritual. Vanilla pompona requires the pollinator for forming fruits and is not self-pollinated.
3) Based on the final pollination ecology outcomes and the assessment on connection level among populations, AP identified crucial strategies in order to improve the natural connection between populations of Vanilla pompona by pollinators:
A) Vanilla essence, containing Vanillina compound, can be used for attracting from distance pollinators and therefore can represent an effective tool for connecting individuals from different populations. AP recommends the use of essential oils derived from Vanilla for promoting the visitation rate of insects. They can be applied like odor diffuser on the tutorial plants, hanging small bags containing the essence. The method can be applied during the flowering period of the species for 4 weeks. Orchid populations can be chosen in wetlands distant each other less than 20 km.
B) Managing the distribution of the pollinator source at wider spatial level: Eulaema cingulata is the pollinator of Vanilla pompona and they are also pollinator of Bertholletia excelsa, the Brazilian nut. The Brazilian nut offers reward to their pollinator in terms of nectar and pollen therefore they represent an enormous source of pollinators for Vanilla pompona (and potentially other species of Vanilla) as well. This ecological link has to be take in account in order to promote the natural spreading of Vanilla. As the males of Eulaema cingulata display fragrance collecting behaviour on Vanilla pompona, the vicinity to Brazilian nuts where the females spend mostly of their time in collecting pollen, is therefore crucial.
C) Managing the content of light through the habitat: as Vanilla pompona needs the direct sunlight, AP recommends that the wetlands that are subjected to area restriction for re-forestation or lack of water drain, are maintained clear by the canopy coverage. This will allow the plants to produce more fruits and be more visible by pollinators.
The strategies identified has been shared on the social media as many of the farmers and association involved (Camino Verde, IIAP - Instituto De Investigaciones De La Amazonía Peruana) are more active on this communication channel. Additional material is available on youtube channel Earth to be group, including videos on the natural habitat of Vanilla pompona, survey / experiments conducted on the species during the course of the project.
4) Based on the preliminary studies on the chemical profile and the current distribution of the species, AP selected Vanilla pompona as the most suitable species to be propagated through stems. Vanilla pompona chemical profile is very interesting in terms of aromatic compounds associated to Vanilla spice and it is already studied and assessed by previous research work.
The experimental for propagation of Vanilla pompona has been identified in the Arbio nursery along Rio Tambopata, surrounded by primary forest. The experimental site (300 m2) contains 10 tutorial trees for Vanilla pompona propagation by stems collected in natural habitats from 4 populations. This site will represent a demonstrative site that will be monitored for testing parameters related to the reproductive cycle of Vanilla pompona in the forthcoming months.