Insufficient Evidence of Jatropha curcas L. Invasiveness: Experimental Observations in Burkina Faso, West Africa

Abstract

Biofuel plants such as Jatropha curcas L. have potential to support the livelihoods of rural communities and contribute to sustainable rural development in Africa, if risks and uncertainties are minimized. Yet, recent papers have warned of the risk of biological invasions in such tropical regions as a consequence of the introduction of exotic biofuel crops. We investigated the seed dispersal risk and invasiveness potential of both J. curcas monoculture plantations and live fences into adjacent cultivated and uncultivated land use systems in Sissili province, Burkina Faso. Invasiveness potential was assessed through (i) detecting evidence of natural regeneration in perimeters around J. curcas plantations and live fences, (ii) assessing seed dispersal mechanisms, and (iii) assessing seedling establishment potential through in situ direct seed sowing. Spontaneous regeneration around the plantation perimeters of the three sites was very low. Individual seedling density around J. curcas live fences was less than 0.01 m −2 in all sites. Seventy percent of the seedlings were found close to the live fence and most of them derived from the same year (96 %), which indicates low seed-bank longevity and seedling survival. J. curcas can be dispersed by small mammals and arthropods, particularly rodents and ants. In some sites, such as in Onliassan, high secondary seed dispersal by animals (up to 98 %) was recorded. There were highly significant differences in germination rates between seeds at the soil surface (11 %) and those buried artificially at 1-2-cm depth (64 %). In conclusion, we failed to find convincing evidence of the spreading of J. curcas or any significant impact on the surrounding environment.

Biofuels in sub-Sahara Africa: Drivers, impacts and priority policy areas

“…Other potential feedstocks include cassava (for bioethanol), palm oil (for biodiesel), sweet sorghum (for bioethanol), tropical sugar beets (for bioethanol), canola oil (for biodiesel) and sunflower oil (for biodiesel) [1,67,145,244]. Second-generation biofuels are unlikely to become an important biofuel option in the short-to-medium term due to the lack of technical expertise, skilled personnel and appropriate infrastructure [31], despite the relatively high feedstock potential in SSA [32].…”

Initial Effects of Fertilization and Canopy Management on Flowering and Seed and Oil Yields of Jatropha curcas L. in Malawi

“…Currently, several large-scale commercial biofuel plantations are being established in the tropics including subSaharan Africa [13][14][15]. In 2008, GEXIS [16] reported 119,000 ha J. curcas plantations in sub-Saharan Africa with an expected rise to two million hectares in 2015, although this has not been realized.…”

Cultivation of Jatropha curcas L. leads to pronounced mycorrhizal community differences

“…Evidence is lacking to convincingly prove the potential of J. curcas for invasiveness (e.g. spontaneous regeneration, seed dispersal, seed-bank longevity) (Negussie et al, 2014). However its potential long-lasting effects on the soil microbiota could be a major issue in terms of food security because they could compromise the development of local staple crops that will sooner or later replace J. curcas plantations.…”