Individual study: Establishing a new population of Scalesia affinis, a threatened endemic shrub, on Santa Cruz Island, Galapagos, Ecuador
Atkinson R., Jaramillo P. & Tapia W. (2009) Establishing a new population of Scalesia affinis, a threatened endemic shrub, on Santa Cruz Island, Galapagos, Ecuador. Conservation Evidence, 6, 42-47
Scalesia affinis is a threatened shrub endemic to the Galapagos archipelago. Its population on the island of Santa Cruz is critically endangered, with only 71 adult plants known. The future of these individuals is unclear due to imminent development of land surrounding the largest population. This paper reports on a project to establish a new population of S.affinis on Santa Cruz within its historical native range from plants grown ex situ. As the plant is known to be self-incompatible, cross pollination was carried out in the wild to try and augment viable seed production. Average seed viability from 22 artificial crosses was 0.58 (SE ± 0.043), a level similar to naturally produced seeds. Survivorship from germination was low, with only 17% of plants surviving to three months post germination. Survival following transplanting out in the wild was also low, with just 19% of plants (11 out of 57) alive after one year. The relative roles of genetic and environmental factors are discussed in relation to these results.