Establishing a new population of Scalesia affinis , a threatened endemic shrub, on Santa Cruz Island, Galapagos, Ecuador

Resumen

SUMMARY Scalesia affinis is a threatened shrub endemic to the Galapagos arc hipelago. Its population on the island of Santa Cruz is critically endangered, with only 71 a dult plants known. The future of these individuals is unclear due to imminent development of land surroun ding 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 f rom plants grown ex situ . As the plant is known to be self-incompatible, cr oss 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 wa s also low, with just 19% of plants (11 out of 57) alive a fter one year. The relative roles of genetic and environmental factors are discussed in relation to these results.