Improving success rates of remote conservation translocations by mitigating harsh in-situ environmental conditions : a case study on a critically endangered succulent

Abstract

Conservation translocations of threatened plants are an important measure used to curb extinctions. Some translocation attempts have had poor success rates, particularly in remote locations where after-care is difficult, and this type of intervention often lacks empirical data to inform protocols for subsequent attempts. To address this issue, we undertook a conservation translocation on a Critically Endangered succulent (Aloe peglerae), with the aim of identifying factors that promote survival rates of transplanted seedlings in remote areas of suitable habitat. Protection from the sun, through shading by grass tussocks, improved survival rates of transplanted seedlings significantly during all three years within the study period. Survival rates were also higher for larger seedlings, but the latter effect was only observed during the first-year post-transplantation. Seedling growth differed between years (being highest in the wettest year), and was improved by the applications of potassium silicate (K2SiO3) during cultivation, a biostimulant that increases drought tolerance in plants. All the observed positive effects on seedling growth were, however, only significant during the first-year post-transplantation. Fire exposure negatively affected seedling growth, but also only during the first-year. Based on these results, a suggested protocol for guiding the planning and implementation of conservation translocations of threatened succulent plant species is provided. This study illustrates the value of generating empirical data prior to undertaking larger scale conservation translocations to maximise resource use and increase success rates. The use of a biostimulant is a novel approach to the field of conservation translocations, and could have wide-ranging applications.