Individual study: Reintroduction of star cactus Astrophytum asterias by seed sowing and seedling transplanting, Las Estrellas Preserve, Texas, USA
Birnbaum S.J., Poole J.M. & Williamson P.S. (2011) Reintroduction of star cactus Astrophytum asterias by seed sowing and seedling transplanting, Las Estrellas Preserve, Texas, USA. Conservation Evidence, 8, 43-52
Star cactus Astrophytum asterias is listed endangered in the USA. The few known extant populations are located in Starr County, Texas and adjacent north Mexican states. According to the United States Fish and Wildlife Service A. asterias recovery plan, reintroduction is an acceptable step in recovery of this species. This paper reports on a pilot A. asterias reintroduction program. Seeds and seedlings (2¼ and 2¾ years of age) were planted in the spring and autumn of 2007. Of the seeds sown (120 each in spring and autumn), less than 4% grew to produce seedlings (five from the spring planting and four from the autumn planting). After a monitoring period of 14 months, spring- and autumn-planted seedling survival was 55.0% and 72.5%, respectively. Mean diameter of the surviving spring-planted seedlings (n = 66) increased from 8.9 (± 1.6) mm at planting to 10.4 (± 2.0) mm. Mean diameter of surviving autumn-planted seedlings (n = 87) increased from 9.4 (± 2.0) mm to 11.3 (± 2.6) mm. Based upon these results, for A. asterias reintroduction purposes transplanting nursery reared seedlings appears a better strategy than sowing of seeds directly into the wild.