Clonal Re-Introduction of Endangered Plant Species: The Case of German False Tamarisk in Pre-Alpine Rivers

Abstract

The scope of re-introduction as a measure for plant species protection is increasing, but as long as no standardized methods are available, species-specific assessments are necessary to determine whether seeds, adult plants or plant fragments should be used. The endangered German False Tamarisk (Myricaria germanica), which occurs on gravel bars along pre-alpine rivers, is difficult to grow from seeds. Thus, propagation of stem cuttings was investigated as an alternative method. Experiments were conducted in a greenhouse and a field site with three treatments: cutting length 5 or 10 cm, vertical burial 5 or 10 cm, and water level low or high. Plants grown in the greenhouse were transplanted to the River Isar to test establishment of rooted cuttings on gravel bars. The cuttings in the greenhouse showed high survival (34-96 %). Survival and biomass production were greatest for 10-cm cuttings buried at 10-cm depth, while only one of the 5-cm cuttings survived at this depth, and no significant effect of variation in water level was observed. None of the cuttings transplanted to field sites survived, most likely because of drought stress and competition. We conclude that for re-introduction of Myricaria germanica rooted cuttings can be easily produced in large quantities, while transplantation to near-natural environments has to be improved to reduce mortality.

European Tamaricaceae in Bioengineering on Dry Soils

“…In the ex situ experiment, the resprouting rate after taking cuttings was consistent with other published results for Mg [95 and 70 %, respectively, in a laboratory experiment for Schiechtl (1973) and Koch and Kollmann (2012)] and for Sp [100 % according to Graf et al (2003); (Venti et al 2003); Zuffi (1989)]. No comparative data were found for Tg, but most of the authors state that cuttings have very good resprouting capacity (Carleton 1914;Gary and Horton 1965;Everitt 1980;Hartmann et al 1996;Walker et al 2006).…”

“…4) confirmed a strong belowground biomass production and an important drought acclimatization. In a recent experiment on Mg cuttings with different treatments in terms of cutting length, planting depth, and water levels, the authors found that an overall SRR of 10 after 4 months is found (Koch and Kollmann 2012), which is consistent with results. They do not find any significant difference in SRR between two tested water levels, even if they find, as in our study, a small decrease of the SRR for the lowest water level.…”

“…Myricaria germanica and different species of genus Tamarix have been shown to be resistant to sedimentary denudation or burial (Müller and Scharm 2001;Qong et al 2002;Sandercock and Hooke 2010) and floods (Tallent-Halsell and Walker 2002;Kumari 2008;Kudrnovsky 2013). The fact that they can establish themselves in perturbed environments as well as the results of some bioengineering experiments indicate good resprouting capacity (Schiechtl 1980;Venti et al 2003;Koch and Kollmann 2012).…”

Conservation-oriented restoration – a two for one method to restore both threatened species and their habitats

“…The problem of propagule supply can be efficiently solved by the quasi in situ living collections as explained below, and the crucial knowledge about species propagation, although still very limited, is steadily accumulating for rare and endangered species (e.g. Iturriaga et al., 1994, Sakai et al., 2002, Danthu et al., 2008, De Motta, 2010, Herranz et al., 2010, Kay et al., 2011, Ratnamhin et al., 2011, Koch and Kollmann, 2012, Castellanos-Castro and Bonfil, 2013, Gratzfeld et al., 2015, Lu et al., 2016). Once the necessary knowledge is acquired and protocols are available, comparable to those for common species, the cost per seedling will make restoration practitioners more likely to incorporate rare and threatened species into their plans (Rodrigues et al., 2011), because availability of seedlings rather than the cost of a seedling per added species is an obstacle to planting high-diversity species pools (Aronson et al., 2011).…”