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Providing evidence to improve practice

Action: Add root associated bacteria/fungi to introduced plants Shrubland and Heathland Conservation

Key messages

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  • Two controlled studies (one of which was randomized) in Spain found that adding rhizobacteria to soil increased the biomass of shrubs. One of these studies also found an increase in shrub height.

Supporting evidence from individual studies


A randomized, controlled study in 2011–2012 in experimental fields in southern Spain (Mengual et al. 2014) found that inoculating soils with rhizobacteria increased the shoot and root biomass of French lavender Lavandula dentata. Lavender plants where soil was inoculated had higher shoot (2–9 g) and root biomass (0–3 g) than where soil was not inoculated (shoot: 1 g, root: 1 g). In March 2011 rhizobacteria cultures were added to the soil of 20 pots where lavender seedlings were growing, but not five others. The seedlings were planted in a field in May 2011. In June 2012 plants were harvested and their dry weight was estimated.


A controlled study in 2008–2011 in a field in southern Spain (Perez-Fernandez et al.2016) found that inoculating shrubs with rhizobial bacteria increased their height and biomass. Cytisus balansae plants that had been inoculated were taller (2–8 m) than those that had not been inoculated (1 m) and the same was true for Cytisus multiflorus (inoculated: 2–6 m, non-inoculated: 1 m), Cytisus striatus (inoculated: 5–6 m, non-inoculated: 1 m), and Genista florida plants (inoculated: 1–7 m, non-inoculated: 1 m). All four shrub species also had higher biomass when inoculated (60–530 mg/plant) than when they were not inoculated (30–110 mg/plant). In 2008 forty seedlings of each plant species were grown in a greenhouse in soil inoculated with rhizobial bacteria, and another 40 in soil that was not inoculated. In 2009 plants were transplanted to a field. In 2011 the height of plants was measured and plants were harvested and dried to allow biomass to be calculated.

Referenced papers

Please cite as:

Martin P.A., Rocha R., Smith R.K. & Sutherland W.J. (2019) Shrubland and Heathland Conservation. Pages 493-538 in: W.J. Sutherland, L.V. Dicks, N. Ockendon, S.O. Petrovan & R.K. Smith (eds) What Works in Conservation 2019. Open Book Publishers, Cambridge, UK.