PRACTICAL GUIDE The planting of Posidonia oceanica Technique used in the R&D+i project ‘Use of seeds and fragments of Posidonia oceanica for the recovery of areas affected by Red Eléctrica de España's activity’ PRACTICAL GUIDE The planting of Posidonia oceanica Technique used in the R&D+i project ‘Use of seeds and fragments of Posidonia oceanica for the recovery of areas affected by Red Eléctrica de España's activity’ CHAPTER 2 CHAPTER 5 Background regarding the Phases during the cultivation and transplanting planting process of Posidonia oceanica 44 14 CHAPTER 4 CHAPTER 7 Phases prior Conclusions to the planting works 54 CHAPTER 1 32 Bibliography Introduction 4 58 CHAPTER 3 CHAPTER 6 Proposed planting Financial cost technique of the planting technique 26 52 Practical guide. The planting of Posidonia oceanica 5 REE understands active restoration CHAPTER as the interventions 1 to enable the natural Introduction recovery process of an ecosystem following its degradation, damage or destruction. Clewell et al. (2004) 6 Introduction Practical guide. The planting of Posidonia oceanica 7 A restoration project can be either active when it involves tech- the combination of conservation (reducing impacts) and restora- niques such as transplantation or the construction of artificial tion (Possingham et al., 2015). habitats, or even passive, when it focuses on eliminating the im- pact that prevents the natural recovery of the ecosystem object of the project (Shuster, 2004). The rapid degradation of ecosystems Conceptual model of ecosystem degradation and response options from has multiplied the number of restoration projects, although most a restoration point of view (Source: International standards for the practice of them are carried out in terrestrial ecosystems (Blignaut et al., of ecological restoration. Society for Ecological Restoration, 2016) 2013) whereby there is still much uncertainty about the feasibility and convenience of carrying out restoration projects of marine ecosystems (Bayraktarov et al., 2015). Furthermore, marine eco- Assisted Natural Reconstruction regeneration regeneration systems are normally not very visible to citizens in general, which implies that the perception of their degradation and the social Fully functional Requires Requires Requires pressure to recover them decrease. physical-chemical biological improved modification modification management The importance of The restoration cost of marine ecosystems is estimated to be Posidonia oceanica 10-400 times higher than that of wetlands and terrestrial eco- BIOTIC BARRIER BIOTIC meadows in the systems (De Groot et al., 2013). In economic terms, assessing BARRIER ABIOTIC control of coastal erosion, carbon ecosystem services, we find that the cost-benefit ratio of marine sequestration ecosystem restorations, although lower than in terrestrial eco- or natural water systems, remains positive (De Groot et al., 2013). Among marine purification, has led ecosystem restoration projects, the restoration of marine angio- these ecosystems to sperm seagrass meadows is among the most expensive with an be ranked as those -1 of higher interest for estimated cost of US$ 383,672*Ha per hectare planted. In ad- DEGREE OF FUNCTIONALITY restoration among dition, the survival results that have been obtained in seagrass the coastal systems. meadow restoration are among the lowest of the marine resto- ration projects, with an average 38% survival rate of the planted Non functional material (Bayraktarov et al., 2015). However, the importance of seagrass meadows in the control of coastal erosion, carbon se- Degraded ECOSYSTEM CONDITION Intact questration or natural water purification, among other things, has led these ecosystems to be ranked as those of greatest interest for restoration among the coastal systems (Barbier et al., 2011; 38% Greiner et al., 2013). At present, Posidonia oceanica planting techniques are in a de- velopment and refinement phase that will allow their application Consequently, the development of seagrass meadows restora- on a larger scale. The bulk of the Posidonia oceanica replanting Average survival rate of marine tion is necessary and has much room for improvement. The most projects have been carried out with a focus on the viability of the angiosperms desirable lines of work in the restoration of seagrass meadows planted material, an effect of the planting period on the survival replanted in are the so-called assisted regeneration options, that is, those and implementation of small-scale techniques. Transplanting suc- restoration projects aimed at helping the ‘repair’ of the ecosystem by reinforcing the cess is quantified by the number of the planted items that survive, recovery processes that occur naturally. The replanting of sea- although the assessment of the success of a restoration project grass plant material shed naturally and collected for this purpose must consider the recovery of the diversity and functionality of the is part of this line of work. Without ever forgetting that the most target ecosystem (Ruiz-Jaen & Aide, 2005). The restoration of sea- appropriate option for the conservation of ecosystems, and es- grass meadows, understood as the true recovery of its functions, is pecially those that are under specific legal protection such as Po- an incipient line of work and there are few projects or studies that sidonia oceanica. Species particularly sensitive to disturbances address it (Dapson, 2011). As yet, no Posidonia oceanica restora- such as the Posidonia oceanica mentioned above, might require tion projects have been conducted using this approach, although 8 Introduction Practical guide. The planting of Posidonia oceanica 9 the planting of 2 hectares in the Bay of Pollença, Majorca, within the Posidonia oceanica horizontal rhizomes show elongation rates framework of the ‘REE Marine Forest’ project (2017-2020), incorpo- (1-6 cm/year) much higher than those of vertical rhizomes (0.1- rates this approach and includes monitoring the recovery of func- 4 cm/year), although both are among the lowest growth rates of tions during the duration of the project, opening the opportunity to marine angiosperms (Hemminga & Duarte 2000). The selection continue well beyond the project's time horizon. of horizontal fragments for the restoration of Posidonia oceanica therefore has advantages over the use of vertical fragments: it Regarding The marine angiosperms have two reproductive mechanisms: veg- facilitates the establishment of the planted material, the consoli- seasonal variation etative and sexual, which give rise to two types of planting material dation of the clones and the colonisation of adjacent areas. in planting works, previous results for restoration, fragments and seedlings respectively, each mate- indicate that rial has different behaviours and needs. The basic architecture of On the other hand, with regard to seasonal variation in planting planting carried marine angiosperms is modular or clonal. Clones have leaf-bearing works, previous results indicate that planting conducted in autumn out in autumn shoots consisting of several leaves and structures responsible for with fragments from deep water meadows with two or more shoots with fragments anchorage to the substrate, the roots and the rhizome, the organ show better survival rates than those transplants conducted in from deep water meadows with two from which the shoot emerges/is born. The rhizomes can have ver- summer using fragments from shallow water meadows and having or more shoots Prior experiences tical or horizontal growth habit, depending on whether the angio- a single shoot (Genot, Caye, Meinesz, & Orlandini, 1994; Meinesz show better planting Posidonia sperm marine species have both or only horizontally growing rhi- et al., 1992; Molenaar & Meinesz, 1992). There is the possibility of survival rates than oceanica with zomes (Hemminga & Duarte, 2000; Hartog & Kuo, 2006). keeping Posidonia oceanica fragments in controlled conditions those transplants adult plant prior to planting, which enables the plants in worse conditions to carried out in the fragments have summer season stemmed from Vegetative reproduction consists of the formation of clones, by be discarded. According to the results of Meinesz, Caye, Loquès, from shallow water both vertical means of the elongation and ramification of the horizontal rhizomes, & Molenaar (1993), fragments previously kept in the aquarium (for meadows and or horizontal the growth of leaf-bearing shoots on them and the fragmentation of 3 months) show greater survival rates after they are transplanted having a single fragments, the rhizomes as a consequence of the death of the oldest parts to to the sea (60-100%) than those collected and transplanted di- shoot. There is whether with one form the clones. This process, also known as ‘vegetative fragmen- rectly (25-80%). Furthermore, prior maintenance in an aquarium the possibility or several shoots, of keeping obtaining better tation’, represents the main mechanism responsible for contributing can represent an adaptation period for fragments whose depth of the Posidonia survival results to the maintenance of seagrass meadows and their expansion (Du- origin is lower than that of the restoration area, a situation that can oceanica with horizontal arte & Sand-Jensen, 1990). Adult plant fragments are obtained by compromise the survival of the plantation as a consequence of the fragments rhizomes. means of this mechanism: i.e. pieces of rhizome with one or several lower concentration of chlorophyll