ACTION A.6: Determination of vegetation structure and flora and fauna composition and phenology in the Mediterranean temporary ponds (3170*)
This action concerns the biotic component of the Mediterranean temporary pond ecosystems (3170*) of the two project sites (GR1150010 and IT603002). It includes an ecological study which will define the reference state of the biotic communities (flora and fauna, including invertebrates) and a follow-up study during the second year of the project which will assess the amplitude and frequency of natural variations in the biota. Moreover, most of the plant, invertebrates, reptiles and amphibians are excellent bioindicators of the conservation status of the ponds, being very sensitive to physical changes and disturbance.
Plants: vegetation structure and flora composition are studied by 1-3 transects placed to cover the spatial succession of the communities of each pond, depending on their area, bathymetry and duration of flooding. Cover-abundance of all flora species is recorded in a grid set along the transects. In temporary ponds, there is also a seasonal succession of plant communities which follows the water level changes from the wet to the dry phase, so sampling for species determination will take place 2-4 times annually, depending on the hydrological characteristics of each pond (e.g. Isoetes spp.). The activity aims to describe the vegetation zonation and succession of all ponds (both in Greece and Italy), to identify the characteristic and keystone species of the different plant communities, and to determine their relationship with the abiotic factors and the seasonal and interannual variation. In Nestos, the phenology (germination, growth, flowering, fruiting, dispersal) of the characteristic plants (e.g., Cyperus flavensvens, Cyperus fuscus, Fimbristylis bisumbellata, Lythrum salicaria, Mentha arvensis, Plantago intermedia, Portulaca oleracea, Juncus articulatus) is also assessed through monthly or bi-monthly visits, and phenological diagrams are drawn. The activity is carried out mostly by the staff of the National Park of Nestos (EMTNP) which will be instructed and trained accordingly. The training will also provide valuable knowledge and experience to EMTNP staff for after-LiFE monitoring and continuation of activities.
Reptiles and amphibians: the reptiles and amphibians that have been found around the temporary ponds of the two sites include the Annex II 92/43/EEC species Bombina variegata (Greece), Testuto greace (Greece), Eurotestudo hermanni (Greece and Italy) and Emys orbicularis (Greece and Italy). The Bern Convention also protects the first three of these species. Of them, Emys orbicularis is directly associated with the wet phase of the ponds. The inventory will include larvae sampling by pond net during a specified period in all possible microhabitats, a survey of eggs, trapping of adults, detection of reproductive sites through the identification of mating calls. Surveys will be monthly from March till October (a total of at least eight surveys per year).
Invertebrates: the invertebrate fauna of the temporary ponds of the two sites is unknown. It consists of an important part of aquatic biocenoses since, in general, insects constitute from 60–70% of the total number of species present over a complete hydrological cycle. It is expected that freshwater invertebrates belonging mainly to flatworms (Phylum Platyhelminthes), roundworms (Phylum Nematoda), rotifers (Phylum Rotifera), leeches and freshwater oligochaetes (Phylum Annelida), snails and mussels (Phylum Mollusca), crustaceans (Subphylum Crustacea) and insects (Subphylum Hexapoda) may be present in the temporary ponds. Population surveys will be carried out in sampling quadrats using pond nets and hand collecting. Flying adults of freshwater insects are surveyed using transects. All surveys are carried out from March till October (a total of at least eight surveys per year).
The survey of the invertebrates is necessary because they consist an important part of aquatic biocenoses (e.g., insects constitute from 60–70% of the total number of species present over a complete hydrological cycle).
Larger animals (mammals and birds) seen or heard in the area of the ponds during surveys and observation visits are also recorded.
The results for all plants, animals and invertebrates will be analysed and possible interactions identified. There is hardly any data on the composition, structure and function of the biotic communities of the ponds in the study sites. This knowledge is essential for sound management and will identify possible problems (e.g., caused by predation and competition). It is not possible to specify where, how, and with which flora species, restoration of the communities (Action C2) will be implemented if their current situation and relation to abiotic factors (established by Actions A2, A3) are unknown. Also, it is not possible to monitor the results of the conservation Actions (through Action D3) if the initial status of the biotic communities is unknown. This baseline is right for any type of biotic community, but even more so for temporary ponds which present high spatial and temporal variation. In addition, Action A2 will contribute to the selection of the minimum required parameters for after-LIFE monitoring.
The survey of the biotic communities of the ponds is carried out over at least 2 years due to the significant interannual variations in hydrology (see Action A2). The vegetation is organised in belts along hydrological gradients. Thus the interannual variation of hydrology causes a change in the spatial succession of plant communities. Moreover, substantial interannual variations can also occur in the breeding of the amphibians. Data on the interannual, seasonal and spatial series and phenology of the biota are finally necessary to draw specifications for the ex situ conservation measures of the key stones (Action C6).
Beneficiary responsible for implementation: