FAUNA AND STRUCTURE OF THE ORIBATID COMMUNITIES (ACARI, ORIBATIDA) IN SOME HAYFIELD PROTECTED AREAS FROM EASTERN ROMANIA

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1 FAUNA AND STRUCTURE OF THE ORIBATID COMMUNITIES (ACARI, ORIBATIDA) IN SOME HAYFIELD PROTECTED AREAS FROM EASTERN ROMANIA Otilia IVAN Institute of Biological Research, Lascar Catargi 47, Iasi, Romania, Abstract. This study finds its place in the field of knowledge of the taxonomic and coenotic diversity of the oribatid mites one of the main groups within the edaphic mesofauna from less investigated habitats and zones of the country. Present researches were carried out in three protected areas placed in the Central Moldavian Plateau, on the territory of Vaslui county: Rupturile slope at Tanacu, Glodeni hayfields, and Burcel s hillock. These nature reserves are included in the List of Natura 2000 sites, and no previous studies regarding the edaphic mites were carried out there. The fauna under study is relatively rich and varied from taxonomic view point: 64 species, belonging to 46 genera and 32 families of the order Oribatida Dugès, 1834; among them, the genera Berlesezetes and Mystroppia, also the species Berlesezetes ornatissimus (Berlese, 1913) and Mystroppia sellnicki Balogh, 1959 are recorded now for the first time in the Romanian fauna. The taxonomic, zoogeographic and ecological spectrum of the fauna was analyzed, as well as the structure of the oribatid communities. Keywords: oribatid mites, fauna, communities, diversity, protected areas. Rezumat. Fauna și structura comunităților de oribatide (Acari, Oribatida) din câteva rezervații de fânețe din estul României. Studiul de față se înscrie pe linia preocupărilor de cunoaștere a diversității taxonomice și cenotice a oribatidelor - grup reprezentativ în cadrul mezofaunei edafice din habitate și zone ale țării mai puțin investigate. Cercetările s-au desfășurat în trei arii protejate situate în Podișul Central Moldovenesc, pe teritoriul județului Vaslui: Coasta Rupturile Tanacu, Fânețele de la Glodeni și Movila lui Burcel. Aceste rezervații sunt incluse în Lista siturilor de importanță comunitară Natura 2000, iar până în prezent nu s-au efectuat cercetări privind acarienii edafici. Fauna studiată este relativ bogată și diversă din punct de vedere taxonomic: 64 specii, ce aparțin la 46 genuri și 32 familii ale ordinului Oribatida Dugès 1834; dintre acestea, genurile Berlesezetes și Mystroppia, precum și speciile Berlesezetes ornatissimus (Berlese, 1913) și Mystroppia sellnicki Balogh, 1959 sunt semnalate pentru prima oară în fauna României. S-au analizat spectrul taxonomic, ecologic și zoogeografic al faunei, precum și structura comunităților de oribatide. Cuvinte cheie: oribatide, faună, comunități, diversitate, arii protejate. Introduction The oribatids are edaphic mites with a detrito-microphytophagous trophic regime which hold a special importance within the decomposers subsystem; due to the high number of species and individuals, their role is determinant in the organic matter s biodegradation processes in most of terrestrial ecosystems. A series of studies proved the special sensitivity of these soil mites in relation with their life conditions; therefore, the oribatids are useful as bio-indicators in monitoring of soil quality and of changes occurred after some human practices or interventions. Previous studies carried out in varied grassland ecosystems from North-eastern Romania evidenced that the richness in species and specific diversity are influenced by the stand conditions and by the manner of exploitation; where the anthropic pressure is minimal (in some nature reserves) a remarkable taxonomic diversity was found, and the oribatid communities are complex and stable, in equilibrium with the biotope (Călugăr, 1973; Ivan, 2005, 2007, 2009). As regards protected areas, especially Natura 2000 sites of Community importance, some updatings and more actions are needed in our country, even more so

2 Otilia Ivan appointed by the European Comission as International Year of Biodiversity is very important in this respect. Material and Methods The investigations were carried out in three protected areas (Mohan, 1993), located in the Central Moldavian Plateau (Vaslui county), as follows: 1 - Rupturile slope at Tanacu - a meadow of Western Pontic type, which vegetate on a slope affected by erosion and landslides. Among the vascular plants identified here rank some rare species in the flora of Romania, which are at the Western boundary of their world areal. 2 - Glodeni hayfields (Rebricea) is a characteristic meadow for the sylvosteppe zone, which includes many rare species of wild flora of Moldova. Currently the land has become private property, being used as hayfield. Human impact exerted by agriculture practiced on the adjacent land is manifested in this protected area by the emergence of weeds or shrubs extension. 3 - Burcel s hillock, located near Iasi Vaslui road (locality Miclesti) has been reduced as surface because of construction of a church and a monumental cross, but mostly because planting Eastern and North-eastern slopes of locust (Robinia pseudacacia). Important was the presence - on a relatively small area - of many rare species, most of which being characteristic to the Pontic and continental steppes, and in addition some infiltration of sub-mediterranean species. Currently, because of the negative influence of anthropogenic factor, a consistent presence of weed species can be observed here. Series of 100 cm 2 soil samples have been taken over from every hayfield. Edaphic mesofauna has been extracted from samples through the Tullgren - Berlese method (the variant suggested by Balogh) and selected by systematic groups. The faunistic material has been submitted to microscopic study, in order to identify the species; it has been also noted the abundance of each species, on samples and ecological stands. The primary data obtained have been processed by means of some analytic and synthetic ecological indices: average abundance of each species (ā) and global average abundance (Ā), expressed as individuals/100cm 2 and, respectively, m 2 ; number of species (S) and average number of species /sample surface (S ); frequency (C) of each species; relative density (D.r.); index of ecological significance (W), expressed as classes: V and IV-edifying species, IIIinfluential species, II and I-accompanying species; specific diversity (H(s)max, H(s), H.r.), estimated by the Shannon - Wienner equation; the adults/preadults ratio. The faunistic synopsis includes the list of recorded taxa, autecological peculiarities and world distribution of each species; the taxa recorded for the first time in Romanian fauna are marked with *. Also, for each species is indicated presence in one or another stand, and relative density, as follows: +++ species with more than 5% of total effectives, ++ species with 2.1-5% of effectives, + species with less than 2% of effectives. Results and Discussion The faunistic material collected from the hayfields under study totals 697 adult individuals and 164 preadult forms (larvae and nymphs); 64 species, which belong to 46 genera and 32 families were identified. The major groups are represented on the whole fauna as follows: primitive oribatids 14.06%, superior, picnonotic oribatids %, and poronotic ones 40.6%. The closed percentage of the two groups of superior oribatids seems to be a characteristic of the sylvosteppe hayfields, being known that in the lawn ecosystems are dominant the poronotic oribatids, while in the forests the picnonotic ones (Aoki, 1983; Ivan, 2007). The families Oppiidae (8 genera, 11 species), Scheloribatidae (1-54-

3 genus, 5 species), Phenopelopidae, Punctoribatidae and Galumnidae (2 genera, 3 species each) are better represented in the taxonomic spectrum (see the Faunistic synopsis below). Faunistic synopsis of the oribatid mites Fam. Brachychthoniidae Thor, 1934 Liochthonius Hammen, L. sellnicki (Thor, 1930): 2(+); sylvicolous, mesophilous; Holarctic Poecilochthonius Balogh, P. spiciger (Berlese, 1910): 1(+++); mainly sylvicolous, meso-xerophilous; Holarctic, Argentina Fam. Cosmochthoniidae Grandjean, 1947 Cosmochthonius Berlese, C. lanatus (Michael 1885): 1(+); cosmopolitan Fam. Sphaerochthoniidae Grandjean, 1947 Sphaerochthonius Berlese, S. splendidus (Berlese, 1904): 1(+++), 2(++), 3(+); thermo-xerophilous; semicosmopolitan Fam. Epilohmanniidae Oudemans, 1923 Epilohmannia Berlese, E. cylindrica (Berlese, 1904): 1(+), 2(+), 3(+); euedaphic, meadow species; cosmopolitan Fam. Euphthiracaridae Jacot, 1930 Acrotritia Jacot, A. ardua (Koch, 1841): 2(+), 3(+); mainly sylvicolous, eurytopic, mesophilous; cosmopolitan Fam. Steganacaridae Niedbala, 1986 Atropacarus Ewing, A. platakisi (Mahunka, 1979): 1(+); sylvicolous, thermo-xerophilous; mediterranean Fam. Trhypochthoniidae Willmann, 1931 Trhypochthonius Berlese, T. tectorum (Berlese, 1896): 1(+); xerophilous; Holarctic, Neotropical Fam. Camisiidae Oudemans, 1900 Camisia Heyden, C. horrida (Hermann, 1804): 1(+); sylvicolous; Holarctic Fam. Hermanniellidae Grandjean, 1934 Hermanniella Berlese, H. dolosa Grandjean, 1931: 1(+), 2(+++), 3(+++); mainly sylvicolous, eurytopic, mesophilous; Palaearctic Fam. Neoliodidae Sellnick, 1928 Neoliodes Berlese, N. theleproctus (Hermann, 1804): 1(++); (mainly) sylvicolous, xerophilous; semicosmopolitan Fam. Licnodamaeidae Grandjean, 1954 Licnodamaeus Grandjean, L. undulatus (Paoli, 1908): 3(+++); Palaearctic (except N), Taiwan Fam. Gymnodamaeidae Grandjean, 1954 Gymnodamaeus Kulczynski, G. bicostatus (Koch, 1835): 2(++); mainly sylvicolous; Holarctic Jacotella Banks, J. neonominata Subias 2004 (= J. ornata Perez Iñigo 1972): 1(++), 2(+++), 3(+++); Mediterranean Fam. Damaeidae Berlese, 1896 Metabelba (Metabelba) Grandjean,

4 Otilia Ivan -M. (M.) papillipes (Nicolet, 1855): 1(+), 2(++), 3(++); eurytopic, mesophilous; Holarctic Fam. Damaeolidae Grandjean 1965 Damaeolus Paoli, D. ornatissimus Csiszár, 1962: 1(+++), 2(+); mainly sylvicolous, meso-xerophilous; S Palaearctic Fosseremus Grandjean, F. laciniatus (Berlese, 1905): 2(+); mainly sylvicolous, mesophilous; cosmopolitan Fam. Astegistidae Balogh, 1961 Cultroribula Berlese, Cultroribula sp.: 2(+) Furcoribula Balogh, F. furcillata (Nordenskiöld, 1901): 2(+); sylvicolous; Holarctic Fam. Liacaridae Sellnick, 1928 Liacarus (Liacarus) Michael, L. (L.) coracinus (Koch, 1841): 2(++), 3(+); eurytopic, mesophilous; Palaearctic Liacarus (Dorycranosus) Woolley, L. (D.) punctulatus Mihelčič, 1956: 2(+); meso-xerophilous, meadow species; S Europe -L. (D.) zachvatkini Kulijev, 1962: 3(+); SE Europe Fam. Microzetidae Grandjean, 1936 Berlesezetes Mahunka, 1980* -B. ornatissimus (Berlese, 1913)*: 2(+); cosmopolitan Fam. Tectocepheidae Grandjean 1954 Tectocepheus Berlese, T. velatus (Michael, 1880): 1(+), 2(+++), 3(+++); eurytopic; cosmopolitan Fam. Oppiidae Sellnick, 1937 Anomaloppia Subias, A. differens Mahunka & Topercer, 1983: 2(+++); mesophilous; Central, S Europe Ramusella (Insculptoppia) Subias, R. (I.) elliptica (Berlese, 1908): 1(+); eurytopic, mesophilous; S Holarctic, Costa Rica -R. (I.) insculpta (Paoli, 1908): 2(++); thermo-xerophilous; Palaearctic (except N). -R. (I.) paolii Ivan & Vasiliu, 1999: 2(+), 3(+); mainly sylvicolous; E Romania Discoppia (Cylindroppia) Subias & Rodriguez, D. (C.) cylindrica (Perez-Iñigo, 1965): 2(+); xerophilous, euedaphic; S Palaearctic, Central America Medioppia Subias & Minguez, M. obsoleta (Paoli, 1908): 1(+); eurytopic; Palaearctic, New Zealand, Hawaii Microppia Balogh, M. minus (Paoli, 1908): 2(+); eurytopic, euedaphic; cosmopolitan Berniniella (Berniniella) Balogh, B. (B.) bicarinata (Paoli, 1908): 1(+); eurytopic; Palaearctic -B. (B.) berninii Ivan & Vasiliu, 1997: 2(+); mainly meadow species; Romania Oppiella (Oppiella) Jacot, O. (O.) nova (Oudemans, 1902): 2(+), 3(+); eurytopic; cosmopolitan Mystroppia Balogh, 1959* -M. sellnicki Balogh, 1959*: 1(+); Central, S Europe Fam. Suctobelbidae Jacot, 1938 Suctobelbella (Suctobelbella) Jacot, S. (S.) arcana Moritz, 1970: 1(++); sylvicolous, eurytopic; Holarctic -S. (S.) subcornigera (Forsslund, 1941): 3(++); eurytopic; semi-cosmopolitan Suctobelbella (Flagrosuctobelba) Hammer,

5 -S. (F.) cf. nasalis (Forsslund, 1941): 1(+); eurytopic, mesophilous; Palaearctic, New Zealand Fam. Scutoverticidae Grandjean, 1954 Scutovertex Michael, S. minutus (Koch, 1836): 2(+); Palaearctic -S. sculptus Michael, 1879: 1(+), 3(+); meso-xerophilous, meadow species; Palaearctic, New Zealand Fam. Phenopelopidae Petrunkevitch, 1955 Eupelops Ewing, E. curtipilus (Berlese, 1916): 1(+); Central, S Europe -E. occultus (Koch, 1835): 2(+); mesophilous, meadow species; Palaearctic Peloptulus Berlese, Peloptulus phaeonotus (Koch, 1844) sensu Sitnikova (in Ghilarov & Krivolutsky, 1975): 1(+), 2(+), 3(++); meadow species; Palaearctic Fam. Oribatellidae Jacot, 1925 Tectoribates Berlese, T. ornatus (Schuster, 1958): 2(++); eurytopic, meadow species; Palaearctic, Argentina, Uruguay Fam. Ceratozetidae Jacot, 1925 Ceratozetes (Ceratozetes) Berlese, C. (C.) minutissimus Willmann, 1951: 2(++), 3(+); thermophilous; S Palaearctic Fam. Punctoribatidae Thor, 1937 Punctoribates Berlese, P. minimus Shaldybina, 1969: 2(++), 3(+++); Palaearctic -P. punctum (Koch, 1839): 1(+++), 2(+); eurytopic, meadow species; semi-cosmopolitan Minguezetes Subias, Kahwash & Ruiz, M. hexagonus (Berlese, 1908): 3(+); hygrophilous; Holarctic Fam. Oribatulidae Thor, 1929 Oribatula (Oribatula) Berlese, O. (O.) pannonica Willmann, 1949: 2(+); meadow species; Palaearctic -Oribatula (O.) sp.: 2(+), 3(+++) Oribatula (Zygoribatula) Berlese, O. (Z.) glabra (Michael, 1890)*: 1(+), 3(+); xerophilous; Palaearctic Fam. Hemileiidae Balogh & Balogh, 1984 Hemileius (Hemileius) Berlese, H. (H.) initialis (Berlese, 1908): 3(+); mainly sylvicolous, eurytopic; semi-cosmopolitan Fam. Liebstadiidae Balogh & Balogh, 1984 Liebstadia Oudemans, L. pannonica (Willmann, 1951): 1(+), 2(+++), 3(+++); mainly meadow species; Holarctic -L. similis (Michael, 1888): 1(++); eurytopic, meadow species; Holarctic, New Zealand Fam. Scheloribatidae Grandjean, 1933 Scheloribates (Scheloribates) Berlese, S. (S.) labyrinthicus Jeleva, 1962: 1(+++), 2(+); eurytopic, meadow species; S and S-E Europe -S. (S.) laevigatus (Koch, 1835): 3(+++); euryplastic; semi-cosmopolitan -S. (S.) latipes (Koch, 1844): 1(+); eurytopic, mesophilous; Holarctic -S. (S.) pallidulus (Koch, 1841): 1(+); cosmopolitan -Scheloribates (S.) sp.: 1(+) Fam. Protoribatidae Balogh & Balogh, 1984 Protoribates (Protoribates) Berlese,

6 Otilia Ivan -P. (P.) capucinus Berlese, 1908: 1(++), 2(+); eurytopic, mesophilous; cosmopolitan Fam. Haplozetidae Grandjean, 1936 Indoribates (Haplozetes) Willmann, Indoribates (Haplozetes) sp.: 1(+), 2(+) Fam. Galumnidae Jacot, 1925 Pergalumna Grandjean, P. altera (Oudemans, 1915): 1(++); thermo-xerophilous; semi-cosmopolitan -P. myrmophila (Berlese, 1914): 1(+++); S Palaearctic Pilogalumna Grandjean, P. crassiclava (Berlese, 1914): 1(++); xerophilous; Central, S Palaearctic. The zoogeographical analysis shows that the widely distributed species are the most numerous, cosmopolitan and semi-cosmopolitan species representing 35.93%, Palaearctic ones 21.87%; these are followed by the Holarctic 18.75%, and European species 15.62%. It is remarkable that 80% of the European species are Southern elements, some of them being here at the Northern limit of their areal (Subias, 2004; Weimann, 2006). As regards the ecological spectrum, the euryplastic forms constitute the most numerous group (25%), followed by the sylvicolous and lawn species (18.75%, respectively 15.62%). If considering the species requirements toward humidity factor, the high proportion of the xerophilous and thermo-xerophilous species can be noticed (over 20%) (Rajski, 1967, 1968; Perez-Iñigo, 1993, 1997; Weigmann, 2006). In this context two genera Berlesezetes and Mystroppia also the species Berlesezetes ornatissimus (Berlese, 1913) and Mystroppia sellnicki Balogh, 1959 have been recorded for the first time in Romanian fauna. Beside them a series of rare, less cited species should be mentioned: Jacotella neonominata Subias 2004 (=J. ornata Perez Iñigo, 1972), Licnodamaeus undulatus (Paoli, 1908), Liacarus (D.) zachvatkini Kulijev, 1962, Eupelops curtipilus (Berlese, 1916), Pergalumna altera (Oudemans, 1915), Pilogalumna crassiclava (Berlese, 1914) (Vasiliu et al., 1993; Ivan & Călugăr, 2004). Other few species need an elaborate study and may be new to science (e.g. Scheloribates (S.) sp. see the Faunistic synopsis). The coenological analysis pointed out that the average abundance is relatively low, comparatively with other such protected areas (e.g. Valea lui David Iasi) (Ivan, 2007). The number of species and specific diversity reach high values, indicating the structural complexity of these communities. The lowest values of global density, as well as of the qualitative parameters were found at Burcel s hillock, where the human impact is more noticeable (Table 1). Table 1. Structural global parameters of the oribatid mites communities. Protected area Ā S S Adults/ preadults Specific diversity total adults H(s)max H(s) H. r. Rupturile slope (Tanacu) 5,040 4, Glodeni hayfields 8,640 6, Burcel s hillock 3,540 2, Legend: Ā-global average abundance, individuals/m 2 ; S-number of species; S - average number of species / sample; H(s)max - maximum specific diversity; H(s)-real diversity; H. r. - relative diversity (%). In the nature reserve Rupturile slope at Tanacu the oribatid mites have a relatively low density, as compared with other natural grasslands from the Northern sylvosteppe (Ivan & Călugăr, 2004; Ivan, 2007), which reflects the concrete stand conditions: the barren habitat, the low amount of vegetal necromass, slope, erosion phenomena etc. -58-

7 Nevertheless, richness in species and specific diversity are relatively high (Table 1). In this hayfield, around Caragana shrubs, the oribatid fauna is more abundant as compared to the grassland itself; differences were found regarding both the abundance and number of species (60% of the species recorded here were found only in Caragana litter), therefore this microhabitat constitutes distinct synusia within the ecosystem. The edifying and influential species cumulate almost 65% of the community s individuals. Among them some typical meadow elements should be noticed, such as Scheloribates labyrinthicus and Punctoribates punctum, this category being well represented among the accompanying species, too (Scutovertex sculptus, Epilohmannia cylindrica, Liebstadia similis, Liebstadia pannonica) (Table 2). The thermo-xerophilous elements hold an important weight within the oribatid coenosis, both as number of species and individuals; among them, more abundant are Sphaerochthonius splendidus, Pergalumna altera, Pilogalumna crassiclava, Neoliodes theleproctus. Taking into account the above mentioned aspects, one may consider that in this protected area the oribatid community comprises in high proportion well adapted species to the concrete stand conditions, being a complex and stable coenosis. In the soil of hayfields at Glodeni the oribatid mites reach the highest density as compared with the other protected areas; the juvenile forms are also better represented, therefore the adults/immature ratio has the lowest value (Table 1). The number of species identified here is higher compared to the other two hayfields, and especially the average number of species/sample surface (S ), which is substantially higher. This fact indicates a relative uniformity of the bio-edaphic conditions in this protected perimeter. Within structure of the oribatid community Tectocepheus velatus and Anomaloppia differens are edifying species and hold almost 1/3 of the total effectives. Alongside them 10 species may be noticed as influential elements, all these species representing 75.96% of coenosis individuals (Table 2). Thus, a relatively even distribution of the effectives on species should be remarked, as indicate the high values of specific diversity (real, relative diversity). In respect to their requirements toward the habitat, the edifying species are less exigent, having a large ecological plasticity; many of the influential species fall into the same category, but beside them are some thermo-xerophilous species, as Jacotella neonominata and Sphaerochthonius splendidus, the first one being relatively rare, less cited in Romanian fauna (Vasiliu et al., 1993). In the third protected area Burcel s hillock, the oribatid mites have a reduced average abundance, but comparable with values observed in other meso-xerophilous grassland from the North-eastern part of the country. As compared to other nature reserves of this type, density estimated here is very low (Ivan, 2007). Number of identified species is also low, especially the average number of species / sample (Table 1). The high proportion of the accidental species almost 1/2 of all leads to low value of the index S', probably a consequence of human impact and less of habitat heterogeneity (as noticed in Tanacu). Specific diversity is also lower than in the other two hayfields, but does not indicate a major disturbance of the coenotic structure. The edifying species Tectocepheus velatus and Scheloribates laevigatus are euryplastic ones and represent 31.29% of the effectives (Table 2). The influential species that cumulate 55.78% of the community s individuals, are mostly characteristic to such ecosystems; among them are some species which prefer grassland soils (Liebstadia pannonica, Punctoribates minimus, Peloptulus phaeonotus) beside several thermo-xerophilous elements (Jacotella neonominata, Licnodamaeus undulatus) (Vasiliu et al., 1993; Ivan, 2005, 2007). -59-

8 Otilia Ivan Table 2. Edifying and influential species of the oribatid communities. Protected areas Rupturile slope (Tanacu) Glodeni hayfields Burcel s hillock Species ā W ā W ā W Pergalumna cf. myrmophila (Berlese, 1914) 6.4 IV Scheloribates (S.) labyrinthicus Jeleva, IV 1 II - - Tectocepheus velatus (Michael, 1880) 0.4 II 14.4 V 6.8 V Anomaloppia differens Mahunka & IV - - Topercer, 1983 Scheloribates (S.) laevigatus (Koch, 1835) IV Punctoribates punctum (Koch, 1839) 3.2 III 0.6 II - - Damaeolus ornatissimus Csiszár, III 0.6 II - - Sphaerochthonius splendidus (Berlese, 1904) 4.4 III 2 III 0.4 II Poecilochthonius spiciger (Berlese, 1910) 2.6 III Protoribates (P.) capucinus Berlese, III 1 II - - Pergalumna altera (Oudemans, 1915) 1 III Liebstadia pannonica (Willmann, 1951) 0.2 I 5.2 III 3.6 III Hermanniella dolosa Grandjean, II 4.4 III 2.8 III Jacotella neonominata Subias, II 4 III 2.4 III (= J. ornata Perez Iñigo, 1972) Punctoribates minimus Shaldybina, III 1.8 III Liacarus (L.) coracinus (Koch, 1841) III 1 II Metabelba (M.) papillipes (Nicolet, 1855) 0.2 I 2.8 III 0.8 II Tectoribates ornatus (Schuster, 1958) III - - Ramusella (I.) insculpta (Paoli, 1908) III - - Gymnodamaeus bicostatus (Koch, 1835) III - - Oribatula (O.) sp I 2 III Peloptulus phaeonotus (Koch, 1844) 0.2 I 0.8 II 1 III Licnodamaeus undulatus (Paoli, 1908) III Suctobelbella (S.) subcornigera (Forsslund, 1941) III Legend: ā average abundance, individuals/100cm 2 ; W index of ecological significance, classes: V, IV edifying species, III influential species, II, I accompanying species. Conclusions The oribatid fauna of the three hayfields (protected areas) from Central Moldavian Plateau reflects by its specific composition the habitat conditions, evidencing a pronounced thermo-xerophilous feature. Two genera and two species have been recorded for the first time in Romanian fauna, alongside a number of rare, less cited species. The global average abundance is relatively low, but the number of species and specific diversity were higher, that characterize some complex structured communities, stable over time. Anthropic impact exerted by grazing, agriculture, construction, tourism and others is reflected in structure of the oribatid coenoses by the high proportion of euryplastic species, which become edifying elements, by the large number of accidental species, by reducing both the density and specific diversity. Therefore, this analysis points out that qualitative and quantitative studies on the oribatid mites may be expressive and useful in monitoring of protected areas, under impact of natural and human factors. -60-

9 Acknowledgements The study was supported by a BIODIV project of the Romanian Ministry of Education, Research, Youth and Sports. Special thanks are due to Prof. Nicolae Ștefan from Al. I. Cuza University of Iasi, for help in the field research, also for updating of the floristic data. References Aoki, J., Analysis of Oribatid communities by relative abundance in the species and individual numbers of the three major groups (MGP-Analysis). Bulletin of the Institute of Environmental Sciences and Technology, Yokohama National University, 10(1): Călugăr, M., Fauna oribatidelor (Acari: Oribatei) din rezervația naturală Valea lui David. Ocrotirea naturii, 17(2): Ghilarov, M. S. & Krivolutsky, D. A. (eds.), Opredeliteli obitaiuscih v pocive klescei, Sarcoptiformes. Izdatelstvo Nauka, Moskva. European Comission, Nature and biodiversity newsletter, no. 27/ Dec (on line). Available from: Guvernul României, Ordonanta-de-urgenta (on line). Available at: Ivan, O., Călugăr, A., On the diversity and distribution of edaphic mites (Acari: Gamasida, Oribatida) in some saxicolous, low-altitude habitats in the North-Eastern Romania. Anuarul Complexului Muzeal al Bucovinei Suceava, XVI-XVII: Ivan, O., Diversitatea taxonomică și cenotică a oribatidelor (Acari, Oribatida) în ecosisteme praticole din lunca Prutului, în condițiile bioedafice modificate prin lucrările complexe de amenajare. Al X-lea Simpozion de Microbiologie și Biotehnologie, Editura Corson, Iași: Ivan, O., Diversity and distribution of the oribatid mites (Acari, Oribatida) in some lawn ecosystems from Moldavian Plain (Romania). Studii și comunicări, Complexul Muzeal de Științele Naturii "Ion Borcea" Bacău, 21: Ivan, O., Diversity and distribution of the oribatid mites (Acari, Oribatida) in some grassland ecosystems from the lower section of the Prut meadow (Romania). Lucrări științifice USAMV Iași, s. Agronomie, 52 (CD-ROM). Ministerul Mediului și Dezvoltării Durabile, Ordinul (on line). Available at: Mohan, Gh., Rezervații și monumente ale naturii din România. Editura Scaiul, București. Perez-Iñigo, C., Acari, Oribatei, Poronota, in Fauna Iberica, vol. 3, Ramos, M.A. et al. (eds.), Museo Nacional de Ciencias Naturales, CSIC, Madrid: 320 pp. Perez-Iñigo, C., Acari, Oribatei, Gymnonota I. In Ramos, M. A. et al. (eds.). Fauna Iberica, vol. 9. Museo Nacional de Ciencias Naturales, CSIC, Madrid. Rajski, A., Autecological-Zoogeographical Analysis of Moss Mites (Acari, Oribatei) on the Basis of Fauna in the Poznań Environs. Part I. Bulletin Entomologique de Pologne, XXXVII(1): Rajski, A., Autecological-Zoogeographical Analysis of Moss Mites (Acari, Oribatei) on the Basis of Fauna in the Poznań Environs. Part II. Fragmenta Faunistica, Polska Akademia Nauk, XIV(12): Subias, L.-S., Listado sistemático, sinonímico y biogeográfico de los ácaros oribátidos (Acariformes, Oribatida) del mundo ( ). Graellsia, 60: Vasiliu, N., Ivan, O., Vasiliu, M., Conspectul faunistic al oribatidelor (Acarina, Oribatida) din România. Anuarul Muzeului Național al Bucovinei, Suceava, fasc. Științe naturale, XII: Weigmann, G., Acari, Actinochaetida. Hornmilben (Oribatida). Goecke Evers, Keltern. -61-