Silva Balcanica, 17(1)/2016 SOIL NEMATODES OF FAMILY PLECTIDAE (NEMATODA, PLECTIDA) IN DIFFERENT PLANT COMMUNITIES IN STRANDZHA MOUNTAIN (BULGARIA, TURKEY) Iliyan Iliev1, Zhenya Ilieva2 1 Faculty of Biology, St. Kliment Ohridski Sofia University 2 Institute of Soil Science, Agrotechnology and Plant Protection – Sofia Abstract During 2009-2010, 30 different localities in the region of Strandzha Mountain were sampled for terrestrial nematodes. Sampling plots were located in plant communities typical for the region in the Bulgarian and Turkish part of the mountain. In total, 15 species of order Plectida were identified and data on their distribution, morphology and morphometrics are provided, Plectus cancellatus and Ereptonema arcticum being new geographical records. Fifteen species are reported for first time from the region of Strandzha, comprising 62% of all species of the family reported for Bulgaria. Twelve species are recorded in the Turkish part of the mountain and 11 of them are new for the nematode fauna of Turkey. The representatives of family Plectidae were the most abundant group and had the highest species diversity of all soil nematodes in the studied localities (Iliev, 2014). The most frequently encountered specieswere Anaplectus granulosus, P. acuminatus and P. cirratus. These three species are the most abundant of all plectids identified in the investigated communities. Key words: abundance, Anaplectus, distribution, Ereptonema, morphology, Plectus, Tylocephalus, Wilsonema INTRODUCTION Strandzha is a low mountain in Southeastern Bulgaria and Northwestern Turkey. The highest peak is Mahiada (1031 m a.s.l.). The Bulgarian part is protected area that includes 33 natural habitats. Strandzha Mountain belongs to the Euxeinos botanic- geographic province. The region was not greatly influenced by Oligocene glaciations and developed a specific flora now distinguished by 63Tertiary relicts and 55 endemic plants (Gussev, Tzonev, 2014). Data on the nematode fauna of the region are scarce (Katalan-Gateva et al., 1991; Iliev, 1992; Lazarova et al., 1998) and the only study that includes species of Plectidae as a part of the general fauna covers three beech forests (Iliev, Ilieva, 2014). Gadea (1978) studied free-living nematodes of mosses in several habitats in the continental part of Turkey. He reported Plectus cirratus from three locations in Capadokia, Pamukkale and Bursa province. In a more recent study Akyazi et al. (2012, 2014) identified the genera Plectus and Wilsonema in potato crops and hazelnut orchards in the province of Ordu, Northeastern Turkey but no species were reported. To the best our knowledge, no investigations of the family have ever been conducted in the Turkish part of the mountain. 71 The aim of present study is to i) elucidate the composition and distribution of species of family Plectidae in Strandzha Mountain, and ii) provide morphological data about the species recovered. MATERIAL AND METHODS Sampling sites. During 2009-2010, 30 different localities in the region of Strandzha Mountain were sampled for nematodes. The plots were located in plant communities typical for the region in the Bulgarian and Turkish part of the mountain. A description of the sampling sites and periods is presented in Table 1. All habitats are distributed in the four Floristic-climatic zones of Strandzha: І. Coastal zone: the eastern low part of the mountain reaching the Black Sea Coast; ІІ. Rhododendron zone: deciduous forest with edificatorFagus orientalis Lipsky and abundant evergreen Tertiary relicts; ІІІ. High zone: Different oak associations; ІV. Northwestern arid zone: mixed forest with much less precipitation during the year, in comparison to the other zones of the mountain (Gussev, Tzonev, 2014). Sampling, extraction and processing. At most sites representing different habitats five bulk samples were collected for faunistic study; ten bulk samples were collected in seven habitats (2, 5, 6, 7, 9, 15, and 16) nine times for the period of investigation in order to describe population dynamics. Habitat 1 was sampled for population dynamics on the first year but at the beginning of the second year it was excluded due to local floods on the first two collection dates. Each sample consisted of 10 soil corers at 20 cm depth. Nematodes were extracted from 100 g of soil after homogenization using a modified Bearman method with 72 h exposition (Bezooijen, 2006), counted alive and gently fixed at 50oC in 4% formaldehyde. Up to 200 nematodes per sample were mounted on temporary slides for quantitative analysis (Paramonov, 1963). The rest of the specimens were mounted on permanent slides in glycerol (Seinhorst, 1959). The mounted specimens were measured and photographs were taken under DIC microscope Olympus BX60 with digital camera DP70 and specialized software Imaging System cell^B (Olympus). Relative densities were calculated on the basis of recovered mature nematodes and morphometric characters were described only from permanently mounted specimens. Terminology of species morphology is after Holovachov (2006). We used the classification of subfamilies and genera of Plectidae proposed by Holovachov, de Ley (2006). Old synonyms used in earlier records for Bulgaria are given for all species. RESULTS AND DISCUSSION During the study a total of 15 species of family Plectidae were identified from 363 samples collected in Strandzha region – 15 species in the Bulgarian part and 12 in the Turkish part of the mountain. 72 Table 1. Description of studied habitats and sampling periods GIS Altitude Sampling N Zone* Locality Habitat coordinates m a.s.l. period** Bulgaria Longose forest of Caucasian ash (Fraxinus oxycarpa Willd.), black alder (Alnus glutinosa Gartn.) Protected and European white-elm (Ulmus laevis Pall.), undergrowth of wood-rush (Luzula sp.), Festuca area sp., sedge (Cyperus sp.), water flag (Iris pseudocorus L.), summer snowflake (Leucojum aestivum N 42o3’40” I, III, IV, 1 I 5 Estuary of L.), common nettle (Urtica dioica L.), Polygonum sp., great water dock (Rumex hydrolapathum E 27o57’55” V, VI Veleka Huds.), bulrush (Typha latifolia L.), etc. Soil type***: Fluvisols Windy coastal forest of Hungarian oak (Quercus frainetto Ten.) and Cerris oak (Quercus cerris L.) I, III, IV, Protected with undergrouth of shrubs: butcher’s-broom (Ruscus aculeatus L.), wild asparagus (Asparagus N 42°03’10’’ E V, VI, 2 I area Silistar acutifolius L.), Crimean comfrey (Symphytum tauricum Willd.), and Black Sea mission bell 15 27°59’13” VII, VIII, – Butamjata (Fritillaria pontica Wahlenb.), Caucasian primrose (Primula acaulis spp. rubra (Sm.) Greut.), etc. IX, X 73 Soil type***: Leptosols, Rendzik Longose forest of Caucasian ash (F. oxycarpa) and black alder (A. glutinosa), climbing plants with Near Rezovo N 41°59’01” E 3 I woody and herbaceous stems: old man’s beard (Clematis vitalba L.), (Smilax excelsa L.), etc. 15 II, VIII village 28°01’41” Soil type***: humid and deep and rich organic Molic Gleyisols N42°18’24” E 4 I Maslen cape Coastal open area with a dominant species Ephedra distachya L. and gramineous grasses 15 VII 27°47’35” Meadows near Veleka river (secondary succession of gardens – 20 years ago). Regularly flooded Near Kosti in late winter to spring with single trees of black alder (A. glutinosa), willow (Salix sp.), Persian I, III, IV, village walnut (Juglans regia L.), blackberry ( Rubus sp.), Poacea gen. spp., Fabacea gen spp., and N 42°03’23” E V, VI, 5 II 105 Locality St. common nettle (U. dioica), etc. At the base of the slope meadows are bordered by aged trees: 27°45’51” VII, VIII, Elijah Strandzha oak (Q. hartwissiana Stev.) and Cerris oak (Q. cerris). IX, X Soil type***: Fluvisols Forest of Oriental beech (Fagus orientalis Lipsky) and Oriental durmast (Q. polycarpa Schur.); I, III, IV, Protected dense undergrowth of shrubs and herbs: pontic rhododendron (Rhododendron ponticum L.), N 42°06’42” E V, VI, 6 II area Marina single shrubs of Pontic daphne (Daphne pontica L.), mouse thorn (Ruscus hypoglossum L.), wood- 250 27°45’53” VII, VIII, reka-1 rush (Luzula sp.), and perennial eastern sowbread (Cyclamen coum Mill.) IX, X Soil type***: well developed, rich and humid Haplic Alisols Table 1. Continued GIS Altitude Sampling N Zone* Locality Habitat coordinates m a.s.l. period** Bulgaria Forest of Oriental beech (F. orientalis) and Oriental durmast (Q. polycarpa); undergrowth with I, III, IV, Protected single shrubs of pontic rhododendron (Rh. ponticum), medlar (Mespilus germanica L.), Pontic N 42°06’58” E V, VI, 7 II area Marina daphne (D. pontica), blackberry (Rubus sp.), perennial: eastern sowbread (C. coum); and different 265 27°45’54” VII, VIII, reka-2 gramineous grasses. IX, X Soil type***: Haplic Alisols Forest of Oriental durmast (Q. polycarpa) and Oriental beech (F. orientalis); single shrubs of Silkosiya pontic rhododendron (Rh. ponticum), Pontic daphne (D. рontica) and herbaceous plants: eastern N 42°18’60” E 8 II 230 II reserve sowbread (C. coum), gramineous grasses, etc. 25°35’14” Soil type***: Luvisols I, III, IV, Protected Forest of Oriental beech (F. orientalis) with undergrowth of Caucasian whortleberry (Vaccinium 74 N 42o05’48” E V, VI, 9 II Zone Bjalata arctostaphylos L.) and moss (Leucobryum glaucum (Hedw.) Angstr.) 278 27o39’55” VII, VIII, prast Soil type***: Haplic Alisols IX, X Near Single trees of Oriental durmast (Q. polycarpa) and Hungarian oak (Q. frainetto) and dense N 42°06’02” E 10 II Kondolovo cover of rockrose (Cistus incanus L.) 270 II, VII 27°40’53” village Soil type***: Alisols Siliceous rock with pioneer vegetation of green olive trees (Phyllyrea latifolia L.), wild asparagus Under (Asparagus acutifolius L.), garmineous grasses, Black Sea mission bell (F. pontica), Spanish N 42o06’24” E 11 II 255 I Papiya peak stonecrop (Sedum hispanicum L.), and etc. 27o50’36” Soil type***: Lithic Leptosols Mixed forest of Oriental beech (F. оrientalis) and Oriental durmast (Q. polycarpa) undergrowth Locality N 42°00’17” E 12 II of Colchis holly (Ilex colchica Poj) 211 I Indipasha 27°39’09 Soil type***: Haplic Alisols Forest of Oriental beech – F.