Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
PROTECTED AREA IN THE LOWLAND PLAINS OF ROMANIA AND THEIR IMPORTANCE FOR BIODIVERSITY CONSERVATION CRISTINA MUICĂ1 Key-words: nature reserves, lowlands, biodiversity The lowland plains of Romania have of old suffered a powerful human influence, an influence that has kept increasing over the past few centuries. Most of the natural vegetation has been replaced by crop cultures; much of the overmoist areas (very extended particularly in the Banat-Crişana Plain) have been drained; sandy grounds in their turn, have been affected by management works. Even in parts where some forest vegetation was still preserved, natural woods were severely modified by frequent and chaotic cuttings, or replaced by wood plantations. In view of the above, the lowland fauna itself has been drastically modified. As it is, natural, and especially social-historical conditions, have contributed to preserving some more or less large forest areas, interesting herbal associations and even valuable animal complexes. Often enough, mesophile, mesoxerophile and even xerophile species combine. Beside them one finds mesohygrophile and aquatic ones wherever there is wetter substrate (which happens where the underground sheet is closer to the surface, in floodplains, wherever springs spread out in a diffuse sheet on the ground, in lakes, especially on the river banks). As a result, several nature reserves have been established over the time, enjoying a more or less strictly protected status. Some are very important for the conservation of biodiversity. And indeed, the southern part of Romania has distinctive biogeographical land specificity due to the complex intertwining of Central - European forest with Pontic, Steppe and Submediterranean elements (with some outstanding Balkan or Balkan-Pontic species). But this characteristic feature is blurred because the natural vegetation and fauna are substituded by agrosystems over wide expanses of land. Thus, instead of forming a welloutlined strip, these vegetation complexes appear rather as pockets of a deeply fragmented range. However, some species, better resisting the disturbing action of man, are still fairly well-spread in the Romanian Plain, fact that confirms the natural specificity of this territory. Sometimes, the diversity of component species makes these forests even more complex than many associations from the hill and mountain regions. Other interesting associations, connected with both local particularities (wetlands, salt grounds, sands) and the presence of some Pontic-Pannonian elements, are found in the BanatCrişana Plain. Unfortunately, today there is very little concern for preserving them and even though they formally may list on the table of protected areas their biogeographical specificity could be irremediably lost. There are many cases when species of scientific interest are regressing and common species, ruderal ones even, grow in their stead. Here are some examples. In the east of the Romanian Plain, in the Lower Siret Plain, there is "Hanu Conachi" Reservation, remarkable for its original landscape of sand dunes with arenicolous vegetation (including Dianthus pontederae), a very rare Balkan-Romanian species and some Pontic and Mediterranean faunistic elements, among which is the notable Pontic-Central Asian lizard Eremias arguta deserti, whose global limit is just here. Although wood pockets of Quercus pedunculiflora (a Pontic species, very characteristic of the southern sylvosteppe), Quercus robur, Quercus petraea, Betula pendula etc., are still in place, most of the sand area has been planted with false acacia and Pinus nigra, fact that altered its natural characteristics. Protected elements are downrightly regressing. The Frasinu and Spătaru forests, extending south of Buzău town, contain two southern species of ash, Fraxinus angustifolia (Pontic-PannonianSubmediterranean) and Fraxinus pallissae, found only in Romania's extra-Carpathian regions 1 University “Valahia” Târgoviste Cristina Muica and in Bulgaria. Beside, there are specimens of Quercus pedunculiflora and Quercus robur. The herbal layer shows two floristic rarities: Serratula bulgarica (initially deemed to be an endemic species, described by the name of Serratula caput-najae, and subsequently equated to the Bulgarian species) and Leuzea salina (growing only in Romania and in the southwestern part of the former USSR). Here grows the protected European species Fritillaria meleagris, and the Pontic one Tulipa bibersteiniana (protected also in the Crângul Buzăului Reservation). Draining works and water intakes from the neighbourhood depleted the underground sheet; the type of forest management made the herbal layer lose its specificity at a fast pace, turning ruderal even, although the ash has still remained the dominant species. The structure of the stands has been substantially modified, mixed species disappearing altogether. The two forests are send to be a true floristic unicity, however there is some evidence that similar ones did exist in the past, but were destroyed when the terrain started being cultivated. Supporting this assumption is the fairly widespread Fraxinus angustifolia in the south of Romania; specimens of Fraxinus pallissae are still in the Danube Delta and in other sylvosteppe forests of the Romanian Plain (particularly at Ciornuleasa). In the central part of the Romanian Plain fragments of some original forest types still cover pretty large areas. South of Bucharest, for example, Comana Forest contains a complex of distinctively different associations in terms of microrelief and topoclimate. Large portions are dominated by forests of Quercus cerris with Quercus frainetto alternating with stands of Tilia tomentosa (a Balkan Pannonian species found over a pretty wide area in the plain and hill regions of Romania) or Carpinus betulus. Towards the southern margin of the Plain there grow Quercus pubescens and Quercus pedunculiflora. The undergrowth is populated by southern or eastern species like Acer tataricum (Eurasian-Continental), Fraxinus ornus (Submediterranean), Staphyllea pinnata (Submediterranean) and Pyrus elaegrifolia (Pontic-Mediterranean). Quite interestingly, beside East-Continental species, there is the protected Atlantic - Mediterranean Ruscus aculeatus (in the Oloaga-Grădinari sector of the reservation), a monument of nature. Herbs are rich and varied, with Paeonia peregrina var. romanica (a Romanian variety of a Balkan species, sporadically spread in the south and east of the country, between Dolj and Vaslui counties; an extreme east occurrence is recorded in the Republic of Moldova), abounding in the Padina Tătarului sector of Comana Reservation. Other notable species are Nectaroscordum dioscoridis (a Pontic Balkan rarity, with sporadic occurrence in Romania between the counties of Dolj and Iaşi), Fritillaria tenella (= orientalis), also Pontic-Balkan; Scilla autumnalis, Mediterranean; Asparagus veridicillatusMediterranean (growing in Comana Forest close to its western global limit). There are also numerous European and Central European mesophile species: Asperula odorata, Mercurialis perennis, Asarum europaeum. Although Crocus flavus (=moesiacus) is very common in the Romanian Plain forests, it does contribute to the biogeographical specificity of this area, because this Balkan species is present only in the southern counties of Romania (from CaraşSeverin to Vrancea), from the sylvosteppe to the durmast belt, but mainly in Quercus cerris and Quercus frainetto forests. The Comana Reservation shelters a series of southern nonvertebrates of great scientific interest, as well as tortoises. Complex stands of Quercus cerris with Q. frainetto, Q. pedunculiflora and a wealth of Paeonia peregrina var romanica are protected in Manafu Forest south of Ghimpaţi. Despite the exceptional value of these forests, there are parcels on which trees have been felled to the ground and then planted with false acacia and stands dominated by Quercus cerris alone. The result was an artificialisated landscape as a whole, and the alteration of the herbal layer growth conditions. The Snagov and Căldăruşani reservations boast lakes with a very interesting water fauna and vegetation and mixed forests (durmast, lime, hornbeam, ash and Quercus cerris), pockets of the vast forest expanses that once covered the Central Romanian Plain. At Snagov 292 Protected area in the lowland plains of Romania and their importance for biodiversity conservation there are occasional occurrences of beech, a mesophile element very seldom seen in lowland plains (toponymy tells us that it has existed in other points of the plain, too). Nowadays, the two reservations, but especially that at Snagov, are severely affected by tourist and recreational activities (there is a vacation house-building boom). The vernal flora is well developed in the majority of the Romanian Plain forests, some notable species being Convallaria majalis ( an European species) and Erythronium dens-canis f. niveus (an Eurasian species widely spread, which shows a special form, with white flowers in the south of Romania) . On the lefthandside of the Neajlov River, at 110 m alt., the complex of cold springs at Corbii Ciungi used to shelter a rare alga (Hildebrandia rivularis), usually found at over 1000 m alt., as well as a series of non-vertebrate species specific to mountain brooks or peat-bogs. It is a true oasis for the relict fauna and flora in its southernmost occurrence site. Despite insistent demands for adequate protection measures to be taken, nothing has been done so far, so these species have become very much endangered now, some might have even disappeared (Negrea, 2001). In the Banat – Crişana Plain the ornithological reservation at Satchinez, a remnant of marshlands (very extended before damming and draining works began), hosts numerous water-fowl. Several rare arenicolous species are protected in some small reservations of the Carei Plain. Edging the Western Hills is Peţea thermal lake, the habitat of a floristic rarity, the Tertiary relict Nymphaea lotus var. thermalis , very much endangered by increased human pressure in the area (pollution and water use, which have largely changed the thermal regime of the lake). Summing up we would say that, although detailed studies have be conducted into these reservations, and they have been listed among protected areas for some time now, their management has sometimes failed to observe the ecological exigences of protected species. In many forests, cuttings made on parcels were followed by rehabilitation steps to the effect of planting or seeding monodominant species at a very great density of seedlings. In these conditions, the whole floristic complex (inclusive of the very interesting undergrowth flora and the herbal layer) was slow to recover. That would explain why many plant communities have now fewer species and unspecific characteristics. Even Quercus pubescens and Q. pedunculiflora, the tree species peculiar to the southern sylvosteppe forests, are significantly regressing, to the benefit of Quercus cerris. Accompanying species have very much restricted their participation. In many instances, the glades covered with silvosteppe grasses were planted with trees or with fodder to feed the game. The uncertain legal regime of these forests raises doubts as to the future of some highly valuable plant and animal species. Therefore, it is imperative to maintain a constant interest in the identification of detrimental factors, in the implementation of environmental-friendly management measures in keeping with the international conventions on the conservation of biodiversity Romania is a party to. BIBLIOGRAPHY Beldie Al. (l977;l979), Flora României. Determinator ilustrat al plantelor vasculare,I, II, Edit. Academiei Ivan Doina (Edit.) (l992), Vegetaţia României, Edit. Tehnica Agricolă, Bucureşti Muică Cristina, Popova Ana (1996), Fenomenul de xerofitizare a covorului vegetal din România, Rev. Geografică, II –III, Institutul de Geografie, Bucureşti Negrea St., Negrea Alexandrina (2001), Problema conservării rezervaţiei “Complexul de izvoare de la Corbii Ciungi” oază acvatică cu faună relictă în Câmpia Română, Ocrot. nat.med. înconj.42-43 (l998-1999) Pop E., Sălăgeanu N. (l965), Monumente ale naturii din România, Edit. Meridiane Popescu A., Sanda V.,Doltu M.I., Nedelcu G.A (1984), Vegetaţia Câmpiei Munteniei, Muz. Brukenthal, St. com.St. naturii 26 Sibiu 293