Sands in Podravina - The past and current situation, research, preservation and development perspectives

Prirodnim progresivnim sukcesijama te raznorodnim čovjekovim djelovanjem, nekad pokretni podravski pijesci koji su kod Đurđevca i Kalinovca najviše istaknuti u krajobrazu, danas su u cijelosti umireni i obrasli. U znanstvenom pogledu najveću vrijednost imaju ostatci pijesaka istočno od Đurđevca, kojih je oko 20 ha od 1963. zaštićeno kao posebni „Geografsko-botanički rezervat Đurđevački pijesci.“ Osebujnost ovog prostora sastoji se još uvijek u nazočnosti zasebne biljne zajednice stepskih trava gladice i bradice (Corynephoreto-Festucetum vaginatae Sokl. 42.) koja se i danas održava kao trajni stadij. U asocijaciji najznačajnije mjesto imaju biljke psamofiti koje su se najbolje prilagodile životu na pjeskovitoj podlozi. Ipak, pokrivenost površina u rezervatu ne-pješčarskim, pretežno grmolikim vrstama, bagremom, zečjakom, crnim trnom, kupinom i travom šašuljicom, danas prelazi 95 %, a psamofilna flora je potisnuta na svega nekoliko malih oaza. Uz više biljke tu obitava i značajna populacija nekoliko vrsta mahovina, lišajeva te osebujne male asocijacije rijetkih gljiva i miksomiceta. Temeljni problem površina rezervata Đurđevački pijesci nije više revitalizacija psamofita i psamofilne vegetacije, jer za to više ne postoje uvjeti, već čuvanje i zaštita preostalih površina sa psamofitima i odgovarajućom faunom. Uz stručno vodstvo i trajnu aktivnost moguće je i u narednom razdoblju održati ta osebujna staništa, jedinstvena u Republici Hrvatskoj. Osobitu pozornost treba posvetiti preostalim dijelovima Kalinovačkih pijesaka na kojima se još uvijek održava kao trajni stadij psamofilna flora i vegetacija i odgovarajući dio faune. U što skorije vrijeme potrebno je zaštititi preostale dijelove Kalinovačkih pijesaka kao zasebni botanički rezervat.Once mobile Podravina sands, which are the most prominent landscape feature around Đurđevac and Kalinovac, have today become not only completely immobile, but also covered with growth due to natural progressive successions and heterogeneous anthropogenic impact. From a scientific perspective, the most valuable remnants of the sands are located eastward from Đurđevac, 20 hectares of which have been protected since 1963 as the Đurđevac sands special geographical-botanical reserve. The distinctive characteristic of this area is the presence of a separate phytocenosis and biocoenosis of Festuca genus steppe grasses (Corynephoreto-Festucetum vaginatae Sokl. 42.), which are still preserved as a permanent stage. Psammophytes, which have adapted to life on sandy soil the best, are the most prominent plants in terms of association. Non-psammophilous, mostly shrub-like species such as the black locust, common broom, bramble and small reed currently cover over 95 % of the reserve soil. The psammophilous flora has been pushed out to only a couple of small oases. The area is not only the home of higher plants, but also a significant population of several species of mosses, lichens and characteristic small associations of rare mushrooms and slime molds. Current conditions render the revitalization of psammophytes and psammophytic vegetation in the Đurđevac sands reserve impossible, thus the preservation and protection of the remaining areas with psammophytes and corresponding fauna has become its main aim. It is possible, with expert guidance and permanent activity, to preserve those characteristic habitats, which are unique in the Republic of Croatia, in the foreseeable future. Special attention needs to be given to the remaining parts of the Kalinovac sands, where psammophytic flora and vegetation, as well as the corresponding part of the fauna, is still preserved as a permanent stage. The remaining parts of the Kalinovac sands should be protected as soon as possible as a separate botanical reserve, together with one Important Plan Area (IPA) in this tract