In the southeastern part of the Drava Forest-park there is a group of white poplar trees, which has been protected under the Nature Protection Act in the category of natural monument, botanical, on an area of 1.8 ha since July 2001. Almost all trees from this group are of impressive dimensions and are among the most striking examples of this species in Croatia and Europe.
The protected white poplar trees represent a special value of this species in Croatia, due to their size and age. In the area of the natural monument, it has been determined that there are about 70 white poplar trees (Populus alba), and in the area of the Forest-park there are at least 4 more trees of similar dimensions and age that have not been recorded and specially protected. All trees have been measured and their health condition has been described. The heights of the protected trees range from 35 to 45 m and the circumference from 200 to 521 cm. The age of the trees is estimated at 80 to 120 years.
According to the survey of the stand and the environment in which the trees are located, it can be concluded that they are the remnants of indigenous black and white poplar forests (Populetum nigro-albae) with fragments of pedunculate oak forests (Carpino betuli-Quercetum roboris). With the land reclamation and construction of hydroelectric power plants on the Drava, the regime of the Drava River between the reservoirs and the regime of groundwater in the hinterland has changed, and we have a slowdown in growth and drying of individual trees and the appearance of forest vegetation succession that is moving in the direction of an increasing proportion of mesophilic plant species, which do not require a constant high level of groundwater. The species that were introduced into the area have successfully adapted to the changed habitat conditions.