PRE-SPRING AT THE FOOT OF OBRUČ MOUNTAIN
While the recently fallen snow still covers the peaks of the Obruč Mountain cluster at the end of the third week of February, some types of plants have begun to blossom in sheltered spots in torrential gullies at the foot of the mountain, heralding the arrival of pre-spring…
In phenology*, pre-spring has arrived when snowdrops begin to blossom and hazel trees start to extend their pollen-producing catkins. In the lower regions of Croatia, pre-spring generally begins between 15 February and 20 February, that is, when average daily temperatures reach between 0oC and 5oC.
There are several deep torrential gullies at the foot of Obruč Mountain and, as far as we can tell, they are especially favourable habitats for snowdrops. Recently, a multitude of snowdrops have blossomed in Bukova gully, near the village of Podkilavac at the foot of Obruč Mountain at about 400 metres above sea level. Many hazel bushes also grow in the gullies, and most of the male catkins on the bushes have already released their pollen.
Warm, sunny weather, in combination with the favourable exposition and microclimate of torrential gullies, has also caused green hellebores to blossom early and, intermingled with snowdrops, they attract pollinators. All these signs imply that pre-spring is in full swing in the sheltered positions of torrential gullies of Obruč Mountain.
When we climb higher up the mountain to Rakov Žlib, another torrential gully at 700 metres above sea level, we notice that the flower buds and leaves of snowdrops have only begun to sprout from their bulbs in soil moistened by recently melted snow. The ground, however, is still covered in patches of unmelted snow. Here, the spring heath that grows in abundance in the black pine forest has not yet blossomed, while some 350 metres below, in the nearby Borovica gully, spring heath is in full bloom.
*Phenology – a scientific discipline dealing with periodic phenomena in living nature (and sometimes in inanimate nature) in relation to the environment, primarily in relation to habitats and climatic conditions. For examples, phenology studies the beginning and end of budding and flowering, the colouring and falling of leaves in plants, the comings and goings of migratory birds, and so on. It contributes significantly to the study of climate change.