FLOODPLAIN FORESTS OF SOČA RIVER BETWEEN KOBARID AND CONFLUENCE WITH RIVER TOLMINKA: CURRENT SITUATION AND DEVELOPMENTJanez Pagon
, 2016, magistrsko delo
Opis: In its upper course the Soča River is one of the best preserved Alpine rivers. Despite that, there have been few studies of its riverine forests, which are an integral part of the river. The research in this thesis encompasses part of the river basin between the towns of Kobarid and the confluence with the Tolminka River. It was found that the riverine forests in the study area are not a homogeneous habitat. Rather, they consist of numerous phytosociological communities with a syn-dynamic connection. The majority of riverine forests in the study area is younger than 50 years old and were established either by the overgrowing of agricultural land or from degraded forests. Accordingly, the forest structure is characterised mainly by uneven-aged stands or younger structural stages, which are frequently returned to their earlier stages due to human impacts. The majority of these forests have low quality prospects. Based on their vegetation and stand characteristics, the riverine forests under study were classified into six stand types. A comparison of the functions and characteristics of particular forest types revealed similarities between the stand types of initial willow, white willow and grey alder. Forests in this cluster are under the influence of soil water and high floodwaters. Their most pronounced function is ecological. In their growing stock, there is a large share of deciduous softwood. Forests in this cluster cover 62% of all riverine forests in the study area. Silvicultural measures are rare in these forests and are less important for the existence of the stands than environmental features like a high level of soil water and minimised human impact on their habitat and the river course. An important characteristic of the second cluster, which consists of pioneer forest on higher-lying river terraces and the riparian corridor stand type is a lack of contact with soil water. In the tree layer of the growing stock in this cluster, species appearing on drier riverine-forest sites prevail (European ash, small-leaved lime, European hornbeam, sessile oak). These forest stands have a greater timber industry potential; therefore, modest measures and limited human impact (especially that which leads to a change in land use like forest grazing and clearing) are recommended. The stands in this cluster cover 30% of the analysed riverine forest area. The third cluster of riverine forests consists of anthropogenic riverine forest stands where the human impact is so significant that they mainly perform a social function. The stand type of this cluster represents 8% of the riverine forests in the study area, and it is suggested that they should be managed as parkland and not as forest areas. Directing visitors to these areas would unburden other, more preserved stand types from the pressures created by human activities (tourism, recreation, construction work). Growth and increment analyses of the most common tree species in the riverine forests in the study area show that mainly olive and white willow, followed by grey alder, have substantial current height (both willow types up to 1.14 m/year), diametric (willow up to 1.4 cm/year) and volumetric increments. However, their rapid growth makes these subjects prone to rapid ageing. The region of northern Primorska was inhabited early in history. Accordingly, there was great pressure imposed on riverine forests already in the past. The analysis of old maps revealed that up to the beginning of the 20th century, the riverine forest area within the scope of analysis was under 50 ha. Within the process of the overgrowing of agricultural land in Slovenia, a process that is currently still underway, the aforementioned riverine forest area increased to 229.16 ha. This thesis shows that the study area is not an unspoiled wilderness. On contrary, just as in the past, it is a crossroads of numerous and frequently conflicting interests. The riverine forest situation on the Soča River in the area b
Najdeno v: ključnih besedah
Povzetek najdenega: ...there have been few studies of its riverine forests, which are an integral part of...
Ključne besede: the Soča river, riverine forests, successional stage, forest stand
Objavljeno: 20.09.2016; Ogledov: 2610; Prenosov: 56
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