Naslov
The Impact of Aleppo Pine Afforestation on the Structure and Dynamics of Landscape in Mediterranean Croatia

Autori
Tekić, Ivan ; Fuerst-Bjeliš, Borna ; Durbešić, Anamarija

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Grandes Problematicás do Espaço Europeu: Programa/ Resumos / Pina, Helena ; Martins, Felisbela ; Ferrera Cármen - Porto : Universidade do Porto, 2014, 11-12

Skup
IX International Seminar ; Overarhing Issues of the European Area

Mjesto i datum
Porto, Portugal, 30.05.2014. - 31.05.2014

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
Aleppo pine (Pinus halepensis Mill.); Croatia; Mediterranean; afforestation; landscape; biodiversity; environment; forest fire

Sažetak
The Croatian Mediterranean, as well as the Mediterranean in whole is recognized by cultural landscapes developed by millennial human impact that mostly affected forest cover. The overall consequence is almost complete missing of autochthonous climatozonal forest vegetation of holm oak (Quercus ilex) and prevalence of degraded forms of forest, such as maquis and garrigue. The investigations of non-wood forest functions have started only in recent history (19th century) and consequently, the massive process of afforestation was launched in the Mediterranean, as well in Croatian littoral. There exists only few tree species that are adequate in the process of afforestation and one of them, Aleppo pine (Pinus halepensis Mill.) prevailed through time. Intentional introduction of one species induced its intensive spatial spreading and led to the forest cover and cultural landscape change. The research area is the central littoral and insular part of the Mediterranean Croatia, Dalmatia. It refers to the wider littoral area of towns of Šibenik and Biograd and Šibenik archipelago, covering 483, 8 km² (sea surface excluded). The main source of data were sattelite images of the State Geodetical Administration of the Republic of Croatia and data from CORINE Land Cover database and Croatian Forests. Supported by the field research where needed, a map of spatial distribution of Aleppo pine was created using ArcMap 10.0. which categorizes the appearance of Aleppo pine in 3 categories. Direct consequence of the afforestation in the Croatian littoral is the appearance of Aleppo pine forests in the areas where it never existed before. The Aleppo pine is considered to be autochthonous only in the southern littoral and insular Dalmatia. The only autochthonous Aleppo pine forest in the research area of the central Dalmatia is found on the island of Krapanj. When recorded for the first time in sources, it occupied over 30 ha, however due to the population of island and wood cutting over time, it was reduced to only 3 ha. That leads to the conclusion that all the other pine forests in this area are introduced. From their primary plantations they have spontaneously spread further in the area. The first plantations of Aleppo pine date from the turn of the 19th and 20th century. They are placed in the immediate vicinity of the town of Šibenik and along the river Krka canyon. Up to the mid 20th century Aleppo pine forests covered 97% of all newly planted area. The prevalence of Aleppo pine in the landscape of the research area is defined in three main categories: „the complete dominance of Aleppo pine“, „larger clusters of Aleppo pine trees“ and „sporadical appearance of Aleppo pine“. Other categories are areas with „no Aleppo pine“, „agricultural areas“ and „settlements“. Comparing present densely forested areas (complete dominance and larger clusters) with those before the afforestation works in the 19th century when the only Aleppo pine forest existed on small island of Krapanj, it can be seen that in the course of 160 years Aleppo pine was spread from 30ha to 15 680ha, that is 52 000%. If one takes the whole area with sporadical appearance of Aleppo pine as well, than the area of prevalence is enlarged 105 000%, or over 600% per year. That makes Aleppo pine the species with the highest rate of spreading in the Croatian littoral. Apart from intentional afforestation works, the successive spontaneous spreading of Aleppo pine is considerably significant process in the ultimate landscape change. Spontaneous spreading of Aleppo pine is strikingly dependent on fire. Its fire surviving mechanism lies in the massive seed production. Aleppo pine, as the most flammable species of the whole Mediterranean, stimulates fires and therefore eliminates competiton. Massive appearance of post-fire Aleppo pine seedling on a small area is leading to the moisture and soil malnutrition and lack of light in such a densely covered area, that is additionaly reducing the potential survival of other species. With the change of livelihood economy and lifestyle in the Croatian Mediterranean karst area, notably in the last half of the century, and the abandonment of the agricultural land and pastures, the spreading of Aleppo pine forest became the main modifier of landscape change in the research area. Aleppo pine occupies abandoned olive groves and pastures and suppresses autochthonous vegetation. Therefore it is considered as invasive species with negative effect on biodiversity. Numerous research results showed the reduction of diversity from 20% to even 50% . Invasive spreading of Aleppo pine and suppressing the autochthonous vegetation is notably advanced on the islands of Šibenik archipelago, Zlarin and Žirje. From the primary plantations it spreaded over the abandoned vineyards and olive groves. Most of the insular territory today is densily covered by Aleppo pine forests, within the categories of complete dominance to larger clusters of Aleppo pine ; i.e. 66% of the island of Žirje and 74% of the island of Zlarin. When compared to the bare karst, the afforestation and growing of Aleppo pine forests is in many ways positive process, but its negative effect on other autochthonous species in the area is directly opposed to the aims of the environmental politics of the EU advocating the preservation of Mediterranean ecosystems. Though, apart from the positive effect on degraded surfaces in term of erosion and flood reduction, Aleppo pine may create conditions for regrowth of autochthonous holm oak (Quercus ilex). However, numerous studies of the Mediterranean in whole, and Croatia in particular, showed that progressive succession of autochthonous vegetation does not really occur. All the authors agree that succession is possible, but only under conditions of intensive forest menagement and silviculture. Still, there is no single example in the whole Mediterranean that Aleppo pine stayed out of forest fire long enough to enable other species to replace it.

Izvorni jezik
Engleski

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