Monitoring forest cover change in Lefka Ori, Crete, Greece from 1945 to 2007 [Thesis (M.Sc.)]
2013
Zubkova Maria
There is a general agreement in the literature that treelines have shown a trend of upward migration in the last few decades all over the world. Despite the potential of such shifts as indicators of global change effects in mountain systems, there are relatively few works focused on the Mediterranean region. In this work our aim was to quantify the altitudinal shifts and forest cover density, and investigate the effect of topogpahy on these changes in Lefka Ori (White Mountains) in the Greek island of Crete. Vertical aerial photographes from 1945, 1996 and 2007 were used to assess spatial and temporal changes in forest cover. Visual photo interpretation and simple plot methods were used to estimate treeline shift and tree canopy density change accordingly. Image processing of digitized aerial photography identified areas of change in tree cover and quantified locations and total hectares of tree invasions into grassland or bare soil areas. Overall, the results clearly show an increase in woodland areas. Considering topographic factors, our results showed that the most preferable conditions for new trees establishing in Lefka Ori had areas with elevation from 1100 to 1500m and a slope of 10-30%. Though statistically the results did not show a very strong relationship, the analysis and figures showed that treeline and canopy density were clearly affected by topographic factors such as aspect, slope and elevation. This study suggests that it is possible to monitor forest cover change based on vertical aerial photographs.
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