Landscapes Forest and Global Change - ESA - Escola Superior ...

F. Peña-Cortés et al. 2010. Spatial and temporal dynamics and future trends of change in La Araucania, Chile
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Cellular Automata algorithm, increasing the likelihood of belonging to a category based on its
local proximity.
3. Results
During the period under review has seen a significant increase in the surface of the forest matrix
dominated over other ground coverage, especially during the first 14 years of analysis.
Moreover, the transition matrix classes and beaches and dunes, have experienced a steady
decline over time. Regarding the projection to 2017 shows that the trend will continue with an
increase forestry positive as the increase in the native forest, although the latter to a lesser
extent. Table 1 shows the annual change rates for each type of landscape.
According to metrics that have characterized the evolution of landscape, it is observed a trend to
increase the number of fragments to the end of the period of analysis, which however, slightly
decreases in 2017 scenario. While 1994 showed a lower number of fragments, their average size
was the largest of the series, which was associated with a low density of edges. The average
shape index indicates that the fragments are generally amorphous except 2017 which
corresponds to oblong oval, also presented an average fractal dimension gives them a moderate
complexity. In relation to the indices of diversity were high for all years with patterns of
evenness than 60% in all cases. The metrics of each year can be seen in Table 2.
Finally, in table 3 is presented the direction of changes occurred in landscape units beginning in
1980 represented by rows, through its new state in 2007 represented by columns. Units with
more significant changes were wetlands and other wet lands, which became part of the
agricultural matrix with almost 15.000 hectares.
4. Discussion
Landscape from the coastal rim of La Araucania is characterized by a marked anthropic
difference (Peña et al. 2006, 2009). A signal of this is that prevailed coverages are related to
productive activities like agriculture, silviculture and developing of human settlements, being
these the one which presented major increases in surface from 1980 to 2007.
Regarding landscape patterns, showed a notable increase in the number of patches during the
first 27 years of study, accompanied by a higher density and lower edges of medium size, what
constitutes clear indicators of processes of fragmentation and habitat loss and it is also
accentuated by the irregular shapes. In relation to the future scenario, it shows a tendency
towards stabilization in the above processes, expressed mainly in a decrease in the number of
fragments, the density of edges and shapes more regular and less complex than previous ones.
Finally, in the period 1980-2007 the direction of changes greatly affected the natural areas with
native forests, wetlands and thicket, becoming part of the forestry and agricultural matrix,
however, the latter also decreases in surface transition to forest matrix, which was identified as
the main agent of change in the current configuration of the landscape of the coast rim.
References
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