LANDSCAPE ECOLOGY ANALYSIS OF MATA ATLANTICA S PATCHES FROM SOUTH BRAZIL USING FREE GIS

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1 LANDSCAPE ECOLOGY ANALYSIS OF MATA ATLANTICA S PATCHES FROM SOUTH BRAZIL USING FREE GIS I. J. M. Ferreira a, E. V.Couto a, L. M. Vieira-Couto a a Deptof Environmental Engineering, Universidade Tecnológica Federal do Paraná UTFPR, 1233 Via Rosalina Maria dos Santos, Campo Mourão-PR, Brazil igorferreira@alunos.utfpr.edu.br, (edivandocouto, lucianevieira)@utfpr.edu.br KEY WORDS: Biodiversity, fragmentation, GIS, landscape ecology metrics, Alonzo River watershed. ABSTRACT: The transformation process of continuous forests to remaining forest fragments may have a negative impact on the fauna and flora of Brazilian biomes. The use of Geographic Information System (GIS) has become an important tool for the development and implementation of researches on landscape fragmentation effects. This paper aims to promote an integrated analysis of the landscape fragments that compose the Alonzo River sub watershed located in the Ivai River watershed, State of Parana in Brazil, by using remote sensing tools and landscape ecology metrics. The analyzed and discussed landscape metrics were the Patton s index, total area of the patches, edge length, edge density, density of forest fragments, patches core area, mean and median area of the patches, and Landscape Division index. As main results, it was noted that of the 953 patches registered in the Alonzo River watershed, 75% of them presented Patton s index less than 3.9. Likewise, it was observed that of all the fragments which showed Patton index value lower than 3.9, three quarters of them presented area values less than 0.2 km² which reflects in small area core of them. Also, the Alonzo River watershed has a Landscape Division index of 99.9%, showing a high degree of division thereof and great influence on edge fragments. As has been shown by the result, it is concluded that the Alonzo River watershed has great edge effect influence because it presents a high landscape division index and many patches with small areas, providing greater vulnerability to fragments and limiting local biodiversity. 1. INTRODUCTION As a result of land use for agropastoral activities, development, and expansion of urban areas, the habitats that compose the Brazilian biomes have undergone a severe fragmentation processes throughout history. The fragmentation by human activities is one of the major causes of diversity loss which leads to changes in the structure and dynamics of animal and plant communities. The fragmentation process has resulted in the formation of an edge environment, which is a contact area between the fragments and the surrounding matrix. This boundary area is related to several factors that directly influence the shape complexity of the fragments. Since the fragment edge can host a larger density of trees and receives a larger amount of solar radiation than forests deeper inside with lower humidity, it impacts the landscape dynamics(collinge, 2009). These factors are known as edge effects and should be taken into account in studies on biodiversity conservation. The spatial gap between the fragments and their size may have a negative impact on the local flora and fauna species, such as the difficulty experienced by some potentially colonizing species in moving among the fragments, thus restricting the genetic variability. This fact may result in the local or total extinction of the species, especially if it is an endemic species(gurevitch, Scheiner, Fox, 2002; Ricklefs, 2010). The use of Geographic Information Systems (GIS) has become an important tool for development and implementation of projects related to the effects on fragmented landscapes and biodiversity preservation and conservation, contributing to the mitigation of the environmental impacts caused by humans(gurevitch, Scheiner, Fox, 2002; Sena et al., 2012). This research uses geographic information systems to process spatial information of the remaining forest fragments in the watershed of Alonzo River in the state of Parana - Brazil. The study sought to promote an integrated analysis of the landscape fragments that compose the Alonzo River sub watershed (popularly known as the River of Fish) located in the Ivai River watershed Parana, by using remote sensing tools and landscape ecology metrics. 2. METHODOLOGY Alonzo River watershed is approximately 2,836 km² and is responsible for an average flow input to the Ivai River of 51 m³/s. The Alonzo River watershed drainage network, which is located between North and the Campo Geraisregions of the Parana state and composed by the cities Faxinal, Rosário do Ivaí, Grandes Rios, Ortigueira, Cruzmaltina, Rio Branco andreserva, is incorporated in the sub basin mosaic of the Ivai River(Leli, Stevaux, Nobrega, 2010; Couto, 2011), as represented in figure 1. The Alonzo River watershed is placed between the transition areas of the Second and Third Parana Plateau geomorphological units(maak, 1984). It is comprised of a very heterogeneous landscape and formed by escarpments ridge, hills, ridges aligned diabase dikes and large areas of pediments; moreover, its geological composition area aggregates geological formation from different ages with rocks ranging from Devonian to Cretaceous, composing a very diverse landscape made up of several forest subtypologies(couto et al, 2012; Couto et al, 2013).. In order to elaborate a geographic database in digital format and georeferenced to the datum SIRGAS 2000 zone 22 South

2 hemisphere, the GIS QGIS was used. In this study, the database used for forest patches of the Parana state and watershed boundaries data come from S.O.S. Mata Atlântica project and ANA/COPEL 2011 respectively. Figure1: Alonzo River watershed location, State of Parana. The statistical data and their interpretations were carried out based on the Landscape Ecology Statistics (LecoS) plugin of the QGIS The metricsanalyzed were the area of all patches, edge density, patch density, patch overall core area and landscape division index.. Also, it was measured the Patton s Index of the patches. This analysis has as its parameters the area and the perimeter of forest patches and it evaluates their shape complexity in order to quantify the edge effect(patton, 1975). The Patton s metric implies that the larger the index, the more complex the shape of the fragment will be, and it results in a higher likelihood of multiple micro-habitats and greater edge effect. The index can be calculated using the equation 1 C = P π AREA (1) Figure2: Alonzo River watershed forest fragments, State of Parana. Based on the distribution of area values in square kilometers for all forest patches of the Alonzo River watershed shown in figure 3, it can be seen that although there are outlier patches with more than 10 km² of area, most of the fragments (75%) have an area value lower than 0.31 km², and 50% of them lower than 0.14 km². Also, it was checked a mean patch area value of 0.35 km² which was superior to the median patch area found for the fragment arrangement.the difference between the mean and median can be explained because the mean is very sensitive to outliers values represented by larger patches found in the watershed. Thus, it is possible to note a high level of asymmetry in the distribution and can be confirmed by the landscape division index 99.9% found for the Alonzo River watershed. Where C is the shape complexity degree of the patches, P is the patch perimeter and AREA is the patch area value. In addition to the landscape metrics mentioned above, it was evaluated the mean and media patch area in order to complement the landscape interpretations. 3. RESULTS The Alonzo River sub watershed is composed of953 forest patches with area values ranging from km² up to 25.1 km², according to figure 2. The total fragmented area accounts for 11.8% of the total land cover area, which means that from an equivalent area of 2,836 km² only km² express the fragmented forest remnants. Figure3: Area distribution of the Alonzo River watershed patches. In general, the watershed shows apatch density of 3.36x10-7 m/ha, a total core area equivalent to 34.2 km². Regarding edge

3 metrics, the Alonzo River watershed indicated edge length of km and edge density corresponding to m/ha. Concerning the shape complexity of the watershed forest fragments, it was applied the Patton s index and its distribution may be observed in figure 4. Figure6: The largest patch of the Alonzo River watershed (A = 15.1 km²; C = 19.2). Figure4: Patton s index of the Alonzo River watershed forest patches. It is noticed that 50% of the values found for Patton s index is lower than 3.2, and 75% lower than 3.9. The distribution has a minimum value of 2.1. The maximum value found for this range was 19.2 and represents the fragment with the most complexshape of the studied watershed, coinciding with the largest patch (Figure 6). Likewise, as it has been shown in figure 5, of all the fragments which showed Patton index value lower than 3.9, three quarters of them presented area values less than 0.2 km² and 50% lower than 0.1 km². Figure7: The second largest patch of the Alonzo River watershed (A = 17.8 km²; C = 6.9). Figure5: Forest patch areasthat showed Patton s index lower than 3.9. Figure8:The thirdlargest patch of the Alonzo River watershed (A = 13.3 km²; C = 12.1). The four largest patches of the studied watershed have an area corresponding to 25.1 km², 17.8 km², 13.3 km² and 12.8 km², and they are represented by figures 6, 7, 8 and 9, respectively. The complexity shape index of those forest patches are19.2, 6.9, 12.1 e 4.2, in a decreasing order to the area.

4 species and cause a greater edge effect. Thus, the highest level of ecological efficiency of a forest fragment based on Patton s index will be linked to the spots with relatively large area values. The edge effect is directly related to higher Patton s ratios, but it also relates to the patch size and the core patch area, making the forest spot more or less ecologically effective and providing higher vulnerability to the invasion or predominance of edge specialist species(laurence et al, 2002; Laurence et al 2007). Figure9: The fourthlargest patch of the Alonzo River watershed (A = 12.8 km²; C = 4.2). 4. DISCUSSION The forests remaining along the Alonzo River watershed are composed of a large number of patches with small areas. The asymmetry degree noted in figure 3 can be confirmed by the landscape division index (99.9%) found for the studied watershed, and it denotes the relationship between the fragments quantity associated with the small area values, describing a highly fragmented landscape composition. The landscape division index is based on the probability that two randomly selected points do not belong to the same fragment spot (Jaeger, 2000). The higher landscape division index indicates highly fragmented landscapes, and it impacts directly on the local biodiversity because the points can be understood as two or more animals of the same species that hadgreat interaction prior to the fragmentation, and now they are no longer in the same habitat spot. The fragmentation process may be related to the intense land occupation and deforestation of the Parana state in the period prior to the year 2000(INPE and FUNDAÇÃO SOS MATA ATLÂNTICA, 2013; Silva et al., 2013). Furthermore, it may be mentioned that the patch area is closely linked to its ability to accommodate greater diversity and species richness since larger areas can offer better conditions of species-habitat interaction and, consequently, it promotes the establishment of viable populations to support local species(collinge, 2009). Regarding the smaller Alonzo River watershed patches, which are somehow isolated from the remaining ones, they can be negatively influenced by the species-habitat interaction, causing local biodiversity loss. The biological diversity decrease is linked to the higher mortality rate of species extinction and lower immigration rate from neighboring fragments. Another aspect observed in this research is the relationship between the shape complexity index calculated for the watershed forest patches and the area thereof. The higher or lower complexity index value is related to the area of the fragments because the area is a component of Patton s equation. For the fragments that present lower index values, a greater ecological functionality is expected. However, it was noted that most of the fragments showed shape complexity indexes relatively low and small areas. Despite the fact that the fragments have shapes with lower complexity, the small area can negatively influence the dynamics of animal and plant The core area is related to forest portion with a lower level of environmental perturbation generated by human action, thereby preserving the original conditions of the local biome and enabling the establishment of sensitive species to environmental changes and more susceptible to predation by edge specialists species (Fisher; Lindenmayer, 2007).Overall, the Alonzo River watershed showed 34.2 km² as total core area, which is a relatively low value that can be explained by the large amount of fragments with area value ranging lower than 0.2 km² and Patton index lower than 3 9 (figure 4). Another factor that influences the amount of the core area and demonstrates the watershed fragmentation level is the comparison between the patch density and the edge density. For the studied area, the edge density was significantly more expressive than the patch density, and because of that, it is possible to infer, along with the shape complexity index and patch area values, the fragments have great edge effect. From Figures 6, 7, 8, and 9 it becomes visible the relationship between the varying shape complexity, the Patton s index value found, the area and the patch environmental functionality. Comparing the four largest forest spots, it can be checked that thosepatches with the highest Patton s indexes(figures 6 and 8) are responsible for the fragment shape with the highest complexity level. Accordingly, these fragments may hold a greater number of habitats and lower richness of existing populations, while the others become less complex according to the decrease of their respective indices. Therefore, it can be inferred that although the fragment represented by figure 6 possesses the largest area, it is the fragment represented by the figure 9 which has the lowest edge effect and is more suitable for conservation of biodiversity and richness of the local biome. 5. CONCLUSIONS The Alonzo River watershed has a high forest fragmentation level with varying Patton s indices and area values. The most of the patches showed small areas. Although the most shape complexity indices are relatively small, the area and the core area of the patches influence a larger edge effect on forested areas, providing an increased vulnerability to the fragments and limiting the local biodiversity.as well as it occurs with the largestpatch found in the studied area, it has the highest complexity index. Further investigation may contribute to the increase and conservation of fragmented forest biodiversity, focusing on the importance of ecological balance. 6. REFERÊNCIAS COLLINGE, S.K., Ecology of fragmented landscapes.the Johns Hopkins University Press, Baltimore, Maryland.

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