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CHAPTER 4
ENVIRONMENTAL FACTORS INFLUENCING THE LAND USE AND LAND
Bonilla-53
Moheno et al. 2012). The biophysical factors identified affecting the rates and patterns of land use land cover changes include elevation, slope, climate, and soil type, while the human factors included road networks, population center/ settlements, and management boundaries. Different LULC change pattern or deforestation rate can be expected dependent on the soil fertility, or the location of the area either is near or away from roads. An area with very high accessibility will result in high rate of deforestation that is independent of soil fertility or others environmental factor. According to Lugo Hubp (1988), slope variable is highly correlated with agriculture development as slope range 0-3 degree is suitable for irrigated agriculture and slope range 3-8 degree is suitable for rain-fed agriculture. For forest conservation, slope range greater than 30 degree will be more suitable.
This chapter evaluated the environmental difference between the national park and its surroundings and assessed the environmental factors that affect the LULC change pattern inside and outside the national park. The influence of proximity to roads, settlements, elevation, slope, agroclimatic zone, and protected area designation to the LULC change and deforestation were examined. The results with particular attention to human drivers of change in the deforestation were discussed. Two research question are addressed: are the environmental conditions significantly different between the ERNP and its surrounding; and what are the factors influencing LULC change and deforestation in and surrounding ERNP. I hypothesize that (1) the ERNP and its surrounding is not environmentally similar (Mas 2005); (2) legal protection status of ERNP prevents deforestation (Forrest et al. 2008 a; Rodríguez-Rodríguez and Martínez-Vega 2018); (3) deforestation rate is higher at region with higher agriculture value (Mas 2005; Forrest et
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al. 2008 a); (4) deforestation rate is higher at region with higher accessibility (Mas 2005;
Forrest et al. 2008 a).
MATERIALS AND METHODS
In order to assess the environmental differences and environmental factor impact to the LULC change pattern in the study area, LULC change pattern maps for different period of time (Figure 4.5) were generated from multidate Landsat images (method refer chapter 3). A digital elevation model generated from contour map (Figure 4.3) along with road network (Figure 4.1), town location map (Figure 4.1), slope range map in degree unit (Figure 4.2), agroecology map in term of agroclimatic zone (Figure 4.4), were obtained from The Department of Survey and Mapping Malaysia (JUPEM), open street maps, Department of Statistic Malaysia, National Spatial Plan Malaysia 2001, and Malaysian Agricultural Research and Development Institute (MARDI) in 1981 respectively.
First, comparison was carried out between the ERNP and its surroundings (extent to the outskirt boundary as defined in Figure 2.1b) regarding selected environmental variables, that are elevation, slope and agroecology because previous studies had shown that LULC changes were highly affected by these variables (Laurance et al. 2002; Mas 2005;
Forrest et al. 2008 a). The extended surrounding beyond the ERNP’s administrative boundary include a 10 km buffer zone. The extended distance chosen as it provides sufficient buffer area to obtain reliable statistic on LULC change pattern (Mas 2005). The comparison between ERNP and its surroundings was done based upon a Chi-square test.
The test compares the observed and expected frequencies in each category and test if all
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the categories contain the same proportion of values. This test identifies whether the environmental condition within the ERNP is significantly different from its surroundings.
In the second part, LULC change and deforestation assessment regarding to environmental variables including elevation, slope, agroecology, distance from roads, and distance from town, onto LULC change and deforestation pattern was done. The relationships between the deforestation and the selected variables were assessed using a chi-square test and Cramer’s V in order to identify more important variables influencing the deforestation process in the study area. The Cramer’s V assessed the associated strength between the deforestation and spatial variables as in Table 4.1 (Mas 2005;
Akoglu 2018).
RESULTS
Comparison of environmental characteristics inside the ERNP and in their surrounding
The comparison of environmental characteristics inside the ERNP and their surroundings was done amongst the environmental variables (elevation, slope, agroclimatic, distance from roads, distance from settlements). ERNP and its surroundings were found environmentally different in the five environmental conditions considered (Table 4.2). In Figure 4.6 to 4.10, comparison was made with reference to the selected variables. The ERNP are remotely located from the settlements and poor in accessibility. In term of elevation, the average elevation of ERNP is higher that its surroundings where an approximate 70% of the park’s surroundings was below 100m in elevation. The slope
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range of the park’s surrounding are generally lower than 13 degree which are suitable for agriculture practice as defined by Lugo Hubp (1998). Whereas, the majority of the slope range in ERNP was greater and comprised more unsuitable agroclimatic zones for agriculture practice (highland 300-900m MSL).
In the ERNP’s surroundings, it was found that the main factors accelerated the deforestation were the elevation, slope, agroclimatic zone, distance from settlements, and distance to roads (Table 4.3). Among the variables, distance from road, distance from settlement, agroclimatic zone, and elevation were strongly correlated with the deforestation while slope was moderately correlated (Table 4.3). Relationship between selected environmental variables and LULC change were shown in Figure 4.6 to 4.15.
Strong deforestation trend exists at lower elevation zone particularly within 0 to 100 meters above mean sea level (MSL) (Figure 4.11). Looking at the slope factor, higher rate of deforestation exists at less steeply zone at region with slope range below 20 degree and more intense at region with slope range below 12 degree (Figure 4.12). Figure 4.13 showed the percentage of land cover change with respect to distance to road. Total land cover change and deforestation increases with increasing proximity to roads primarily within 1 km of roads. With respect to agroclimatic characteristics, deforestation and changes were strong at region where the agroclimatic characteristic are suitable for commercial plantation (short but fairy regular dry season and without regular dry season).
High deforestation also found at histosols predominate area and highlands 300-900m MSL (Figure 4.14). While in Figure 4.15, significant deforestation trend was traced at the distance greater than 10 km from the nearest settlement center. From the results, the forested area with elevation below 100m MSL, region with agroclimatic zone that is
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suitable for commercial plantation (oil palm and rubber) and within 1 km buffer from the road are under high risk to deforestation.
DISCUSSION
The large environmental difference between the ERNP and its surrounding was understandable as the area is designated as national park which represent a higher level of conservation for their restriction, inaccessibility and unsuitability for agricultural activities. In comparison, the deforestation rate inside the ERNP was extremely low while the deforestation rate in its surrounding was intense and in increasing trend. Such results could be interpreted as an effective impact of ERNP in against deforestation. However, when considering the environmental criteria for both ERNP and its surroundings (both ERNP and its surrounding are totally environmentally different) the protection status of ERNP play a significant role in stopping deforestation but the environmental factors of ERNP (distance from roads, distance from settlements, agroclimatic zone, and elevation) that had significantly reduced the rate of human disturbance and inappropriate for commercial plant (oil plant) plantation are more important.
Land use land cover change were found strongly influenced by the accessibility to road and settlements especially (Figure 4.13 and 4.15)(Table 4.3) which is consistent with findings of previous studies (Mas 2005; Forrest et al. 2008 b). As we look at the distance from the settlement, the intense deforestation was occurred at distance 10 km away from the settlement. This was understandable as the ERNP and its surrounding is remotely
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located. Rather than urbanization, agricultural development, oil palm is the major focus in that area as we had concluded in the chapter 3. Considering these phenomena, the roads network accessibility was the most significant variable in affecting and accelerating the deforestation rate. The agroclimatic zone was found also strongly influenced the deforestation rate (Table 4.3). According to the MARDI, the agroclimatic zone, short but fairly regular dry season and without a regular dry season are suitable for rubber and oil palm plantation. The results indicated that the LULC changes occurred were mainly aimed for the expansion of commercial plantation, the oil palm. The intense deforestation and LULC changes occurred mostly at area with agroclimatic criteria that suitable for oil palm plantation (short but fairly regular dry season and without a regular dry season) which are easily accessible.
Although the low deforestation rate inside the ERNP suggest a generally positive results for forest conservation inside the ERNP, the continual increase in deforestation rate in its surroundings provide cause for concern. According to the assessment results, the deforestation trends occurred are more significant to the environmental factors that are the distance to roads, distance to settlements, agroclimatic zone, and elevation.
CONCLUSION
This study presents a generally present an optimistic view for the forest conservation inside the ERNP in certain degree is due to its inaccessibility, agroclimatic zone, elevation range and slope degree that are unsuitable for agriculture development are the major
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factors for low deforestation rate inside the ERNP. The environmental condition between ERNP and its surroundings are significantly different. Accessibility (distance to roads and settlements), agroclimatic zone that is suitable for oil palm plantation, and elevation were found to be the main factors affecting the LULC change pattern in the ERNP’s surroundings. The remaining forest land in the ERNP’s surrounding are mainly located at the region that is high risk to deforestation. Although ERNP had showed its significant role in preventing deforestation inside the park. The intense deforestation trends in the surrounding posed a great threat to the species conservation of the ERNP. Crucially, the lower elevation forest habitat outside the ERNP are an important habitat to support the threatened mammal species in ERNP. Compare to the higher elevation, the lower elevation forest support higher density of mammals population in this region (Kadir 2006).
In comparison to the ERNP, the unprotected adjacent surrounding experienced greater scale of changes and forest loss (Figure 4.6). The protection status of ERNP is effective in preventing and reducing forest loss in the ERNP as intense changes and forest loss were traced in all the year assessed right beyond the boundary of ERNP at the northeast corner but do not encroach the administrative boundaries of ERNP. The selection of the ERNP at the region that less agricultural had improved the effectiveness of ERNP in prevent and reduce forest loss. The continual deforestation in the park surrounding could reduce the effective habitat size to support the mammals species inside the park thus increase the extinction risk of mammals inside the ERNP.
60 FIGURES & TABLES
Figure 4.1: Road network (source: open street maps 2018) and town location map (source:
Department of Statistic Malaysia).
Outskirt boundary
20 km
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Figure 4.2: Slope range map in degree unit (source: National Spatial Plan Malaysia 2001)
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Figure 4.3: Digital elevation model generated from contour map (source: Department of Survey and Mapping Malaysia, JUPEM)
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Figure 4.4: Agroecology map in term of agroclimatic zone (source: Malaysian Agricultural Research and Development Institute, MARDI). Agroclimatic zone is a land unit in term of major climate suitable for a certain range of crops and cultivars (FAO). According to MARDI, clear& regular dry season zone is suitable for rice, coconut and cocoa plantation;
short but fairy regular dry season zone is suitable for rubber, oil palm, cocoa, papaya, durian, and cassava plantation; without a regular dry season zone is suitable for oil palm, rubber, cocoa, banana, and pepper plantation; highland 300-900m MSL and histosols predominate are not suitable for plantation.
64 (a) 1992-2007
LULC change Forest Loss (b) 2007-2012
(c) 2012-2016
Figure 4.6: LULC change pattern at time period (a)1992-2007; (b)2007-2012; and (c)2012-2016.
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Figure 4.6: Comparison between ERNP and their surroundings with regard to the elevation. The graph expresses the proportion (%) of land in the different elevation zones (meters).
0.00 10.00 20.00 30.00 40.00 50.00 60.00 70.00 80.00
land proportion, %
elevation zones, meters
ERNP Surrounding
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Figure 4.7: Comparison between ERNP and their surroundings with regard to the slope.
The graph expresses the proportion (%) of land in the different slope angle range (degrees).
0 10 20 30 40 50 60 70
0 to 11.9 12 to 19.9 20 to 24.9 above 25
land proportion, %
Slope angle range, degree
ERNP Surrounding
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Figure 4.8: Comparison between ERNP and their surroundings with regard to the agroclimatic characteristic. The graph expresses the proportion (%) of land in the different agroclimatic zones.
0.00 10.00 20.00 30.00 40.00 50.00 60.00 70.00 80.00 90.00
Short But Fairly Regular Dry
Season
Highlands 300-900 m MSL
Without A Regular Dry
Season
Histosols Predominate
Area
Clear & Regular Dry Season
land proportion, %
Agroclimatic zones
ERNP Surrounding
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Figure 4.9: Comparison between ERNP with its surroundings with regard to accessibility (Distance from roads). The graph represents the proportion of roads in different distance range buffer zones from roads.
0 10 20 30 40 50 60 70 80 90
>10KM 8 TO 10KM 6 TO 8KM 5 TO 6KM 4 TO 5 KM 3 TO 4 KM 2 TO 3 KM 1 TO 2 KM 0 TO 1 KM
no. of roads, %
range of distance, km
ERNP Surroundings
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Figure 4.10: Comparison between ERNP and their surroundings with regard to accessibility (Distance from town). The graph expressed the distance from the nearest settlements to the boundary of ERNP and the outskirt.
0.00 5.00 10.00 15.00 20.00 25.00 30.00 35.00 40.00
Distance, km
Town ERNP Surroundings
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Figure 4.11: Percentage of land cover change with respect to the elevation. Strong deforestation trend exists at lower elevation zone particularly within 0 to 100 meters above mean sea level (MSL).
0.00 10.00 20.00 30.00 40.00 50.00 60.00 70.00 80.00 90.00
0 TO 100 101 TO 200
201 TO 300
301 TO 400
401 TO 500
501 TO 600
601 TO 700
701 TO 800
801 TO 900
901 TO 1000
land proportion, %
Elevation zones, meters
TOTAL CHANGE FOREST LOSS
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Figure 4.12: Percentage of land cover change with respect to the slope. Strong deforestation trend exists at less steeply zone. Stronger deforestation trend existed at region with slope range below 20 degree. Intense deforestation occurred at region with slope range below 12 degree.
0.00 10.00 20.00 30.00 40.00 50.00 60.00 70.00 80.00
0 TO 11.9 12 TO 19.9 20 TO 24.9 ABOVE 25
Land proportion, %
Slope range, degree
TOTAL CHANGE FOREST LOSS
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Figure 4.13: Percentage of land cover change with respect to distance to road. Total land cover change and deforestation increases with increasing proximity to roads.
0.00 10.00 20.00 30.00 40.00 50.00 60.00 70.00
0 TO 1 1 TO 2 2 TO 3 3 TO 4 4 TO 5 5 TO 6 6 TO 8 8 TO 10 >10
land proportion, %
Distance to road, km
TOTAL CHANGE FOREST LOSS
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Figure 4.14: Percentage of land cover change with respect to agroclimatic characteristics.
Deforestation and changes were strong at region where the agroclimatic characteristic are suitable for commercial plantation (short but fairy regular dry season and without regular dry season)
0 5 10 15 20 25 30 35 40 45
Clear & Regular Dry Season
Highlands 300-900 m MSL
Histosols Predominate Area
Short But Fairly Regular Dry Season
Without A Regular Dry Season
Land proportion, %
Agroclimatic characteristic TOTAL CHANGE
FOREST LOSS
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Figure 4.15: Percentage of land cover change with respect to distance to settlements.
0 10 20 30 40 50 60 70 80
>10KM 8 TO 10KM 6 TO 8KM 5 TO 6KM 4 TO 5 KM 3 TO 4 KM 2 TO 3 KM 1 TO 2 KM 0 TO 1 KM
Proportion of land , %
Distance to settlements, km
Total Change Forest loss
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Table 4.1: Interpretation of Cramer’s V (Akoglu 2018) Cramer’s V Interpretation
>0.25 Very strong
>0.15 Strong
>0.10 Moderate
>0.05 Weak
>0 No or very weak
Table 4.2: Environmental difference between ERNP and its surroundings with regards to 5 variables (p = 0.05)
Variables ꭓ² df Significance
Elevation 81.281 9 0.000
Slope 40.681 3 0.000
Agroclimatic zone 77.718 4 0.000
Distance from roads 130.980 8 0.000
Distance from settlements 41.3761 12 0.000
Table 4.3: Results of chi-square test and Cramer's V calculation between forest loss and environmental variables
Variables ꭓ² df Significance Cramer's V
Elevation 4301.779785 18 0.000 0.159
Slope 4151.651476 6 0.000 0.146
Agroclimatic zone 5948.839506 8 0.000 0.187
Distance from roads 6636.268103 16 0.000 0.198
Distance from settlements 6043.786494 16 0.000 0.189
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