Analysis of the environmental damage and agricultural utilization in Forest Area of Dieang Plateau, Central Java, Indonesia

Dieng Plateau is a renowned tourist attraction due to its captivating panoramas, protected forest, agricultural viability, and geothermal resources. However, encouraging social life forces the local community to depend on the surrounding forest by utilizing the forest area as agricultural land. These activities harm the environment. This study aimed to determine the level of environmental damage and agricultural utilization in forest area of Dieng Plateau. Data collection methods were observation and interviews, with a purposive determination of the sample. Data analysis was carried out spatially to determine the level of environmental damage. The results showed that the erosion rate in the Dieng Plateau was in the moderate (33-35 cm), heavy (86-100 cm) and very heavy class (92-235 cm). The level of canopy cover is in the moderately dense class (60%), sparse class (20-40%) and very sparse class (<20%). The level of land productivity is in the low class (40%), moderate class (45-53%), high class (70%) and very high (93%). The level of environmental management ranged from poor to excellent. The level of environmental damage in total is in the rather severe and damaged class. For this reason, it is necessary to implementing environmental damage control strategies by land rehabilitation and closely monitoring agricultural activities by the forest area management and local government authorities are essential measures.


Introduction
Dieng Plateau is one of the famous tourist attractions in Central Java.The area is renowned for its beautiful landscapes and cool weather.It is located between two regions, namely Wonosobo Regency and Banjarnegara Regency.Some of the local residents in the area work as farmers.The high fertility of the soil in this region makes Dieng well-known for its agricultural produce, such as potatoes, carrots, cabbages, and more [1].Dieng Plateau is also a volcanic complex with various natural resources potential, including tourism, protected forests, and geothermal resources [2], [4].
These potentials can boost the national and local income if utilized properly.However, various socioeconomic pressures significantly affect changes in land use by humans.The current land use growth is greatly influenced by spatial utilization patterns in the region, resulting in land utilization that may not be appropriate or neglecting environmental sustainability [5].The majority of the Dieng Plateau's population relies on agriculture for their livelihood with a simple mindset.People living near forests or forested villages depend on agricultural land for their survival.When rural communities face economic needs, they may resort to unwise actions, including engaging in illegal logging in the forests [6].
The utilization of protected forest areas for agricultural purposes has been practiced by the local community for a long time.However, the designation of protected forest areas with the purpose of maintaining ecosystem balance and ecological functions makes any changes in land use have negative 1315 (2024) 012049 IOP Publishing doi:10.1088/1755-1315/1315/1/012049 2 impacts on the environment.The observed impacts include an increase in the frequency of landslides and a decline in land productivity [7].These effects are attributed to continuous monoculture agricultural practices that lead to a decrease in soil aggregate strength and loss of topsoil.[8] supports this claim by stating that the soil characteristics (texture, structure, and color) found in the Dieng Plateau and its surrounding areas have empirically and theoretically exhibited high fertility levels.Nevertheless, scientific studies indicate that the land conditions have changed, resulting in a loss of soil fertility.Furthermore, asserts that the overall land conditions in this region are critical, with erosion rates exceeding 180 tons/ha/year.The increasing frequency of landslides over the last 40 years is attributed not only to the reduction in forest cover but also to the rising number of rainy days during the wet season [9], [10].
Based on the background, it is essential to conduct an analysis to assess the environmental damage level in the forest areas of Dieng Plateau, which have experienced changes in land use.The extensive agricultural activities in these forest areas have received insufficient attention, while the observed negative impacts have reached concerning levels.Therefore, it is crucial to understand the extent of these impacts on the environment and the local community.The assessment of the environmental damage level considers both biophysical and social factors.The results of this analysis can serve as a basis for preventing potential disasters in damaged areas and can be utilized by the government or forest area managers to improve policies and evaluate land use strategies by the local community.

Research Location
The research was conducted in the Dieng Plateau Forest Area.Administratively, the Dieng Plateau is situated in two administrative regions: Dieng Wetan Village, Kejajar District, Wonosobo Regency, and Dieng Kulon Village, Batur District, Banjarnegara Regency.This study took place in Dieng Wetan Village and Sikunang Village, Kejajar District, Wonosobo Regency, as well as Dieng Kulon Village, Karangtengah Village, and Bakal Village, Batur District, Banjarnegara Regency, Central Java, Indonesia.

Instruments and Material
The research utilized various instruments, including GPS, a compass, a measuring tape, a tally sheet, a camera, and stationery.As for the materials used, an administrative map with a scale of 1:25000 was employed to determine administrative boundaries; a forest area status map with a scale of 1:100000 was used to identify forest area divisions; a land use map with a scale of 1:25,000 was used to identify land use types in a specific region; a slope map with a scale of 1:25000 was used to determine the slope in a particular area; a soil type map with a scale of 1:300000 was used to identify soil types in the research area, and rainfall data was utilized to understand the local precipitation.

Data Collection
The method used for data collection was observation, which involved gathering data by directly observing facts in the field.Additionally, interviews were conducted to obtain more in-depth information related to the occurring issues.The sampling was carried out purposively, based on certain criteria, these criteria are forest areas that have been used as agricultural land.The selection of research locations was based on land cover maps, forest area maps, slope maps, and soil type maps.Forest area maps and land use maps indicated the ecological boundaries in the Dieng Plateau, distinguishing between forest and non-forest areas to obtain biotic conditions.On the other hand, slope maps and soil type maps represented differences in abiotic characteristics in the Dieng Plateau.The forest area map from 2016 was overlaid with the land cover map from 2018, as well as the slope map and soil type map, to determine the research analysis units.Areas that underwent transformation from forest areas to agricultural land and were selected as sample locations.
The selected consideration in this research was the area.The chosen sample locations were areas within the forest region that had undergone transformation due to agricultural activities.All areas falling within this category were selected as samples.The determination of sample locations was analyzed using ArcGIS 10.3 software.The processing resulted in 9 observation sample points, as shown in Table 1.The sample collection was conducted using the transect method, which involved observing and measuring environmental damage by drawing straight lines from one point to another.Meanwhile, interviews were conducted using the accidental sampling method.Accidental sampling is a technique for selecting respondents suddenly.The selected respondents were not planned before but were determined based on respondents who were accidentally found at the research location.The Accidental Sampling technique was chosen because it is deemed to be more representative.Samples were taken based on justifiable considerations, as long as they fulfilled the research needs.

Data Analysis
The data collected in the field is subsequently subjected to quantitative and spatial analysis.Spatial analysis is employed to determine the level of damage and requires several parameters.The analysis of these parameters yields spatial data on environmental degradation.The parameters used in the spatial analysis of land degradation are as follows: 2.4.1.Erosion Level Erosion has a significant impact on environmental degradation and is assigned a weight of 3. The classification of erosion levels will be displayed in Table 2.The land cover category becomes a highly contributing parameter as it indicates the extent of forest area opening due to human activities.Moreover, vegetation plays a vital role in soil conservation, water regulation, microclimate maintenance, and serves as a habitat for wildlife.Therefore, the loss of vegetation as land cover intensifies the level of environmental degradation.The land cover classification is presented in Table 3. Land productivity contributes insignificantly, and as such, it is assigned a weight of 1.The classification of land productivity will be displayed in Table 4. Management of the environment has a considerable contribution to environmental degradation due to human influence, thus it is assigned a weight of 3. The classification of environmental management will be presented in Table 5.In each analysis unit, an analysis of attribute data was conducted, which consists of tabular data.The method used in tabular analysis was the scoring method.In the analysis unit, the overlay results were subjected to score summation, which was then classified to determine the level of environmental degradation.The classification of environmental degradation levels is presented in Table 6.

Erosion Level
Erosion is the process of soil material being moved or transported from one place, such as the upper slopes, by natural agents, in this case, water, and then deposited in lower areas as sediment or deposits [12].Two main causes of erosion are natural erosion and erosion caused by human activities [13].
Natural erosion can occur to maintain soil balance naturally and typically provides sufficient media for plant life.On the other hand, erosion due to human activities is often caused by the stripping of the topsoil layer due to improper agricultural practices or construction activities that disrupt the physical state of the soil, such as road construction in steeply sloped areas.The erosion process consists of three sequential stages: detachment, transportation, and deposition [14].
A wider extent of land exposure indicates a higher level of erosion occurrence [15], because more soil particles are lost and carried away by surface runoff.Naturally, a certain level of soil loss is permissible if it is in line with the regional conditions.Generally, the allowable erosion rate on hilly or sloping land is 25 mm/year or 25 tons/ha/year [16].However, in reality, the erosion rate occurring in the Dieng Plateau exceeds the permissible limit, reaching 463.86 tons/ha/year with an erosion hazard rate of 48.31 tons/ha/year [17].These findings indicate that erosion in the Dieng Plateau is significantly high, surpassing the allowable limit.According to [18], erosion is influenced by several factors, including erosion processes, climate, topography, vegetation, soil, and human activities.The erosion level in the Dieng Plateau Forest area ranges from moderately severe to very severe.The classification results of the 9 observation points will be shown in Table 7. Tabel 7 shows that out of the 9 observation points in the sample locations, there are 2 points classified as "very severe" erosion.These points are situated in hilly areas at an elevation of approximately 2100 meters above sea level, with a slope gradient exceeding 90% and sparse to very sparse land cover.These factors contribute to extremely high erosion rates in these locations.Additionally, there are 4 observation points classified as "severe" erosion.These points are categorized as severe due to a moderate to very sparse canopy cover percentage and slope gradients ranging from 87.5% to 100%.Furthermore, 3 observation points are categorized as "moderately severe" erosion, with slope gradients ranging from 87.5% to 92.4% and a canopy cover percentage varying from sparse to very sparse.The erosion occurring in the Dieng Plateau Forest area as a result of forest utilization for agricultural activities falls into the "moderately severe," "severe," and "very severe" erosion categories.However, forest areas that have been preserved as intact forest regions fall into the "slight" erosion category.
The result shows that Dieng Plateau erosion is influenced by steep slopes, land use types, and canopy cover, because the steeper the slope, the faster the runoff rate will be [19].Land use as dry-field has a high risk of erosion due to the absence of a multilevel strata arrangement, this is related to canopy cover where the canopy plays a role in breaking down the kinetic energy of rain which can breaks down the soil aggregates.

Canopy Covers Degradation Levels
Canopy cover is the most crucial element in determining the level of environmental degradation [20].The canopy refers to the entire upper part of a tree that is attached to the trunk.Canopies can vary in shape, and these different canopy forms have varying effects on microclimate.Each canopy form provides distinct impacts [21].The conversion of forest areas into agricultural land usually begins with the removal of vegetation covering the area.In protected forest regions, vegetation plays a vital role in safeguarding the areas beneath and serves as an essential element in ecosystem balance [22], [23].Changes in canopy cover result in environmental degradation, starting with the loss of vegetation or tree canopy, which triggers erosion and accelerates surface runoff on the soil, leading to the depletion of nutrients in the topsoil.
The vegetation commonly found in the Dieng Plateau includes cemara (Casuarina sp.), akasia (Acacia decurrens), and pine (Pinus mercusii).Additionally, other tree species, such as puspa (Schima noronhae) and several shrub species, can be found in the area.These species are typical of mountainous regions.The majority of forest areas that have been converted into agricultural land lack the original vegetation or trees.A significant difference in canopy cover exists between the forest areas and the areas that have been utilized for agriculture.In the converted agricultural lands, trees are only found on the edges, providing shade for farmers.The canopy cover degradation level is calculated based on the percentage of canopy cover in each observation point.If the canopy cover seen through the ocular tube is >50%, it is marked as a positive sign (+), while if the canopy seen is <50%, it is marked as a negative sign (-).A total of 20 canopy measurements are observed in one sampling point, and then they are averaged to obtain the total percentage of canopy cover in that particular observation point.Data on canopy cover percentage were collected from 9 sample observation locations, each with varying levels of canopy cover degradation.The results of the canopy cover percentage classification will be shown in Table 8.Table 8 shows that the canopy cover is classified as ranging from moderately dense to very sparse.The canopy cover is classified as moderately dense in observation location 7, sparse in observation locations 1, 3, 5, 6, and 8, and very sparse in observation locations 4 and 9.These locations have undergone a change in land use from forest to agricultural fields.The canopy cover condition in observation location 2 can be seen in Figure 1.Excessive canopy openness can lead to regeneration problems, especially in highly open conditions where the soil quickly dries out, and nutrients are lost due to heavy surface runoff.Herbaceous vegetation and shrubs usually associated with wide openings can disrupt regeneration and slow down recovery.This becomes a challenging issue, especially if these shrubs are non-native plants.Additionally, wide canopy openings significantly alter soil conditions.Slow regrowth can attract herbivorous animals that may damage new plants and maintain the area in an open state.However, on the other hand, an increase in animal density can positively contribute to forest dynamics [24].The damages occurring in the forest areas due to the loss of vegetation can lead to disturbances in the ecological balance.If not managed and controlled promptly, these damages may result in more significant impacts.
The loss of land cover in the Dieng Plateau Forest area, which serves as a protected forest, has significant consequences.This is because the loss leads to the disappearance of forest functions [25], such as the regulation of water resources, flood prevention, erosion control, and soil fertility maintenance.The loss of these functions can threaten the ecological integrity of the area.The canopy cover percentage falls into the categories of moderately dense to very sparse.Areas classified as moderately dense are those adjacent to forest areas and still possess moderately dense canopy cover.On the other hand, areas with sparse and very sparse canopy cover are located close to tourist areas or main roads.

Land Productivity Degradation Levels
Productivity refers to the ratio of output to input used in production, and land productivity, according to [26] [27] land productivity measures the amount of output generated by a given amount of land.The inputs in this context encompass all the costs involved in farming production.In this study, the farming operational costs considered include seed costs, fertilizer costs, pesticide costs, labor costs, and equipment supply costs.The costs and income of farming operations are calculated over a one-year period per hectare.
Factors influencing land productivity include labor, capital, and land.An increase in abundant labor without adequate labor quality can result in negative productivity impacts [28].Capital, in this context, refers to agricultural tools, seeds, pesticides, and other physical resources; the better the quality of capital, the more positive the level of productivity [29].Land has a significant impact on land productivity.The land's ability to produce output is a crucial factor, as better soil quality leads to increased output production, enabling the coverage of farming operational costs.Poor soil quality is a cause of low land productivity, mainly due to its vulnerability to erosion and lack of nutrient availability.
This study classifies land productivity into 5 classes.To determine the land productivity at the location, interviews with farmers are conducted to assess their total needs, costs, and income from farming operations on their land.The classification of land productivity in the Dieng Plateau Forest area is presented in Table 9.Table 9 shows that low land productivity, which is 40%, is observed at observation point 2, located in Bakal Village, Banjarnegara Regency.There are 5 observation points with moderate land productivity, meaning that the land can only provide or return output ranging from 41% to 60% of the total input.Most of these locations are in the forest areas of Wonosobo Regency, namely Sikunang Village and Dieng Wetan Village.Observation point 9 is located in Banjarnegara Regency, specifically in Dieng Kulon Village.High land productivity, at 70%, is observed at observation point 3, located in Bakal Village, Banjarnegara Regency.Very high land productivity, at 93% and 86%, is observed at observation points 1 and 4, respectively, in the areas of Banjarnegara Regency, namely Karangtengah Village and Bakal Village.
The impact of decreasing land productivity is decreasing farmer income.If this condition continues, it will have a bigger impact.According to [30] the decline in income experienced by most people in suburban areas will lead to poverty.This condition will continue to occur until it forms a cycle of poverty traps.Another impact that occurred was the opening of new forest areas by the community for agricultural land and an increase in abandoned unproductive lands.

Environmental Management Degradation Levels
The level of environmental management degradation is assessed in this study based on three factors.Firstly, the presence or absence of clear boundaries that demarcate the forest area from other land uses or areas designated for agricultural purposes.Secondly, the presence or absence of extension and supervision activities conducted by forest area managers or the government to monitor and control the increasing trend of forest conversion for agricultural purposes.Supervision is crucial to prevent unauthorized forest clearing for agricultural purposes, while extension activities aim to provide guidance and knowledge to the local community.Thirdly, the presence or absence of soil conservation measures implemented by farmers to reduce the impact of land degradation resulting from agricultural activities in the forest area.The more comprehensive the environmental management in the area, the better the chances of controlling and mitigating the degradation [31].
The forest boundaries in the research location are marked with posts or markers established by forest area managers.However, many of these markers are difficult to find as they have been covered by overgrown bushes or have been damaged, making them hard to recognize.Although farmers are aware of the existence of clear boundaries, they often still conduct activities in these areas, driven by economic motivations and the lack of clear sanctions for violators.The findings in the field indicate that farmers IOP Publishing doi:10.1088/1755-1315/1315/1/0120499 tend to disregard these boundaries due to economic pressures.Some markers are even found in the middle of agricultural land owned by farmers.Most of the boundary markers cannot be found due to their deteriorated condition, hidden by vegetation growth.Based on field observations, only a few boundary markers can be identified, those that are still in good condition and easily accessible.The forest boundary markers found in the field are depicted in Figure 2. Two observed methods of soil conservation are the vegetative and mechanical approaches.The vegetative method involves employing plant cover to mitigate the impact of rainfall on the soil surface, thereby reducing surface runoff and erosion.Conversely, the mechanical method entails employing physical interventions to curtail surface runoff, erosion, and enhance land utilization [18].The most prevalent vegetative method observed in the field encompasses the cultivation of permanent vegetation, such as Acacia decurens trees, dense grass, alang-alang (Imperata cylindrica), Carica papaya trees, and chili plants, which also provide resources for the local farmers.The forms of vegetative soil conservation measures can be discerned in Figure 3. Another soil conservation practice involves the mechanical method, specifically soil management based on contour lines.The customary forms of mechanical soil conservation identified in the field are the construction of terraces and ridges.Ridges are soil mounds erected along or perpendicular to the contour lines, while terraces entail reducing slope length and retaining water to minimize the velocity and volume of surface runoff, as well as enhancing water infiltration into the soil [18].The manifestations of soil conservation measures observed in the research location will be illustrated in Figure 4 and Figure 5.The classification is categorized into three tiers, namely "Exemplary" when all environmental management criteria are fully met, "Intermediate" when two criteria are fulfilled, and "Inadequate" when only one or none of the criteria are met.The classification of environmental management will be displayed in Table 10.The worse the environmental management, the worse the environmental quality [32].This is because the community feels free to exploit the forest areas caused no clear boundaries, there are no improvement efforts, and the knowledge that the community gains about the environment.

Environmental Degradation Level
The total level of environmental degradation is analyzed by summing up the values of the four environmental degradation parameters.This total value is then compared with Table 6 to determine the specific environmental degradation level for each location.The classification of environmental degradation levels is established as a basis for formulating strategies to control environmental damage.The classification of environmental degradation levels for each observation point will be presented in Table 11.Based on Table 11, out of 9 observation locations, 2 observation points are categorized as having a moderately severe degradation level.The differentiation between these two observation points lies in the factors of land productivity and environmental management.Observation point 7 has lower productivity and environmental management classes compared to observation point 3.Meanwhile, in locations with a severe level of environmental degradation, the most influential factors are canopy cover and erosion.In addition to quantitative analysis, spatial analysis is also conducted to facilitate the identification of locations corresponding to their environmental degradation levels.The map depicting the environmental degradation levels in the Dieng Plateau Forest Area can be observed in Figure 6.The results of the spatial analysis reveal an area of approximately 50.1 hectares classified under the moderately severe environmental degradation level, while the area falling under the severe degradation level amounts to 17.1 hectares.
The analysis indicates that agricultural activities conducted within the forest area have significant impacts on severe environmental degradation.Unmonitored and inadequately evaluated agricultural practices can lead to more serious environmental issues.Additionally, the designated protective functions of the forest ecosystem will continue to diminish.The environmental effects of this level of degradation are often experienced by the local community, such as frequent landslides, decreased land productivity, and perceived changes in the region's temperature that are no longer cool in the Dieng Plateau area.This underscores the importance of controlling agricultural activities and implementing rehabilitation measures on damaged land.Vigilant supervision by relevant management authorities is imperative to prevent encroachment on the forested areas for agricultural purposes.The forested areas in Dieng Plateau play a critical role in maintaining the sustainability of the underlying landscape.Subsequently, land rehabilitation efforts are essential to be undertaken, which may include soil fertility improvement measures, prudent and precise utilization of agricultural chemicals, and planting of forest vegetation around agricultural lands to mitigate surface runoff.Realizing such strategies demands collaborative efforts from various stakeholders to ensure long-term effectiveness and sustainability.

Figure 1 .
Figure 1.Canopy cover conditons at each observation locations

Figure 2 .
Figure 2. Boundary markers of observation locations

Figure 6 .
Figure 6.Cartographic Representation of Environmental Degradation Classification Levels in Dieng Plateu Forest Area

Table 1 .
Location data collected

Table 2 .
Classification of Erosion Level

Table 3 .
Classification of Canopy Cover Levels

Table 4 .
Classification of Land Productivity

Table 5 .
Classification of Environmental Management

Table 6 .
Classification of Environmental Degradation Levels

Table 7 .
Classification of Erosion Level in Dieng Plateu Forest Area

Table 8 .
Classification of Canopy Cover Level in Dieng Plateu Forest Area

Table 9 .
Classification of Land Productivity in Dieng Plateu Forest Area

Table 10 .
Classification of Environmental Management in Dieng Plateu Forest Area

Table 10
indicates that the majority of locations exhibit intermediate levels of environmental management, where two criteria are fulfilled, namely the presence of area boundaries and soil conservation measures.Locations with intermediate levels of environmental management include observation point 1 in Karangtengah Village, observation point 4 in Bakal Village, observation point 6 in Sikunang Village, observation points 7 and 8 in Dieng Wetan Village, and observation point 9 in Dieng Kulon Village.On the other hand, observation point 3 in Bakal Village demonstrates exemplary environmental management, meeting all three criteria.However, observation point 5 in Sikunang Village exhibits inadequate environmental management, as it only meets one criterion, which is the presence of area boundaries.

Table 11 .
Environmental Degradation Level in Dieng Plateu Forest Area