30 years trend of peatland utilization in Riau Province

The peatland was a type of wetland ecosystem that was easily damaged. Damage to peatlands is generally caused by various types of unmanaged land use. The linear increase in the number and needs of the population has triggered the conversion of peatlands every year. This study reveals facts in an exploratory descriptive manner on the trend of peatland use in Riau Province from 1990-2020. The determination of the type of land use is based on changes in the condition of the peatland cover derived from Landsat images in 1990, 2000, 2010, and 2020. The analysis was carried out with a spatial approach with overlay techniques using geographic information system applications. The results of the analysis found that the area of forest cover on peatlands in Riau Province has experienced a very large decrease from 71.71% to 35.93%. The rate of decline in forest cover area to non-forest is around 59,311.65 ha/year. The use of peatlands for cultivation activities continued to increase over the previous 30 years, from 28.29% to 64.07%. The largest utilization came from plantation activities by 44.48%. This value is very large compared to other activities such as dry land agriculture, rice fields, open land, settlements, infrastructure, mining, swamps, scrub bushes, and transmigration. This shows that plantation activities have dominated the use of peatlands, even faster than other types of land cover. Plantation activities in Riau province are dominated by oil palm, both company plantations and smallholder plantations. The increase in the area of oil palm plantations was triggered by an increase in demand and a very high economic profit value compared to other types of agricultural commodities. So that the ability to manage plantations on sustainable peatlands is very important.


Introduction
The rate of population growth has triggered increases and shifts in social and economic needs in human life.Social needs include the completeness needed by humans to interact with each other as social beings.Economic needs include financial availability for the needs and desires of life [1].To fulfill this need, natural resources are utilized, including peatlands.
Peatland is a type of wetland ecosystem that is rich in organic matter formed from the accumulation of decaying organic matter over thousands of years.Peatlands have hydrological and ecological functions for life [2].The hydrological functions of peat include storing water reserves, preventing flooding during the rainy season and releasing water during the dry season, as well as preventing seawater intrusion into the mainland [3].While the ecological function of which is as a living habitat for various types of flora and fauna [4].The high hydrological and ecological functions cause peat ecosystems to be managed sustainably.Utilization of peatlands has provided increased economic and social value for the community [5].But on the other hand, it has had an impact on changes in peat conditions.Peatlands formed from the accumulation of organic matter have biophysical properties that are easily damaged.Damage to peatlands triggers the loss of peat's hydrological function as water control [6].Forest and land fires that occur every year indicate that peatland degradation has occurred.The impact of the fires has been felt in Indonesia and several surrounding countries.
The existence of peatlands in Indonesia is around ±24,667,804 Ha, which consists of 865 Peat Hydrological Units.Peat Hydrological Units are spread across various provinces in Indonesia.Riau Province has 59 Peat Hydrological Units with a total area of ±4.9 million hectares [7].Peatlands in Riau Province are spread over 11 Regencies/Cities in Riau Province.Only 1 district does not have peatlands, namely Kuantan Singingi District.The existence of peat ecosystems in Riau Province reaches 64% of the total land area.Thus, the peat ecosystem problems faced by Riau Province can reflect the condition of peat ecosystems nationally in Indonesia.
In the last few decades, conversion of peatlands has been very intensive in Indonesia, especially in the province of Riau.Conversion of peatlands can disrupt the balance of ecosystems [8].The complexity of the problems that occur in peat ecosystems need to be managed comprehensively.Efforts to protect and manage peat ecosystems have become a national to global commitment.This is evidenced by the formation of a special institution by the central government in Indonesia to handle efforts to restore peat ecosystems, namely the Peat Ecosystem Restoration Agency in 2016.However, land use conversion is expected to continue.Therefore, the conservation of peat swamp forests with all their wealth must be followed up seriously.
Efforts to control and manage peatlands need to start with a good understanding of the root causes of the use of peatlands.It is necessary to know the complexity of utilizing peatlands for subsistence needs.This makes it easier to formulate recommendations and efforts to manage peatlands in a sustainable manner.In order to understand more comprehensively the conditions and problems of the peat ecosystem, an analysis of peatland utilization in Riau Province was carried out.This is needed to see which utilization pattern is a priority to control in the long term in peatlands.

Method
This study reveals facts in a descriptive exploratory way about the trend of peatland use in Riau Province in 1990-2020.Determination of the type of land use is based on changes in the condition of peatland cover using a spatial approach.The classification of land cover types is interpreted based on the criteria set by the Indonesian Ministry of Environment.
The scope of the study area is peatlands in Riau Province which are spread over 11 districts, including: Bengkalis, Dumai, Indragiri Hilir, Indragiri Hulu, Kampar, Pelalawan, Rokan Hilir, Siak, Meranti Islands and Pekanbaru City (figure 1).Data collection was carried out by reviewing the literature from various authorized and relevant data trustees.The data collected consists of peatland distribution from the Ministry of Environment and Forestry in 2017, land cover conditions from landsat imagery in 1990 and 2020.The types of landsat imagery used consist of Landsat 5 (TM) for land cover on 1990 and Landsat 8 (OLI) for land cover on 2020.Landsat imagery data comes from USGS.The data used has gone through a data screening process to ensure spatial data accuracy.
Data analysis was carried out using a spatial-based exploratory descriptive approach based on data that had been collected both primary and secondary data [9].Spatial data analysis was carried out to obtain spatial distribution of conditions and extent.The spatial analysis technique used is the land cover interpretation technique and the overlay technique on the spatial data that is owned.Interpretation of land cover images is carried out using image processing software and geographic information systems.The interpretation uses 8 elements consisting of: (1) Color hue, namely the gradation of relative brightness and color of objects in the image.(2) Texture, is the difference in the degree of roughness of the object; (3) Pattern, is the difference in the spatial arrangement of objects visually, (4) Shape, is the general appearance, (5) Shadows that help identify objects, (6) Size is a function of the scale of the object's relative size to other objects, (7) Association used when several objects are closely adjacent and (8) Site, describes the position of the earth's surface from the observed image in relation to the surrounding features [10].Interpretation and classification results based on landsat data are validated by carrying out an accuracy assessment.The accuracy assessment technique is carried out by taking random sampling points that represent each type of land cover [11].The results of field observations at sample points serve as a basis for calculating the error matrix with the confusion matrix technique.The validation results met the standards with the percentage value of the land cover accuracy test being > 80% in the very good category.
The data analyzed is data on the distribution of peat hydrological units on land cover conditions.To see the change in land use function, the peatland spatial data is analyzed spatially for changes in land cover from 1990 to 2020 with a Geographic Information System.Land cover data was obtained based on the interpretation of landsat imagery data and aerial photographs.The next data visualization interpretation and intersection between the spatial data that has been collected.

Land cover on peatlands in Riau Province
The results of the analysis show that the area of peatlands in Riau Province ranges from ±4,972,355.09 ha.The peatlands are scattered along the coast of the mainland.The results of an analysis of the interpretation of land cover on peatlands in Riau Province found 21 types of land cover, namely: Primary Dryland Forest, Secondary Dryland Forest, Primary Mangrove Forest, Secondary Mangrove Forest, Plantation Forest, Open Land, Plantation, Settlements/Built-up Land , Airports/ Ports, Mining, Mixed Dryland Agriculture, Dryland Agriculture, Swamps, Paddy Fields, Shrubs, Swamp Shrubs, Ponds, Transmigration, and Water Bodies.Each type of land cover has a different area and has undergone extensive changes.The results of land cover analysis on peatlands in Riau Province are presented in table 1.
Table 1.Types of land cover in peatlands of Riau Province in 1990 and 2020.The condition of land cover on peatlands in Riau Province in 2020 has changed compared to 1990.In 1990, 20 types of land cover were found, namely Primary Dryland Forest, Secondary Dryland Forest, Primary Mangrove Forest, Mangrove Forest.Secondary, Plantation Forest, Open Land, Plantation, Settlements/ Built-up Land, Airports/ Ports, Mining, Mixed Dryland Agriculture, Dryland Agriculture, Swamps, Paddy Fields, Shrubs, Swamp Shrubs, Ponds, and Water Bodies.The type of land cover that was not found was transmigration.Where in 1990 the transmigration program did not yet exist on peatlands in Riau Province.
In 2020 there will also be 20 types of land cover found.The type of land cover that was not found was Primary Dryland Forest, while transmigration was found in 2020.So the types of land cover found were Secondary Dryland Forest, Primary Mangrove Forest, Secondary Mangrove Forest, Plantation Forest, Open Land, Plantation, Settlements/ Built-up Land, Airports/ Ports, Mining, Mixed Dryland Agriculture, Dryland Agriculture, Swamps, Paddy Fields, Shrubs, Swamp Shrubs, Ponds, Transmigration, and Water Bodies.Loss of primary dryland forest because it has changed to another type of land cover.The loss of primary forest indicates a change in function in peatlands [12].
Based on the wide distribution of land cover types, it is known that most of the peatland cover in Riau Province in 1990 was still classified as forest.The area of forested land cover is 3,565,761.67ha or 71.71%, while the land that is not forested is only 1,406,593.42ha or 28.29%.The most extensive type of land cover is Secondary Swamp Forest with an area of 3,120,146.91ha or 62.75 ha.However, in 2020, the area covered by forested land is only 1,786,412.14ha, or 35.93%, while land that is not forested reaches 3,185,942.95ha, or 64.07%.This proves that there has been a conversion of forest functions to non-forested peatlands in Riau Province.The conversion of forest functions to non-forests can cause damage to peatlands.
The trend of increasing peat damage due to land conversion has become an important concern in Indonesia.Policies on the protection and management of peatland ecosystems in Indonesia began to be carried out massively by issuing Government Regulation Number 71 of 2014 in conjunction with Government Regulation Number 57 of 2016.This policy is a corrective action to prevent damage and preserve peat ecosystems.So that peat can be used sustainably with the desired quality level.These policies, among other things, regulate the determination of peat ecosystem protection function areas and peat ecosystem cultivation function areas.The regulation aims to protect and maintain the hydrological and ecological functions of peat ecosystems, as well as regulate environmentally friendly peat ecosystem cultivation activities.Implementation of peat ecosystem protection and management policies is also carried out at the regional level, including Riau Province.Where currently the Riau Province is compiling a Peat Ecosystem Management and Protection Plan Document.In the last 30 years, forest conversion on peatlands from 1990 to 2020 was 35.78% or 1.19% per year.If the rate of conversion of forest functions is still linear without any effort to control it, then the existence of forests on peatlands will be threatened with extinction.This can be seen from the large proportion of peatland that is still forested in 2020 is plantation forest.Plantation forest is a forest area used for industrial activities with certain types of forest plants [13].Meanwhile, primary and secondary forest types have decreased to 21.99%.
The conversion of peat lands has caused the loss of the ecological and hydrological functions of peat.The impacts that occur are (a) loss of diversity of vegetation and animals, (b) loss of water content in peat, (c) subsidence, (d) land fires, and (e) loss of carbon stocks from peat.Clearing land from forests to non-forests such as plantations will eliminate the diversity of vegetation that turns into monocultures.The land clearing that has been carried out has reduced the amount of vegetation as a producer in the life chain of the biological structure that makes up the ecosystem.Extinction of vegetation will put pressure on various types of fauna as consumers on it.This triggers the extinction of fauna that are unable to adapt to changes in their environment.In addition, the loss of vegetation also affects the constituent and water-holding structures in peatlands [14].
Utilization of peatlands is usually followed by the construction of a drainage network so that there is a change in the hydrological system of the natural water table in peatlands.Making drainage generally aims to lower the groundwater level, so that land can be used for certain purposes.Making drainage that is not controlled and is not accompanied by proper water regulation and management, can trigger the release of moisture content in peat.The condition of water content determines the biophysical characteristics of peat.Loss of moisture causes peat to become dry and flammable.Peat which is formed from various organic materials will be easily damaged and trigger further damage such as loss of water control function, increased subsidence, drought and fires in the dry season and floods in the wet season [15].
The impact of peatland fires always occurs every year in Riau Province, especially during the dry (dry) season.The area of former peatland fires in Riau Province during 2015-2020 reached 284,474.16ha (BRGM 2021).In addition to fires, the impact of peat damage also occurred in Riau Province.Based on data from the Ministry of Environment and Forestry (2021) it is known that most of the peat in Riau Province has experienced damage in the categories of light damage, moderate damage, severe damage and very heavy damage.The accumulated impact of peat damage will cause permanent damage to peatland function and will be difficult to reverse.Efforts to restore peatlands will require a large amount of money and take a long time [16].So that the existence of forests on peatlands is very important to maintain.

Trend of change in of peatland utilization in 1990 -2020
Changes in the use of peatlands can be seen based on the condition of the land cover.Land cover conditions provide an overview of the conditions of land use activities in general.Comparison of the condition of land cover on peatlands in Riau Province between 1990 and 2020 is presented in figure 3. The results of the analysis show that the condition of land cover from 1990 to 2020 varies greatly.There are types of land cover that are increasing but there are also those that are decreasing.Plantation Forests, Open Land, Plantations/Gardens, Settlements/Built-Up Land, Airports/Harbors, Mining, Dryland Agriculture Mixed with Shrubs, Swamps, Swamp Thickets, Ponds and Transmigration.These conditions indicate that all types of forested land cover have decreased except for plantation forests.The increase occurred on non-forest land.This shows that the conversion of functions to peatlands occurs when the forest becomes non-forested.The largest decrease in land cover was secondary forest, while the largest increase in land cover was plantations.This value indicates the conversion of forest and plantation functions.Although not all of the secondary swamp forest has decreased due to plantation activities.Overall, it indicates that changes in peatland use are dominated by plantation activities [17].The increase in plantations also comes from other types of land cover.
The conversion of functions to peatlands in the tropics is generally caused by land use by the community to make it more productive, including agriculture and plantations [18].The types of plantations in Riau Province are dominated by oil palm plantation activities consisting of large plantations (companies) and smallholder plantations.The clearing of peatlands for large plantations is determined by granting concession permits to certain companies.While smallholder plantations develop due to the knowledge and needs of the community.Currently, the area of smallholder plantations is larger than that of corporate plantations.However, the productivity level of oil palm is lower.So that the community continues to expand land clearing.Efforts to stop the opening of new oil palm land for companies have been carried out, by establishing a policy of stopping the issuance of new permits.However, land clearing activities in smallholder plantations are still difficult to control.This is due to the clearing of oil palm land by the people aiming to support the fulfillment of the living needs of the surrounding community.Land use for plantations in Riau Province has provided benefits to increase economic value for the community [19].The direct economic contribution comes from smallholder plantation activities.

Patterns of changes in of peatland utilization
To find out changes in the use of peatlands in Riau Province, an identification and analysis of the pattern of change is carried out.The analysis was carried out based on the type of land cover change before and after utilization.Before utilization was seen based on land cover in 1990, while after utilization it was seen based on land cover in 2020.The results of the analysis of patterns of changes in peatland use in Riau Province are presented in table 2.
Changes in the use of peatlands that have occurred in Riau Province are very diverse.Change does not only occur from forest to non-forest.However, changes were also found from non-forest to other non-forest, non-forest to forest and forest to other forest.The type of land that experienced the most variation of change was secondary forest with 19 types of utilization.The secondary forest has undergone changes into primary forest, plantation forest, and non-forest.While the types of land use activities that cause the most changes in peatland cover are plantation activities, open land and swamp shrubs, with 18 types of land cover each.
The diversity of land use patterns is influenced by the activities that occur on it.Although with a very small amount, peatlands that change from secondary forest to primary forest occur due to natural succession.Succession is the ability of natural land recovery [20].Land that is not disturbed for a long time will gradually appear pioneer vegetation and trigger the emergence of other vegetation.The presence of various types of vegetation that make up the ecosystem will again support the improvement of the biophysical function of the environment.So that the land can again function as a habitat for various types of ecosystems [21].This will trigger the presence of various types of fauna.The presence of fauna indicates natural succession.Changes from forest utilization to non-forest use can be grouped into non-productive and nonproductive forest utilization.Utilization of non-productive forests is carried out by the community in the form of plantation businesses, settlements/built-up land, airports/harbors, mining, mixed dryland agriculture, dryland agriculture, paddy fields, ponds, and transmigration.This utilization develops along with the need for land clearing by the community and the rate of population growth [22].In addition, uncontrolled changes in peatland cover are caused by more and more actors at the site level having an interest in land accompanied by unclear land ownership [23].Changes in land use to non-productive non-forest include open land, swamps, shrubs, and swamp scrub.These changes occur generally due to the absence of land use in the long term by the community [24].Plantation activities have become one of the land use activities that dominate changes in the use of peatlands, both from forest and other nonforest areas.Even faster than the expansion of residential areas.So that the priority of efforts to protect and manage peatlands is largely determined by the success of sustainable plantation management.

Conclusion
In the last 30 years, peatlands in Riau Province have been utilized for various functions.The area of forest cover on peatlands in Riau Province experienced a very large decrease from 71.71% to 35.93%.The rate of decline in forest cover area from 1990 to 2020 is around 59,311.65 ha/year or 1.19% per year.The decline in forested land cover is inversely proportional to other non-forest cultivation activities.The area of non-forest land cover showed a large increase from 1990 to 2020, from 28.29% to 64.07%.
Plantation activities have become one of the land use activities that dominate changes in the use of peatlands, both from forest and other non-forest areas.The value of the increase in plantation land cover is very large when compared to other cultivation activities such as dry land farming, paddy fields, open land, settlements, infrastructure, mining, swamps, shrubs, and transmigration.This shows that plantation activities have dominated the use of peatlands, even faster than the increase in the area of settlements.So that the priority of efforts to protect and manage peatlands is largely determined by the success of sustainable plantation management.

Figure 1 .
Figure 1.Map of study locations on peatlands in Riau Province.

Figure 2 .
Figure 2. Maps of land cover on peatlands in 1990 and 2020.

Figure 3 .
Figure 3. Types of peatland utilization changes in 1990 and 2020.

of Peatland Utilization Changes in 1990 and 2020 1990 2020
The types of land cover that decreased were Primary Swamp Forest, Secondary Swamp Forest, Primary Dryland Forest, Secondary Dryland Forest, Primary Mangrove Forest, Secondary Mangrove Forest, Dryland Agriculture, Rice fields, shrubs and bodies of water.While the types of land cover that increased were

Table 2 .
Pattern of changes in peatland utilization in Riau Province in 1990-2020.