Impact of climate change on cayenne pepper availability in Sleman District, Yogyakarta with dynamic system modelling

The availability of cayenne pepper in Sleman District is influenced by cayenne pepper production factors and demand of consumers. Climate change greatly affects the demand and supply of cayenne pepper. The value of Mean Absolute Percentage Error (MAPE) in the dynamic system model is 5.18%. The simulation of Cayenne Pepper availability scenarios in the Sleman District that was made scenarios by rule of the Government to increase of planting area by 20 ha per year. The other scenarios were changing a temperature increase 1 degree Celsius and increase of 2 degrees Celsius. The result of the research showed that first scenario made the supply of cayenne pepper decrease 15 %/year. The second scenario made the supply of cayenne pepper will be decrease up to 30 %/year in 2024-2030. It means that the temperature change can influence significantly with the supply of cayenne pepper in Sleman District. Moreover, the supply has not been fulfil to the very high demand by consumers of households, Industries and Horeca (Hotel, restaurant and catering) in this district.


Introduction
Indonesia is often referred to as an agricultural country, which is a country that prioritizes the agricultural sector as a source of livelihood and even as a support for development.The agricultural sector in Indonesia consists of sub-sectors of food crops, horticulture, animal husbandry and plantations.The horticulture sub-sector is the most potential commodity to be developed because it has high economic value compared to other commodities [1].One of them is cayenne pepper, because cayenne pepper is often used as a cooking ingredient and is much loved by the Indonesian people.
Cayenne pepper plants originate from Latin America which has the scientific name Capsicum frutescens L. Cayenne pepper in Indonesia can be cultivated almost throughout the region, with altitudes ranging from 0-1,000 m above sea level with temperatures of 26-28 ° C and rainfall of 1,000-3,000 mm / year [2].Based on this, the Directorate General of Horticulture stated that cayenne pepper commodities are among horticultural commodities that receive development priorities from the government.One form of cayenne pepper commodity development carried out by the government is by determining the location of cayenne pepper production centres [3].
Sleman District is one of the districts designated as the location of cayenne pepper production centres by the Indonesian government through the Decree of the Minister of Agriculture of the Republic of Indonesia Number 472 / Kpts / RC.040 / 6 of 2018 [4].Sleman District is designated as a national cayenne pepper centre due to agro-ecological compatibility, regional potential, institutions, and cayenne pepper market opportunities that are sufficient to guarantee in Sleman District.The need for cayenne pepper continues to increase along with the increase in population every year.However, cayenne pepper production in Indonesia has not been able to meet the national cayenne pepper needs.The average production of cayenne pepper has only reached 4.35 tons / ha, while the potential for cayenne pepper production can reach more than 10 tons / ha.One of the causes of the unmet needs of cayenne pepper is uncertain climate change.Climate change has caused a significant decrease in cayenne pepper production, this is because cayenne pepper plants are very sensitive to environmental changes [5].
Dynamic system modelling and simulation methods are proposed to simulate the impact of climate change on cayenne pepper availability.Simulation refers to a collection of methods and applications to show up the behaviour of an actual system.The simulation aims to assist in making the right decisions in a short time without having to spend a lot of money [6].The dynamical systems method is used to study problems based on a system point of view, where the elements of the system will interact with each other in a feedback relationship to produce a definite behaviour [7].System dynamics is a method of problem analysis where time is one of the important factors.
This study aims to model and analyse simulations of the impact of climate change on the availability of cayenne pepper in Sleman District and analyse policy recommendations for increasing planting area to fulfil the increasing demand and the availability of cayenne pepper in Sleman District due to the impact of climate change.

Methods
The method of conducting this research was used a dynamic system simulation.The dynamic systems method is an approach to studying problems from a systems point of view.Researchers will model, explain, and simulate data related to the conditions and phenomena of cayenne pepper availability in the Sleman District.The data required is in the form of five-year time series data from 2018 to 2022 regarding the availability of cayenne pepper and climate change.The data in this study was analyse using modelling and simulation as tools [8].Modelling and simulation in this study using Ventana Simulation (Vensim) software including the validation of data with the Mean Absolute Percentage Error (MAPE) approach.

Factors influencing the climate change impact model on the availability of cayenne pepper in Sleman District
The availability of cayenne pepper in Sleman District is influenced by two main factors, namely supply factors and demand factors.According to [9], supply and demand for goods are related to the interaction between buyers and sellers in the market which will determine the price level and the amount of goods traded in the market.The large supply of cayenne pepper in Sleman District is influenced by farmers' cayenne pepper production, land productivity, land area and the results of land development policies.This is in accordance with research by Liska, et al (2023), which states that cayenne pepper supply is strongly influenced by farmers' production sourced from land area and land productivity.The wider the increase in planting area, the more cayenne pepper production will increase [10].
The large demand for cayenne pepper to Sleman District is influenced by the demand for cayenne pepper from cayenne pepper traders to meet household needs, industrial needs, hotel, restaurant, and catering (Horeca) needed.This is in accordance with the research of [11], saying that the source of the large demand for cayenne pepper comes from household needs.The increasing population will affect the growing demand for cayenne pepper.In addition, the demand for cayenne pepper for industrial needs that use raw materials from cayenne pepper also makes an increase in demand for cayenne pepper.

Causal loop model of climate change impact on cayenne pepper availability in Sleman District
The causal loop dynamic system model is made based on factors that affect the availability of cayenne Pepper in Sleman District.The model is compiled by creating a loop causal diagram and a flow chart (Stock Flow Diagram) using Vensim PLE software.The MAPE value for the availability model is 5.18%.That is, the model created has an error rate of 5% or has an accuracy rate of 95%.According to [12], the level of accuracy in a forecasting method can be measured using the MAPE method.The lower the MAPE value, the more accurately the model can predict the possibilities that occur in the future.An accurate model can be used as a basis for making various decisions.Figure 1 shows a causal loop model of the impact of climate change on the availability of cayenne pepper in Sleman District.

Availability of cayenne pepper in Sleman District
A combination of existing sub-model simulations is then compiled to produce cayenne pepper availability model simulations.imbalance in the number of cayenne pepper es supplies with high demand for cayenne pepper [13].Figure 2 shows the results of a simulation of the impact of climate change on the availability of cayenne Pepper in Sleman District.

Policy recommendations carried out to stabilize cayenne pepper availability in Sleman District due to climate change
Policy recommendations to stabilize cayenne pepper availability in Sleman District due to the impact of climate change are carried out by developing various model scenarios.Model scenarios are created to improve the system to achieve the desired goals.The scenarios created will be formulated and reanalysed to see if the goals can be achieved.In this study, several scenarios were carried out including the scenario of increasing planting area by 20 Ha / Year, the scenario of a temperature increase of 1o Celsius reducing production by 15% and a temperature increase of 2 degrees Celsius reducing production by 30%.

Scenario of increasing planting area of 20 ha/year. The La Nina effects during 2020-2022 in
Indonesia make the production of cayenne pepper in Indonesia, and in Sleman district decrease from 5942.35 Ton /Year to 5211.95 Ton/year.It makes the availability of Cayenne pepper also decrease from 8143.27 Ton/year to 7865.27Ton/year.La Nina refers to the reduction of the temperature of the ocean surface across the central and eastern equatorial Pacific.This situation makes the high rainfall in Sleman district and make the cayenne pepper is in poor condition.In mid-year 2023 the condition of climate change to high temperature.El Nino could appear during the June 2023, which could affect agricultural production, also the cayenne pepper production in Sleman district.Extreme heat is already being felt with the hottest temperature in Sleman.Regarding this condition we simulated about the temperature change in two condition and the effect about production of cayenne pepper.The area of land cultivated by farmers greatly determines the size of production [14].The wider the land, the more production and vice versa, the narrower the land, the less production obtained.Inversely proportional to climate change which will reduce production results.Climate change affects 11% of agricultural land in developing countries, reducing agricultural production [15] and reducing Gross Domestic Product (GDP) by up to 16% [16].Therefore, it is necessary to make policies related to increasing land area [17] and yard land utilization to maximize cayenne pepper production in Sleman District.

Conclusion
Based on the results of research on the impact of climate change on the availability of cayenne pepper with dynamic system modelling in Sleman District, the following conclusions were obtained, Factors that influence the impact of climate change on the availability of cayenne pepper by modelling the dynamic system in Sleman District are supply and demand.Offerings come from cayenne pepper production, land area, productivity, and planting area development policies.Demand comes from household consumption, demand of HORECA and industry.The model of the impact of climate change on the availability of cayenne pepper with dynamic system modelling in Sleman District made in this study has been valid and can describe the real system.Value of Mean Absolute Percentage Error (MAPE) in the dynamic system model, the availability of cayenne pepper in the Sleman District <10%, which is 5.18%.The simulation of cayenne pepper availability scenarios in the Sleman District Market that was made was a scenario of increasing planting area of 20 ha per year, a temperature increase scenario of 1 degree Celsius, and a temperature increase scenario of 2 degrees Celsius.The supply of cayenne pepper in Sleman District has not been Fullfill the very high demand for cayenne pepper.However, an alternative scenario of increasing land area of 20 ha per year can decrease the product pepper in Sleman District by 15 % and 30 % annualy.It means the change of temperature can be influence siqnificanly to supply of Cayenne pepper in Sleman District.

Figure 1 .
Figure 1.Causal loop model of climate change impact on cayenne pepper availability

Figure 3 .
Figure 3.The Impact of increasing area planting to production of cayenne pepper Sleman District

Figure 5 .
Figure 5. Production cayenne pepper regarding temperature increase of 2 o Celsius.