The abundance of soil mesofauna and macrofauna at different altitudes in Mount Gede Pangrango National Park

Soil fauna is important in the breakdown of organic matter for soil fertility. Various environmental factors, including edaphic, climatic factors, and overlying vegetation, influence the abundance of soil fauna. This study aims to analyze the abundance of soil fauna at different altitudes and the influence of the environment on it. The research was conducted at three different altitudes, namely 1,550 m asl, 1,650 m asl, 1,750 m asl, and in open land (1,200 m asl). The LSD test results showed that the abundance of soil fauna significantly differed between the altitude of 1,650 m asl and open land. In comparison, the abundance of soil fauna at the 1,550 m asl and 1,750 m asl was not significantly different at the 95% confidence interval. The results of the correlation analysis show that the climatic factors of light intensity and air temperature are negatively correlated. In contrast, air humidity positively correlates with the abundance of soil fauna. Factors strongly correlated with abundance are litter wet weight and soil pH.


Introduction
Indonesia is a tropical country with diverse soil types and abundant biological resources.Soil comes from the weathering of rocks mixed with the remains of organic matter, water, air, and organisms (vegetation or animals) that live on it or in it [1].Soil has different properties and characteristics, so it also affects the biota that lives above and in it.Forest soil becomes a storage place for mineral elements as well as a place for humus formation which will also affect the composition and structure of the forest vegetation formed.Soil fertility is influenced by soil properties, both physical and chemical properties [2].
Physical properties of soil are soil properties which include texture, structure, volume weight, permeability, and porosity which also affect the availability of water in the soil matrix, affect the reactive properties of soil colloids, regulate air circulation in the soil, affect root growth and their ability to absorb water and nutrients, and affect plant growth and development [3].Soil chemical properties are soil properties that show ionic activity that cannot be seen directly but can be tested using chemicals.Chemical properties are one of the indicators to determine the level of land capability and recommendations in fertilization for plant nutrients [4].
Abiotic and biotic conditions of the soil also affect the existence of living things in it, especially soil fauna.Soil fauna is the inhabitant of the soil environment that contributes energy from an ecosystem because it can decompose plant and animal matter that has died [5].Soil fauna can be grouped into three groups based on body size, namely (1) microfauna (20-200 microns), such as Protozoa and Nematodes, (2) mesofauna (200 microns-1 cm), such as Acarina and Collembola, and (3) macrofauna (>1 cm) such 1315 (2024) 012028 IOP Publishing doi:10.1088/1755-1315/1315/1/012028 2 as Insecta and Crustacea [6].The existence, abundance, and diversity of soil fauna depend on the land's type, use, and management [7].Macrofauna, mesofauna, and microfauna are important in improving physical, chemical, and biological, and soil properties and increasing soil fertility [5].
According to the database from [8], Mount Gede Pangrango National Park (TNGGP) has an area of ± 21,975 Ha and is located in three regencies, namely Cianjur, Sukabumi, and Bogor.Mount Gede and Pangrango forest areas as national park areas are based on the Decree of the Minister of Agriculture Number 736/Mentan/X/1982 and the Decree of the Minister of Forestry Number 174/Kpts-II/2003 that the forests of Mount Gede and Pangrango are the original landscape of intact mountain tropical rainforests, with high biodiversity and are important habitats for various protected plant and wildlife species such as leopards (Panthera pardus), surili (Presbytis comata), Javanese owa (Hylobates moloch), and various species of birds.According to its height, the TNGGP area is divided into 3: lower mountain forest, upper mountain forest, and subalpine.
The lower mountain forest area (1,000-1,500 m asl) is characterized by high species diversity with three clear canopy strata, which are characterized by the presence of tall trees such as Altingia exelsa and Castanopsis argentea, small/medium trees (10-20 m high) such as Antidesma tetandrum and Litsea sp., and shrub trees (3-5 m high) such as Ardisia fuliginosa and Dichora febrifuga.The upper mountain forest area (1,500-2,400 m asl) is characterized by species diversity that is starting to decline, which is characterized by at least understory plant species, and generally, the trunks of trees that grow in this ecosystem are overgrown with moss.The dominant species in the lower mountain forests, such as Schima wallichii and Castanopsis javanica, are scattered and commonly found in this forest.In addition, there is also a type of Dacrycarpus imbricatus with needle leaves.The sub-alpine area (2,400-3,019 m asl) is characterized by medium and short canopy strata arranged by dwarf tree species and undergrowth that are not too dense [8].
The height of the place will affect the ecosystem's life, without exception, soil fauna.The microclimate influences soil fauna in abundance, namely soil temperature and moisture.Air temperature will drop by 0.6 o C every 100 meters increase in altitude [9].Data on the abundance of fauna at different altitudes in TNGGP are not yet available, so research is needed to analyze the effect of height differences on the abundance of soil fauna.This study examined the abundance of mesofauna and soil macrofauna at an altitude of 1,550-1,750 m above sea level in the TNGGP Area.This research also examined the effect of the environment on the abundance of mesofauna and soil macrofauna in Cibodas Resort, Mount Gede Pangrango National Park at different altitudes (1,550 m asl, 1,650 m asl, and 1,750 m asl) and open land (1,200 m asl).

Location and Time of Research
The study was carried out in January-March 2023 at Cibodas Resort, Mount Gede Pangrango National Park, precisely at an altitude of 1,550 m asl, 1,650 m asl, 1,750 m asl, and open land at an altitude of 1,200 m asl as a control location.The open land that became the place of research was the Mandalawangi Campground, with conditions without vegetation and compacted soil because it was often stepped on.Mesofauna, macrofauna, and soil samples from each plot were analyzed at the Forest Entomology Laboratory and Forest Influence Laboratory, Department of Silviculture, Faculty of Forestry and Environment, Bogor Agricultural University.

Research Plot Establishment
Data collection is initiated by making research plots.The placement of the research plot was carried out using the purposive sampling method [10].The research plot was built at a location with sufficient litter as a marker of the presence of soil fauna.The research plot is marked with a Global Positioning System (GPS) for mapping purposes.The research plot measured 20 m × 20 m with several research subplots.3 subplots were established with a size of 1 m × 1 m.Soil fauna and soil samples were taken on 1 m × 1 m subplots with 3 subplots with purposive sampling method [11]

Soil Sampling
Soil sampling is carried out by 2 methods: disturbed soil sampling and undisturbed soil sampling.Disturbed soil samples were taken at 4 separate points in a 1 m × 1 m subplot with a depth of 5 cm from the soil surface.Then soil samples from the 4 points were composited.Undisturbed soil samples were taken from one ring of soil samples in each 1 m × 1 m subplot.Disturbed soil samples are used for soil chemical analysis: pH, CEC (cation exchange capacity), and C-organic.Undisturbed soil samples analyze soil physical properties in bulk density and soil porosity.This follows the research of [12], which suggests that disturbed soil samples are used to calculate soil C-organic content.In contrast, undisturbed soil samples calculate bulk density and soil porosity.All samples were analyzed at the Forest Influence Laboratory, Department of Silviculture, Faculty of Forestry and Environment, Bogor Agricultural University.

Soil Fauna Extraction
Mesofauna and soil macrofauna were extracted using the hand sorting method and the Barlese-Tullgren-Pour funnel method [13,14].Hand sorting is carried out by capturing soil fauna found on the surface and in the soil.The collected organisms are then put into plastic bags filled with alcohol to be identified in the laboratory.The method of extracting fauna using the Barlese funnel is carried out by pouring soil samples and litter into the Barlese pour funnel.The fauna is made down into a glass containing 70% alcohol under the funnel using a heat source in the form of a yellow 5 W light bulb.A 70% alcohol solution serves to preserve soil fauna [15].Extraction of soil fauna with a Barlese funnel is carried out once every 3 days [16].

Soil Fauna Identification
Samples of soil fauna that have been extracted are then identified using stereo and optilab microscopes at the Forest Entomology Laboratory, Department of Silviculture, Faculty of Forestry and Environment, Bogor Agricultural University.Identification was carried out in the identification keys' book [17], [18], and [19].

Measurement of Environmental Parameters
2.6.1.Soil pH.Soil pH assessment is carried out using a pH meter.The soil sample is put in a film bottle, then add aquades in a ratio of 1:3 and shaken for 5 minutes.The next step is to insert a pH meter into the solution and wait for three minutes until the pH value can be read [15,20].[21], 100 g of soil samples weighed were then placed into an airtight plastic jar along with two film bottles containing 5 ml of distilled water and 10 ml of 0.2 N KOH and then incubated for three days.After incubation, the film bottle containing KOH was removed from the plastic jar.Two drops of phenolphthalein indicator were added until it turned pink, then titrated back with HCl solution using a digital burette until it became colorless.The solution was added with two drops of methyl orange indicator to make the solution yellow.The solution is titrated again with HCl solution until it is pink.The number indicated on the digital burette is recorded, and the amount of CO2 is calculated using the equation [22]: Measurements of bulk density and porosity were carried out using undisturbed soil samples.According to [23], bulk density and porosity were calculated using the ring method.This parameter is calculated using the following formula: Bulk density (g/cm 3 ) = ) × 100% BK = dry weight without ring (g) Vt = ring volume (cm 3 ) BI = weight of soil content/bulk density (g/cm 3 ) BP = weight of soil particles (cm 3 )

Soil Cation Exchange Capacity (CEC).
Soil CEC measurement is carried out by titration method at the Laboratory of the Department of Soil Science and Land Resources, Faculty of Agriculture, Bogor Agricultural University.
2.6.6.C-organic.Ash content is measured by ashing at a 550-600 O C temperature.The process causes organic matter to become CO2 and metal to become its metal oxide.The weight of the missing organic matter can be converted to C-organic levels after multiplying by a factor of 0.58.The C-organic measurement formula based on [24] is as follows: Ash content (%) = = organic matter to the carbon conversion factor 2.6.7.Soil temperature.Soil temperature is measured using a digital thermometer by plugging the thermometer into the ground in a subplot of 1 m × 1 m.Measurement of soil temperature is carried out every 30 minutes for 3 repetitions.

Measurement of climatic data.
Climatic data was measured on a subplot of 1 m × 1 m.The climatic parameters measured are light intensity, air temperature, and air humidity.Light intensity was measured using a lux meter and carried out in 4 different directions in each subplot.Air temperature and air humidity were measured using a thermohygrometer for 3 repetitions every 30 minutes in each subplot.

Analysis of Soil Fauna Data
2.7.1.Soil fauna abundance.Abundance describes the large number of individuals occupying a particular location.Therefore, the abundance value of mesofauna and soil macrofauna used in this study refers to the number of individuals of a species found in a particular location [25].

Species diversity index (H').
The species diversity index (H') is calculated by applying the Shannon-Wiener index to determine the level of species diversity in an ecosystem [26].
Pi follows the following formula:

H' = Shannon-Wiener species diversity index ni = number of individuals per type N = number of all individual types
The calculated H' values were then categorized according to Shannon-Wiener species diversity indicators (Table 1).The calculated Dmg values are then categorized according to [27] type species richness indicator (Table 2).
Table 2. Index classification to type richness (Dmg) Value Category Dmg < 3,5 Low 3,5 < Dmg > 5 Medium Dmg > 5 High Source: [27] 2.7.4. Magguran species evenness index (E).The Magguran species evenness index (E) describes the degree of distribution of one type against another (dominant or non-dominant) in an ecosystem.This parameter is determined using the following formula [28]: The calculated E value is then categorized according to the indicator of the evenness of the Magguran type [28].An E value close to 0 indicates that a type dominates at the study site, while an E value close to 1 indicates that the types are evenly distributed.

LSD test.
LSD test is a test carried out to determine whether or not there are differences between one treatment individual and another treatment individual [29].LSD test with a 95% confidence interval was conducted using R-studio software to determine whether the difference in abundance at each study site had a real difference or not.A test was conducted to discover more deeply the differences between variable variables affecting response variables [30].
point of distribution t for real α% and the degree free of the error.r = number of repetitions.

Pearson Correlation Analysis.
Pearson correlation is one of the correlation testing methods used to determine the degree of closeness of the relationship between two variables that have intervals or ratios, are normally distributed, and return the value of the correlation coefficient with a range of values between -1, 0, and 1 [31].The Pearson correlation test was conducted to determine the correlation between the abundance of soil fauna with climatic factors (air temperature, air humidity, and light intensity) and edaphic factors (soil temperature, bulk density, porosity, litter wet weight, pH, respiration, C-organic, and CEC).The formula for determining the Pearson correlation is as follows: The correlation coefficient r(xy) can be positive (+) or negative (-) and is in the range of −1 and 1.If r(xy) is close to −1 or 1, then the correlation relationship between the two variables is stronger.If the value is close to 0, then the correlation between the two variables is weaker.

The Influence of Altitude on The Abundance of Soil Fauna
The abundance of soil fauna showed different values at four sites with different elevations.The results showed that the abundance of fauna at an altitude of 1,550 m above sea level was not significantly different from the abundance of fauna at an altitude of 1,750 m above sea level (Table 3).Meanwhile, the abundance of fauna at an altitude of 1,650 m above sea level and on open land had significantly different results at the test level of 5%.The highest average fauna abundance was found at an altitude of 1,650 m above sea level, with an abundance of 29 individuals/m 2 .In comparison, the lowest average fauna abundance was found on open land (1,200 m asl) with an abundance of 4 individuals/m 2 .Factors affecting the abundance of soil fauna at an altitude are differences in edaphic and climatic conditions and the vegetation growing on them.4 b ± 3.61 *The numbers in the same row followed by the same letter show no real difference at the test level of 5%, the number followed by the letter is the average value The composition of the soil fauna found at each altitude also showed different results.Based on the study's results, the entire soil fauna found was as many as 16 orders (Table 4).The highest number of orders is found in the 1,550 m above sea level and 1,650 m above sea level plots which are both found in 11 orders, while the smallest number of orders is found in open land with 3 orders of land fauna.The number of orders found tends to decrease with increasing altitude.The total number of families found in this study was 37 families.The highest number of families found in plots at an altitude of 1,550 m above sea level was 22 families, while the smallest number of families was found in plots in open land (1,200 m asl), that is, as many as 3 families.The number of families found tends to decrease with increasing altitude.The number of individuals of land fauna found in this study was 260 individuals.The largest number of individuals found at an altitude of 1,650 m above sea level is 97.In contrast, the smallest number of individuals is found on open land, as many as 11 individuals.
Based on its size, the soil fauna found in the study was dominated by mesofauna.The total number of mesofauna found was 198, while the total macrofauna found was 62. Soil macrofauna plays a role in the decomposition of organic matter by breaking down dead vegetable substances into simpler materials that are removed in the form of manure called humus material [32].Meanwhile, the mesofauna plays a role in improving soil conditions through decreasing bulk density, mixing soil particles, and decomposition of residual organic matter [33,34].The most commonly found orders include Hymenoptera, Collembola, Haplotaxida, Geophilomorpha, and Blattodea.The family Formicidae is a family that can be found throughout the study plot.Formicidae found include mesofauna.Based on observations, the morphology of Formicidae found has the characteristics of a head facing down, no wings, and a pair of antennae (Figure 2).The family Formicidae is found in various varieties: large black ants, small black ants, and small red ants.Ants can be found in every type of ecosystem except the polar regions.Ants can account for more than 30% of the total insect biomass in tropical ecosystems [19].Ants have various roles in ecosystems, including ecological functions, such as loosening the soil, spreading grain, and preying on other insects to help pest control [35,36].
Ants can be environmental bioindicators by responding to vegetation and soil in their living habitat.Several factors, such as soil pH, humidity, and light intensity influence the presence of ants in a habitat.The distribution of ant species and their abundance are also influenced by several other factors, such as soil texture, food type, competition for food, and area [36].
The Order of Collembola is the order with the largest population found during the study.The order of Collembola is found at every height of the study site except in open ground.The order is not found in open ground because its regeneration requires canopy shade [37,38].The order Collembola includes the mesofauna because it measures about <4 mm.Esophageal organisms, including Collembola, can indicate soil quality because it is a soil fauna that is more representative and sensitive to changes in soil physical, biological, and chemical [34].Soil mesofauna live in groups and have a higher level of activity [32].
The families found from the order Collembola are Isotomidae and Onychiuridae.Both families are most commonly found at an altitude of 1,650 m above sea level.The family Isotomidae has a higher abundance than the family Onychiuridae.The family Isotomidae found has a characteristic shape of long-round, body colour tends to be white to grey, and has slightly shiny furcula (Figure 3A).According to [39], Isotomidae has osmopo with four distinguishable segments.This family also usually lives in litter and the soil.Meanwhile, the Onychiuridae family was found to have a long-round shape, slender, white body, and lack of eyes and furcula (Figure 3B).This family lives in litter and the soil.The family Onychiuridae belongs to cosmopolitan species with a wide distribution [39].The order Haplotaxida (Family Lumbricidae) was found at all study sites.Lumbricidae are most commonly found in elevation plots of 1,550 m asl.Family Lumbricidae found include macrofauna and have the characteristics of an elongated cylindrical body, bilaterally symmetrical, segmented, and dark brown.Earthworms play an important role in the ecosystem, including in the overhaul of organic matter, soil flipping, and as a bioindicator of soil fertility [40].
The order Geophilomorpha (Family Geophilidae) is found at almost every elevation of the study site except in open land.The family Geophilidae is most commonly found in elevation plots of 1,650 m asl.The family Geophilidae found has morphological characteristics of elongated and threaded bodies, white in colour, antennae, and brown heads.The family Geophilidae includes macrofauna.The habitat of this family is usually in the ground, in ruins, or rotten wood [19].The value of diversity can define the ability of soil fauna to face disturbances to organism activities and environmental changes in an ecosystem [5].Diversity analysis using the Shannon-Wiener index shows that soil fauna at an altitude of 1,550 m above sea level has the highest diversity value of H'=2.41, which is included in the medium category (Table 5).The lowest soil fauna diversity is found in fauna in open land with an H' value of 1.04, which is included in the low category.The richness of soil fauna species based on research results tends to decrease along with the increasing height and openness of the research site.Soil fauna at an altitude of 1,550 m above sea level also has the highest species richness index (Dmg) compared to other study locations, which is 4.85 (medium category) (Table 5).The richness of soil fauna species at the study site tends to be low, except for species richness at an altitude of 1,550 m above sea level.The lowest soil fauna species enrichment index is found in open land (1,200 m asl), which is 0.83.The index of diversity of soil fauna species and species richness tends to decrease as the height of the study site increases.This follows the research of [42], which states that the richness and diversity of land fauna decreases with increasing altitude.
The evenness of soil fauna types based on the results showed values that varied between research locations.The highest evenness index of soil fauna species is found in fauna at an altitude of 1,550 m above sea level, with a value of E = 0.77 (Table 5).In comparison, the lowest value is found in fauna at an altitude of 1,650 m above sea level, with a value E=0.38.A low species evenness value at an altitude of 1,650 m above sea level indicates the presence of dominant species on the plot.The dominating species on the plot belong to the order Collembola.

Relationship Between Soil Fauna Abundance and Climatic Factors
The difference in altitude of the place also affects climatic conditions such as light intensity, air temperature, and air humidity.The difference in climatic conditions also affects the abundance of soil fauna living at the location.Based on the study's results, light intensity negatively correlates with the abundance of soil fauna (Table 6).Changes in light intensity in the study plot have a moderate correlation to the abundance of soil fauna, where the higher the light intensity, the lower the abundance of soil fauna.This is due to the absence of vegetation that blocks direct light from hitting the land surface and impacts the death of soil fauna [25].Light intensity at three different heights showed no different values (Table 7).Tabel 5. Species diversity, evenness, and richness index of soil fauna Air temperature shows a negative correlation with fauna abundance (Table 6).High air temperatures can cause soil temperatures to rise so that they can kill soil macrofauna.Air temperature can also affect the reproduction, growth, and proliferation of soil organisms.The abundance of fauna in open land is reduced dramatically because the air temperature is too high to exceed the optimum temperature for breeding organisms, which is between 15-25°C [43].The average air temperature measured on the study plot showed higher values as altitude increased.This is contrary to research by [9] states that the air temperature will drop by 0.6 o C every 100 meters of altitude increase.The measured air temperature tends to be low at low altitudes, allegedly due to rain, when measuring in plots of 1,650 m asl and 1,550 m asl.Based on research conducted by [44] and [45], rain negatively correlates with air temperature, which means that rain decreases the air temperature.

Index
The correlation between the abundance of fauna and air humidity shows a positive value which means that the higher the humidity, the higher the abundance of fauna will be.The results showed that air humidity decreases with increasing altitude and land openness (Table 7).Humidity exerts a more critical effect on organisms when temperatures are extreme (too high or too low).High humidity is more suitable for the living habitat of soil fauna [46].

Relationship between Soil Fauna Abundance and Edaphic Factors
Soil edaphic factors can influence the abundance of soil fauna.The edaphic factor of the soil is a factor that depends on the condition of the soil and the content of water and air in it, which discusses not only the parent material but also the content in it both physically and biologically [47].Analysis of soil edaphic factors conducted in this study include soil temperature, bulk density, porosity, litter wet weight, pH, soil respiration, C-organic, and CEC.
Environmental conditions in the mountains are influenced by climatic conditions that are influenced by altitude, especially temperature, and rainfall.Such factors, together with the edaphic conditions of the soil, will affect the composition of the plant, which will further affect the abundance of invertebrate and earthworm communities.The abundance, diversity, and biomass of soil fauna tend to decrease with increasing altitude [48].Soil temperature is one of the soil physical factors that greatly determines the presence and density of soil organisms because it is related to the rate of decomposition of soil organic matter [49].The correlation between soil temperature and fauna abundance shows a positive correlation that is categorized as moderate (Table 8).Soil temperature does not have a more critical effect than moisture.Temperature can have the effect of limiting the growth of organisms if humidity is in extreme conditions [46].
Soil porosity is the ratio of non-solid volume to total soil volume.Soil porosity is important for draining water, air, and nutrients into the soil [50].Soil porosity is related to soil aeration.Soil porosity is inversely proportional to bulk density [51].Bulk density is the ratio of soil mass to soil volume.Bulk 13 density is a highly dynamic property of soil, a function of soil texture and organic matter.Bulk density is influenced by water, aeration status, root penetration, clay content, texture, and land use and management [52].The correlation between porosity and abundance of soil fauna shows positive results so that the greater the porosity causes the abundance of fauna to be higher.Soil with good porosity will be an optimal growing space for soil fauna.Meanwhile, the correlation between bulk density and soil abundance shows negative results, which means that the higher the bulk density, the lower the abundance of soil fauna.The increasingly dense soil causes the soil fauna to tend to be few who can live in it.
Based on the results of the study, the correlation between the wet weight of litter and abundance showed positive results, which means that the more litter in a location, the higher the abundance of fauna (Table 8).The highest average litter wet weight measurement results were found in the study plot at an altitude of 1,550 m above sea level and tended to decrease with increasing height and land openness.Litter is a food source for most soil fauna that has a major role as a decomposer.The high availability of food will lead to a high abundance of soil fauna [53].
The degree of soil acidity (pH) measures soil acidity and alkalinity, representing the concentration of H + in the soil solution.Soil pH is a key index of soil properties, which is considered one of the main variables affecting other soil properties.Studies have shown that soil pH can affect soil nutrient release and soil microbial activity to a large extent [54].The correlation of soil pH with soil fauna abundance shows positive results, which means that the greater the pH value, the higher the abundance of soil fauna (Table 9).The pH measurement results showed that the highest average soil pH was found in the research plot of 1,550 m above sea level with a value of 5.70, while the lowest value was found in the research plot at an altitude of 1,750 meters above sea level with a value of 4.53.This is in accordance with the research of [55], which states that the pH value tends to rise at lower slopes.The high pH of the soil on the lower slope is estimated due to the addition of alkaline elements derived from the upper and middle slope soils carried by surface flow.In addition, higher organic matter at an altitude of 1,550 m above sea level also contributes to an increase in soil pH on the lower slopes.The decomposition of organic matter can release basic elements such as K, Ca, and Mg and organic acids into the soil [55].The overall soil pH measurement results are categorized as acidic.However, soil fauna, especially Collembola, can survive in these conditions.Based on the research of [57] posits that Collembola does not die or show growth inhibition under acidic conditions, which suggests that they have strong environmental adaptability and tolerance to various acidity even at pH 3.
Ground respiration refers to the removal of carbon dioxide (CO2) released into the atmosphere from the ground surface [58].The correlation of soil respiration with abundance shows a positive correlation (Table 8).The higher the soil respiration, the higher the abundance of soil fauna.Based on the results of the study, the highest soil respiration was found in plots at an altitude of 1,650 m above sea level with an average of 70.65 mg CO 2 / day / 100 g soil, while the lowest average soil respiration was 21.91 mg CO2/day/100 g of soil (Table 10).The high average value of soil respiration in the 1,650 m above sea level study plot was caused by the abundance of soil fauna, which also had the highest abundance value compared to the three plots.Other research at an altitude of 1,550 m asl, 1,750 m asl, and open land.Limiting factors that cause variations in soil respiration values can differ in different ecosystems.For example, climatic factors may not be limiting factors in mountain rainforests with hot and humid climates [59].Meanwhile, in mountain rainforest ecosystems, substrate quality in decomposition [60], soil nutrient supply, physical and chemical properties, and decomposition activity may be more important for soil respiration [58].
C-organic is soil's organic carbon, referring to the carbon present in organic matter.The soil can be either organic or inorganic carbon (especially carbonate, CaCO3).Soil organic matter comes from all living and inanimate organisms (roots, litter, fauna, microfauna, and microorganisms) [61].The correlation of C-organics with the abundance of soil fauna shows low category yields.This means that the content of organic matter only slightly affected the abundance of soil fauna in this study.The average C-organic measurement results showed the highest value in plots at an altitude of 1,750 m above sea level at 14.25%, while the lowest value in plots at open land altitudes was 6.35% (Table 9).This is thought to be because, at an altitude of 1,750 m above sea level, it has a higher vegetation density at the growth rate of stakes, poles, and trees so that C-organic correlated more strongly with the nature of vegetation above ground level compared to climate or altitude [62,63].
Cation exchange capacity (CEC) is the amount of positive charge that can be exchanged per land mass [64].The correlation of CEC with the abundance of soil fauna shows a negative value which means that the higher the abundance of soil fauna, the lower the soil CEC.However, the results of this correlation have a low correlation level (-0.11), so it is not too related to the abundance of soil fauna in the study plot (Table 8).

Conclusions
The abundance of soil fauna varies according to the difference in height.The highest abundance of fauna is found at an altitude of 1,650 m above sea level, with 97 individuals/m 2 of 11 orders and 16 families.The abundance of soil fauna at an altitude of 1,550 m above sea level is 93 individuals/m 2 consisting of 11 orders and 22 families.The abundance of soil fauna at an altitude of 1,750 m above sea level is 59 individuals/m 2 consisting of 8 orders and 13 families.The lowest abundance of soil fauna is found in open land with 11 individuals/m 2 consisting of 3 orders and 3 families.The abundance of soil fauna is influenced by edaphic and climatic factors.Climatic elements have a medium category correlation with the abundance of soil fauna.Edaphic elements that strongly correlate with the abundance of soil fauna are the wet weight of litter and soil pH.
in 20 m × 20 m plots at each altitude, 1315 (2024) 012028 IOP Publishing doi:10.1088/1755-1315/1315/1/0120283 namely 1,550 m asl, 1,650 m asl, 1,750 m asl, and open land (1,200 m asl).The selection of the location of the sub-plot is carried out by looking at the availability of litter and the representativeness of the entire plot.

Figure 1 .
Figure 1.Illustration of the plot for fauna sampling and soil sampling for soil sample b = mL HCl for blanks t = normality of HCl used (0.1 N) n = length of incubation days 2.6.4.Bulk density and porosity.

Table 3 .
BNT test results at each altitude

Table 4 .
Composition of soil fauna at each altitude

Table 6 .
Climatic parameter correlation test results

Table 7 .
Average measurement results of climatic element parameters

Table 8 .
Edaphic parameter correlation test results

Table 9 .
Average measurement results of edaphic element parameters