Population Study of Endemic Java Palm Pinanga javana in Mount Ungaran, Semarang, Central Java, Indonesia

. The discovery of Pinaga javana Blume in Mount Ungaran is new information for the distribution of this palm because there was no record of this palm on Mount Ungaran. Therefore, to reveal the population of P. javana in Mount Ungaran, this research was carried out to determine the population structure and habitat preference of P. javana . The study for P. javana was conducted using the focused survey method to explore all the side of Mount Ungaran (northern, southern, western, and eastern). The total area explored is 13 locations. All palm individuals have been recorded for diameter, height, and habitat. The results showed that from 13 locations, the population of P. javana was only found in 5 locations. Mainly on the southern side of Mount Ungaran. The total population of P. javana is around 213 individuals. The highest number of individuals is in the seedlings stage. The population of P. javana found is mostly on steep slopes compared to ridges that tend to be flat. In addition, the suspected habitat as a specific preference is the position of the slopes that are closer to the water source (river). The study also found that the distribution of P. javana was assisted by a dispersal agent (forest civet). In general, this study provides new information for the distribution records of P. javana in Java. Therefore, in this palm conservation function, special efforts are needed to increase the population of P. javana on Mount Ungaran.


INTRODUCTION
Mount Ungaran is one of the most explored and hiked Mountains in Central Java Province, Indonesia. The forest cover is estimated to be 5.500 hectares in Mount Ungaran (Utami et al., 2019). The majority of the forest is managed by Perhutani, and these areas are classified into protection forest (2670.25 ha), production forest (622.33 ha), and limited production forest (618.93 ha). There is only one conservation area in Mount Ungaran, namely Gebugan Nature Reserve. This Nature Reserve covers only 1.8 ha and it is currently under the management of BKSDA -Central Java Province (Natural Resources Conservation Center), Ministry of Environment and Forestry. Mount Ungaran is reported to have a high level of biodiversity, mainly plant species (Rahayuningsih et al., 2017;Hidayat et al., 2018).
The discovery of Pinanga javana in mount ungaran is new information about the distribution of this species (new locality). The genus Pinanga has a widespread distribution from the Himalayas, the south-western part of China to New Guinea, and consists of 132 species (Govaerts & Dransfield, 2005). The center diversity of this genus is in Borneo, with at least 45 species. In Indonesia, there are approximately 40 species of Pinanga, of which 14 are endemic to several islands (Witono et al., 2006). P. javana is one of the endemic palm species of the Arecaceae family found on Java Island. P. javana is classified as Endangered by the IUCN Red List 1997. The species is also listed as protected species in the Minister of Environment and Forestry Regulation Number 106 of 2018. The species has several local names in Java, such as Njawar (Central Java), Palem Barong (East Java), and Hanjawar (West Java) (Zulkarnaen et al., 2019). P. javana distribute mostly in West and Central Java at an elevation between 800-1.700 m asl. A population study of this species has not much been done. A recent report that focuses on the population of this species was done by Zulkarnaen et al. (2019) in Mount Slamet, Central Java. Other studies were done by Mogea (2004) in Mount Halimun Salak, Wihermanto (2004) and Alandana et al. (2015) in Mount Gede Pangrango, and Witono (2006) in many locations focused on the diversity of palms, dispersion pattern of P. javana and genetic diversity of P. javana, respectively.
This study aims to assess the population and habitat preference of P. javana in Mount Ungaran. Therefore, information about this species population, abundance, and habitat requirements will be presented in this paper. The results will provide recommendations to the management authority for developing a conservation strategy for P. javana in Mount Ungaran.

Study site
The study was conducted in Mount Ungaran, Central Java Province, Indonesia (Figure 1)

Samplings
The study for P. javana was conducted using a focused survey method (Brewer, 2013). This method focused on the intensity of surveys on areas with high potential habitats for the targeted species. In each location where the species was found, site characteristics (elevation, slope, aspect, soil pH, soil humidity, temperature, air humidity, and topography), geographical location, number of individuals, and any apparent threats were recorded. Data of all parameters were subsequently processed to provide information on the condition of the habitat where the species lives. Total visited locations were 13 locations which represent all sides of the mountain. Sampling was started when P. javana was found. An individual with inflorescence or fruits was recorded and assigned as a mature palm. The population structure of P. javana was recorded.

Stage structure
Stage structure was classified into seven different stage classes within the populations depending on the size of the leaves for seedlings and the height of the stem for juvenile and mature (Table 1).

Data Analysis
The occurrence of P. javana determines its position from Mount Ungaran. The distribution pattern was analyzed using the Morisita index (Morisita, 1962). The habitat of P. javana is descriptively described based on this data and analyzed with environmental factors using PAST3 (Paleontological Statistics). Old mature individual with stem height > 300 cm Source: Ratsirarson et al. (1996).

Structure Population
The results showed that P. javana was only found at 5 from 13 locations ( Figure 1). The total population of P. javana on Mount Ungaran was 213 individuals (Table 2). This number is less than the population of P. javana found on Mount Slamet (Zulkarnaen et al., 2019). The limited occurrences indicate that P. javana requires specific habitat conditions to support the success of growing and spreading. P. javana is more commonly found on the southern side of Mount Ungaran ( Figure 1) and is also supported by the highest number of individuals found on this site, particularly Bantir and Klenting Kuning (Table 2).
On Mount Ungaran, P. javana was found at 1.000-1.300 m asl and similar to other studies about the natural elevational range of this species (Witono et al., 2002;Zulkarnaen et al., 2019;Zulkarnaen et al., 2020). However, Alandana et al.    (2015) reported that a population of P. javana in Mount Gede Pangrango National Park was found at 600-700 m asl. Zulkarnaen et al. (2019) observed that on Mount Slamet, P. javana predominantly grows at the southern side. A similar condition was also found on Mount Ungaran, P. javana were also at the southern sides. The population structure of P. javana on Mount Ungaran is dominated by the seedlings stage ( Figure 2a). The number of individuals in the mature and juvenile stages is lower than the seedlings stage. The diameter classes in the mature stage range are between 7-9 cm with a height of 10-11 m (Figure 2b). However, the number of seedlings-juveniles is very small even though the palm reproduction process is classified annually. The survival rate of this species is relatively low. Therefore, this palm produces as many seeds as possible as a form of adaptation. Zuhri et al. (2019) reported that one individual of P. javana can produce 2800 fruits in the mature stage with 5-6 inflorescence.
The occurrence of an individual P. javana in the middle of a Medini tea plantation is unusual. More studies are required to know how this individual occurs there, while other populations are on natural forests at the southern sides. This individual was found on a roadside ravine in the middle of the Medini tea plantation. The Medini tea plantation has an area of 386.82 ha with an elevation range of 950 -1.775 m asl (Wachjar & Supriadi, 2015). Therefore, based on the altitude of the Medini tea plantation, P. javana is still suitable to be found (Witono et al., 2002). This location has relatively high rainfall, about 4.060 mm/year (Archive of Medini Plantation Office, 2011). Based on the study of the population of P. javana in the montane forest in Java, it is known that the distribution of this palm is not influenced by conditions of rainfall and other microclimate factors (Zulkarnaen et al. 2019). However, this type of palm is very restricted, only found in the lower montane forest (800-1.700 m asl) in West Java and East Java (Witono et al., 2002). Therefore, this possibility is accidentally by humans, or it could be by animals-the striking red color of the fruit. Naturally, the spread of P. javana is usually assisted by forest civets .
The Perhutani has never planted P. javana on their forest concession in Mount Ungaran. The community around Mount Ungaran does not use the species as well. P. javana on Mount Slamet, while at Mount Halimun-Salak, and Mount Gede Pangrango is used as functional food ingredients such as young shoot vegetables by the local community living around the mountains (Mogea et al., 2002;Alandana et al., 2015;Zulkarnaen et al., 2019;Zulkarnaen et al., 2022). Thus, its existence on this mountain is considered natural.
The results of the morisita index show that the distribution pattern of P. javana in Mount Ungaran is clumped distributed (Id=0.52). This result is similar to the dispersion pattern of this species in Mount Gede Pangrango and Mount Slamet that resemble clump distribution (Wihermanto, 2004;Zulkarnaen et al., 2020). Generally, the distribution pattern of plant species tends to be clumped because plants reproduce by producing seeds that fall close parent (Wahyuni et al., 2017). However, uniform patterns of dispersion are generally the result of interactions between individuals, such as competition (Walker, 2011). In the case of P. javana, competition is very likely due to the invasion of alien invasive species. Based on our observation in Mount Ungaran, coffee plants, most likely Coffea canephora (Rubiaceae), dominate the forest's understorey. The dominancy of this species hinders the regeneration of P. javana, that might indirectly shape the dispersion pattern.

Habitat Requirement
The growth of a plant, in general, has a certain tendency towards a suitable habitat to grow (abiotic and biotic factors) to support its survival in its natural habitat (Yudaputra et al., 2022;Latifah et al., 2020;Zulkarnaen et al., 2017). In addition, sometimes, plants also influence the presence of other plants (plant associations) (Helmanto et al., 2020). Latifah et al. (2020) also added that there are special strategies that plants usually do, germination strategies and increasing seedling survival. This condition also occurs in palms. In general, palms have relatively easy growing requirements, especially supported by year-round reproduction and fast germination (Zuhri et al., 2019).
The occurrence of P. javana in Mount Ungaran is relatively similar to other studies. The majority are found only on the southern side. The condition was also similar in Mount Gede Pangrango National Park (Selabintana), where the P. javana population is dominant on the southern sides (Zuhri et al. 2020). The environmental factors recorded in the P. javana habitat are an average temperature of 18.8 C, soil humidity 79.45 RH, and air humidity 74.4 RH (Table 3). Therefore, there is a special preference that this palm growth prefers moist locations. Table 3 also provides information that the level of slope that becomes the distribution of P. javana is in the slope range from 35-70. The slope is steep to the very steep slope. This condition may be one of the causes for the distribution of P. javana seeds not being around mature palms because they are carried away by water flows or fall down the slopes.
Principal component analysis (PCA) revealed that the aspect factor had a dominant role in the presence of P. javana (Figure 3). Previously it was known that most P. javana is in aspect near 200° (Southern). The southern aspect is certainly strongly correlated with a stable and humid microclimate because the intensity of sunlight on the southern sides in the morning and afternoon has no effect on the microclimate, so the southern sides tend to be more humid than other sides that  are directly exposed to sunlight. The theory is that high sunlight will reduce high humidity (Gunarsih, 2016). Humidity levels are also known to significantly influence the presence of P. javana on the southern sides of Mount Slamet (Zulkarnaen et al., 2019). In another study of palm habitat, Yudaputra et al. (2022) that suitable habitat for the endemic population of the Pinanga arinasae palm in Bali is influenced by several variables, including litter depth and elevation canopy openness and slope. Pinanga arinasae growth tends to be more in flat locations, although some populations are also found on steep slopes.
Meanwhile, the distribution of P. javana seems to prefer locations with steep to very steep slopes. It is caused by the majority of the population of P. javana in Mount Ungaran located in areas with steep slopes (Figure 4). Figure 4 also provides information that a small population is growing on  (Zulkarnaen et al., 2019). Zulkarnaen et al. (2019) provide information that the total population of P. javana found is on very steep slopes (>45°). However, it is also possible that the spread in the slopes is a form of defense from P. javana, which is threatened by other factors when in sloping areas, such as humans and other predators like wild boar. This animal is known to be one of the predators of P. javana on Mount Slamet (Zulkarnaen et al., 2019). Figure 5 generally provides an overview of the growth and distribution of P. javana on Mount Ungaran. Figure 5a showed that the majority of mature individuals grew up in open and shaded areas. Therefore, from the point of view of where it grows, there are no problems in open or shaded conditions. However, the development of the survival rate from the seedling-mature stage is still low. However, many seedlings were found in several locations close to the mature palm ( Figure  5b). The number of juvenile stages was not matched as well. There are abundant seedlings which indicate that reproduction occurs annually.
Furthermore, Figure 5c illustrates one of the pieces of evidence of P. javana seed dispersal assisted by forest civet as its dispersal agent. Based on the explanation above, the growth cycle of P. javana is no problem. The threat of population reduction is more natural, such as landslides, because most of the population is on slopes. Therefore, even though the population is large but its habitat is very vulnerable, the conservation status of this palm can increase in the coming years. However, to know the distribution area and habitat of P. javana, a detailed population assessment is needed throughout Java.

Conservation Implications
Indonesia has 959 plants that are included in threatened species (IUCN, 2021). This number is predicted to continue increasing with conservation threats, such as land conversion, deforestation, land degradation, and others. These threats also threaten Indonesian palm species, where Indonesia has a 20% contribution to world palm diversity (Widyatmoko, 2019). Widyatmoko (2019) also revealed that around 53% of Indonesian palms are endemic.
The existence of P. javana, which is recorded as an endemic Java palm, should be one of the concerns in future conservation activities.
According to fields data and herbarium records, the predicted distribution of P. javana may also be widespread throughout the Java mountain forests. However, a re-assessment is needed to determine the existence of this palm. From the assessments that have been carried out in several locations, this palm growth trend shows a declining population trend for survival to mature individuals. Not to mention its preferred habitat on the slopes, which indicates a higher potential threat due to natural factors.
The growth of P. javana is necessary to analyze the decrease from seedlings to mature. Because as is known that this palm always produces fruit is annual. The process of successful germination is also very easy. The total number of seedlings population is very abundant, however, in contrast to the total population of mature individuals. In addition, the conservation efforts of P. javana can also be replanted in locations where this species is not known. This action aims to maintain the availability of the P. javana population in the wild. For example, areas on the edges of the forest or in other open areas in the forest.
In addition, P. javana has been successfully grown as a collection plant in two ex-situ conservation areas: Cibodas Botanic Gardens and Baturraden Botanic Gardens (Sujarwo et al., 2019;Irawan et al., 2015;Zulkarnaen et al., 2021). Nevertheless, the source of P. javana collections is limited only around the botanic garden location. It has not been enriched from other locations that have recorded populations of P. javana. Therefore, conservation efforts to conserve this palm from montane forest others are still needed.

CONCLUSION
The population of P. javana on Mount Ungaran is new information for its distribution in Java. The population structure of P. javana was dominated by the seedlings stage. The majority of the locations found in P. javana are located in the Klenting Kuning forest and Bantir forest (most population). Some individuals are also found in the Medini forest, Nirwana forest, and Merangan hill forest. The habitat requirement of P. javana in Mount Ungaran is mainly found on the intact forest with slopes (>40°) (most population) and ridge (15°-35°) and mainly distributed in the aspect near 200° (Southern side) of the Mount Ungaran. In addition, other environmental factors that support the existence of this population include air humidity and soil humidity.