Ecological Dynamics of Forest Stands with Castanopsis argentea (Blume) A.DC. in a Mountain Ecosystem: Vegetation Structure, Diversity, and Carbon Stock Under Tourism Pressure

Abstract

Saninten (Castanopsis argentea (Blume) A.DC.) is a protected plant that grows in the Mount Gede Pangrango National Park (MGPNP) area in West Java. Its population is limited, and as a valuable biological resource, Castanopsis has traditionally been utilized by indigenous communities, particularly those residing in proximity to the forest. However, the expansion and development of tourism pose a potential threat to the ecosystems of C. argentea and other endemic plant species, as well as to the wildlife that depend on these habitats. Comprehensive data on biodiversity, species composition, forest structure, and carbon stock status are crucial for assessing the potential impact of future tourism development. Our investigation was conducted from November 2023 to March 2024 in a three-hectare utilization zone within the confines of the national park. The findings documented a total of 36 species across 23 distinct plant families, with the families Fagaceae, Moraceae, and Myrtaceae exhibiting the highest levels of dominance. The regeneration of stands at the study site predominantly comprised arboreal species with the most substantial carbon stocks, including C. acuminatissima (Blume) A.DC. (Riung anak), C. argentea (Saninten), and Litsea sp. (Huru). C. argentea supplies several functions within this ecosystem that are interconnected with other components. With aboveground carbon stocks reaching 560.47 tons C/ha, the forest demonstrates high sequestration potential, reinforcing the need to conserve mature stands for both biodiversity and climate benefits. Therefore, in the future, the conservation of C. argentea will benefit the maintenance of the ecosystem’s attractiveness without adversely affecting the social and cultural structures of the local population.

1. Introduction

Indonesia is home to many important and valuable tree species, including berangan, a popular name for Castanopsis spp. in the Fagaceae family [1]. This family is well known for its chestnut tree species, as well as for its valuable timber. Castanopsis argentea (Blume) A.DC., a member of the Fagaceae family, is a native species commonly found in Assam, Borneo, the Eastern Himalayas, Java, Myanmar, Sumatra, and Thailand [2]. As stated in Flora Malesiana, Castanopsis argentea is an evergreen tree that grows to a height of 15 to 30 m [3], and its trade name is berangan timber. Castanopsis argentea is a dominant species in certain areas of Java. This species can be found in primary or old secondary forests, typically on dry, fertile soils with stoniness at altitudes ranging from 150 to 1750 m above sea level [4,5]. However, the optimal altitudinal range for C. argentea is between 1400 and 1500 m above sea level [6]. In West Java, C. argentea grows at altitudes ranging from 150 to 1500 m above sea level and is dominant on the eastern side of the Mt. Gede forest [7,8]. This species is useful; its bark is a blackish dye used for debarking rattan, and tannins can be extracted from the core wood. The fruits are edible and are collected and sold on-site [4]. This species is also ecologically important for animal feeding and bird nesting.

While being of high importance as a valuable tree species, C. argentea is also facing a serious threat to its population, as it has a high risk of extinction. This species is listed as endangered under criteria A2c on the IUCN Red List of Threatened Species [1]. The population continues to decrease for various reasons. Research conducted in the Cibodas Botanical Gardens, within the Mount Gede Pangrango National Park, found that C. argentea is one of the Fagaceae members with the highest importance in the Cibodas residual forest, particularly at the tree stage. Castanopsis is less prevalent in the sapling and seedling strata, likely due to its poor germination ability, competition with dominant introduced species on the forest floor, and damage due to its nuts being eaten by animals or harvested by humans. The Cibodas residual forest succession also supports the Castanopsis population; however, interspecific relationships show that not all species in the genus Castanopsis are associated [9]. According to these associations, the presence of Castanopsis argentea may enhance the composition of the vegetation and the health of the environment by providing food and shelter [9]. In addition to habitat degradation, Cisneros [10] stated that the presence of C. argentea tends to decrease with increasing elevation. Altitude is a determining factor in the suitability of a habitat for a type of vegetation). The research carried out by Nurdiana and Buot [9] revealed a relationship between Castanopsis and environmental factors related to diversity, distribution, and reproduction, which influenced the decline in the saninten population.

Environmental factors and anthropogenic activities are other factors that affect the C. argentea population. A previous study pointed out that 61.5% of this species’ distribution and dominance is also affected by cation exchange capacity, temperature, and total N in the soil [11]. At the research location, saninten mostly grows on hill ridges, with a few plants also growing on hill slopes. Anthropogenic activities have the most significant effect on the population decline of C. argentea [1]. Additionally, the decreased capacity for natural regeneration, driven by the excessive harvesting of natural products and the removal of wood for timber, poses a significant threat to this species. In Sumatra, the indigenous ecosystem of C. argentea has been adversely affected by anthropogenic land transformation, exemplified by the conversion of forested areas into monoculture oil palm plantations. Over the past three decades, the population of this species has decreased by approximately 50% due to habitat degradation [12].

Currently, the populations of C. argentea and other endemic vegetation, particularly in the West Java region, face challenges related to the development of natural tourism, including infrastructure and supporting facilities. Without sufficient planning, these practices may potentially endanger Castanopsis populations and their local habitats in the future.

Mount Gede Pangrango National Park (MGPNP), recognized as one of Indonesia’s foremost natural tourism destinations, plays a significant role in supporting various forms of nature-based tourism. In recent years, portions of the park and its surrounding areas have been designated as ecotourism development concessions. These areas are being developed to accommodate a range of ecotourism activities, including forest exploration, cultural heritage walks, adventure-based recreational areas, traditional village tourism, wildlife sanctuary visits, hiking, camping, overlanding, and other nature-oriented activities. To facilitate and enhance the quality of these activities, a series of supporting infrastructures has been planned for development. These include but are not limited to, designated camping grounds, forest camp facilities, zipline installations, suspension bridges, road compaction work, electrical infrastructure, and other auxiliary facilities deemed necessary for sustainable ecotourism operations.

An important tool for achieving ecosystem protection is safeguarding indigenous ecosystems and cultural heritage while simultaneously providing social and economic benefits to local populations. This concept aims to strike a balance between sustainable economic activities, education, and environmental preservation [13]. The objective of ecotourism is to provide educational facilities to raise tourist awareness of conserving biodiversity and the natural environment, which includes the protection of rare species. There are four direct and indirect ways in which ecotourism can support biodiversity conservation while addressing social and environmental objectives. These include the following: (a) protection of animals and protected areas, (b) diverse sources of income, (c) promotion of ethics and interpretation of environmental issues, and (d) enhancement of institutions for resource management [14]. Das and Chatterjee [15] concluded that ecotourism is a successful instrument for environmental conservation in many locations. Their examples include the Galapagos Islands, ecotourism sites in Costa Rica, Chitwan National Park in Nepal, the Sundarbans in India, the Periyar Tiger Reserve in India, Kilum-Ijim National Park in Central Africa, the Cuyabeno Wildlife Reserve in the Amazon region of Ecuador, and community-based tourism initiatives in Indonesia. However, studies have also shown that ecotourism can potentially impact ecosystems. The management of national parks, conservation areas, and natural resorts is often integral to the concept of ecotourism; however, the provision of facilities and infrastructure frequently pays insufficient attention to the environmental conditions. Ecotourism development can lead to a decline in environmental quality, particularly when it disturbs vegetation and disrupts local ecosystems [16]. Previous studies have indicated that ecotourism in Indonesia has impacted several environmental factors. For instance, Sofiyudin et al. [17] stated that the carrying capacity for tourism in one of the resort areas in Mount Gede Pangrango National Park (MGPNP) is often exceeded, leading to environmental degradation and the need for better management strategies. Furthermore, Rezki et al. [18] noted that the economic value derived from ecotourism in the GGPNP must be balanced with environmental sustainability to prevent long-term ecological damage. This is due to the fact that not all Indonesian ecotourism destinations properly implement ecotourism concepts, especially conservation [19]. Additionally, Butarbutar and Soemarno [20] stated that even though ecotourism is supposed to have as minimal an impact on the environment as possible, an enormous number of visitors could lead to ecological distress. Brandt and Buckley [21] said that ecotourism in Indonesia has been linked to the pressures of a rising population, agricultural development driven by increased access to markets, and the degradation of forests as a result of infrastructure development. The ultimate objective of these changes must be to establish a new ecological balance that preserves the existence of all ecosystem elements, particularly those components that currently support tourism.

In order to accomplish the aforementioned ultimate objectives, further research on ecosystem components and their interactions, including the function of C. argentea in Mount Gede Pangrango National Park, must be carried out to encourage the continued development of adaptive ecotourism. Therefore, an assessment of the diversity, structural characteristics, and species composition of forest stands with C. argentea and other endemic vegetation within the mountainous tropical rainforest is critical for understanding the current ecological conditions in light of ongoing infrastructure development in the region. Additionally, evaluating the carbon stock is crucial for quantifying the ecosystem services provided by this vegetation, particularly regarding its contribution to greenhouse gas mitigation and climate regulation. The findings of this research are expected to be not only valuable for the conservation of C. argentea and other endemic vegetation but also to be used as a reference to examine whether tourism affects the existence of other species besides C. argentea. It is essential to help managers and local governments design and implement policies and programs that aim to reduce the potentially destructive impacts of unsustainable recreational practices on the ecosystem.

2. Materials and Methods

2.1. Experimental Site

The research was conducted from November 2023 to March 2024 in the ecotourism development concession area in Megamendung, Bogor Regency, West Java Province (Figure 1). Geographically, the research area is located at 6°43′16.60″ S and 106°55′54.57″ N. In the ecotourism-focused forest area, it is forbidden to throw garbage away anywhere except its designated places and to cause damage, e.g., by taking away parts of trees, seedlings, and tree seeds. This area covers 253 hectares and includes the utilization zone of Mount Gede Pangrango National Park (MGPNP) and State Plantation Ltd. Regional 1 Tea Plantation area, West Java, Indonesia. The Barubolang utilization zone belongs to the MGPNP and consists of disturbed primary natural forest and expansion forest from Perhutani, West Java region (a company from the Indonesian government that handles forestry) and is characterized by pine plantation forests. The disturbance of primary natural forests has been caused by human activities such as ecotourism and logging.

The research locations are situated at an altitude of approximately 1100 m above sea level and are part of a disturbed primary forest. The topography is mountainous, with average slopes of 40–75% at Cable Car station2 (CC2) and Cable Car station3 (CC3) and an average slope of 70% at Cirembes. The soil in the Barubolang utilization zone at the research site consists of intermediate brown volcanic Latosol [22,23].

Ecotourism in Mount Gede Pangrango National Park primarily includes activities such as trekking, camping, waterfall visits, panoramic views, lake exploration, and flora and fauna observations. The species diversity in the ecotourism area of Mount Gede Pangrango National Park offers stunning beauty, particularly to tourists. However, these activities may have an impact on the local ecosystem. Ecotourism growth can negatively affect the environment, especially vegetation. The ecological balance of a location may be compromised by ecotourism activities, which can lead to the destruction of flora and native habitats for animals. Therefore, these activities must be properly controlled, for instance, by strengthening laws related to environmental conservation. The areas affected by ecotourism development at the study site are presented in

Table 1. The area potentially affected by ecotourism development at the study site.

No	Location	Area (ha)	Sample Plot (ha)
1	Cable Car Station 2/CC 2	3	1
2	Cable Car Station 3/CC 3	3	1
3	Cirembes Disturbed Primary Forest	2	1

.

Based on the Schmidt and Ferguson classification, the climate of this area is classified as type A, with an average annual rainfall ranging from 3000 to 4200 mm and a Q value of 5–9%. The highest rainfall typically occurs from December to May, reaching up to 4000 mm, while the lowest rainfall occurs from June to September, totaling approximately 1000 mm. The minimum temperature is 18 °C, the maximum temperature is 32.8 °C, and the average air humidity is 79% [24].

2.2. Sampling

The research plots were situated on hillsides with slopes ranging from 45% to 75%, encompassing the locations of Cable Car Station 2 (CC2), Cable Car Station 3 (CC3), and Cirembes Disturbed Primary Forest. The layout of the subplots is illustrated in Figure 2.

The stand conditions at each research location were relatively uniform. Therefore, an area of one hectare (20 m × 500 m) was selected to represent the stands at each location. Within this one-hectare plot, 25 nested subplots were established, comprising the following:

• Tree Measurements: 20 m × 20 m subplots for measuring tree species.
• Belt Transects: 5 m × 5 m subplots for assessing saplings.
• Seedling Measurements: 2 m × 2 m subplots for recording seedlings.

2.3. Data Collection

The following data collection procedures were applied:

• Soil samples: Soil samples were collected from a depth of approximately 0–20 cm in three sampling plot locations (CC2, CC3, and Cirembes forest). Samples were collected from five points in each plot (20 m × 20 m) and combined to obtain a composite sample. This work was undertaken in three replications for each plot; thus, each plot produced three composite soil samples. The samples were sealed in plastic bags and transported to the laboratory. The soil samples were analyzed in the laboratory of Bogor Agricultural University (IPB University). Not all soil properties were analyzed, but the analysis was carried out based on the most important soil nutrient properties that influence plant growth, the limitations of the materials, and the practicality of the analysis. The analyzed properties included water content measured using gravimetry, pH measured using a pH meter, total C measured using the colorimetric method, total N measured using the Kjeldahl method, available P measured using the Bray II method, base cations (K, Mg, Ca, and Na), cation exchange capacity measured using the NH4 OAc (pH 7.0) extraction method, and Texture 3 fractions (sand, ash, clay; %).
• Species Identification: All species names of trees, saplings, and seedlings were recorded. Samples of unidentified materials were collected and identified at the Forest Research and Development Laboratory, Bogor, using the World Flora Online database [25] for nomenclature reference.
• Tree Measurements: The heights and stem diameter at breast height (DBH) of trees were measured. For trees with buttresses, diameters were measured 20 cm above the buttress.
• Growth Stage Criteria: The trees, saplings, and seedlings were classified according to the following criteria [26,27], which are suitable for use in tropical vegetation to assess tree stand structure in conservation areas.
  • Trees: Diameter at breast height (DBH) ≥ 10 cm at 1.3 m above the ground level.
  • Saplings: Diameter < 10 cm and height > 1.5 m.
  • Seedlings: Height < 1.5 m, including sprout.

The parameters measured and analyses performed for each subplot type are listed in

Table 2. Parameters measured and analyses performed.

Plot	Parameter	Type of Analysis
20 m × 20 m	Soil Analysis	pH (H2O), Water Content, C, N, P2O5, CEC & Texture
20 m × 20 m	Name of species	Species composition Endemism Conservation status
	Number of species	Species density
	Frequency of species	Importance value index Shannon index
	DBH and height	Stand biomass Carbon stock
5 m × 5 m	Name of species	Species composition Endemism Conservation status
	Number of species	Species density
	Frequency of species	Importance value index Shannon index
	DBH and height	Stand biomass Carbon stock
2 m × 2 m	Name of species	Species composition Endemism Conservation status
	Number of species	Species density
	Frequency of species	Importance value index Shannon index

.

2.4. Data Analysis

All scientific names of plants were standardized based on accepted names from the World Flora Online database [25] using the R package “WorldFlora” [28]. The status of tree endemism was created using the BGCI Global Tree Portal Database [29]. The conservation status of the plants was determined according to the IUCN.

The major species were analyzed by calculating their importance value index (IVI). The IVI measures the level of dominance of a species in an environment as a percentage; the higher the value, the more dominant the species [30,31]. IVI was calculated using the parameters of relative dominance, relative density, and relative frequency [6,32,33], which were calculated using the following formulae (Equations (1)–(3)):

$$\mathrm{R}\mathrm{e}\mathrm{l}\mathrm{a}\mathrm{t}\mathrm{i}\mathrm{v}\mathrm{e} \mathrm{d}\mathrm{e}\mathrm{n}\mathrm{s}\mathrm{i}\mathrm{t}\mathrm{y}\left(\mathrm{\%}\right)={\displaystyle \frac{\mathrm{n}\mathrm{u}\mathrm{m}\mathrm{b}\mathrm{e}\mathrm{r} \mathrm{o}\mathrm{f} \mathrm{i}\mathrm{n}\mathrm{d}\mathrm{i}\mathrm{v}\mathrm{i}\mathrm{d}\mathrm{u}\mathrm{a}\mathrm{l}\mathrm{s} \mathrm{f}\mathrm{o}\mathrm{r} \mathrm{a} \mathrm{s}\mathrm{p}\mathrm{e}\mathrm{c}\mathrm{i}\mathrm{e}\mathrm{s}}{\mathrm{t}\mathrm{o}\mathrm{t}\mathrm{a}\mathrm{l} \mathrm{n}\mathrm{u}\mathrm{m}\mathrm{b}\mathrm{e}\mathrm{r} \mathrm{o}\mathrm{f} \mathrm{i}\mathrm{n}\mathrm{d}\mathrm{i}\mathrm{v}\mathrm{i}\mathrm{d}\mathrm{u}\mathrm{a}\mathrm{l}\mathrm{s} \mathrm{f}\mathrm{o}\mathrm{r} \mathrm{a}\mathrm{l}\mathrm{l} \mathrm{s}\mathrm{p}\mathrm{e}\mathrm{c}\mathrm{i}\mathrm{e}\mathrm{s} \mathrm{i}\mathrm{n} \mathrm{t}\mathrm{h}\mathrm{e} \mathrm{p}\mathrm{l}\mathrm{o}\mathrm{t}}}\times 100\mathrm{\%}$$

(1)

$$\mathrm{R}\mathrm{e}\mathrm{l}\mathrm{a}\mathrm{t}\mathrm{i}\mathrm{v}\mathrm{e} \mathrm{f}\mathrm{r}\mathrm{e}\mathrm{q}\mathrm{u}\mathrm{e}\mathrm{n}\mathrm{c}\mathrm{y}\left(\mathrm{\%}\right)={\displaystyle \frac{\mathrm{t}\mathrm{o}\mathrm{t}\mathrm{a}\mathrm{l} \mathrm{f}\mathrm{r}\mathrm{e}\mathrm{q}\mathrm{u}\mathrm{e}\mathrm{n}\mathrm{c}\mathrm{y} \mathrm{o}\mathrm{f} \mathrm{a} \mathrm{s}\mathrm{p}\mathrm{e}\mathrm{c}\mathrm{i}\mathrm{e}\mathrm{s}}{\mathrm{f}\mathrm{r}\mathrm{e}\mathrm{q}\mathrm{u}\mathrm{e}\mathrm{n}\mathrm{c}\mathrm{y} \mathrm{o}\mathrm{f} \mathrm{a}\mathrm{l}\mathrm{l} \mathrm{s}\mathrm{p}\mathrm{e}\mathrm{c}\mathrm{i}\mathrm{e}\mathrm{s} \mathrm{i}\mathrm{n} \mathrm{t}\mathrm{h}\mathrm{e} \mathrm{p}\mathrm{l}\mathrm{o}\mathrm{t}}}\times 100\mathrm{\%}$$

(2)

$$\mathrm{R}\mathrm{e}\mathrm{l}\mathrm{a}\mathrm{t}\mathrm{i}\mathrm{v}\mathrm{e} \mathrm{d}\mathrm{o}\mathrm{m}\mathrm{i}\mathrm{n}\mathrm{a}\mathrm{n}\mathrm{c}\mathrm{e}\left(\mathrm{\%}\right)={\displaystyle \frac{\mathrm{t}\mathrm{o}\mathrm{t}\mathrm{a}\mathrm{l} \mathrm{b}\mathrm{a}\mathrm{s}\mathrm{a}\mathrm{l} \mathrm{a}\mathrm{r}\mathrm{e}\mathrm{a} \mathrm{o}\mathrm{f} \mathrm{a} \mathrm{s}\mathrm{p}\mathrm{e}\mathrm{c}\mathrm{i}\mathrm{e}\mathrm{s}}{\mathrm{t}\mathrm{o}\mathrm{t}\mathrm{a}\mathrm{l} \mathrm{b}\mathrm{a}\mathrm{s}\mathrm{a}\mathrm{l} \mathrm{a}\mathrm{r}\mathrm{e}\mathrm{a} \mathrm{o}\mathrm{f} \mathrm{a}\mathrm{l}\mathrm{l} \mathrm{s}\mathrm{p}\mathrm{e}\mathrm{c}\mathrm{i}\mathrm{e}\mathrm{s} \mathrm{i}\mathrm{n} \mathrm{t}\mathrm{h}\mathrm{e} \mathrm{p}\mathrm{l}\mathrm{o}\mathrm{t}}}\times 100\mathrm{\%}$$

(3)

IVI (%) = Relative dominance (%) + Relative density (%) + Relative frequency (%)

(4)

The calculation of the stand’s species diversity index (Shannon–Wiener index) was performed using the following formula [34] (Equation (5)):

$${\mathrm{H}}^{\prime }=\sum _{i=1}^{s}pi \ln pi$$

(5)

where H′ is the Shannon-Wiener index, ni is the importance value of each species, e is a constant, and N is the total importance value.

The quantification of stems per hectare was divided into five categories of different diameters: 10–19 cm, 20–29 cm, 30–39 cm, 40–49 cm, and ≥50 cm. In the context of this study, the calculation of aboveground biomass was carried out using Chave’s equation (Equation (5)); consequently, the implementation of a destructive sampling methodology was rendered unnecessary [35]. The use of this equation is based on tropical rainforest rainfall levels of between 1500 and 4000 mm/year, while the research location has a rainfall level of 3000 to 4200 mm/year.

Y = 0.0673 × (ρ D²H)^0.976

(6)

where the variable Y is the total biomass (kg), D is the diameter at breast height (cm), ρ is the wood density (gr/cm³), and H is the height (m), respectively. The values of wood density (ρ) were obtained from references based on the species found [36,37].

Equations (7) and (8) were used to determine the carbon stored in plants and the carbon dioxide sequestration [38,39]:

Stock of carbon = vegetation biomass × 47%

(7)

Sequestration of carbon dioxide (CO₂) = 3.67 × stock of carbon

(8)

The use of these equations depends on the climatic conditions of the study. In this case, the study location has a precipitation level of 2141 mm per year and is classified as being in the wet category (precipitation at a rate of 1500–4000 mm per year). We analyzed the data using tables with Microsoft Excel Windows 10 software [40].

3. Results

3.1. Soil Characteristics

The quality of soil cannot be accurately quantified due to its intricate nature; however, it may be inferred from measurable soil characteristics that serve as proxies for the intrinsic quality of the soil itself. The results obtained from the analysis of the physical and chemical characteristics of the soil in each of the three study plots are shown in

Table 3. Results of the analysis of the soil’s physical and chemical characteristics at the research location.

Location	pH (H2O)	Water Content (%)	C Organic (%)	N Total (%)	P2O5 (mg/kg)	CEC (Cmol (+)/kg)	Texture 3 Fractions (%)
							Sand	Silt	Clay
CC2 (disturbed primary forest dominated by saninten, earmarked for cable car 2)	5.5/a	32.30	4.54 h	0.36 m	<1.79 l	28.30 h	97	3	0
CC3 (disturbed primary forest earmarked for cable car station 3)	5.3/a	29.21	6.08 vh	0.50 m	<1.79 l	22.90 h	98	2	0
Cirembes disturbed primary forest	4.9/va	43.90	8.11 vh	0.67 h	<1.79 l	33.34 h	97	2	1

Notes: a = acidic; va = very acidic; h = high; vh = very high; m = medium; l = low.

.

The type of soil in the research areas of Mount Gede Pangrango National Park, West Java, as indicated by the district land map of Bogor, is classified as latosol soil with a yellowish-brown hue [41]. This type of soil is generally dark in color, possesses high porosity, has a loose structure, and exhibits high water-holding capacity [5]. The soil texture is predominantly sandy, with a high organic carbon content and elevated cation exchange capacity (CEC) across all locations. The soil pH indicates acidic conditions, ranging from 4.9 to 5.3. Total nitrogen levels are medium to high, whereas P₂O₅ (available phosphorus) content is low.

3.2. Plant Species Diversity

The species diversity index results, namely the Shannon–Wiener index (H′) for each growth stage at the three sample sites, are presented in

Table 4. Species diversity index of Shannon-Wiener.

No.	Sample Site	Stages	Shannon–Wiener Species Diversity Index (H′)
1	CC2	Tree	2.16 **
	CC3	Tree	1.93 **
	Cirembes	Tree	1.91 **
	All sites combined	Tree	2.11 ***
2	CC2	Sapling	2.11 **
	CC3	Sapling	4.39 ***
	Cirembes	Sapling	2.23 **
	All sites combined	Sapling	2.31 ***
3	CC2	Seedling	4.84 ***
	CC3	Seedling	2.27 **
	Cirembes	Seedling	1.98 **
	All sites combined	Seedling	2.43 ***

Notes: ** medium category, *** high category.

.

As shown in Table 4, a comprehensive assessment of biodiversity and regeneration dynamics was conducted at the three sample sites (CC2, CC3, and Cirembes). The Shannon–Wiener index (H′) was employed to quantify species diversity taking into account the number of species and their individual distribution within the community [42]. A higher value of H′ indicates enhanced diversity within the community, suggesting a more stable ecosystem. The CC3 sample site exhibited the highest diversity levels at the sapling (4.39) and seedling (4.84) stages, signifying optimal regeneration and a robust ecosystem at the juvenile vegetation level. In contrast, the CC2 sample site demonstrated moderate diversity across all vegetation levels (H′ ranging from 2.1 to 2.3), indicating sufficient stability but not achieving the same levels of diversity as CC3 at the sapling and seedling stages. The Cirembes sample site exhibited the lowest diversity (H′ = 1. 9–2.2), suggesting a less diverse ecosystem potentially dominated by certain species [43]. The combined tree diversity of all sample sites (H′ = 2.11) indicated a medium-high level, reflecting good species diversity at the landscape scale, meaning that each site possesses unique characteristics that contribute to the overall biodiversity [44].

3.3. Species Composition

The research conducted at the three sample sites revealed the presence of 36 species belonging to 23 distinct families. The dominant tree species, defined as those with a diameter of ≥10 cm or an importance index rating of >10%, are presented in

Table 5. Dominant tree species and their threat levels (according to the IUCN) at the three sample sites.

No.	Sample Site and Species	IUCN	Density (N/ha)	Importance Value Index (IVI) (%)
A.	CC2
1	Castanopsis acuminatissima (Riung anak)	Least concern/LC	132	85.95
2	Litsea sp./Huru	Least concern/LC	93	55.07
3	Schima wallichii (Puspa)	Least concern/LC	59	36.95
4	Castanopsis argentea (Saninten)	Endangered under criteria A2c./EN	47	32.86
5	Altingia excellsa (Rasamala)	Least concern/LC	26	18.27
6	Decaspermum fruticosum (Kisireum)	Least concern/LC	19	12.41
7	Maesopsis eminii (ky afrika)	Least concern/LC	9	10.33
B.	CC3
1.	Pinus merkusii (Pinus)	Vulnerable under criteria B2ab(ii,iii,v). /VU	32	84.60
2.	Castanopsis argentea (Saninten)	Endangered under criteria A2c./EN	26	74.63
3.	Schima wallichii (Puspa)	Least concern/LC	12	38.16
4.	Castanopsis acuminatissima (Riung anak)	Least concern/LC	13	38.09
5.	Litsea sp. (Huru)	Least concern/LC	5	15.64
6.	Altingia excellsa (Rasamala)	Least concern/LC	5	15.31
C.	Cirembes
1.	Castanopsis acuminatissima (Riung anak)	Least concern/LC	88	102.82
2.	Castanopsis argentea (Saninten)	Endangered under criteria a2c./EN	43	55.33
3.	Schima wallichii (Puspa)	Least concern/lc	38	42.78
4.	Litsea sp. (Huru)	Least concern/LC	23	28.82
5.	Pinus merkusii (Pinus)	Vulnerable under criteria B2ab(ii,iii,v). /VU	25	27.01

.

As illustrated in Table 5, this analysis allows for the assessment of the composition of dominant species and vegetation structure based on the Importance Value Index (IVI), thereby enabling the identification of ecological and conservation indicators [45]. The species C. acuminatissima (riung anak) was predominant at the sample sites CC2 and Cirembes, exhibiting the highest IVI values of 85.95% and 102.82%, respectively. Pinus merkusii was dominant at sample site CC3, with an IVI of 84.60%, and was also present in Cirembes, although with a lower IVI of 27.01%. Schima wallichii (puspa), C. argentea (saninten), and Litsea sp. (huru) were observed across all sites, exhibiting varying degrees of dominance.

The vegetation structure assessment, based on density and IVI results, revealed that the sample site CC2 exhibited a higher tree density than the other sites, with C. acuminatissima identified as the most prevalent species (132 trees/ha). In contrast, sample site CC3 was predominantly characterized by P. merkusii (32 trees/ha) with a notably high IVI. The Cirembes sample site exhibited a pronounced dominance of C. acuminatissima, with an IVI exceeding 100%, indicating that this species exerts a substantial influence on the community structure at the site.

3.4. Forest Structure and Regeneration

The structure of forest vegetation can be used to illustrate the conditions of forest regeneration. If the distribution is inverted J-shaped (indicating a greater number of small trees than large ones), then regeneration is likely to occur. Conversely, if the distribution is not inverted J-shaped (e.g., with few young trees), regeneration may be inhibited. The structure of the forest according to the distribution of diameter classes is illustrated in Figure 3.

Finally, the forest structure shown in the diagram reflects the characteristics of a forest exhibiting optimal regeneration, albeit with a limited number of large individuals. Further monitoring is imperative to ensure that regeneration progresses to the large-diameter tree stage and to understand the potential threats to the sustainability of this forest.

Tree species regeneration patterns can also be observed through the distribution of the importance value index at each growth level (seedling, sapling, and tree), as presented in

Table 6. Important value index of tree species and their threat level (according to IUCN) with complete regeneration at the three sampling sites.

No.	Sample Sites and Species	IUCN	IVI (%)
			Seedling	Sapling	Tree
A.	CC2
1	Castanopsis acuminatissima/Riung anak	Least concern/LC	21.32	20.39	85.95
2	Castanopsis argentea/Saninten	Endangered under criteria A2c./EN	17.33	14.55	32.86
3	Decaspermum fruticosum/Kisireum	Least concern/LC	17.95	71.15	12.41
4	Syzygium nervosum DC. = Eugernia overculata/Salam anjing	Least concern/LC	14.31	15.92	6.27
5	Litsea sp./Huru Litsea angulata/Huru Litsea tomentosa/Huru meuhmal	Least concern/LC Least concern/LC	47.33	73.82	55.07
6	Macaranga tanarius/Mara	Least concern/LC	6.80	5.85	7.47
7	Schima wallichii/Puspa	Least concern/LC	26.04	16.41	36.95
8	Sterculia oblongata/Hantap	Least concern/LC	3.03	41.30	1.95
9	Symplocos fasciculata/Jirak	Least concern/LC	15.38	12.24	1.25
B.	CC3
1.	Calliandra calothyrsus/Kaliandra	-	34.97	202.48	7.80
2.	Castanopsis argentea/Saninten	Endangered under criteria A2c./EN	5.41	11.74	74.63
C.	Cirembes
1.	Castanopsis acuminatissima/Riung anak	Least concern/LC	70.30	19.44	102.82
2.	Castanopsis argentea/Saninten	Endangered under criteria A2c./EN	31.22	7.05	55.33
3.	Syzygium nervosum DC. = Eugernia overculata/Salam anjing	Least concern/LC	7.00	28.62	10.69
4.	Litsea sp./Huru	-	56.30	75.71	28.82
5.	Schima wallichii/Puspa	Least concern/LC	51.43	31.87	42.78

. If a species exhibits a high IVI at all vegetation levels (seedlings, saplings, and trees), then the species demonstrates complete and sustainable regeneration. Conversely, if the IVI is high in the tree stage but low in the seedling and sapling stages, then the regeneration of the species is potentially compromised. Compared to other vegetation types, Castanopsis argentea was notably dominant at the CC3 and Cirembes sites, particularly at the tree level. At CC3, where only two species were recorded, C. argentea exhibited a significantly higher Importance Value Index (IVI) of 74.63%, which was nearly ten times greater than that of Calliandra calothyrsus (7.8%). In contrast, at site CC2, C. argentea was not dominant at any vegetation level.

3.5. Carbon Stock

Figure 4 shows the carbon stock in the aboveground biomass pool for trees with a diameter of at least 10 cm. As indicated in Figure 4, the carbon stock of forest stands with a diameter of at least 10 cm, as determined by the formula proposed by Chave et al. [35], is notably high at 560.47 tons C/ha, equivalent to 2056.92 tons CO₂/ha. Figure 5 presents the tree species with the highest carbon stock, all of which have a diameter of at least 10 cm. The three species with the largest carbon stock are Litsea sp. (Huru), C. argentea (Saninten), and C. acuminatissima (Riung anak).

4. Discussion

4.1. Soil Characteristics

The soil pH values of all research plots are relatively low, indicating acidic conditions (5.1–5.7). However, these values are higher than those found in the Cirembes disturbed primary forest forest, which is considered very acidic (4.9) despite being a natural forest. This situation is particularly evident in the CC2 and CC3 areas, where the conditions have become more open due to the installation of piles for the construction of the gondola station, and litter from the felling remains scattered throughout the site. According to Angst et al. [46], the effect of litter on soil chemistry enhances nutrient availability in the soil, thereby supporting the growth of plants. This finding aligns with the results of the C-organic values in almost all research plots (Table 4), which fall within the high category. Notably, the C-organic content in the Cirembes disturbed primary forest forest plot is very high [47]. According to Franco et al. [48], a high soil organic matter content can significantly improve soil physical properties and provide essential nutrients, thereby increasing soil fertility.

The CEC and total N in the soil determine C. argentea distribution and dominance [11]. The results indicated that almost all research plots exhibited moderate nitrogen (N) values, except for the Cirembes natural forest, where the N content was high. The phosphorus (P) content across all plots at the research site was low despite the fact that phosphorus is essential for plants, particularly for root development. Phosphorus is a key element in several fundamental plant processes. It is crucial for the formation of nucleic acids (DNA and RNA), ATP, and phospholipids, all of which are essential for energy transfer, cell division, and membrane structure [49]. The impact of phosphorus deficiency on Saninten species includes root system limitations and stunted vegetative growth. The low phosphorus (P) content in this area is believed to be attributed to a lack of microbial activity in the mineralization of phosphate, which is likely a consequence of the low soil pH. In addition, P content is often bound by ions such as Ca²⁺, Al³⁺, Fe³⁺, and Mn²⁺, so it is difficult to provide it without the added C-organic materials. C-organic materials can reduce P bonds with these ions, allowing them to be released and made available [49]. Other results show that the CEC values in all research plots are high (Table 4), indicating that the land has a better soil ability to store and provide nutrients for plants.

The research results indicate that the soil texture is predominantly composed of a sand fraction, with a percentage exceeding 90%, and a small amount of silt, resulting in very crumbly soil at the research location. This condition is believed to be a consequence of the historical eruptions of Mount Gede Pangrango, which frequently occurred in the area [50]. The composition of these fractions influences the soil’s ability to retain water and the rate of water infiltration. Sandy-textured soil has a relatively small surface area; therefore, its capacity to hold water and nutrients is low [51]. The sand fraction plays a crucial role in determining the air dynamics within the soil, including infiltration speed, penetration, and the soil’s ability to retain air [52]. Smaller soil particle sizes are positively correlated with soil water content, soil erodibility, and soil cation exchange capacity (CEC) [53,54]. The absence of clay content in two plot locations (CC2 and CC3) and the minimal amount present in the Cirembes plot (1%) indicate that the soil’s capacity to retain water is low, resulting in low soil moisture. This is attributed to the fact that the clay fraction acts as a binder for soil aggregates, thereby preventing soil transport by surface flows [55]. The characteristics of soil dominated by sand, combined with chemical conditions that tend to be acidic, significantly impact the carbon storage capacity and biodiversity in mountain forest ecosystems [56]. Soils with high acidity levels and low nutrient content can serve as limiting factors for plant species diversity, particularly for species that require a high nutrient supply [57]. However, species such as C. argentea and several others in the area appear to have developed adaptations to less-fertile soil conditions [9]. For example, adaptations to low phosphorus levels can be supplied from litter found on the forest floor to supplement phosphorus deficiency.

According to the findings from the analysis, the condition of the Cirembes research location prior to its conversion into an ecotourism site reflected a level of soil fertility that was sufficient for the natural growth of Saninten and approached the conditions of a natural forest; this was also true for areas CC2 and CC3, where gondola poles had been installed [58]. When developing infrastructure for ecotourism, it is crucial to consider its potential impact on biodiversity, especially if ecotourism activities lead to increased disturbance of soil and natural vegetation [14]. The high organic carbon (C) content in certain areas, such as Cirembes, which reached 8.11%, indicates the significant potential of mountain forest ecosystems for carbon storage [59]. However, sandy soils, which have a low capacity to retain nutrients, can be vulnerable to degradation, particularly when influenced by human activities such as infrastructure development for ecotourism [60]. Therefore, appropriate protection and management efforts are necessary to maintain the function of this ecosystem as an effective carbon sink and storage system [61].

4.2. Plant Species Diversity

The results of this study indicate that CC3 exhibits superior natural regeneration capacity compared to CC2 and Cirembes, as evidenced by the substantial diversity observed in seedlings. Notably, CC3 demonstrated optimal regeneration, characterized by high seedling diversity and species abundance. This finding suggests that the site possesses considerable conservation potential [62]. In contrast, CC2 exhibited a moderate level of regeneration, displaying relatively stable diversity but not reaching the same level as that of CC3.

Cirembes may be experiencing the dominance of certain species or ecological disturbances, necessitating further assessment of the factors contributing to low diversity. CC3 demonstrates the best regeneration and should be prioritized for conservation, as it harbors a more diverse array of species and exhibits strong regeneration. Cirembes have low biodiversity and require specific strategies to enhance their regeneration and diversity, such as restoration interventions, including species enrichment and protection from disturbance. Anthropogenic factors are likely to be one of the most disturbance-inducing factors, namely the possibility of disturbance to saninten (C. argentea) seedlings and others taken by the communities. In addition, there are many old pine stands in Cirembes. CC2 exhibited moderate diversity but necessitated continued observation to determine whether certain species dominated and impeded the regeneration of others and to ensure that adequate regeneration was underway.

4.3. Species Composition

A comparative analysis of species composition across the three sample sites revealed that sample site CC2 exhibited a mixed forest community comprising species such as Decaspermum fruticosum and Maesopsis eminii, which were absent from the other sites. In contrast, sample site CC3 demonstrated a pronounced predominance of plantation forest species, such as P. merkusii, in contrast to the other sites, which exhibited a greater prevalence of typical mountain forest species [63]. The Cirembes site was found to be a habitat that strongly favored C. acuminatissima, which was significantly more dominant than other species. It was discovered that C. acuminatissima was greatly favored by animals at the Cirembes site [64,65]. Norden et al. [66] noted that the presence of dominant species in the montane ecosystem indicates that the study area has a diverse forest community. The presence of exotic species like M. eminii in one area suggests that ecological disturbances or an ongoing secondary succession process may be at play.

The prevalence of C. acuminatissima was particularly pronounced in CC2 (IVI 85.95%) and Cirembes (IVI 102.82%), indicating its high adaptability and significant role in the forest ecosystems of these locations [9]. The predominance of C. acuminatissima in Cirembes and CC2 also suggests that these areas may still possess favorable forest conditions, especially regarding edaphic factors [9], supporting a diverse array of native species. P. merkusii dominated CC3 (IVI 84.60%), suggesting the possibility of plantation forest or human-driven regeneration [67]. Schima wallichii (Puspa) was previously found to be distributed in all sites with high IVI, indicating that this species has wide adaptability in various environmental conditions [68]. On the other hand, according to Hidayah [69], S. wallichii was distributed throughout all sites because it can adapt to critical soils; therefore, this species has the best growth performance compared to other tree species in this location. In addition, S. wallichii is a fast-growing species that can grow in nutrient-poor soil conditions. Similarly, the invasive plant species M. eminii has spread worldwide [70]. This plant was first introduced as a substitute for wood in Indonesia due to its easy maintenance and capacity for overgrowth [71].

This discussion indicates that the CC2 and Cirembes sample sites maintain species characteristics of tropical montane forests (Castanopsis, Schima, Litsea, and Altingia), suggesting conditions conducive to enhanced natural biodiversity that potentially facilitates effective regeneration [68,72]. C. acuminatissima’s substantial tree density, reaching 132 trees per hectare, suggests a high probability of successful natural regeneration in the CC2 area. Conversely, CC3 exhibits a lower tree density, predominantly comprising P. merkusii at 32 trees/ha, suggesting potential limitations in regeneration or the presence of more open forest conditions. The prevalence of P. merkusii in CC3 could be indicative of ecological shifts resulting from human disturbance, which often impedes the regeneration of other species through the release of allelopathy (chemical substances that inhibit the growth of other plants) [63,73]. The analysis further reveals a pronounced dominance of C. acuminatissima in Cirembes, with an observed density of 88 trees per hectare and a notably high IVI, suggesting a relatively stable forest ecosystem [74].

The presence of non-endemic or alien species, such as M. eminii, at sample site CC2 suggests that this area has been disturbed. The presence of invasive species, particularly those of concern, necessitates monitoring to prevent their dominance, which could hinder the natural regeneration of native species [75]. M. eminii (density 9 trees/ha, IVI 10.33%) was only found in CC2, which may also indicate a process of succession or recovery from the secondary forest. According to Richardson and Rejmánek [76], invasive species such as Maesopsis eminii have been shown to compete with native trees for nutrients, water, and light, which can lead to a decline in biodiversity. Furthermore, the research findings indicate that the presence of both Maesopsis eminii and Pinus merkusii necessitates meticulous monitoring and, when necessary, controlled measures to ensure the continued regeneration of native species and prevent the spread of these two alien species, which have the potential to disrupt natural regeneration and reduce biodiversity [77].

4.4. Forest Structure and Regeneration

The bar chart in Figure 3 demonstrates the predominance of small diameters. This observation suggests that the forest is characterized by a substantial presence of young trees or exhibits robust regeneration [78]. Furthermore, Figure 3 shows a smaller proportion of trees in the larger diameter classes, with a gradual decline as the diameter class increases. This trend suggests that few trees are capable of attaining large sizes, which may be attributable to natural factors (e.g., competition and natural mortality) or anthropogenic disturbances (e.g., logging and land conversion). The regeneration of the saninten community at the study site (CC2) that we encountered (habitat at the microscale) indicates that the regeneration process occurs naturally and is influenced more by edaphic (soil) conditions than by climate. With a soil pH of 5.5 (relatively less acidic and closer to neutral) and a high organic matter content, the soil in CC2 makes an important contribution to nutrient availability, water retention, and soil structure that supports the growth of seedlings and saplings. Anthropogenic disturbances (disturbance of Saninten’s ecology/natural habitat due to human activities) referred to in this study include the following: the installation of gondola station poles (Cable Car Stations 2 and 3) for ecotourism infrastructure, tree felling, and transportation of construction materials, and the introduction of invasive species. Anthropogenic disturbances and natural dynamics occur simultaneously. Anthropogenic disturbance in CC2 caused canopy opening and increased light intensity on the forest floor, which stimulated the seed germination (regeneration) of several pioneer species, including saninten. However, natural dynamics, such as species competition, litter decomposition, and natural changes in stand structure, continue to occur and determine the direction of vegetation succession.

The tree diameter class distribution in Figure 3 also illustrates the forest structure commonly found in secondary or highly regenerated forests [79]. The number of very large diameter trees (≥80 cm) is only 47 individuals [80], so the conservation of large trees is imperative, as they play a pivotal ecological role in storing carbon, providing a habitat for wildlife, and maintaining ecosystem stability [81]. The observation of a limited number of large trees necessitates the conservation and protection of these remaining specimens.

At CC2, regeneration is diverse but uneven. Castanopsis acuminatissima dominates at the tree stage but shows weaker regeneration at the seedling stages, while Litsea sp. has strong regeneration across all stages. Decaspermum fruticosum shows an imbalance, with a high presence in the sapling stage but a low presence in others, indicating regeneration challenges possibly caused by ecological filtering or microsite conditions [82].

In CC3, natural regeneration is weak. C. argentea is dominant as a mature tree but lacks younger growth, and Calliandra calothyrsus is dominant in the sapling stage but absent in the tree stage, suggesting possible ecological disturbance or transition in species composition [14,83].

Cirembes exhibit the most stable and continuous regeneration. C. acuminatissima, Litsea sp., and Schima wallichii show a strong presence across all vegetation levels, highlighting their role in supporting long-term ecosystem stability and restoration [84,85].

4.5. Carbon Stock

Biomass data are beneficial for assessing the productivity of different ecosystems [35]. Forest biomass, expressed as dry weight per unit area, includes leaves, flowers, fruits, branches, small branches, main stems, roots, and fallen or decaying trees. Diameter, height, and wood density are measured to determine the amount of forest biomass [86], approximately 47 percent of which contains carbon [38]. Therefore, estimating in tropical forests is important because of its impact on the carbon cycle [87]. This critical aspect has garnered the attention of many stakeholders, highlighting the necessity of conserving carbon stocks, especially in endemic and endangered species. Compared to the primary forest of Batang Toru, North Sumatra (100.36 tons C/ha) [88], and in Sarawak, Malaysia (165–202.5 tons C/ha) [89], the carbon stock in this study is higher, amounting to 560.47 tons C/ha. This demonstrates that the carbon stock condition of the forest at the research location is still good.

At the study site, the regeneration of C. argentea and other endemic vegetation is still in good condition and has good potential for carbon sequestration. In the context of management, undisturbed forests in the study locations, which function as conservation areas, have a further impact on the sustainability of carbon sequestration and biodiversity conservation. Natural forest regeneration is frequently considered an efficient, low-cost technique for sequestering carbon, especially in tropical areas [90,91,92].

4.6. Ecotourism Development in Study Site as Potential Threat to the Habitat of C. argentea

The Barubolang Zone, designated as a usage area within the Mount Gede Pangrango National Park (MGPNP), is slated for ecotourism-related growth. The establishment of stations, poles, and structures necessitates about 1000 square meters of land clearance, heightening concerns about habitat fragmentation and disruption of ecosystems [93,94]. Considering these potential impacts, it is essential to conduct in-depth studies on risk mitigation and effective management strategies to ensure that ecotourism can thrive without compromising the natural preservation of this area.

The study site is known as a habitat for several rare species, including dominant tree species listed in the IUCN Red List [1,95], such as C. argentea (Saninten) (endangered status based on criteria A2c/EN), C. acuminatissima (Riung anak), Altingia excelsa (Rasamala) (least concern status/LC), and Litsea sp. (Huru). In the study of vegetation structure in the MGPNP area conducted by Sadili et al. [96], several Litsea species were identified and included in the IUCN Red List [97,98], including L. brachystachya (Blumea) Fern., L. glutinosa (Lour.) C.B. Rob., L. ligustrina (Nees) Fern., and L. noronhae Blume (Least Concern status/LC). The removal of vegetation caused by the development of this attraction can significantly affect the survival of these species, which contribute to the biodiversity of the GGPNP. Efforts aimed at conserving biodiversity and protecting species, particularly those centered on rare trees such as C. argentea, are essential for the continued existence and growth of these species within their habitats. The conservation of biodiversity encompasses not only the safeguarding of endangered species but also initiatives to preserve their natural environments. By safeguarding rare trees like C. argentea, we are not only protecting the species itself but also bolstering the entire ecosystem that relies on it. These trees frequently provide habitats for numerous flora and fauna and contribute to ecosystem equilibrium [9]. For the sustainability of ecotourism, it is necessary to analyze the carrying capacity of the ecotourism environment for visits and visitor behavior without causing damage to the physical, economic, and socio-cultural environment or reducing tourist satisfaction [99].

Effective species protection programs typically involve a science-based approach that identifies and addresses threats to these species. Efforts to manage and recover endangered species occur through collaboration between national parks and conservation agencies worldwide. By implementing well-planned strategies, species like C. argentea can be guaranteed not only to survive but also to thrive in their habitats, contributing to broader biodiversity. Hayward [100] asserted that a robust conservation strategy necessitates the use of the IUCN Red List. This list provides important information regarding the conservation status of species and helps prioritize management and resource allocation for more effective protection efforts. By understanding the status and challenges faced by species, researchers and conservationists can design better interventions to enhance the chances of biodiversity survival and ensure that the measures taken can be tailored to the specific conditions of each habitat. To minimize the impacts that will occur, tourism stakeholders, including the government and the private sector, must ensure that ecotourism development is well-planned and managed. According to Curovic et al. [101], assessing natural and spatial cultural values is an important step in the landscape planning process. The evaluation and mapping of landscape features is carried out considering several factors (naturalness, diversity, and culture). Assessments of ecotourism appropriation in Indonesia are based on tourist scenery, land cover, zone type, biodiversity, and slope grade [102], and recommending areas for tourism activity planning can utilize a nature-based approach, considering high levels of attractiveness and high levels of accessibility [103]. Ecotourism is rising globally as a solution for balancing livelihood improvement and biodiversity conservation issues. It is a form of tourism that showcases the beauty of natural landscapes while addressing both ecological and economic aspects to achieve sustainable tourism development goals [15,104,105,106,107].

5. Conclusions

This study emphasizes the ecological importance of Castanopsis argentea (Saninten), an endangered species that plays a crucial role in the structure of forest ecosystems and carbon storage in Mount Gede Pangrango National Park (MGPNP). While C. argentea is dominant in mature tree strata, its regeneration remains inconsistent, particularly in areas like CC3, suggesting its vulnerability despite the presence of diverse and resilient companion species such as C. acuminatissima, Litsea sp., and Schima wallichii. The development of ecotourism infrastructure, particularly cable car stations, has altered soil characteristics, including a decrease in pH and an increase in sandiness. These changes have had a subsequent impact on the potential for vegetation regeneration in the affected areas. The proliferation of disturbance-tolerant and invasive species indicates threats from trampling, habitat fragmentation, and vegetation homogenization due to anthropogenic pressures. With aboveground carbon stocks reaching 560.47 tons C/ha, the forest demonstrates high sequestration potential, reinforcing the need to conserve mature stands for both biodiversity and climate benefits. In order to ensure the continued viability of ecotourism practices, conservation efforts must prioritize the enrichment of C. argentea in CC3, control of invasive species, establishment of vegetation protection measures (e.g., designated trails), and integration of long-term biodiversity monitoring into management plans.