TREE SPECIES DIVERSITY AND MANAGEMENT IN AGROFORESTRY POHPOHAN (Pilea melastomoides)

THE CASE IN THE TRADITIONAL ZONE OF GUNUNG HALIMUN SALAK NATIONAL PARK, INDONESIA

Article Highlights
- Pohpohan (Pilea melastomoides) is the main commodity cultivated by using traditional agroforestry in the traditional zone of Gunung Halimun Salak National Park as a fresh vegetable.
- There is a limited database of plant species diversity in the traditional zones, which is dynamic and needs further research.
- This study found 54 tree species from 37 families with the dominant family being Rubiaceae.
- Most farmers cultivated Pohpohan by conducting plant spacing, maintenance, and harvesting. Their income is USD 154 – 256/month.

Abstract
Gunung Halimun Salak National Park (GHSNP) is Java's largest tropical mountain forest. GHSNP is still facilitating community grounds around GHSNP with the existence of a traditional zone. Pohpohan (Pilea melastomoides) is the primary commodity in the traditional zone cultivated by the local people around GHSNP. Pohpohan is planted using traditional agroforestry planting patterns. The traditional zone has a limited plant species diversity and management database, so further study is necessary. This study was conducted in the traditional zone of GHSNP, specifically at the agroforestry system in Tamansari Village, Bogor Regency. Data collection of tree diversity was conducted by establishing 25 plots. This study also interviewed 30 local farmers belonging to the Mandiri farmer group. There are 54 species from 37 families. Rubiaceae, Malvaceae, Fabaceae, and Phyllanthaceae families are the most common families. Pinus merkusii, Agathis dammara, and Maesopsis eminii have the highest important value index (IVI) values. Understorey and seedlings have a low category on H' due to the dominant planting of Pohpohan. Most respondents are people aged 35-55 (70%) with a farming area of 1000 m². They cultivate Pohpohan by conducting plant spacing, plant maintenance (e.g., soil cultivation, weeding, fertilization), and harvesting. Most farmers conduct fertilization 9 times/year. Farmers produce 30.000-50.000 bunches/harvest. The price of a bunch of Pohpohan is 0,00054 USD. Their income is about 154 USD – 256 USD/month.

INTRODUCTION

Gunung Halimun Salak National Park (GHSNP) is an area of natural conservation. It is the largest tropical mountain rainforest on Java Island. Administratively, GHSNP is located in three regencies, namely Bogor Regency, Lebak Regency, and Sukabumi Regency. The designation of the GHSNP area as a conservation area began with the Decree of the Minister of Forestry of the Republic of Indonesia Number 282/Kpts-II/1992 issued on 28 February 1992 declaring an area of 40,000 ha as the Gunung Halimun National Park (GHNP). Subsequently, the Minister of Forestry of the Republic Indonesia issued a Decree Number 175/Kpts-II/2003 dated 10 June 2003 to expand the GHSNP area to 113,357 ha as a response to the growing occurrences of forest disturbances. This expansion included the forests of Mount Salak, Mount Endut, and the surrounding areas, which had previously been classified as limited- production forests and protected forests managed by State-Owned Forest Enterprise (Perum Perhutani). Since then, the GHNP area has been transformed into a unified GHSNP conservation area(Ekayani et al., 2014).

Gunung Halimun Salak National Park is classified into several zones to facilitate spatial arrangement within the national park. These zones are generally classified based on the community’s ecological, social, economic, and cultural conditions. According to the 2007-2026 GHSNP Management Plan, the GHSNP area is divided into eight zones: traditional zone, cultural zone, special zone, rehabilitation zone, utilization zone, jungle zone, core zone, and enclave. However, zoning in the GHSNP forest area was slightly altered based on the Decree of the Minister of Environment and Forestry of the Republic of Indonesia Number 327/Menlhk/Setjen/PLA.2/4/2016 dated 26 April 2016, which changed the function of 17,373 ha in the GHSNP forest area and returning another use area (enclave) covering 7,847 ha. As a result, the GHSNP is divided only into seven zones, covering an area of 87,699 ha(Salak, 2021).

The expansion of the GHNP into the GHSNP area, which includes land used for community economic activities, has created a conflict between ecological (conservation) and economic interests. This issue is addressed by allowing a small portion of the GHSNP area for community use, which permits local farmers to continue their economic activities. The Gunung Halimun Salak National Park Office (GHSNPO) still facilitates several community grounds around GHSNP, designating these areas as the traditional zone. Local communities use the traditional zone to supply their daily necessities by using non-timber forest resources, such as tapping pine sap, tapping copal sap, and farming Pohpohan leaves.

Pohpohan (Pilea melastomoides) is the main commodity cultivated by using traditional agroforestry planting patterns in the traditional zone as fresh vegetable, mainly by the Sundanese people in Indonesia. Pohpohan cultivation is particularly significant in Tamansari Village, Bogor Regency. Agroforestry is a form of multi-story land use that includes a mixture of trees and annual plants. Agroforestry land must have at least woody plant species(Olivi et al., 2015). In the traditional zone of GHSNP, Pohpohan is shaded by pine (Pinus merkusii), agathis (Agathis dammara), and African wood (Maesopsis eminii), which are planted by Perum Perhutani. Local communities have been practising the Pohpohan agroforestry system in this area for decades, considering ecological, social, and economic factors. Therefore, to accomplish sustainable management, studying agroforestry systems is crucial. Additionally, there is a limited database of plant species diversity in the traditional zones, particularly in the Pohpohan agroforestry system, which is dynamic and needs further research. The purpose of this study is to analyze the diversity of tree species and management in the Pohpohan agroforestry of Gunung Halimun Salak National Park, built upon Traditional Ecological Knowledge (TEK).

MATERIALS AND METHODS

Study Area

This study was carried out in the traditional zone of Gunung Halimun Salak National Park (GHSNP), West Java Province, Indonesia. The specific study site is the Pohpohan (Pilea melastomoides) agroforestry system in Tamansari Village, Bogor Regency, West Java Province, Indonesia (Figure 1). GHSNP is administratively divided into three districts: Bogor Regency, Lebak Regency, and Sukabumi Regency. Geographically, the national park is located between 106°21’ - 106°38’ E and 6°37’ - 6°51’ S.

GHSNP is vital in maintaining biodiversity, regulating water management, supporting education and research, and functions as germplasm sources, cultivation development, and tourism. Salak Mountain has a height ranging from 400 to 2,210 masl. The climate type of GHSNP is classified as type B according to Schmidt and Ferguson, characterized by wet conditions with rainfall of 4,000-6,000 mm/year and a dry season that lasts less than three months, typically from May to September. The average monthly temperature in GHSNP ranges from 19.7 °C to 31.8 °C and the average air humidity is 88%(Adalina, 2014).

Figure 1.Study area in the traditional zone of GHSNP

Figure 2.Design of observation plots

Procedures

Plot Establishment

Data on tree diversity was collected by establishing 25 plots within GHSNP. The plot selection was carried out using the purposive sampling method, with criteria including representing an agroforestry system containing at least one species of woody plant, managed by the local community for generations, and having at least one main commodity species contributing to the income of the local community. Each of the 25 plots measured 20 m × 20 m. The square plots were divided into several square subplots. For detailed observation, 20 m × 20 m plots for tree level, 10 m × 10 m for pole level, 5 m × 5 m for sapling level, and 2 m x 2

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