Diversity of spice plants in the MADAPI Forest, Kerinci Seblat National Park, Rejang Lebong

. A study of the potential of spice plants in the Kerinci Seblat National Park area particularly in the MADAPI Forest was conducted to find out the types of the plants as well as their number and abundance. The method used in this research was a survey using a proportionate stratified random sampling technique. The size of the observation plot was 20mx20m. The total number of observation plots was 80 plots. Based on the observations, it was found 13 types of spice plants from 10 families, mostly dominated by the Zingiberaceae. The abundance value of the plants was low (small). Most types of spice plants in the MADAPI Forest grew in a clumped distribution pattern. The most spice plant species were found in the Pinus merkusii area and the least was in the Aleurites moluccana area.


Introduction
Kerinci Seblat National Park (KNSP) is a high biodiversity conservation area.Some areas of the park are located in Rejang Lebong Regency, Bengkulu Province, Indonesia.The MADAPI Forest is located within the KNSP area.This forest contains a variety of food plants, latex, resins, gums, medicinal plants [1,2], and spice plants which are grouped as nontimber forest products.
In conservation areas, only non-timber forest products are allowed to be exploited.Extraction of timber forest products is prohibited there since it will disrupt the ecological functions of the ecosystem and reduce biodiversity.However, land encroachment for coffee plantations and illegal logging are common occurrences in the KNSP.The anthropogenic activities include logging, the opening of roads to haul timber, and visiting the area for tourism potentially damaging and threatening the biodiversity including spice plants.
Indonesia is one of the biggest spice producers in the world as well as a prominent spices exporter [3].Indonesian people as well as people around the world commonly use spice plants as food flavoring ingredients, flavor enhancers, food colorants, and air fresheners [4][5][6].There are around 400-500 different types of spices in the world, with Southeast Asia having approximately 275 different types of spice plants [4].Spice plants are widely grown on cultivated lands and home gardens, but many are still taken from their natural habitat in the forest [7][8][9].Kerinci Seblat National Park (KNSP) has grown a lot of plants, however, we found still limited information that reported the plant diversity, particularly the spices plants there.Several kinds of research have been done in the KNSP to identify some plants [1,2,10,11], but there is no specific research yet for identifying spice plants in the MADAPI Forest.Therefore, we researched to determine the number and types of spice plants in the MADAPI Forest as well as their abundance.
The topography of Aleurites moluccana and Agathis dammara areas is sloping, whereas the topography of Pinus merkusii area has some steep points.The study site is shown in Fig. 1.A purposive sampling technique was used in this study to determine the number of plots in each area of the MADAPI Forest.The sampling intensity used was 1.5% of the entire area of the forest.The plot size used was 20 m x 20 m with a total of 80 plots divided according to the size of each area, namely 4 plots of Aleurites moluccana area, 8 plots of Agathis dammara area, 12 plots of Swietenia mahagoni area, 56 plots of Pinus merkusii area.Plant identification was carried out directly in the field with the assistance of local guides.
Species diversity was analyzed using the Shannon-Wiener Index.From this formula, we continued to analyze the species abundance using Simpson's Diversity Index.The species distribution was analyzed using the Morisita Index.

Plant diversity
Based on identifying the spice plants, we found 13 species belonging to 10 families.There were 9 species from different families and 4 from the same family.Etlingera coccinea was found in the greatest number of individuals.Meanwhile, the smallest number of individuals, namely Garcinia xanthochymus, Pangium edule, and Syzygium polyantum were found in only 1 plant.Table 1 shows the number and types of spice plants.Most of the spice plants were found dominated by the Zingiberaceae family and the herbs.The same result was also reported by Priyanka Singh et al. that the Zingiberaceae and herbs species were dominant [5].This is presumably because these species have a rhizome which causes them to spread easily and quickly.
In the area of Aleurites moluccana stands, we found 3 types of spice plants, namely Etlingera elatior, Etlingera coccinea, and Aleurites moluccana.This area was used as community cultivation land which was dominated by A. moluccana trees.This area was grown by E. elatior whose flowers are commonly used as spices.
The plants found in Agathis dammara area included Etlingera elatior, E.coccinea, Aleurites moluccana, Melastoma malabathricum, Curcuma longa, Amomum compactum, and Pangium edule.Agathis dammara area covered a larger area than Aleurites moluccana area (21.521 ha).In this area, Agathis dammara trees grew so close to each other that their canopy blocked sunlight to get into the forest floor.It was a suitable habitat for Etlingera coccinea plants.Other spices from the Zingiberaceae found in Agathis dammara area included Etlingera elatior, Curcuma longa, and Amomum compactum.The Zingiberaceae plants can be found in primary and secondary forests up to 1600 meters above sea level where there is sufficient sunlight.Furthermore, only one Pangium edule tree was found in Agathis dammara area and it was already quite large.This plant can grow well at altitudes of 10-1,000 m above sea level on rocky soils or even nutrient-poor clays.The Swietenia mahagoni area was grown by six different types of spice plants, including Etlingera elatior, E. coccinea, Aleurites moluccana, Syzygium polyantum, Amomum compactum, Melastoma malabathricum.Syzygium polyantum was the only spice plant found in Swietenia mahagoni area.It is assumed that the S. polyantum tree was a community plant when they had a plantation in the MADAPI Forest before reforestation.This is supported by field observation, which showed that there were coffee plants around the S. polyantum tree.The environmental conditions in the Swietenia mahagoni area were similar to those in the Agathis dammara area, with no distinguishing characteristics.At an altitude of 300-700 masl, with a soil pH of 7, good environmental conditions for S. polyantum trees to grow well.
The Pinus merkusii area had the largest area of 148,796 ha.We found the most species and number of spice plants (9 species).Citrus sp, Capsicum frutescens, Mangifera foetida, Piper nigrum, and Garcinia xanthochymu are some of the spice plants that only be found in the pine zone.This is most likely caused by the remnants of garden plants belonging to the community that opened coffee plantations in the area.Garcinia xanthochymu is a spice plant that is only found in pine forests.These plants prefer shade and a humid environment and are usually found in the second layer of the tree.
Most of the spice plants were found dominated by herbaceous species, and only 6 types of the plants had tree habitus.According to Shameem et al., the composition of herbs is affected by many factors, particularly environmental factors, namely climate, and soil [12].The availability of suitable growing space and sufficient rainfall will affect its growth.

Plant abundance
The number of plant species in an area is indicated by species abundance.Table 2 shows the abundance of spice plants.Table 2 shows that the abundance value of each spice plant species is low, and only one species, Etlingera coccinea, dominates in the forest.According to Mahajan et al., the value of 61%-80% is categorized as common (abundant) [13].Several factors contribute to the presence of Etlingera coccinea being common in the forest.The biotic factor of the Etlingera coccinea extremely affects its growth.The method of breeding and the time of reproduction of the Etlingera coccinea is relatively fast when compared to other plants in the same family.The breeding time affects Etlingera coccinea population since it occurs in a relatively short time.
In addition to biotic factors, environmental factors in the MADAPI Forest support the survival of Etlingera coccinea.This plant, according to Mark et al. and Dosuil et al., is commonly found in primary forests or secondary forests at elevations ranging from 300 to 1400 masl [14,15].According to field observations, Etlingera coccinea is frequently found under trees with dense crowns, which shade the forest floor.The environmental conditions on the floor of the tree stands were very humid, ranging from 55-70%, with temperatures ranging from 20-30 o C, litter thickness ranging from 3-10 cm, and soil pH ranging from 6.7 to 7.2.
Other types of spice plants are considered very rare because their range is less than 20%.Aleurites moluccana, Syzygium polyantum, Pangium edule, and Garcinia xanthochymus, for example, are woody plants with a relatively long breeding time compared to herbaceous plants.As a result, the number of plants found is limited.Meanwhile, the low abundance value of herbaceous plants such as Etlingera elatior, Melastoma malabathricum, and Coffee sp. are most likely due to environmental factors that are not suitable for the growth of these plants.Etlingera elatior requires adequate sunlight to grow properly.In addition, the community takes flowers of this plant, disrupting its propagation.

Plant distribution
The distribution pattern of the spices plants is shown in Table 3. Syzygium polyantum --Table 3 shows that the distribution of the spice plants in the MADAPI Forest is mostly clumped.In tropical forests, clumped distribution patterns are very common.This grouping is caused by the response of plants to different habitats.Herbaceous plants are spice plants with clumped distribution patterns.The spatial pattern of the plants is affected by an interaction between the plants and environmental factors [16,17].
The Zingiberaceae plants, breed with rhizomes, causing these plants to clump together biologically.Furthermore, pollination agents play an important role in the spread of spice plants.Melastoma malabathricum plants are pollinated by insects, specifically butterflies, and beetles, which have a short cruising range, causing the plants to clump together.
Citrus sp. and Mangifera foetida are also planted with a uniform distribution pattern.Usually, this distribution pattern is very difficult to find in forests.Uniform distribution will occur if the environmental factors for the entire area where the plant lives are very diverse, and there are no biological characteristics of the plant that allow it to live in groups.The spices plants with uniform distribution are possible since the community had purposefully planted these plants in the MADAPI forest.The MADAPI area was previously an abandoned community plantation.
Other spice plants, such as Garcinia xanthochymus, Pangium edule, and Syzygium polyantum did not have a distribution pattern since the plants were found in only one species.These plants that grew in the MADAPI Forest were already mature, with no-tillers found around them.It is assumed that these plants are difficult to grow naturally in the MADAPI Forest, or that they lack pollination and dispersal agents.

Conclusions
Based on the results of the study, the MADAPI Forest of Rejang Lebong Regency has 13 types of spice plants from 10 families, dominated by Zingiberaceae.The abundance value of the majority of spice plants is very rare and the distribution pattern is clumped.

Fig. 1 .
Fig. 1.Plot distribution of the study site.

Table 1 .
Number and types of the spice plants.

Table 2 .
The abundance of the spice plants.

Table 3 .
Distribution of the spice plants.