A Contribution to Trees and Shrubs Checklist in Kuala Keniam at Taman Negara, Pahang, Malaysia

The forested area around Kuala Keniam is a part of Taman Negara (Pahang) and is categorized as a primary lowland dipterocarp, riparian fringe and limestone forests. A study of flora that focuses on the trees and shrubs was conducted during the scientific expedition in September 2020, organised by Universiti Teknologi MARA (UiTM). The results identified as many as 187 taxa of trees and shrubs consisting of 124 genera and 49 plant families from the lowland dipterocarp forest. A total of nine endemic taxa to Peninsular Malaysia were also recorded namely Aporosa globifera, Baccaurea pyriformis, Cinnamomum mollissimum, Enicosanthum fuscum, Lithocarpus curtisii, Mallotus griffithianus, M. penangensis, Ryparosa fasciculata and Schoutenia kunstleri. Another three taxa viz. Elaeocarpus obtusatus ssp. apiculatus, Popowia tomentosa and Sterculia rubiginosa var. setistipula were considered as the new additional record for Pahang state. It is hoped that the information from this study can be used as references to help other researchers as well as stakeholders in ecotourism management and forest conservation plan.


Introduction
Taman Negara with an area of 434,351 ha of primary forest is the largest protected area in Peninsular Malaysia. These areas straddle across three states, namely, Pahang, Kelantan and Terengganu. The highest point in this forest is notably located on Gunung Tahan with the elevation of 2,187 m above sea level, the highest mountain in Peninsular Malaysia. These areas are also considered as one of the oldest rain forests in Peninsular Malaysia of more than 130 million years old. Based on classification by Symington [1] and Wyatt-Smith [2], there are several forest types which can be found in Taman IOP Publishing doi: 10.1088/1755-1315/1019/1/012029 2 Negara such as lowland dipterocarp, hill dipterocarp, upper hill dipterocarp, montane oak, montane ericaceous, riparian fringe and limestone forests. Several rivers drain from Taman Negara (Pahang), viz. Sungai Tembeling, Sungai Tahan, Sungai Riul, Sungai Sat, Sungai Kenyam, Sungai Sepia and Sungai Teku. It has been considered as a hotspot for biodiversity as it hosts many species of flora and fauna and many of them are endemic and rare in Malaysia. Therefore, further studies on flora should be conducted to gather more information from these areas. The objective of this study is to record the diversity of trees and shrubs species found in Taman Negara at Kuala Keniam. The collection was then compared to other previous studies done in Pahang.

Materials and Methods
The study of flora was conducted in Taman Negara at Kuala Keniam for four days during a scientific expedition from 4th to 8th September 2020. Specimens of flowering or fruiting plants were collected around the permanent forest trails. Additional data were also obtained from five ecological plots with the size of 25 m x 20 m each. All trees with DBH ≥ 5 cm were tagged and measured. Samples were collected and marked with number tags, together with relevant information and photos were also captured. All specimens collected were identified by their family, genus and species. The identification method used was by matching the morphological similarities of the specimens with the existing collection from Herbarium, Universiti Kebangsaan Malaysia (UKMB) and Herbarium of Forest Research Institute Malaysia (KEP) as well as by using several publications on the morphological features that have been provided by taxonomists. In general, references for all plants are as described by Turner [3] and other verification references for tree species were referred to Ng [4] [5] and Whitmore [6] [7]. All voucher specimens were dried, identified and then deposited at the Herbarium of Universiti Kebangsaan Malaysia (UKMB). We have Brummit [8] for the classification of the flora with only a few exceptions for the recognition of genera [3]. Floristic compositions were tabulated into families, genera and species. The status of endemic species was derived from [3].

The floristic composition
A survey of flora conducted in Kuala Keniam at Taman Negara (Pahang) has found a total of 187 taxa of trees and shrubs consisting of 124 genera and 49 plant families ( Table 1). The most speciose family species is Euphorbiaceae with 24 species, followed by Annonaceae with 12 species, Rubiaceae with 11 species and Leguminosae and Myrtaceae with 8 species each. The largest genus is Syzygium with eight species followed by Aporosa with seven species and Diospyros with five species (Table 2).

The pioneer species
As the forest is not disturbed, the pioneer species stands are rare and the species that can be found include Arthrophyllum diversifolium, Cratoxylum formosum and Macaranga hypoleuca. Both A. diversifolium and M. hypoleuca are short-live pioneers that usually be found in the forest margin or secondary forest [3], [9].

The endemic taxa
From the total 187 taxa of flowering plants in the lowland forest at Kuala Keniam, nine species are identified as endemic species for Peninsular Malaysia (Table 3).

Additional new records for Pahang
A total of three taxa are the new records for Pahang after being compared with the checklist of [3] namely Elaeocarpus obtusatus ssp. apiculatus, Popowia tomentosa and Sterculia rubiginosa var. setistipula. According to [10], Elaeocarpus obtusatus ssp. apiculatus was previously recorded in Kedah, Kelantan, Terengganu and Perak. Meanwhile, Popowia tomentosa was previously documented in three states, viz. Pulau Pinang, Perak and Melaka [11]. Sterculia rubiginosa var. setistipula was only found in Selangor state [12].

The checklist of Trees and Shrubs
List of families, genera and species of flowering plants in alphabetical order are presented in Table 4. Habit of all taxon is also given either trees or shrubs. Teijsmanniodendron coriaceum (C.B. Clarke) Kosterm. Tree

Comparison with other studies
Compared to plant inventories of several localities in primary lowland forest of Peninsular Malaysia such as in Bukit Nanas Forest Reserve, Kuala Lumpur, the total number of trees and shrubs is quite similar. For instance, Ahmad Fitri et al. [13] reported 183 of trees and shrubs from 232 species of flowering plants in Bukit Nanas Forest Reserve. However, Kochummen et al. [14] reported more than 800 species of trees and shrubs in Pasoh Forest Reserve in the 50-ha plot.

Conclusion
This study recorded a total of more than 150 species of trees and shrubs around Kuala Keniam in Taman Negara (Pahang) including nine endemic taxa for Peninsular Malaysia and three additional new records for Pahang state. The findings emphasised that further studies on the flora in Taman Negara need to be conducted as many new records from the collection of plant specimens were found although the expedition was carried out in a short time (four days). Almost all of the plants found in this study are often seen in other lowland dipterocarp forest such as Baccaurea brevipes, Elateriospermum tapos and Xerospermum noronhianum.