Mosses of Gunung Senyum Recreational Forest, a tropical limestone forest in Pahang, Peninsular Malaysia

Abstract Gunung Senyum Recreational Forest harbours 59 species, two subspecies and five varieties of mosses in 32 genera and 16 families that had been identified from a total of 589 specimens collected from the area. These figures represent 11.8% out of the 558 taxa, 20.2% out of the 158 genera and 34.7% out of the 46 families of mosses reported for Peninsular Malaysia. The total also represents 14.9% of the 442 taxa, 24.0% of the 133 genera and 40.0% of the 40 families of mosses recorded in Pahang. The largest family of mosses found in this limestone forest is Calymperaceae followed by Fissidentaceae. There are two new records for Pahang, Calymperespallidum Mitt. and Taxitheliumbinsteadii Broth. & Dixon. The analysis of species similarities of mosses found in the study area with some other selected areas showed that Gunung Senyum Recreational Forest had a high percentage of species similarity with Perlis State Park at Wang Kelian, another limestone forest, at 38%. Corticol is the main habitat utilised by mosses in Gunung Senyum Recreational Forest with 47 taxa, followed by the lignicol and calcicol each with 35 and 26 taxa, respectively.


Introduction
Forested limestone areas in Peninsular Malaysia are estimated at about 26,000 ha, mostly concentrated in the northern states and 50,000 ha in Sabah and Sarawak according to the World Wildlife Fund Malaysia (2018). More than 300 scattered limestone outcrops have been found in the Peninsular Malaysia which consist of limestone islands in the Langkawi archipelago, with major outcrops in Kelantan, Perlis, Kedah, Perak and northern Pahang.
Gunung Senyum Recreational Forest is one of the limestone forests in Peninsular Malaysia and is located in Jengka, Pahang (latitude 3°43.0683'N and longitude 102°26.0043'E). This recreational forest consists of several series of limestone hills, including Gunung Senyum and Gunung Jebak Puyuh. They are hills located northeast of Temerloh and north of Kampung Awah (Fontaine et al. 1988). In addition to limestone hills, this area also comprises lowland forest, especially in the area between Gunung Senyum and Gunung Jebak Puyuh. Gunung Senyum has 18 caves, while seven caves have been recorded at Gunung Jebak Puyuh. These caves originated from weathering activities where some of them are archaeological sites. Several studies in geological, human civilisation and rock life have been conducted in the areas of Jengka including Gunung Senyum and Gunung Jebak Puyuh by Jasin et al. (1995) and Fontaine et al. (1988).
The collection of plant specimens from limestone hills in Peninsular Malaysia started in August 1880 by Kunstler, a collector for Sir George King, who collected specimens in the limestone area of Gopeng, Perak. In addition, there are other collectors, namely Fox, Ridley, Kelsall and Wooldridge. As a result, about 4,500 plant specimens have been collected (Chin 1977).
The study of the limestone flora in most parts of Peninsular Malaysia was initiated by Henderson from 1923 to 1935, including Gunung Senyum and other limestone areas where about 745 plant taxa were recorded here. Also, Carr had collected plant specimens at Gunung Senyum from 1928 to 1930 but most specimens collected by him are orchids and ferns (Chin 1977). Then, Chin (1977) listed about 1216 plant taxa in a comprehensive study of limestone hills in Peninsular Malaysia consisting of pteridophytes, angiosperms and gymnosperms. He also listed Gunung Senyum as one of the largest distribution area of limestone hills in Peninsular Malaysia.
The first comprehensive study on limestone moss flora in Peninsular Malaysia was conducted by Mohamed (1987), in which about 21 limestone outcrops mainly in the northern half of the country were surveyed. He listed about 73 taxa in 40 genera and 18 families of mosses. After that, Damanhuri and Maideen (2001) recorded a total of 71 taxa in 34 genera and 18 families of mosses in Perlis State Park, Wang Kelian, Perlis. Yong et al. (2002) collected about 57 taxa in 28 genera and 13 families of mosses in Wang Mu Forest Reserve, Perlis State Park, Perlis. Later, Damanhuri et al. (2007) reported about 112 taxa in 45 genera and 19 families of mosses in Kenong Forest Park, Pahang. Lastly, Kiew et al. (2014) listed about 25 taxa in 14 genera and 11 families of mosses found in Gunung Kanthan, Perak.
Some studies in Gunung Senyum had been reported before by Chin (1977), but their collections did not cover mosses. Until now, the Gunung Senyum Recreation Forest had not been explored in terms of its moss flora. Therefore, this is the first study of moss conducted there. Also, from this study, a new record for Peninsular Malaysia has been made in this area, Calymperes pallidum Mitt. (Ellis et al. 2018).

Methods
This study is based on samples collected at Gunung Senyum Recreational Forest located in the Jengka Reserved Forest, Pahang ( Figure 1). Collections were made along the trails in the Gunung Senyum Recreational Forest. All the specimens are curated and deposited in the Herbarium of Universiti Kebangsaan Malaysia, Bangi (UKMB).
The information regarding collection numbers, altitudes of each sample collected, date and locality of each specimen collected in Gunung Senyum Recreational Forest are shown in Table 1. Various microhabitats of mosses such as tree trunks, buttresses, rotten logs, surfaces and crevices of rocks, soil and soil banks were carefully surveyed in order to obtain as many samples and species as possible.

Results and discussion
A total of 59 species, two subspecies and five varieties of mosses in 32 genera and 16 families was found in Gunung Senyum Recreational Forest, Pahang (  . The new discoveries of moss species in this area can also increase the bryoflora of Pahang in which the current record is about 442 taxa of mosses in 133 genera and 40 families. The total is higher compared to neighbour states such as Kelantan (299 taxa in 105 genera and 37 families) and Terengganu (253 taxa in 88 genera and 31 families). This shows that Pahang has the highest record of moss species compared to other states in the east coast region of Peninsular Malaysia. Amongst the 15 families recorded, Calymperaceae has the highest number of members (20 taxa), followed by Fissidentaceae with nine taxa. Hypnaceae, Neckeraceae and Pylaisiadelphaceae are the third largest families, each represented by six taxa. This is followed by Sematophyllaceae with five taxa, Pottiaceae and Thuidiaceae with three and two taxa, respectively. The rest, Bartramiaceae, Brachytheciaceae, Bryaceae, Leucomiaceae, Meteoriaceae, Orthotrichaceae, Plagiotheciaceae and Pilotrichaceae have one taxon each ( Table 2).
Calymperaceae is indeed a major family in lowland forest areas in Peninsular Malaysia (Damanhuri and Maideen 2001;Damanhuri et al. 2007). In this study area, Fissidentaceae, Hypnaceae, and Neckeraceae are represented by a fairly high number of taxa since the limestone rocks are largely a habitat of choice for the members of these families (Mohamed 1987).
The moss species found in Gunung Senyum Recreational Forest is compared to three other limestone forests in Peninsular Malaysia using Jaccard Coefficient of Similarity. Other limestone forest selected for comparison are Taman Rimba Kenong in Pahang (Damanhuri et al. 2007); Taman Negeri Perlis in Wang Kelian, Perlis (Damanhuri and Maideen 2001) and Gunung Kanthan in Perak (Kiew et al. 2014). Taman Rimba Kenong has the highest number of taxa, 114 taxa, followed by Taman Negeri Perlis in Wang Kelian and Gunung Senyum Recreational Forest with 72 and 66 taxa respectively. Gunung Kanthan recorded the lowest number of taxa, just 25 (Table 3).
Taman Negeri Perlis in Wang Kelian exhibited the highest degree of species similarity with Gunung Senyum Recreational Forest, which is 38.8% (Table 4). This is due to both areas consisting of limestone forests. Topographic factors also play an important role in shaping the vegetative patterns that are present in certain areas. Taman   Table 2. Summary of mosses found in Gunung Senyum Recreational Forest and its vicinity.   Rimba Kenong shows the second highest similarity with Gunung Senyum Recreational Forest, which is 33.6%, meanwhile, Gunung Kanthan show the lowest degree of similarity with this forest which is 19.7%. This may be due to the fact that the number of mosses found in Gunung Kanthan is distinctly low compared to other comparable areas because the plant biodiversity in this location has been under threat from quarrying activity conducted there (Kiew et al. 2014). The limestone habitats found in Gunung Senyum Recreational Forest can be divided into five groups based on classification by Chin (1977) and Mohamed (1987 Species found in this study can also be divided into four categories on the basis of their affinity to the limestone habitat (Mohamed 1987)  Ectropothecium dealbatum.
In this study, corticol is the most dominant way of life for mosses collected in this area with 47 taxa. Lignicol is second with 35 taxa, followed by calcicol or live on limestone with 26 taxa, then the terricol, with about 16 taxa. Rupicol and ramicol recorded the lowest number of taxa with eight and one taxa only. No moss species is found growing on leaves.
The mosses in Gunung Senyum Recreational Forest mostly live as corticol because this habitat provides adequate nutrients, water and exposure to sunlight. In contrast to the limestone rock which has few resources, the growth of mosses here is limited. The land surface is often limited to interstitials and limestone depressions. This factor makes the limestone environment vulnerable and hotter, even the absorption capacity of the soil is limited (Crowther 1987). In addition, the hot environment also accelerates decomposition of humus, thereby reducing the growth of mosses on decomposed materials.

List of mosses taxa found in Gunung Senyum Recreational Forest, Taman Rimba Kenong, Wang Kelian State Park and Gunung Kanthan
The arrangement of moss taxa are arranged alphabetically. The accepted taxa for Peninsular Malaysia follow Yong et al. (2013)

Conclusion
Gunung Senyum Recreational Forest with its two unique and pristine limestone outcrops is suitable for exploration and study as this forested limestone area is inhabited by interesting flora and fauna. It is hoped that in future, the composition of moss flora in these limestone outcrops, Gunung Senyum and Gunung Jebak Puyuh, will be studied more deeply. Specimens from the steep cliffs in this area should be collected regularly to assess the true diversity of mosses in this unique limestone hill.  Damanhuri 40,353,355,356,373,418,446,452,471,473,480,486,492, 520, 528a, 548 & 555. On exposed roots and on base of trees.  Damanhuri 17,29,36,39,45,50,72,89,94,100,102,241,279,281,291,296,313,332,352,355a,380,392,455,462,469,511,528 & 551. On limestone, on exposed roots, on soil, on rotten logs and on base of trees. Neckeropsis Reichardt N. gracilenta (Bosch & Sande Lac.) M. Fleisch. -H. Aznani & A. Damanhuri 250,253,255,258,306,340,401,440,503,509,525,529,530,543 & 556. On base of trees.  Damanhuri 126,127,307,312,320,333,336,359,391,413,433,437,439,466,467 & 501. On rotten logs, on soil, on exposed roots, on limestone and on bark of lianas.  Damanhuri 46,53,73,269,273,299,304,305,402 & 533. On rotten log, on exposed roots, on stumps of tree inside the lake and on wood.