Plant Checklist of the Bukit Nanas Forest Reserve , Kuala Lumpur , Malaysia

Bukit Nanas Forest Reserve, the oldest forest reserve in Malaysia established in 1900, lies in the center of Kuala Lumpur, the capital city. Over time it has been reduced from 17.5 ha to 9.37 ha but still retains important biodiversity. Its lowland equatorial rain forest has never been logged and tall emergent species to 35 m tall and 124 cm diameter persist. Since 1900, 499 plant species (2 lycophytes, 25 ferns, 39 monocots and 433 dicots) have been recorded. This year-long survey refound 425 species, including the rare Tarenna rudis (Rubiaceae), a local endemic found only in Selangor state. The multi-layered structure of lowland dipterocarp forest (16 Diperocarpaceae species were recorded) is intact. However, with diminishing size, the edge effect is more pronounced with secondary forest species, from trees to herbs, becoming established. In 2009, declared as the KL Forest Eco Park, it is important for its biodiversity, history, accessibility to the public for recreation (forest walks), scientific study, education (natural history, bird-watching, etc), as well as serving as a green lung in the bustling city. Baseline data, such as this survey, enables scientific management that will maintain the forest structure and biodiversity. ‡ ‡ ‡ ‡ ‡ © Salleh N et al. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.


Introduction
Bukit Nanas Forest Reserve (BNFR), formerly known as the Weld Hill Forest Reserve, was gazetted in 1900 and is the oldest forest reserve in the country.In 1930, its name was changed to Bukit Nanas Forest Reserve and in 1934, it was gazetted as a Wildlife Reserve and Bird Sanctuary.In 1950, the central pristine section of about 5 ha was gazetted as a Virgin Jungle Reserve (VJR) for the purpose of research and experiment (Putz 1978).Until now, the area still remains as a VJR (JPSM 2007).
It is a historic site.During the early years of Kuala Lumpur's formation in the 19 century, there were pitched battles between Raja Mahadi bin Raja Sulaiman and Raja Abdullah bin Raja Jaafar (JPSM 2007).The forested hill was the site of a fort and, according to historical accounts, prickly pineapples ('nanas' in Malay) were planted all around the fortress to deter attackers because, at that time, soldiers were barefooted.Raja Mahadi was defeated in 1874, thus ending the war.To commemorate the war, the locals called the hill Bukit Nanas ('bukit' means hill).Recently, a 10-metre tunnel was discovered.It is believed that the tunnel was used to store weapons, food and perhaps even treasure and was part of a complex of underground tunnels that have disappeared over time with developments in the area (Nair 2015).Another suggestion is that during the Klang or Selangor Civil War between 1867 and 1874, the Mandahiling community used the narrow tunnel to launch surprise attacks or as an escape passage from their enemies.
Because of its accessibility, the forest has long suffered from encroachment and even war activities in the last forty years, it has seen many changes.In the late 1970s, the hill was the site of a small cable car project, but the project was scrapped soon after and the cable car service was shut down and dismantled (Kiew et al. 1985).City Hall relocated a troupe of silvered leaf monkeys (Trachypithecus cristatus) into the forest that have since become residents in the forest (The Star 1986).During 1996, about 1 ha of the area was taken up for building the KL Tower and other purposes (JPSM 2007).Today, the area of BNFR is reduced to 9.37 ha (Latiff 2010) from its original area of 17.5 ha and is now surrounded by buildings and busy roads.On 12 November 2009, Dato Sri Douglas Uggah Embas, the former Minister of Natural Resources and Environment Malaysia, officially launched this last remnant of pristine forest in Kuala Lumpur as the KL Forest Eco Park, (Latiff 2010) for three main reasons: it is the only primary lowland rain forest that still remains intact in the city; it is rich in flora and fauna (formerly it was home to the Malayan tiger and elephant, but it still harbours monkeys, pythons, squirrels, and monitor lizards and a variety of birds); and it is the oldest forest reserve in the country.th th As the only remaining rain forest in the city of Kuala Lumpur, BNFR is the 'Green Lung' of Kuala Lumpur by purifying the air of its dust and toxic pollutants (Latiff 2010).It enables the general public to experience, explore and enjoy the beauty of nature.It is home to a rich variety of flora that flourishes within the forest including shrubs, trees, herbs, ferns, climbers, palms, bamboos and other indigenous plants.It is also refuge for fauna.As a recreation forest for the public, several nature trails accessible to visitors run through the forest.Facilities for visitors inside the forest include the Forest Information Centre, bird watching area, canopy walk, playground, exercise stations, picnic benches and access to the KL Tower.Entrance is free and the forest is open from 8 am until 6 pm daily.
Today, BNFR (3°09'N, 101°42'E) is a landmark in the capital city Kuala Lumpur (Fig. 1).It is a hilly area about 225 m above sea level (Putz 1978).Based on records from the Department of Forestry, the highest point on the hill itself is 280 m at the main entrance to the KL Tower.The forest experiences an equatorial climate that is hot and humid all year round.The average temperature is 26.7°C with a daily maximum of 33°C and a minimum night temperature of 24°C.To make a comprehensive study of the vascular plants by collecting specimens and taking photos in BNFR. 2.
To assess the biodiversity value of BNFR. 3.
To assess changes in species composition in the last hundred years.4.
To identify whether weedy or alien species have started to invade the BNFR and endanger the native species.

Data collection
This checklist is specimen-based using both herbarium specimens and specimens collected during the field survey.The earliest collections date from 1901.Major collectors were forest rangers who worked in the Forest Department include Hashim bin Mohamed, Hamid bin Mohamed Sah and Ahmad bin A. Bakar.Their collections are deposited in the Herbarium of Forest Research Institute Malaysia (KEP) and also in the Herbarium of Singapore Botanic Gardens (SING).The collections in KEP used the Forest Research Institute (FRI) numbers while collections in SING used the Conservator of Forest series numbers (CF and SFN).Herbarium specimen data from KEP for the period 1901 to 2014 was accessed using the Botanical Research and Herbarium Management System (BRAHMS) database programme.Herbarium specimen data from our current survey is accessioned in BRAHMS and for vouchers (sterile specimens) in an electronic file available in Forest Research Institute Malaysia (FRIM).Existing published plant lists, those of Henderson (1928) and the Forest Department of Kuala Lumpur (JPSM 2007), in general did not cite specimen.Some specimens on Henderson's plant list were tracked down in SING.For others, identifications could not be verified so any considered doubtful were discarded.

Field survey
Field surveys were carried out three times per month from April 2015 until May 2016.Plant specimens were collected by exploring along existing paths and trails, namely the Jelutong, Penarahan, Suboh, Merawan and Arboretum Trails and the Bamboo Walk (Fig. 2) in such a way as to cover all types of terrain and habitats.Almost all the 9.37 ha of BNFR was inventoried.All species were collected when first sight or whenever there was doubt regarding their identity.Fertile specimens deposited in KEP herbarium were individually numbered using the FRI number series with data recorded in the KEP field collection book.
Duplicates are deposited in the herbarium of Taman Botani Perdana, Kuala Lumpur City Hall.Sterile plant material was also collected and made into voucher specimens under a BN number series and are deposited in Taman Botani Perdana, Kuala Lumpur City Hall.The plants were pressed, dried and mounted on paper to serve as a permanent record (Bridson and Forman 1992).In addition, spirit collection of flowers and fruits were also made.The photographic record included images of the flowers, fruits, bark, inner bark, crown and habit.
Some parts of BNFR have been cleared for the infrastructure purposes such as the canopy walk, waterfall, kiosk, and road.This might have affected several species of forest plant.Some species recorded during the JPSM 2006 survey were not recollected during our survey and might have totally disappeared because of the clearing of the forest area.There are also several species that have been wrongly identified or only identified to genus during previous surveys.These are omitted from our checklist.In addition, indigenous plants that are cultivated by the forest management have also been excluded from the checklist to avoid future confusion about which is parts of the original flora of BNFR.Weed species are also excluded.

Species identification
Identification of specimens was made with the help of expert KEP staff and/or by comparing the specimens with those in the KEP herbarium and by consulting the literature.The trails in the Bukit Nanas Forest Reserve, Kuala Lumpur, Malaysia (Reproduced with permission from Forestry Department Peninsular Malaysia, JPSM).
The main references used were the Flora of the Malay Peninsula (Ridley 1922, Ridley 1923, Ridley 1924a, Ridley 1924b, Ridley 1925), the Tree Flora of Malaya (Whitmore 1972, Whitmore 1973, Ng 1978, Ng 1989), Pocket Checklist of Timber Trees (K.M Kochummen (Wyatt-Smith 1999), Flora of Peninsular Malaysia (Kiew et al. 2010, Kiew et al. 2011, Kiew et al. 2012, Kiew et al. 2013, Kiew et al. 2015, Parris et al. 2013, Parris et al. 2010), Wayside Trees of Malaya (Corner 1988) and Plants in Tropical Cities (Min et al. 2014).Turner (Turner 1997) was used for information on species distribution.The authority of each species was checked using The Plant List (The Plant List 2016) while the name of family follow The Plant List, Turner and Flora of Peninsular Malaysia.
Endemic species are defined as being restricted to a particular place, e.

Assessment of conservation status
The conservation status assessment is based on the Malaysia Plant Red List 2010 (Peninsular Malaysia Dipterocarpaceae) that was derived from (Chua et al. 2010) and also Flora of Peninsular Malaysia (Kiew et al. 2010, Kiew et al. 2011, Kiew et al. 2012, Kiew et al. 2013, Kiew et al. 2015, Parris et al. 2013, Parris et al. 2010).The assessment was based on the baseline information contained in the Taxon Data Information Sheet (TDIS).
The TDIS comprises scientific name, taxonomy details, common names, habitat preferences, geographical range, general distribution pattern, population decline, threats, Red List Category and Criteria, a rationale for the listing, current conservation measures, utilisation, literature used in assessment, details of assessor(s), date of assessment and names of evaluators.This information is to support the Red List category given to the study taxon.

Collections
The flora is relatively well known botanically because prior to the establishment of the Forest Research Institute (FRI) in 1926, BNFR was the site used by the many Forest Department officers as a place to study plants (Burkill 1927).

Biological groups
Among the ferns, Tectariaceae is the largest family with 5 species, followed by the Polypodiaceae with 4 species.Tectaria is the most speciose genus with 4 species.Only two species of lycophytes are recorded from BNFR: Selaginella wallichii and Selaginella willdenowii.Selaginella wallichii was found under the forest canopy but S. willdenowii grows in disturbed areas of BNFR.
Adiantum latifolium under the fern family is one of the naturalised species found in BNFR.This species is native to tropical America and naturalised in BNFR on the forest floor and disturbed area.Only one species, Syngonium podophyllum from the monocot species become naturalised on BNFR.Graph in (Fig. 4) shown during the second decade in between 1911 to 1920, number of species increase is 127, followed by 1921 to 1930 with 117 species because in 1928 Henderson had done his survey at BNFR.After two decades, there is no new species recorded in that area since there are no significant declining or increasing number of species until year 2000.The reduction of species collected at BNFR are caused by the decrease in number of research and researcher during that period.Most of the researchers expanded their study site to other forest in Malaysia.
Almost 100 years later, in 2006, forest department done their survey in BNFR and recorded another 51 species.After that, our completed survey in 2015 to 2016 that covered all the trees, shrubs and herbs in Bukit Nanas area shown the highest peak of new collection of the species.Our survey collected 159 new record species including Syzygium, Tabernaemontana, Sterculia, Smilax, Ficus, Garcinia, Artocarpus and others.We also have the additional Dipterocarpaceae family which is Shorea glauca and Shorea assamica.In the monocot categories, we make many collections on Araceae family like Scindapsus hederaceus, Schismatoglottis scortechinii, Aglaonema simplex, Aglaonema nitidum and also Zingiberaceae (Zingiber zerumbet).Our collections were higher than other collections because we did the inventory regularly (3 times per month) and involved the expert around us to identify the species.Many of the collections before are not fully identified and they only focus on certain groups of plants and preliminary survey.

Forest structure
It is quite a surprise to still find some enormous trees in BNFR that appear to be several hundred years old (Table 3).From its structure and species composition BNFR is lowland dipterocarp forest (Saw 2010) and it has retained the typical three tree layers including the upper layer of emergent trees, the main stratum about 24-36 m high; and the lower layer with smaller, shade-tolerant trees and immature trees of the upper two layers, and below the shrub and herb layers.According to JPSM (2007), BNFR never been logged and because of these, the big emergent trees still exist.

Change over time
For more than a hundred years, BNFR has been an isolated forest island in a sea of urbanisation.Although it was never logged, its size has been reduced from 17.5 ha in 1928 to 9.37 ha today and its accessibility in the centre of a busy city means it is vulnerable to disturbance.It is therefore to be expected that over the years, sensitive species will loss as the climate in the city has become hotter and less humid and many of the birds, mammals and presumably also insects that were pollinators or fruit and seed dispersers died out.Species loss is particularly conspicuous among the endemic species.Of the 267 species listed by Henderson ( Table 6.

The future
At the present time, the presence of tall emergent trees and a complete canopy structure provides stable cooler, humid conditions suitable for the growth and regeneration of shade tolerant shrubs and herbs.But with development, the central area has become smaller in proportion to the margin.Additionally, the edge effect with conditions of high light, high temperatures and low humidity will, on the one hand, encourage the invasion of secondary and naturalised species, while on the other hand preventing the growth and regeneration of primary rain forest species.
Native secondary forest tree species, Macaranga tanarius, Macaranga triloba, Macaranga gigantea and Mallotus paniculatus form thickets along the forest margin.The fern Lygodium microphyllum is most common on the forest margins.However, some naturalised exotic species are invasive or have the potential to become established within the forest because they are adapted to forest habitats, such as Syngonium podophyllum, Cleome rutidosperma and Melothria pendula.Asystasia gangentica ssp.micrantha is an invasive weed introduced in the 1970s but is now naturalised and widespread and ubiquitous (Kiew and Vollescen 1997).
Secondary species and weeds are light demanding so if forest structure is not disturbed nor fragmented, they are unable to penetrate into the forest and therefore cannot compete with primary forest species.Over time, secondary forest trees can form a stable canopy.
The shade demanding forest species can invade and become established and eventually grow taller and overshadow the secondary forest trees.Gradually over time primary forest species will replace the secondary ones.However, this depends on a seed source and being an island in a sea of urbanisation, recruitment of primary forest species can only be obtain from the existing stocks.
Using IUCN categories and criteria, five species was categorized as nearly threatened such as Dipterocarpaceae family including Anisoptera costata, Shorea sumatrana and two other species, Magnolia montana and Memecylon campanulatum (Table 7).In BNFR, there is only one tree of Shorea sumatrana with the diameter of 108 cm.The area where it grows needs to be protected to conserve the tree and enable its saplings to become established to ensure this species is not lost from BNFR.List of the endangered species in BNFR based on Flora Peninsular Malaysia (Kiew et al. 2010, Kiew et al. 2011, Kiew et al. 2012, Kiew et al. 2013, Kiew et al. 2015, Parris et al. 2010, Parris et al. 2013) and Malaysia Plant Red List (Chua et al. 2010).
Plant Checklist of the Bukit Nanas Forest Reserve, Kuala Lumpur, Malaysia

Cultivated species
Another source of invasive plants is from the planting of both of the native and exotic ornamental species around the Forest Department Information Centre and along paths (Table 8).One example is the ornamental Dioscorea zanzibarica, a most invasive species that is recorded in the Bukit Nanas area.Another species found in the open and near the canopy area is Hemigraphis reptans, an invasive shade-tolerant species that should be removed to prevent its spread.These two species need to be monitored to prevent their spread and impact on the natural habitat.The other problem is the addition of several native tree species, such as Hopea odorata, H. helferi and Vatica pauciflora, planted around the Visitor Centre and along the trails.If they become established, they will merge into the forest area and, in future, it will not be possible to distinguish the original BNFR forest species from those brought in.Care needs to be taken to maintained the original forest and to prevent the invasion of both exotic species and native species brought in from elsewhere.

Conclusion
Bukit Nanas Forest Reserve is the only forest in the city that gives a green view surrounding.It must be maintained to provide good conditions for the development of the trees and become a reference centre for learning in the future.Our study provides the baseline data for the existing flora 88 years after it was inventoried by Henderson in 1928 and also records the existence of new and introduced species into this area that become invasive and naturalised.Bukit Nanas Forest Reserve is still categorised as a good forest with good forest structure and diversity because there are still many species, especially large trees that form the emergent layer and a complete tree canopy that provide cool, humid, shaded conditions for the shrubs and herbs below.In this area, the management department of forestry also grows some of the forest species and exotic plants to close the open area caused by the constructions.However, the operation and management of these introduce species into the area must be controlled to prevent taxonomic confusion in the future.In addition, the area is also increasingly disturbed by the construction of a pedestrian.Therefore, the management department of forestry must have the good plan structure for future conservation.
Bukit Nanas Forest Reserve had the privilege to serve as biodiversity centre, research, education, recreation, tourism, heritage and green lung area with monitoring and rigorous forest management.With an area of 9.37 ha, BNFR provides a good habitat for a diversity of plants and mammals.

Figure 1 .
Figure 1.Location of the Bukit Nanas Forest Reserve in Kuala Lumpur, Malaysia.

Figure 4 .
Figure 4. Graph shown the increase number of species by decade at Bukit Nanas Forest Reserve from 1901 to 2016.
g. to Peninsular Malaysia or to Selangor.Selangor is a state in Peninsular Malaysia and now surrounds the capital city of Kuala Lumpur that was once under Selangor's territorial sovereignty.Native species are defined as indigenous species; naturalised species are exotic species that are self-sustaining and have spreading populations.Common species are species that exist in large numbers and are abundant.Primary species are species that live in the undisturbed or pristine forest; secondary species are those that invade open areas of disturbed forest that is generally unstable and represents successional stages.

Collecting between 1931-2014 continued sporadically by FRI botanists, majorly by Omar bin Mohamed, K.M. Kochummen and C.F. Symington after the establishment of Forest Research Institute (FRI). Specimens were deposited in KEP.
The first collections of plant specimens from BNFR, then known as the Weld Hill Forest Reserve, were made in 1901 by Charles Curtis, an English botanist in charge of the Penang Botanic Garden, and in 1908 by Hashim bin Mohamed, a Forest Ranger with the Forest Department (Steenis-Kruseman et al. 1950).Collecting peaked between 1911 and 1920 (Fig. 3) and included 354 specimens.During 1911-1920, many collections were amassed by forest ranger Hashim bin Mohamed, Hamid bin Mohd.Sah, Abdul Rahman and Ahmad bin Abu Bakar.Their collections are deposited in KEP and SING.

Table 1 .
Checklist of the taxa recorded in the Bukit Nanas Forest Reserve from 1901 to 2016 including their category (naturalised or native), (weed or forest plant) and forest type (primary or secondary).

Table 2 .
Number of native and naturalised taxa recorded in Bukit Nanas Forest Reserve for the different biological groups.

Table 6 )
, 15 species are endemic to Peninsular Malaysia but after 87 years only about 20% still remain including Tarenna rudis that have been recollected in the BNFR.

Table 8 .
List of the cultivated species planted in Bukit Nanas Forest Reserve.