Aquatic Botany, 47 (1994) 91-96 91 Elsevier Science B.V., Amsterdam Short Communication

Cryptocoryne elliptica, an endangered amphibious in Pondok Tanjung Forest Reserve, Peninsular Malaysia

Mashhor Mansor*, M. Masnadi School of Biological Science, UniversitiSains Malaysia (USM), 11800 Minden, Penang, Malaysia (Accepted 31 August 1993)

Abstract

Cryptocoryne elliptica Hook. f. is an endangered plant species endemic to Peninsular Malaysia. The species thrives in swampy and shaded habitats. In its natural habitat, Pondok Tanjung Forest Reserve, this plant coexists with other such as Cryptocoryne purpurea Ridl. and Homalomena nutans Hook. f. High population densities were observed where the depth of the water was not more than 0.5 m, the pH values ranged between 4.50 and 6.65, conductivity ranged from 7.0 to 10.4 #S cm-~ and dissolved oxygen concentrations and redox poteniial were relatively low. On the other hand, the hab- itat had a comparatively high concentration of soluble reactive phosphate and a high percentage of organic matter in the sediment.

Introduction

Although several species of Cryptocoryne are well documented (Jacobsen, 1980, 1982, 1985; Mansor et al., 1990; Mansor, 1991; Dawes, 1992), overall information is still limited. Ridley (1924) pioneered taxonomic studies on Cryptocoryne and listed only five species from Peninsular Malaysia. Jacobsen (1985) added a few more species, but in the latest survey, Mansor (1991) has indicated 11 endemic Cryptocoryne species relatively common in Penin- sular Malaysia. Among the common species is Cryptocoryne elliptica Hook. f., which occurs only in the northern part of Peninsular Malaysia. Jacobsen ( 1987 ) listed this endemic as an endangered species. One of the main reasons is a decline in its population, mainly as a result of habitat destruction. Fortu- nately, Pondok Tanjung swamp forest is a reserve, so survival of this species can be guaranteed. The aim of this paper is to present information on the

*Corresponding author. 92 M. Mansor, M. Masnadi /Aquatic Botany47 (1994) 91-96 habitat and biology of this endangered plant species, as a start in defining the conditions necessary for its conservation.

Method

Surveys were conducted in the Pondok Tanjung Forest Reserve from May 1992 to November 1992. The 7240 ha forest reserve is situated at latitude 5 °0.5'N and longitude 100°45'E in the state of Perak, Peninsular Malaysia. A large part of the reserve is swampy and several species of Cryptocoryne in- cluding C. elliptica thrive in the habitat. A 1 m 2 quadrat was employed in the areas of high population densities. As this species is an endangered one, only limited samplings were made. There- fore, plant species were harvested from only six quadrats, each being 50 m apart. The plants were observed to grow in not more than 0.5 m water depth.

Table 1 Some physico-chemical parameters measured at the sampling sites (range of values)

Parameters Range of values pH 4.5-6.65 Conductivity (/zS cm- 1) 6.0-10.4 Alkalinity (rag 1-1 ) 0.1-0.2 Dissolved oxygen (mg 1- ~) 2.3-6.4 Redox potential (mV) 180-240 Soluble reactive phosphate (mg 1- m) 0.057-0.462 Sediment (% organic matter) 0.429-2.873 Water temperature ( ° C) 25-27

Fig. 1. Cryptocoryne elliptica in flower. M. Mansor, M. Masnadi / Aquatic Botany 47 (1994) 91-96 9 3

Water and sediment samples were taken for further analysis in the laboratory. Physico-chemical parameters measured in situ were pH, conductivity, dis- solved oxygen (DO) and redox potential values. Soluble reactive phosphate (SRP) and alkalinity were analysed from water samples in the laboratory. SRP was analysed according to Hardwood et al. (1969) and alkalinity read- ings were made according to Mackereth et al. ( 1978 ).

A B C

F

Fig. 2. The developmental structure of the leaf forms; (A) 3 days (6 mm), (B) 1 week (12 ram), (C) 3 weeks (19 mm), (D) 3 months (29 ram), (E) the leaf is about 1 year (54 ram), (F) a young plant grows without rhizome ( 1 cm ), ( G ) a mature plant before flowering (2 cm ), (H) the development of an adventitious plantlet on the isolated old leaf. 94 M. Mansor, M. Masnadi /Aquatic Botany 47 (1994) 91-96

Results

In the quadrats at most three species were found, and the areal coverage of C. elliptica which was the dominant species, ranged from 25 to 95%. The bio- mass of individual plants ranged from 0.07 to 0.18 g and root/shoot weight ratios ranged from 0.67 to 1.83. Some of the environmental parameters taken from the habitat are shown in Table 1. Associated species thriving in the same habitat were C. purpurea Ridl., Homalomena nutans Hook. f., Asplenium spp. and Zingiber spp. Figure 1 shows the habit of the plant with its . The flowers emerge from the water, and are generally white. The sexual reproduction of this species is yet to be studied; however, the development of an adventitious plantlet on an isolated old leaf was observed in the laboratory. In addition, the plant can propagate by vegetative means although there is no rhizome present. Figure 2 shows the development of the leaf structure. The part played by wild pig (Sus scrofa L. ) is still unknown. At the sites of high population densities, footmarks of wild pigs were prominent. Most prob- ably they help to distribute the species widely in this swampy forest. The plants thrived in clear tea-coloured water with a depth of not more than 0.5 m. The roots were embedded in the muddy substrate, and the plants were generally found in the stagnant waters on the higher ground which are seldom affected by floods. Their habitats were shaded by tree canopies, and a maximum light intensity of 200 ft candle was recorded at 12:00 h on 29 Sep- tember 1992.

Discussion

Kiew (1990) stressed that the conservation of plant species in Malaysia as compared with animals has been relatively neglected, and the Malaysian Na- ture Society is currently compiling a conservation database on Malaysian plants and publishing a series of portraits of threatened species. Only one spe- cies of Cryptocoryne, namely C. elliptica, has been listed as being one of the 20 most endangered species in Malaysia, by Jacobsen (1987). However, Mansor ( 1991 ) has added more Cryptocoryne species to the list. Almost all species of Cryptocoryne in Malaysia can be considered endemic and also endangered. As a result of massive land clearance, logging and other human activities, their habitats are gradually being lost. Evidently, there are two types of habitat in which species of Cryptocoryne can thrive. One is fast-flowing pristine rivers with sandy and rocky sediment. An example of this type of habitat is Kenchin River, where C. affinis Hook. f. was found on a sandy substrate in the clean fiver (Mansor et al., 1990). The other set of Cryptocoryne species is found in swampy areas, where they thrive in muddy substrates. These substrates are relatively low in DO and have a M. Mansor, M. Masnadi /Aquatic Botany 47 (1994) 91-96 95 low redox potential. According to Bedford et al. ( 1991 ), the ability of aquatic plants to transport oxygen from their shoots to their roots and rhizosphere is a phenomenon which explains the survival of these plants under permanent or intermittent anaerobic conditions in the sediment. In Pondok Tanjung swampy areas, the alkalinity and conductivity readings were relatively low and the water was clear. The soft water was low in nutrient concentration, and had a low value of SRP in particular. According to Mansor ( 1991 ), most species of Cryptocoryne are highly ex- ploited for the aquarium industry, and apparently fetch high prices in the international aquarium market. Like species of orchids, the species of Cryp- tocoryne should be protected. Unfortunately, owing to the lack of information on these plant species, most people are still unaware of the value of these endemic aquatic plants. In addition to this, C. elliptica is found only in the deep interior and swampy areas which are not easily accessible, and for this reason the species are not well studied. Furthermore, once the habitat be- comes accessible, the population of the species can no longer survive, most probably as a result of massive disturbances. Apart from the destruction of plant canopies which shade the species, soil erosion from the adjoining lands, particularly owing to agriculture, logging, highway construction and other hu- man activities, are factors contributing to the destruction of Cryptocoryne habitats. Therefore, it is fortunate that in this case the Pondok Tanjung Forest Reserve has sheltered and protected the population of C. elliptica from de- struction. So far, there is no trace of C. elliptica in the adjacent oil palm es- tates in Pondok Tanjung. It is likely that transformation of swampy areas into agricultural land has resulted in massive destruction of this species.

Acknowledgements

We are grateful to A. Jaafar, Ganesh, Razak, M. Akhir and Nurdin, for their help in the fieldwork, and to the Universiti Sains Malaysia (USM) for pro- viding the facilities and a research grant. Dato' Ismail Awang, Director of the Perak State Forestry Department, is acknowledged for giving us permission to work in the Pondok Tanjung Forest Reserve.

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