perspectives for sustainable resource utilization and management of nipa vegetation

PERSPECT IVES FOR SUSTAINABLE RESOURCE

UT IL IZAT ION AND MANAGEMENT OF NIPA VEGETAT ION 1

F .W. FONG

Fang, F. W. (Field Studies Centre. % Department of Zoology, University of Malaya, 59100 Kuala Lumpur, Malaysia). PEIR~PECTIVES FOR SUSTAINABLE RESOURCE UTILIZATION AND MAN- AGEMENT OF NIPA VEGETATION. Economic Botany 46(1):45-54. 1992. Nypa fruticans Wurmb. dominated wetlands are commonly found where brackish waters overflow with the tides. This swamp palm is harvested for a variety of purposes, including roofing, construction materials and peels for rolling cigarettes from its leaves, and sugar syrup, an intoxicating juice, vinegar and alcohol from its floral and fruit stalk exudate. Extraction techniques are traditional, and current resource development strategies are non-existent in areas where nipa palms are being harvested. Maintenance of adequate supplies of the resource requires knowledge of demand on the resource and its renewability under natural and harvest regimes. To sustain production, indigenous populations follow conservation-oriented practices in husbanding the natural resource.

Key Words: Malaysia; nipa palm; Nypafruticans; Southeast Asia; sustainable resources.

The nipa palm and the true mangrove are an integrated part of the tidally influenced wetlands in Southeast Asia. Mangrove colonizes the upper part ofthe intertidal zone of shorelines and fiver mouths. Near the entrance of larger rivers with high discharge of freshwater, mangrove is often replaced by nipa palm vegetation, which per- forms the same ecological function as mangrove in trapping suspended sediments. On accreting shores where mangrove spreads forward and de- position attains high tide level, nipa palm moves in from the rear. In many places, nipa forms the transition belt between mangrove and freshwater swamps (Fig. 1).

These plant communities are increasingly tar- gets of conflicting interests. Conservatists stress their importance as traditional providers of subsistence materials such as sugar, wood, thatch and tannins for the local people, as detritus sources for productive fisheries and as natural barriers to wave scouring along coasts. Propo- nents of development, however, exert pressures to develop or reclaim these areas as a means to increase food production or resettle people (Bur- bridge and Stanturf 1985). In Southeast Asia, nipa vegetation is among the most ecologically

Received 8 Februrary 1990; accepted 22 July 1991.

and economically important wetland ecosystems currently subject to such pressures. It also rep- resents an important forest resource in current subsistence economies throughout the Indo-Pa- cific region including Malaysia (Fang 1984).

Yet local people--the de facto resource users and managers of nipa--are often ignorant of the destruction they are causing to this resource. Subsistence uses of nipa may prove unsustain- able in some circumstances if no management is practiced. The primary materials of nipa in demand are the leaves and the sap that issues from wounded floral or fruit stalks. This paper de- scribes observations carried out in Kuala Selang- or (320'N 10114'E), Peninsular Malaysia, on the availability of these resource materials under natural conditions, the demands for them by local populations and their production in experimental plantations. The traditional husbanding methods for the wild palms are also discussed with a view towards identifying promising ap- proaches that might warrant further analysis and dissemination.

METHODS

Field work was undertaken in protected and relatively well preserved stands of nipa in the Kuala Selangor area on the west coast of Pen- insular Malaysia. Tides in this region of Selangor

Economic Botany 46(1) pp. 45-54. 1992 1992, by The New York Botanical Garden, Bronx, NY 10458 U.S.A.

46 ECONOMIC BOTANY [VOL. 46

State are predominantly semi-diurnal with diurnal tides occurring twice a month. The altitude in Port Kelang close to Kuala Selangor is 2.9 m above the minimum sea level. The tidal range is 4.1 m at spring tide and 1.3 m at neap tide, while maximal tidal stream velocities during spring tides range from 1.5 to 2.2 knots and during neap tides from 0.1 to 0.7 knots. Tidal flows in the open shores are considerably less, unless oceanic currents are operating during the monsoon seasons. Temporal variation in salinity level cor- relates with rainfall, i.e., there are two depres- sions in the rainiest period of the year--October- November and Apri l -May--coinciding with the onset of the monsoons.

Experimental plots (100 x 100 m) were es- tablished at Teluk Penyamun (Site I), Teluk Piai (Site II) and Teluk Permata (Site Ill) on the Se- langor River system. Within the experimental areas, 20 x 20 m subplots were demarcated and phenological observations carried out over three years.

Observations were made every two to three months (from late 1978 to early 1981) on palm clumps within the subplots to record the number of immature, mature and dead leaves. Each new or sword leaf emerges from a vertical groove or cleft in the swollen leaf base of the preceding leaf. In this study, sword leaves, as well as young leaves in which the leaflets have not fully expanded, are categorized as immature while living leaves with fully expanded leaflets are labeled mature. Leaf counts are obtained easily by tagging the already fully expanded ones and recording the emergence of new leaves as they appear. Concurrent with monitor ing vegetat ive growth, reproduct ive palms were observed to determine whether inflorescences had just emerged, inflorescences were maturing, flowers were in bloom, fruits had just formed, fruits were maturing or fruits were being shed. These brief monthly counts gave an overall picture of the flowering and fruiting pattern of the population at large.

To ascertain the amounts ofregrowth after different resource uses, selected palm individuals were subjected to two sets of cutting regimes: clear cutting, in which all the leaves were removed from the clump at the beginning of the experiment; and continuous cutting in which only leaves of the specified stage of maturity were cut at the beginning of the experiment and on all subsequent visits. Continuous cutting was divid- ed into two subtreatments, i.e., variation a in which

only mature leaves were removed (both immature and sword leaves being left behind on the clump) and variation b in which both mature and immature leaves were removed (only sword leaves left untouched on the clump). Inspection visits were made at two- to three-month intervals to record the rate of regrowth of treated palms.

RESULTS

MATERIALS OBTAINED FROM THE NIPA PALMS

The important parts of the palm are the leaf, the fruit and the sap drained from cut floral or fruit stalks (Fig. 2-5). The leaflets are woven into thatch, sun-hats, sleeping mats, bags and baskets; the midribs stripped from the leaflets are utilized as brooms when bundled together and as tying materials; the leaf petiole (leaf base) serves as floats for fish nets and the rachis (main axis) as fishing poles; the young leaflets are used as cigarette wrappers and also for wrapping cooked rice; the sap is taken for sugar, alcohol or vinegar manufacture; the endosperm of young seeds is eaten raw or preserved in syrup, and is often added to iced desserts. To a lesser extent, ash salt is also obtained from leaching the ashes of burnt palm leaf bases.

The practice of harvesting leaves and sap was observed in Kuala Selangor to ascertain the kind of damage inflicted to the wild palms. For thatch and cigarette wrappers (Fig. 2, 3), leaves are harvested continuously throughout the year and the amount harvested is governed only by the demand of the market. Nipa leaflets are gathered from mature leaves of at least twelve months of age for thatch. The leaves are cut about 0.6-1.0 m from the ground level and below the lowest leaflet but above the cleft in the leaf base. About a meter-long section is cut away from each end of the leaf, leaving only the middle section with the longest leaflet for use as weaving material. Leaflets that are dry or brittle at the tips are not utilized.

For the purpose of making cigarette wrappers, sword leaves of 4.5-5.5 m length are usually cut, as they provide the largest number of suitable leaflets for peeling. These normally have attained at least four months of growth since emergence. The sword leaves are pried open and the leaflets severed from the midrib of the leaf a short dis- tance from their point of attachment. Leaflets at the upper tip section of the leaves are then dis-

1992] FONG: NIPA PALM 47

Fig. 1. The nipa palm growing in clumps at the water's edge. Note the erect, stemless habit with leaves and inflorescences arising from a subterranean, dichotomously branching rhizome.

Fig. 2. The cleared area within the swamp where nipa collectors converge to sort and grade the leaves for thatch or cigarette wrapper making.

Fig. 3a, b. Subsistence use--thatch weaving: a. Thatch is made by folding about I/3 the length of the leaflets over a slender bamboo split; these are stitched into place with a fiber of vine or palm leaf midrib, b. Completed thatch is left to dry in the sun for 4-5 d; colour changes from bright green to light brown.


Fig. 4a, b. Subsistence use--making cigarette wrapper: a. A villager stripping the epidermis from individual leaflets to prepare cigarette wrappers. Beginning from the basal outer edge, the epidermis is separated sufficiently to allow the introduction of a finger which is quickly forced against the point of attachment and moved through the whole length of the blade, b. The blade peels, now curled and dried to a straw colour, are cut into suitable lengths and packed in bundles of one hundred each for sale.

Fig. 5a, b. Subsistence use--tapping the sap: a. The young nipa infructescence at the right stage for lapping. b. After the floral or fruiting head has been removed, the sap that drips from the cut end is collected in bamboo joints.

carded because o f their smal l size and tenderness. About 80-100 leaflets may be obta ined per cut sword leaf and f rom these the leaf b lade peels are str ipped. Blade peels are dr ied in the sun and the final product is cut into short (cigarette) lengths.

The n ipa pa lm yields abundant sap f rom the cut stalks of fully deve loped inf lorescences or young infructescences after the fora l or fruit heads have been removed. The exudate flows freely. Because a th in slice is pared off the stalk end twice a day to facil itate exudat ion, the per iod of sap col lect ion lasts up to four months , unti l the stalk length reduces to a short stub. In all local-

ities v is i ted a pre l iminary t reatment that in- vo lves regular bending and twist ing o f the stalk pr ior to cutt ing is required. Not all inf lorescences or infructescences can be tapped at the same time. Suitable inf lorescences are those in which the female heads are about 15 cm in d iameter with several subtending male branches. On fruit stalks, the process is started when the head is about 8 - 12 cm in d iameter but before any darkening in co lour o f the head has commenced. The sap is slightly alkal ine in react ion when first col lected and has a sucrose content. Sugar is made by boil- ing and evaporat ing the "n i ra , " as the sap is often called locally, in large pans as soon as it is col-


lected. However, without adequate means of preservation, the nira rapidly ferments. The production of sap depends on the flowering frequency, which varies with swamp localities and is normally restricted to those months of the year when the flowers have matured and the fruits are developing.

YIELDS FROM THE PALMS IN THE WILD STATE

One of the primary objectives of this study was to carry out observations on the vegetative and reproductive growth of the palm under natural swamp conditions, since its growth would govern the supply of resource materials so needed by the local people.

During the observation period, mean monthly air temperatures showed little seasonal variation. The ranges of monthly means obtained were small: early morning temperatures ranged from 23.0C to 25.2C, while mid-day temperatures ranged from 30.0C to 32.7C. Mean monthly relative humidity readings (taken at 1.30 pm) were variable, from 55% to 70% over the period of observation. In 1978, the mean was 63.75 +__ 3.00%; in 1979, it was 62.36 ___ 3.31%; and in 1980 it was 64.0 + 3.70%. Relative humidity followed closely the rainfall patterns. Monthly rainfall ranged from 32.2 mm in the dry season to as much as 307.7 mm in the peak rainy months. Total annual rainfall averaged around 2000 mm for the three consecutive years. Two distinct dry periods alternated with the two wet ones, although they did not necessarily occur in the same months from year to year. The first dry spell, which occurred between January and March during the study period, was spread over not more than 10 days during which less than 160 mm of rain was recorded. The second dry period normally spanned a number of months, generally from May-June to September-October. Like- wise, the wet periods can shift one or more months according to the year with peaks generally in April and from October to December.

The observed growth states of the palms that are clearly circumscribed in time are referred to here as phenophases. Given the relatively long period of time involved in the onset, duration and cessation of a particular phenophase, the temporal spreads are represented here in histo- gram format. Computations are based on the proportion of individuals in the population ex- hibiting a certain phenophase during the period

of observation. One should bear in mind, however, that a clump may exhibit several phenophases at a particular time, as for example, si- multaneous death and emergence of leaves or flowering and fruiting.

Leaf flush among the palms was heavily recorded in the period following month(s) of low rainfall (Fig. 6). Peak months for the production of new leaves were February and December re- spectively for 1979 and 1980. Although new leaves sprouted throughout the year, 86.6% of the annual total production occurred between the months of September and January The number of sword leaves produced per year ranged from two to five with a mean value of 3.04 __+ 0.8 leaves per clump. More leaves were produced in 1979 than in 1980. The period ofleast active leaf emergence in the two years was from May to August- September, roughly coinciding with the period of heavy inflorescence production. Palm clumps consistently produced from two to four leaves in the year irrespective of their size, which varied from seven to sixteen living leaves per clump. The clumps examined contained an average of 11.7 ___ 2.08 living leaves. From the point in time when they first appeared as spikes in the clefts of the leaf bases, sword leaves took about four months to attain the length of mature leaves, another two to three months for the leaflets to attain length of mature leaves and another two to three months for the leaflets to fully expand. By dividing the average number of mature leaves present by the average number of leaves produced per year, the turnover rates were found to be 2.5 years for 1979 and 3.1 years for 1980. Natural death of the tagged sword leaves was not recorded during the period of observation but it is estimated that the palm leaves remain green for at least 33 months. A loss rate of 2.7 senescent leaves per clump per year was obtained from fitting a regression to the records of mature leaves turning senescent during the observation period. Extrapolating the data on individual loss (in terms of senescent and dead leaves) and gain (in terms of sword leaves initiated) for a one-hectare population, the results suggest a slight net gain of leaves per year in the Kuala Selangor swamps (Table 1).

The major reproductive phenophases, i.e., appearance of new inflorescences, flowering and shedding of fruits, are shown in Fig. 7. Inflores- cences appeared sporadically throughout the year, but peak production occurred from May-June to


TABLE 1. LEAF PRODUCTION AND LOSS IN THE NATURAL POPULATION AT KUALA SELANGOR.

Number of leaves per hectare

1979 1980 Mean value for both yeats

Sword leaves ScnescenUdead Sword leaves Senescent/dead Sword leaves Senescent/dead Site initiated leaves recorded initiated leaves recorded initiated leaves recorded

I 1169 741 883 940 1026 841 II 1561 1254 1221 1121 1391 1188

III 2135 1769 1927 1613 2031 1691

Total 4865 3764 4031 3674 4448 3720

TABLE 2. POPULAT ION DATA OF THE PALMS UNDER OBSERVATION AT KUALA SELANGOR.

Number of palms in vegetative or reproductive state Stocking density of palms

1978 1979 1980 Sample plots (20 x 20 m) Average Number of inflorescenceg/infructescences present per clump

per Site a b c hectare 0 1 2 3 4 0 I 2 3 4 0 1 2 3 4

I 13 15 13 342 22 6 10 3 -- 19 11 8 3 -- 21 14 3 3 -- II 18 17 22 475 37 13 3 3 1 31 19 4 2 1 35 13 8 1 --

III 25 22 28 625 60 l0 5 58 12 5 -- -- 62 II 4

September . These emerged as short stubs and deve loped to full height wi th in three to four months . Anthesis, which commenced about a month after the inflorescences attained full height, is one phenophase that may be spread throughout the swamp over a protracted per iod f rom October -November to January -February de- pending upon the schedule of rainy months . F rom the onset of anthesis there is usually a lapse o f three months before the first fruit heads are formed. Shedding o f mature fruits begins after another three to four months , peaking dur ing the dr ier months at mid-year.

O f the total o f 173 pa lms that were tagged, 31.21% were in var ious stages of sexual reproduct ion in 1978, 37.57% in 1979 and 32.95% in 1980. The palm c lumps bore from one to as many as four inf lorescences and/or infructescences per c lump in different stages o f deve lopment (Table 2). Approx imate ly ha l f (49.71%) o f the pa lm popu lat ion came into the reproduct ive state during the three-year study period. Of these 60.55%

flowered or fruited once in three years, 30.2% twice and 5.85% three t imes, whi le less than 1% bore fruits that were in i t iated pr ior to the per iod of observat ion. There were signif icant differences in the proport ion of reproduct ive pa lms present between years and between sites. In 1979, there was a greater number of pa lm c lumps coming into reproduct ion than in the preceding or suc- ceeding year on all sites. N ipa stands at Site III, however, consistent ly produced fewer inflorescences and infructescences than at the other two sites. Pa lm density at this site was the highest, and on average, close to 80% of the pa lms re- ma ined sterile in the three years o f observat ion. A regression of the number of inf lorescences enu- merated per year against stocking densi ty in the three sites suggests that dense stands of pa lms exhib i ted a less f requent inc idence o f flowering.

EJ-t-ECTS OF CUTTING ON NIPA GROWTH

Leaf remova l at different intensity (clear cut- t ing verses cont inuous cutt ing) and selectivity

---4

Fig. 6. (Top) Temporal pattern of leaf emergence and senescence on censused palms (n = 38). (Bottom) Distribution (according to leaf type) of leaves recorded per palm clump over a two year period.

Fig. 7. Periodicity of floral initiation, bloom and fruit shedding among the palms in their natural habitats in Kuala Selangor from January 1978 through January 1981.

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Fig. 8. Cumulative leaf production curves over a two year period under different cutting regimes. (See text for details of continuous cut methods.)

(continuous cutting of either mature or immature but not sword leaves) simulates the harvesting ofnipa palm leaves by the locals. The cumulative number of leaves produced per clump over a two-year period, as shown in Fig. 8, shows the effects of different cutting treatments. Palm clumps denuded of their vegetative parts (clear cutting) showed a decline in growth performance as compared to the other treatment and the control. New leaves began to sprout about six months after the first cut but were limited to only a few palms. On average there were 2.06 + 0.24 leaves on these palms at the end of the two-year period. On Site III, two of the 30 experimental clumps succumbed to the treatment, thus giving a mor- tality rate of 6.67% for the clumps under clear cutting. There was also a marked reduction in leaf lengths. After two years, leaves were ap- proximately half the length of those measured prior to treatment. In both of the continuous cutting subtreatments, regrowth patterns were similar although those palms under continuous cut variation b produced more new leaves. After two years, the mean number of leaves initiated per clump was 4.37 _+ 0.40 for variation a and 5.9 _+ 0.22 for variation b continuous cutting subtreatments. The average leaf lengths on the clumps after two years, for both subtreatments, fell within 10% deviation of the mean leaf lengths of the same clumps measured at the beginning of the experiments.

DISCUSSION

In general, over-harvesting is a significant fac- tor in declining resource availability only for those

products for which there is commercial demand. Nipa traditionally has contributed both to the subsistence as well as the commercial economy in this region. Long-term productivity is depen- dent upon the level of harvesting and natural regeneration. Whereas numerous sources (e.g., Buza 1989; Gonzales 1979) extol the versatility of this palm, few dealt with limits to its sustained use, which are determined by current demand for raw material and the regenerative capacity of the resource. Cutting of mature leaves for thatch and immature leaves for cigarette wrappers is a common practice, reported from areas where nipa occurs in great abundance in its present geo- graphical distribution (Ahmad 1951; Doscas 1927; Robillos 1978; Smitinand 1961). Exces- sive collecting can result in declining leaf production.

There is little published information on the response of palms to destructive harvest in the long term. Fox (1977) noted that in the Borassus palm, careless pruning by the Rotinese people in the eastern parts of Indonesia can destroy the plant or render it unproductive. In Sarawak (East Malaysia), the rattan palm, Ca lamus manan Miq.--which consists of single-stemmed canes that do not regenerate after cutting--are becom- ing especially scarce. Even the multi-stemmed species will fail to regenerate if the entire clump is cut, the cuts are made too low or if immature clumps are cut.

The experimental results on simulated harvest of the nipa palms showed that cutting intensity can affect regrowth. The imposition of the clear cutting regime, which simulates complete but destructive utilization of the resource, had resulted by the end of two years in a highly significant drop in the number of leaves regenerated compared to other treatments. Damaged palms showed losses ofvigour, with fewer growing points and shorter leaves and exhibited reduced leaf area. Continuous cutting, in which only the de- sired plant parts in suitable harvestable condi- tion were removed, simulates selective harvesting of leaves for thatch and cigarette wrappers on separate palm clumps. In each of the subtreatments for continuous cutting, defoliated plants rapidly restored leaf numbers in the en- suing months to values comparable to those of the corresponding controls. No significant differences were noted between variation ~ and variation b, either in the rate of growth of individual leaves or in the period between the appearance


of successive new sword leaves. There was, however, a slight indication that the latter subtreat- merit led to accelerated growth in terms of number of new leaves initiated. The difference in response between these subtreatments and clear cutting is probably due to the fact that continuous cutting provided an adequate recovery period, particularly when at least some mature or unexpanded leaves were left intact. However, as noted in other plant species, continuous or re- peated cutting is harmless only when a sufficient leaf area is left on the plant to allow rapid regrowth (Langer and Steinke 1965).

Sexual reproductive activity was observed on the palms subjected to experimental leaf remov- al. Defoliation causes a rapid redistribution of limited resources to vegetative growth rather than to reproductive ends. Monitoring the palms for longer periods would reveal the impact on production of inflorescences and infructescences. Under normal circumstances, plants respond to a severe drain of resources by not bearing flowers for one or more subsequent flowering seasons in order to replenish their vegetative reserves. Aside from this, relatively low flowering frequencies observed can be attributed to competitive inter- actions, particularly in dense swamp conditions. Individual palms would have to compete for in- solation amongst the mass of fresh green foliage and slowly decaying leaves in the swamps. (Se- nescent nipa leaves do not abscise neatly but merely flop over and rot while still attached at the base to the parent palm.) Plants therefore can ill afford an energetically expensive outlay in flowers and fruits in such an environment, especially when they can reproduce not only by seeds but also by branching of subterranean rhi- zomes as in nipa.

Considerable evidence suggests that rain forest hunters and gatherers traditionally keep exploitation within limits of the carrying capacity of the ecosystem on which they depend (Dunn 1975). For example, in Sarawak, the sago palm (Eugeissona utilis Becc.), which grows in dense clumps with between three to six trunks per clump arising from a mass of aerial roots, are felled for starch. To maintain the stability of the resource, the local Penans rotate their extraction ofctumps systematically from one palm grove to another, always harvest by cutting only one or two of the trunks leaving the palm to resprout, and never cut down the entire plant at the root as this would surely kilt it (Brosius 1986),

Similarly, the villagers in the Kuala Selangor area adopt practices that contribute to sustaining the nipa swamps' continued productivity. When cutting the palm clumps for thatch, the mature leaves on the outer whorls are removed, leaving at least one immature leaf in addition to two or three other unopened sword leaves around the growing points. Harvests in a given clump are staggered at four-month intervals. During this period, the spared immature leaves spread their leaflets and achieve increased rigidity, while emerging sword leaves grow a meter or so in length. Because mature leaves are needed for thatch and sword leaves for leaf peels in rolling tobacco, the palm clumps are exploited for only one type of utilization and never both in order to sustain renewability. When cutting sword leaves for making cigarette wrappers, the cuts are made at a point well above the leafstalk, leaving a number of leaflets behind that will later unfold and assimilate for the palm. If the palms are used for extraction of sap, the fresh leaves are not cut since such a practice would interfere with the productivity of the plant and greatly decrease the flow of nira. On large clumps containing more than one flower or fruit stalk, the usual practice is to tap from only one and remove the others, although tapping intensity varies according to the fertility of the swamps. Areas harvested during one flowering or fruiting season are generally left alone to recover during the following season.

Although such conservation-oriented behav- iour is passed from generation to generation, many of the resource users may no longer be in consonance with the goals of sustainable management. Increasing scarcity ofresources through the loss of common lands reduces the management options for rural inhabitants. As a result, local people increasingly operate to maximise their immediate returns, regardless of the long- term costs that result from over-exploitation of the resource. For instance, Pelusco (1983) cites the disappearance of traditional management systems as one cause of the over-exploitation of rattan in East Kalimantan, Indonesia.

Where over-exploitation is a current or poten- tial problem, improved management of resources in their natural habitat is essential. Hab- itat preservation should not be the only means of conserving natural resources; utilization on a sustainable basis under sound management re- mains a practical necessity. The design of an ap- propriate management regime for a given species


requires at least a basic knowledge of its reproduct ive biology as well as of its abundance, dis- t r ibut ion and growth rate in the areas to be man- aged. Wi thout this in format ion , it is difficult to establ ish harvest ing regulat ions that will guar- antee the maintenance of the resource.

L ITERATURE C ITED

Ahmad, M.U . 1951. Golpata. Pakistan J. For. 1:55- 61.

Brosius, J . P . t 986. River, forest and mountain: the Penan gang landscape. Sarawak Mus. J. 36(57): 173- 185.

Buza, A. 1989. The treasure o fa nipa swamp. Asian Wetland News 2(1):20.

Burbridge, P. R., and J. StanturL 1985. The development and management of tidal wetlands in Southeast Asia. Pages 157-160 in T. Saeki, A. Hino, T. Hirose, M. Sakamoto, and K. Ruddle, eds., Proc. MAB/COMAR Regional Seminar: Man's impact on coastal and estuarine ecosystems. Nov. 13-16 1984, Tokyo.

Doscas, A. E .G. 1927. The preparation of cigarette wrappers from nipah palm. Mal. Agric. J. 15:85- 86.

Dunn, F.L. 1975. Rainforest collectors and traders: a study of resource utilization in modem and an- cient Malaya. Monogr. Roy. Asiatic Soc. (Mal Br.) No. 5. Kuala Lumpur.

Fong, F .W. 1984. Nipa swamps--a neglected mangrove resource. Pages 663-671 in E. Soepadmo, A. N. Rao, and D. J. Macintosh, eds., Proc. Asian Symp. on Mangrove Environment: Research and management. August 25-29 1980, Kuala Lumpur.

Fox, d . J . 1977. Harvest of the palm--ecological change in eastern Indonesia. Harvard Univ. Press, Cambridge.

Gonzales, L L 1979. Nipa and its innumerable uses. Canopy 5(5):9.

Langer, R. H. M., and T. D. Steinke. 1965. Growth of lucerne in response to height and frequency of defoliation. J. Agric. Sci. 64:292-294.

Pelusco, N.L. 1983. Networking in the commons: a tragedy for rattans? Indonesia 35:95-100.

Robilios, Y .U . 1978. The nipa shingle industry of Batangas. Forpride Digest 2:56-57.

Smitinand, T. 1961. Materials used for thatching in Thailand. Pages 248-249 in C. Ratanarat et al., eds., Proc. Ninth Pac. Sci. Congr. 5(Bot). Nov. 18- Dec. 9 1957, Bangkok.

perspectives for sustainable resource utilization and management of nipa vegetation

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