Pteridophyte Flora of Khun Korn Waterfall Forest Park, Chiang Rai Province, Thailand

16 Pages·2002·0.63 MB·English

by  Boonkerd, Thaweesakdi

NAT. HIST. BULL. SIAM Soc. 50(2): 195-210，2 002
PTERIDOPHYTE FLORA OF KHUN KORN WATERFALL
， ，
FOREST PARKCHIANG RAI PROVINCETHAILAND
Thaweesakdi BoonkerdJ and Piyapong RatchattJ
ABSTRACT
An enumeration of白epteridophytes of Khun Kom Waterfall Forest Park，C hiang Rai
丹ovince，is presented. This is the first report for the area，wh ich inc1udes 154 species and 11
infraspecific taxa in 24 families and 64 genera. Selaginella ciliaris (Retz.) Spr・mg
(Se1aginellaceae) and Dicranopteris linearis (Burm.f.) Underw. var. montana Ho1ttum
(G1eicheniaceae) are newly recorded for Thai1and. Furthermore，u nusual distributions of 14
pteridophyte species are discovered. This forest park，in comparison wi白 theother a匂oining
protected areas，sh ows high pteridophyte diversity. However，tw o endemic fem species origi-
nally collected from Chiang Rai Province cou1d not be found. Habitat degradation by humans
has probab1y reduced pteridophyte diversity in the park.
Key words: Chiang R剖附'Ovince，Dicranopteris linearis v訂'.montana，fe m survey，ne w records，
pteridophytes，Se laginella ciliaris
INTRODUCTION
Thailand is estimated to have 10，000 species of vascular plants by SANTISUK ETA L.，
(1991)，b ut as many as 20，00ι25，000 species by白eNATIONAL BIODIVERS汀YUNIT
(1992). It is expected that with continued site-specific botanical surveys，m any new taxa
or new records will be found (OEPP，1 996). Thus，b otanical research in many specific
areas of百 ail佃 dis needed to add new knowledge ω出.eFlora of Thailand Proj倒 (SANTISUK
ETA L.，1 991).
Despite its rich plant diversity，C hiang Rai is rather poorly explored botanically as
comp釘edwith the neighboring province Chiang Mai. A prelim泊紅ysurvey of Khun Kom
Waterfall Forest Park revealed the fem，Lo magramma grossoserrata Holttum. This species
was hitherto known only from the type collection from Phrae Province (TA GAW A &
IWATSUKI，1 988). It is believed that the forest park also houses other百laiendemics，s uch
as Antrophyum winitu Tagawa & K. Iwats. which has been found only once in Chiang Rai
(TAGAWA & IWATSUKI，1 988).百lisresearch project aimed to explore plant diversity at
Khun Kom Waterfall Forest Park with specific reference to pteridophyte diversity.
IDepartment of Botany，Fa culty of Science，C hulalongkom University，B angkok 10330，T hai1and
Received 25 September 2001; accepted 25 Ju1y 2002.
195
196
THAWEESAKDI BOONKERD AND PIYAPONG RATCHATA
Figure I. Map of Khun Korn Waterfall Forest Park, Chiang Rai Province.
PTERIDOPHYTE FLORA OF KHUN KORN WATERFALL FOREST PARK 197
THE STUDY AREA
Khun Korn Waterfall Forest Park (190 51-54' N，9 90 35-39' E) was established in
1979. It is located on the westem side of Mae Lao Forest and on the eastern side of
Mae Kok Forest in Muang District，C hiang Rai Province (Fig. 1)，a nd is about 26 km
northwest of the city center. The forest park occupies parts of Mae Korn and Huai Chomphu
subdistricts and has at otal area of 18 km2.It is bounded on the north by Doi Mae Korn
at Ban Pang Takhrai and Ban Pang Khon，o n the south by Doi Chang and Doi Mae Mon
at Ban Li So Mae Mon，o n the east by Huai Ya Dee，a nd on the northwest by Doi Kia.
It is am ountainous area，l ying in the continental highlands. PENDELTON (1962) described
this physiographic region as as outhward extension of the Shan Hills of Myanmar. Its
elevation varies from about 625 m above sea level along highway 1208 to 1，635 m at the
summit of Doi Kia.
The climate of the area is monsoonal with as trong alternation of wet and dry seasons.
The northwest monsoon causes heavy rain during August-September. February is出e
driest month due to the occu町'enceof the dry northeast monsoon. The nearest meterological
station is in Chiang Rai at 394 m elevation. Climatological data covering 1970-2000
(Meteorological Department，20 00) show average annual rainfall of 1755 mm，a nd average
annual relative humidity of about 77%，wi th the highest humidity during August-December
c.
of 95%. The average annual temperature is about 24.1 The average maximum temperaωre
o
is about 34.80C in April，a nd the average minimum is 12.00C in January (Fig. 2).
The vegetation of Khun Korn Waterfall Forest Park can be classified into moist upper
mixed deciduous forest，dr y upper mixed deciduous forest and hill evergreen forest (Royal
Forest Department，1 962). Some pa口sof the forest park，e specially the hill evergreen
forest，ar e disturbed by hilltribe people.
PREVIOUS STUDIES
During 1902-1932，Dr . A. F. G. Kerr was among the first pioneer botanists to explore
plant diversity in Thailand. Most of his collections，ab out 25，000 numbers including several
type specimens，w ere sent to Kew Herbarium for identification. Most of the flowering
plants were studied by Dr. W. G. Craib who published his taxonomic work in Florae
Siamensis Enumeratio (LARSEN，19 79) but fems were studied by Dr. Eryl Smith.
During 1957-1960，D r. R. E. Holttum of Kew collaborated in“Studies in the Flora of
Thailand". He examined and identified 157 species of ferns，m any of them reported for the
first time，a nd new species were found. It was the first time that fern collections from
various p tsof Thailand were studied together (SMITINAND，1 962).
訂
During 1965-1966，Dr . M. Tagawa and Dr. K. Iwatsuki from Kyoto University collected
more than 7，000 specimens of pteridophytes from all over the country. A total of 633
species belonging to 132 genera and 34 families were enumerated and 25 new species were
found，2 1 of these endemic to Thailand (TAGAWA & IWATSUKI; 1979，1 985，1 988，1 989).
BOON阻 RD&P OLLAW A T N (2000) compiled data from various sources as well as
from their own field trips to produce ac hecklist of ferns and fern allies in Thailand.
A total of 671 species，4 subspecies，a nd 28 varieties belonging to 139 genera d35
姐
families were enumerated. This checklist included 27 new records for Thailand.
198
THAWEESAKDI BOONKERD AND PIYAPONG RATCHATA
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Figure 2. Climatological Data during 1970-2000 from Chiang Rai Station at 394 m above sea level (Meteoro-
logical Department, Bangkok, Thailand). • • mean rainfall .................. mean rainy
days
PTERIDOPHYTE FLORA OF KHUN KORN WATERFALL FOREST PARK 199
Botanical surveys of pteridophytes in Chi gRai Province，ho wever，ha ve been scarce.
叩
More site-specific plant collections are needed to determine the distribution of the
pteridophyte flora.
METHODS
Wem ade botanical surveys and collections from Khun Kom Waterfall Forest Park
from October 1997 until October 1999. Attempts were made to visit all habitats and
areas every month so as to cover all species distributions. Herbarium specimens were
determined using keys to the families，ge nera and species in TA GAW A & IWATSUKI (1979，
1985，1 988，1 989). For comparison，w e examined herbarium specimens deposited at the
following herbaria: BCU，B K，B KF，B M，K ，L ，an d P. Thef amilies of pteridophytes in也is
paper are arranged according to BOONKERD & POLLAWATN (2000)，w ith genera listed
alphabetically. Herbarium specimens have been deposited at the Professor Kasin
Suvatabhandhu Herbarium，De partment of Botany，C hulalongkom University (BCU)，釦d
at the Forest Herbarium of the Royal Forest Department (BKF).
RESULTS
At ota1 of 357 specimens of fems and fem allies were collected. Appendix 1e numerates
138 species and 11 infraspecific tabelonging to 60 genera and 21 families of fems and
蹴
16 species belonging to 4g enera and 3f amilies of fem allies，to gether with their habits，
habitats，an d abundance.
Pteridophyte Habitat
τ
'hef ems and their allies in the study area include terrestrial，ep iphytic，li thophytic
drheophytic species (Table 1). Among the species collected，te rrestrials were the richest
釦
in number (96 species)，wh ilst rheophytes were represented only by Microsorum pteropus
(Blume) Cope .l(Polypodiaceae)，a m edium-size fem growing on rocks in streams or
waterfalls. During the rainy season it can withstand flooding for ac onsiderable period of
time. It is not surprising that this rheophyte is ac ommon aquarium species worldwide.
百ledistinction between terres甘ialand lithophytic species is not always obvious. Lithophytes
grow on top of or beside mostly bare rocks. These pteridophytes grow fme，ex tensive root
systems，en abling them to penetrate the rock crevices where humidity is available. Some
of出.eteη'es凶alspecies include those growing on soil-covered rocks; for example Bolbitis
heteroclita (Presl) Ching ex C. Chr.，Bo lbitis virens (Hook. & Grev.) Schott var. virens
(Lomariopsidaceae)，O leandra undulata (Willd.) Ching (Oleandraceae) and Microsorum
cuspidatum (D. Don.) Tagawa (Polypodiaceae); and also Selaginella minutifolia Spring
(Selaginellaceae). Apart from the 9l ithophytes，2 o ther species of fems were found in two
other subs回.tes:Lomagramma grossoserrata Holttum (terres住ialor lithophyte) and Drynaria
bonii (epiphyte or lithophyte).
200 THAWEESAKDI BOONKERD AND I'rYAPONG RATCHATA
Table 1. Number of pteridophytes according to habitat.
Group/Habitat Terrestrial Epiphyte Litho。phyte Rheo。phyte
Fem allies 14 2
Fems 82 49 9 1
Total 96 51 9 1
Pteridophyte Diversity and Vegetation
Moist upper mixed deciduous forest exists from 650 to 800 m. This type of forest is
characterized by seasonally high air humidity， as well as as hady ground environment.
Eighty species of pteridoph戸eswere found in血isforest type with 59 te汀'es凶al，91i出ophytic，
and 11 epiphytic species. Thef amilies best represented were Polypodiaceae (16 species)，
Thelypteridaceae (13s pecies)，Se laginellaceae (8 species) and Dryopteridaceae (7 species).
Dry upper mixed deciduous forest is found along ridges from 650 to 800 m. The
ground vegetation泊 thistype of forest is more frequently affected by fire，e specially
during Januy-April.Fifty-two species of pteridophytes were collected; including 39
紅
terrestrial species and 13 epiphytic species.百leywere mostly members of Polypodiaceae
(11 species)，T helypteridaceae (7 species)，A diantaceae (5 species)，D ryopteridaceae (4
species) dSelaginellaceae (4 species).
叩
Hill evergreen forest is usually found above 1，000 m.百lerelative humidity is high，
and this type of forest contains more epiphytic species. In all，8 0 species of pteridophytes
were found including 41 species of epiphytes and 39 terresialspecies. Polypodiaceae
住
(25 species)，D ennstaedtiaceae (7 species)，Se laginellaceae (6 species)，a nd Davalliaceae
(6 species) were the most common families.
Endemic Species
Of the 154 species of pteridophytes，3 s pecies endemic to Thailand were found in the
study area: Selaginella lindhardii Hieron，Ch ristella siamensis Tagawa & Iwatsuki.，a nd
Lomagramma grossoserrata Holttum. Selaginella lindhardii，wi th ar estricted dis仕ibution
in Tak，Ba ngkok and Ratchaburi (TAGAWA &I WATSU阻，1979).Lomagramma grossoserrata，
known only from the type locality of Phrae Province (TAGAWA & IWATSU阻， 1988)，
thrives along strensor waterfalls from 650 to 800 m in moist mixed deciduous forest.
創
Christella siamensis has been collected from Phu Miang in Phetchabun and Phu Luang in
Loei Provinces (TAGAWA & IWATSUKI，1 988).
New Records
Two taxa of ferns and fem allies enewly recorded for Thailand. Selaginella ciliaris
釘
(Retz.) Spring，k nown from mainland China，T aiwan，P hilippines，I ndia，a nd Australia
(DEVOL，1 975a)，is common in Khun KomW aterfall Forest Park in slightly exposed eas
訂
on the mountain slopes at 670-800 m altitude (RACHATA &B OON阻 RD，2001).百leother
new record，D icranopteris linearis (Burrn.f.) Underw. var. montana Holttum，is known
from tropical A合ica，Asia，a nd Australia (DEVOL，1 975b). This variety occurs in soil of
mountain ridges in dry forests from altitudes of about 950 to 1，300 m.
PTERIDOPHYTE FLORA OF KHUN KORN WATERFALL FOREST PARK 201
Figure3 -6. 3，S elaginc/la ciliari.l'， an cw J巴corclfor Thailancl on hill slopcs al6 70-800 III allilucles.4 ，S lrobili
ofS clagine/la ciliari.l'. S，D icmllojJleris lillearisv ar. IIIOlllol1a，a n ew J巴corclforT haliancl onI lloun-
lain riclge al 975 III孔Ililuclc.6，V enaliona ncl sori 01'D icrallOIJleris lil1earisv ar. IIIOlllOlla
202
THAWEESAKDI BOONKERD AND PIYAPONG RATCHATA
Figure 7-10. 7, A populmion of wan kai noi, Cib01iwn baromelz on hill slopes at 900-1,200 m. 8, Drynaria
parishii on a fallen mossy log in hill evergreen foresl a1 I ,350 m altitude. 9, Lomagramma
grossoserraw. an endemic fern along stream from 650-800 m in moist mixed deciduous foresr;
showing ferlile pinnae. I 0, Diplaziwn murica/um by stream in moist mixed deciduous forest.
PTERIDOPHYTE FLORA OF KHUN KORN WA'τERFALL FOREST PARK 203
DISCUSSION
Expected Species
A total 155 species of fems and fem allies are reported from Chiang Rai Province by
TAGAWA & IWATSUKI (1979-1989). These include 3e ndemic fem species，vi z. Bolbitis
tonkinensis (C.Chr. ex Ching) K. Iwats. (Lomariopsidaceae)，An thophyum winittii Tagawa
& K. Iwats. (Vittariace鵠)， and Cyathea chinensis Copel. (Cyatheaceae) only collected
from Chiang Rai. These were not found during our surveys. However，Bo lbitis tonkinensis
is rare加Thailandsince only one collection has been made in Chiang Rai at 550 m altitude
(TAGAWA & IWATSUKI，1 988). Anthophyum winittii also ar are endemic species known
only from the type specimen，a lthough ANUSARNSUNTHORN ETA L. (1999) reported this
species in Doi Luang National Park，Ch iang Rai. Cyathea chinensis，a 位'eefem，is also rare
in百四land，with its southem-most distribution in Chiang Rai (TAGAWA &I WATSUKI，
1979).
Khun Kom Waterfall Forest Park is in am ountainous area where tribal people still
practice shifting cultivation and the forests have been severely degraded and modified.
Parts of the study 'eahave been deforested，an d ac onsequence，so me pteridophytes have
紅
prob油lybeen extirpated.
New Information on Pteridophyte Distribution in Thailand
Among the 154 species and 11 infraspecific taxa studied，79 taxa have been previously
recorded from Chiang Rai Provinc(TAGAWA& IWATSUKI; 1979，1 985，1 988，A ND 1989)，
怠
whereas 86 tahave not been recorded previously，in cluding widespread species such as
鉱
Bolbitis appendiculata (Willd.) K. Iwats. (Lomariopsidaceae)，B lechnum orientale L.，
(Blechnaceae) and Tectaria angulata (Willd.) C. Chr. (Dryopteridaceae).
Fourteen species have never been found in northem 百lailandpreviously (MAXWELL，
2002; TAGAWA & IWATSUKI; 1979，1 985，1 988 AND 1989).百lese釘e:
Aspleniaceae: Asplenium macrophyllum Sw.，As plenium perakense Mathew &C hrist，
Gleicheniaceae: Dicranopteris curranii Copel.;
Hymenophyllaceae: Hymenophyllum acanthoides (van den Bosh) Cope ，.lTrichomanes
bimarginatum van den Bosch;
Polypodiaceae: Belvisia mucronata (Fee) Cope ，.l Pyrrosia varia (Kaulf.) Farw.，
Lepisorus suboligolepidus Ching;
Pteridaceae: Pteris tripartita Sw.;
Selaginellaceae: Selaginella wallichii (Hook. & Grev.) Spring;
Thelypteridaceae: Pronephrium glandulosum (Blume) Holttum;
Vittariaceae: Vittaria angustifolia Bl.;
Woodsiaceae: Diplazium petri Tard.，Di plazium simplicivinium Holttum.
Four of these 14 species，n amely Asplenium perakense，P ronephrium glandulosum，
Selaginella wallichii and Trichomanes bimarginatum，ha ve previously been recorded only
in peninsular Thailand，Ma laysia and Indonesia. Their occu'encein Chiang Rai indicates
町
ad isjunct dis凶bution(Ho1.:甘UM，1954; TAGAWA AND IWATSUKI，1 979，1 985，A ND 1988).
204 THAWEESAKDI BOONKERD AND PIYAPONG RATCHATA
Pteridophyte Diversity
Some workers have used the species/genus ratio to assess taxonomic diversity of
plants and animals (e.g. BARNOSKY Ef AL.， 2001; CONGDON，1 982). Accordingly，出e
pteridophyte diversity found in the pkcan be comp'edwith that reordedin nearby
ぽ 紅 氾
protected紅'eas也ChiangMai and Chi組 gRai (Table 2).τ'hes pecies/genus ratio for Khun
Kom Waterfall Forest Park is 2.33，w hile the highest and lowest values were from Doi
Suthep-Puian d Doi Luang，r spectively.百egeneral similarity between Khun KomW aterfall
巴，
Forest Park and the other four sites，de spite its much smaller size，su ggests白at血ispark
is Pticularlyrich in pteridophyte diversity. However，m ore comprehensive studies and
紅
intensive surveys of pteridophytes need to be carried out in the other four areas mentioned.
Table 2. Summary of pteridophyte diversity in five northem protected areas.
WS= w ildlife sanctuary，N P =n ational park
Protected area Bedrock Altitude Tota! area Families Genera Species Species/
(m) (km2) genus ratio
Doi Chiang Limestone 300ー2，225 521 18 46 98 2.13
Dao WS1.2.3
Doi Inthanon Granite， 300ー2，565 272 24 67 171 2.55
Np4 !imestone
Granite 35ι1，685 261 27 65 174 2.67
Dpuoi iNSP u血5，6ep-
Doi Luang Gr;佃 ite， 400-1，710 1170 21 48 87 1.81
Np7 limestone
Khun Kom Granite， 625-1，635 18 24 66 154 2.33
Waterfall limestone
Forest Park
Notes :I NANAKORN (1998); 2MAXWELL (1992); 3MAXWELL (1998); 4KoYAMA (1986); 5TAGAWA & IWATSUKI
(1979，1 985，1 988 AND 1989); 6MAXWELL & ELLlOTT (2001); 7ANusARNSU附 HORNETA L. (1999)
ACKNOWLEDGMENTS
百1Iswork was supported by血eTRF/BIOTEC Biodiversity Research and Tra加ing
Program Grant BRT 140009. Wew ish to exp民ssour sincere血創1ksto白ecurators and
staff of the following institutions: BK，B KF，B M，K ，P a nd L，fo r their kind permission
to study pteridophyte specimens. Our thanks are due to the former and present heads and
staff of Khun KomW aterfall Forest Park for their cooperation during our fieldwork.官1Is
paper improved marked!y from the comments of anonymous reviewers，to whom 1a m very
grateful.