DA DANG THI/C VAT KHU BAO TON LOAI Vuofn CAO VIT TRUNG

HQI NGHI KHOA HQC TOAN QU6C V£ SINH THAI VA TAI NGUY£N SINH VAT LAN THU" BA

DA DANG THI/C VAT KHU BAO TON LOAI VUOfN CAO VIT TRUNG KHAJVH, TINH CAO BANG NGUYEN Htru TlT, VU ANH TAI PHAM THE ViNH, TRAN THI THUY VAN Vien Dia ly NGUYEN THI THANH NGA To chuc Bao ton dong thuc vat hoang da Quoc te

Trong nhimg nam gan day, truoc xu the ngay cang giam ve so lugng ciia cac loai dpng, thuc vat quy hiem, cac quoc gia va cac to chuc phi chinh phii da va dang rat no luc hanh dgng de bao ton cac nguon gen quy hiem ciia trai dat. Viet Nam la mot nuoc c6 nguon tai nguyen sinh vat da dang va phong phii nhung cung la nai toe do tan pha thien nhien va qua do lam suy giam tinh da dang sinh vat nhanh chong. Hien nay, cac loai linh truang la doi tugng quan tam hang dau trong cac chien luge bao ton ciia cac quoc gia va cac to chure bao ton phi chinh phii. 0 Viet Nam, c6 nhieu loai linh truang rat quy hiem nhu Voge mili heeh, Vugn cao vit, Cha va chan nau... la nhung loai dac hii^ ciia Vi?t Nam va da so dang tren ba tuyet chimg. Cac khu bao ton thien nhien, bao ton loai va sinh canh dugc thanh lap lien tue trong nhung nam qua la de khac phuc tinh trang suy thoai va gop phan tich cue trong cong tac bao ton. Tren nui da voi, do tinh chat djc bi?t ciia no, cac h? sinh thai hinh thanh a day c6 tinh nhay cam cao, de bi thay doi do cac tac dgng ciia eon nguai Ian cac tac dgng ngi sinh (nhu sup do, hap thu nhiet, ran niirt...). Tham thye vat dong vai tro quan trgng nhat trong eau true eiia h? sinh thai tu nhien. Su bien doi ciia no se keo theo hang loat nhung bien doi ciia he sinh thai va tai nguyen thien nhien, dac biet la tai nguyen sinh vat. Ngoai ra, no eon la nguon song, la mai nha cho sy cu ngu ciia cac loai dgng vat, nhat la cac loai linh truang quy hiem nhu Vugn cao vit, Voge miii heeh... Khu vuc bao ton loai Vugn cao vit nam tren dja ban ba xa Phong Nam, Nggc Con va Nggc Khe ciia huyen Triing Khanh, tinh Cao Bang vai tong dien tich gan 7600ha, trong do viing loi c6'1600ha. Nhin tong quan, khu vyc da voi eiia viing nghien curu la mgt phan nho ciia viing da voi rgng Ion cao tdi tren 1000m ciia 2 tinh Quang Tay va Van Nam, tren dja hinh cac khoi nui da voi do so va rat dac trung ciia viing Dong Bac. Vimg trung tam thugc h$ tang Carbon - Permi {C-?bs), thanh phan thach hgc chinh la da voi, da voi set hay da voi silie vai tang day 650 - 800m. Khu vyc bao quanh c6 da voi thugc phan he 2 h? tang Na Quang (Dx-inq:) vai thanh phan silic kha cao, day toi 300-320m. Khu vuc eo khi hau nhi?t ddi gio miia eo miia dong lanh, mua he, khong c6 thang kho. Sinh khi hau chung la a nhi?t dai am vdi nhi?t dg trung binh nam 16-20°, miia lanh dai tren 4 thang, lugng mua trung binh nam vira phai tir 1.500 -2.500mm, miia kho ngin, thudng dudi 2 thang Viec nghien curu tham thuc vat d khu vyc nay, ngoai muc di'ch gop phan vao cong tac bao ton loai linh trudng quy hiem ciia Vi?t Nam ma no eon cho thay dugc nhirng net dac thii eiia tham thuc vat chi tim thay d khu vyc nui da voi.

I. PHirONG PHAP NGHIEN ClTU Ap dung cac phuang phap di6u tra, xir ly, phan tich va dinh danh thye vat thong thudng. Cac dgt diSu tra dugc tiln hanh lien tyc tir nam 2006 din 2007 dudi sy tai trg eiia t6 chirc FFl, nam 2008 va 2009 dugc tai trg bdi ngan sach nghien eini ca ban ciia Vi?n Dia ly. MIU vat thu thap dirge luu trir tai Bao tang Thye vat, Trudng Dai hgc Khoa hgc ty nhien- Dai hgc Quoc gia Ha Ngi va Vi?n Dia ly, Vi?n Khoa hgc va Cong ngh? Vi?t Nam.

875 HQI NGHI KHOA HOC TOAN QUOC Vt SINH THAI VA TAI NGUYSN SINH VAT LAN THU' BA

n. KET QUA NGHIEN ClTU

1. Da dang tham thye vat - Rirng a nhiet dai thuang xanh cay la rong a thung lung Trong cac thung liing, thudng c6 lap dat mong, khong khi am udt han so vdi viing sudn va dinh nhieu suang dgng. Tham thye vat trong c6 ve giong vdi rimg nhiet ddi thudng xanh binh thudng d viing niii thip. Tuy nhien, tham thye vat d day da bi tac dgng bdi cu dan dja phucmg trong qua khur, cau triic eiia no da bi bien doi. Tang tan rimg khong lien tue. Cac cay con sot lai cao tdi tren 30m nhu May tho (Dau gia xoan - Allospondias lakhoensis), Moc (Caryota bacsonensis)... Loai Sung (Ficus oligodon) c6 rat nhieu qua moc ra tir cac canh nho tren be mat dlt trong nhu rl mang qua. Tang cd cd nhieu loai dac trung cho nen da voi nhu cac loai thugc cac hg Gai (Urticaceae), Thugng tien (Gesneriaceae), Ray (Araceae), Cau (Arecaceae)... Tang cay go gom cac loai mgc nhanh (nhung loai tien phong) dac trung cho giai doan tai sinh nhu cac loai Quang (Alangium kurzii), Simg (Ficus spp.,), Dudng (Broussonetia papyrifera), Xoan^ nhir {Choerospondias axillaries), Ndng (Saurauia tristyla), Ra d^t (Radermachera boniana), Sau sau (Liquidambar formosana), Tam thy himg (Trigonostemon sp.) ... Mgt so loai cay rung la ciing cd mat gom Thich (Acer spp.), Bang, lang (Lagerstroemia sp.), Lat (Chukrasia tabularis), Queeh (Chisocheton sp.), Xoan nhir (Choerospondias axillaries), Seu {Celtis spp.), Xoan (Melia azedarach), Sau sau (Liquidambar formosana).... Trong rimg cd nhieu loai lam thuc an cho Vugn cao vit nhu May tho, Moc, Sung la tim (Ficus cardiophylla) va Dudng... - Rimg tre nua a nhiet dai a thung lung Kieu nay it gap d khu vyc nghien cuu, chi vdi mgt vai manh nho, khong lien tue. Cac loai thudng gap cd Sat (Arundinaria sp.), Tre gai rimg (Bambusa bambos), Mai (Dendrocalamus giganteus). Tang cd chu yeu la cac loai thugc hg Hoa thao (Poaeeae), C6i (Cyperaceae) va mgt so loai Duong xi. - Rimg a nhiet dai thuang xanh cay Id rgng a suan nui Day la trang thai rimg tot nhat ciia khu vyc nghien cuu. May puon (Cephalomappa sinensis) thugc hg Thau dau (Euphorbiaceae) la loai uu thS gin nhu tuy^t ddi, dae bi?t nai sudn cd dat mim tho. Chiing chiem den 76%) dg quan trgng (IVl) trong cau triic eiia cac 6; ve so ca the, khoang 72%); 80% tiet dien goc. Phan Idn chiing la cac cay gd cao > 18m, dudng kinh >30cm. Nhilu cay go to ciing goc. Cay gd thudng xanh chiem uu the. Cac cay gd rung la nhu cac loai Thich, Bang lang, Xoan nhir cimg mgt so loai khac thugc hg Xoan (Meliaceae), bat dau rung \i vao thang 8. Dudi tan ed cac cay Nghien nho dang tai sinh. Tren cac yen ngya cd uu hop gdm Dau gia xoan (Allospondias lakhoensis) + Nghien (Burretiodendron hsienmu) + Si (Ficus racemosa) + Trai (Garcinia fragaeoides) + Huan lang (Wendlandia tonkinensis) + Bdi Idi (Litsea spp.) va Seu la re (Celtis cinnamomea). - Rimg a nhiet dai thudng xanh hon giao cay Id rgng vd hat trdn a khu vuc dinh nui Cau true cua rimg tren dinh va vimg can dinh kha khac biet so vdi cac kieu con lai. May puon khong cd mat d day. Sat (Arundinaria sp.) la diu hieu bat dau cua kilu tham nay, no mgc

876 HOI NGHI KHOA HQC TOAN QUOC V£ SINH THAI VA TAI NGUY£N SINH VAT Li>N THIJ BA bit dau tir lung chimg nui trd len. Day la kieu tham it bj tac dgng nhit ciia khu vyc. C4u true ciia rimg kha dan gian vdi chi mgt tang cay go - tang uu the sinh thai va cay go chi cao 10-12m do do kieu nay doi khi con dugc ggi la rimg liin. Cac loai Hat tran nhu Thong pa c6 {Pinus kwangtungensis), Thiet sam gia (Pseudotsuga sinensis) va Thong do (Taxus chinensis) moc Ian vdi cac loai cay la rgng nhu cac loai De (Castanopsis spp.), Platycarya strobilifera, Engelhardtia roxburghiana, Triadica rotundifolia, Phyllanthus sp., Vemicia montana, Celastrus sp., Sterculia sp,, Acer tonkinensis, Wrightia sp., Cinnamomum spp., Litsea spp.... Theo Leonid va tap the (2004), trudc day rimg con cd Thiet sam gia la ngan (Pseudotsuga brevifolia) va Thong (Pinus fenzeliana) nhung khao sat mdi day khong gap chiing. - Trang bui nhiet dai thuang xanh thu sinh Trang bui nhiet ddi thudng xanh thiir sinh d khu vyc nghien etiu dugc hmh thanh sau mgt thai gian canh tac dai d cac thung liing. Kieu nay phan bd xen gi&a vimg ed cay go va trang c6, a dg cao dudi 600m. Cac loai byi trudn uu the thugc ve cac hg Dan nem (Myrsinaceae): Measa spp., Ca phe (Rubiaceae): Mussaenda, Hoa hong (Rosaceae): Rubus spp. va cac loai Vi hoang leo (Senecio scandens), Rau bd khai (Erythropalum scandes)... Cac loai cay byi gdm Dan buot [Bidenspilosa). Hong bi rimg (Clausena sp.), Byp (Abelmoschus spp.), Han xanh (Dendrocnide sinuate), Bd cu ve (Breynia sp.), Nai bia nguyen (Villebrunea integrifolia), Cd duoi chugt [Stachytarpheta jamaicensis), Nggc nir (Clerodendrum spp.), Lau (Psychotrya sp.), Gai (Boehmeria holoserica)... Mgt so loai cd dang liia cao mgc xen vdi cay byi la Lau (Saccharum spontaneum), Cd tranh (Imperata cylindrica)... va cac loai cay gd mgc nhanh gom Thudc voi [Pouzolzia sp.), Nong (Saurauia tristyla), Biim byp (Mallotus barbatus, Mallotus sp.), Soi la tron (Triadica rotundifolia). Ma rang (Macranga sp.), Dau gia xoan (Allospondias lakhoensis), Dudng (Broussoneratia papyrifera), Chan chim (Schefflera sp.), Hemiscolopia trimera...

- Trang cd nhi^t dai thic sinh "Trang ed dugc hinh thanh sau canh tac d tren cac thung liing, dg cao dia hinh thudng dudi 600m. Cac loai cd dang liia uu the gom Co tranh (Imperata cylindrica). Chit (Thysanolaena maxima), Che ve (Miscanthus spp.), Lau (Saccharum spontaneum), Cd ke (Panicum sp.), Cd la tre (Paspalum sp.) ... do la cac dang c6 cao. Cac ed dang khac gdm Thom Idm (Polygonum chinensis), Thdc lep (Crotalaria sp.), Thii lii (Physalis minima , Lycianthes lysimacanthoides). To lien (Torenia glabra), Duong xi va hg hang than can nhu Selaginella sp., Diplazium esculentum, Dipteris chinensis..., cac loai trong hg Cue: Vemonia sp., Blumea sp.. Mgt so loai cay bui va cay gd nho mgc lln trong trang ed g6m: Budm bac (Mussaenda sp.), Tao (Ziziphus incurva), Biing bye (Mallotus sp.), Soi la trdn (Triadica rotundifolia). Ma rang (Macranga sp.), Choi mdi (Antidesma sp.), Hdng bi rimg (Clausena sp.), Byp (Abelmoschus spp.), Gai (Boehmeria spp.), Han xanh (Dendrocnide sinuate), Thuoc voi (Pouzolzia spp.), Nai bia nguyen [Villebrunea integrifolia), Co duoi chugt (Stachytarpheta jamaicensis), Nggc nir (Clerodendrum spp.), va eac loai day leo nhu Ngiy (Rubus sp.), Kh6 ao (Thlandiantha spp.), Cdu qua (Zehneria spp.), Hong bi (Trichosanthes spp.), G6i hac (Leea indica). Day khe rimg (Connarus sp.), Lai niii (Jusminum sp.), Tir thu (Tetrastigma spp.). Ha thu d tring (Strebtocaulonjuventas), Moc bd (Uncaria scandens), Lac tien (Adenia, Passiflora foetida)...

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2. Da dang h? thye vat Bang 1 Thanh phan h? thifc vgt khu bao ton loai Vu-(rn cao vit Trung Khdnh Hg Chi Loai Nganh, lop So hp %, So chi %, So loai % Lycopodiophyta 2 1,4 3 0,6 5 Nganh Thong dat 0,5 Polypodiophyta 15 10,4 27 5,0 53 Nganh Duong xi 5,5 Pinophyta 5 3,5 8 1,5 8 Nganh Thong 0,8 Magnoliophyta 122 84,7 503 93,0 894 Nganh Mgc Ian 93,1 Magnoliopsida 103 71,5 372 68.8 645 67.2 Lap Moc Ian Liliopsida 19 13.2 131 24.2 249 25.9 Lap Hanh Tong so 144 100 541 100 960 100 Mau vat tir cac dgt khag sat, sau khi dinh danh loai va sap xSp theo h? thdng cua Brummit (1992) cho ket qua: hg thye vat gdm 960 loai (bao gdm cac loai mgc ty nhien chua sir dung trong trong trgt va mgt so loai cay trong mgc hoang dai, cay ty nhien d khu vyc dugc gay trong), 541 chi, 144 hg, thugc 4 nganh thye vat, thS hien d bang 1. He thye vat d khu vyc thieu dai di^n cua nganh Psilotophyta (La thong) va nganh Equisetophyta (Than dot). Nganh Mgc Ian chiSm ty Ig cao (93,1%) trong h? thye vat, tiep den li nganh Duong xi (5,5%>), Thdng (0,8%), Thdng dat (0,5%). Nhm chung, nganh Mgc Ian c6 ty 1? cao, nen da vdi kho han khong thuan Igi cho nganh Duong xi. Than ddt .phat triSn nen da nang cao ty le ciia nganh Mgc Ian. Ty le so loai cua Idp Mgc lan/ldp Hanh d khu vyc nghien cuu la 2,6/1. So sanh vdi he thirc vat Vigt Nam (8000/2775) ty Ig nay la 2,8/1. Theo De Candolle, ty le ciia Idp Hanh giam tirBac eye den Xich dao. Tai dn ddi va Bac eye, ty le nay la 2,3 - 2,9/1. Nen nhigt tucmg d6i thap cimg vdi nen da khdng thuan Igi da han chS sy phat triSn cua cac loai trong Idp Mgc Ian. Mudi hg giau loai nhat he thye vat khu vyc nghien cuu gdm: Orchidaceae (Lan, 130 loai, chiem 13,5%) so loai cua he thye vat), Fabaceae (gdm ca hg phy nhu each phan chia trudc day, 38 - 4%), Rubiaceae (Ca phe, 37 loai - 3,9% ), Urticaceae (35 -3,6), Moraeeae (32 - 3,3), Thiu dau (29 - 3,0), Poaeeae (28 - 2,9), Araceae (Ray, 21 loai, 2,2%), Asteraeeae (Ciic, 21 loai, 2,2%), Verbenaceae (Cd roi ngya , 19 loai, 2%) [ ngoai ra hg Rutaceae (Cam chanh, 19 loai, 2,0%) khong tinh]. 10 hg nay ed 390 loai ehilm 40,6%) so loai cua he thye vat. Qua do cho thiy, che dg mat am da thuan Igi cho cac loai Phong lan, Gai phat triSn. Chi giau loai nhit cua hg thye vat la Ficus cd 26 (2,7%>), tiep theo la Liparis (14 loai, 1,5%), Schefflera (11 loai, 1,1%), cac chi Tetrastigma. Eria, Boehmeria. Asplenium (cimg c6 9 loai, 0,9%)) va cac chi Setaria, Pilea, Paphiopedilum. Dendrobium, Ardisia (ciing ed 8 loai, 0,8%). Trong sd mudi chi nhieu loai nhat nay, mgt iin nifa thly sy hien dien cua hg Phong lan (Orchidaceae) vdi 4 chi qua do cho thay Triing Khanh la nai rat thuan Igi cho sy phat triln cua chung. Dang sdng dugc phan tich 937 tren 960 loai cua hg thye vat (3%) sd loai chua dii du li?u), ket qua phd dang song dugc xay dyng nhu sau: SB = 76.4Ph + 8,9Ch + 4,4Hm + 3,6Cr + 6,7Th

878 HQI NGHI KHOA HQC TOAN QUOC V£ SINH THAI VA TAI NGUY£N SINH VAT U\N THli BA

Noi chung phd dang sdng ciia khu vyc c6 sy sai khac so vdi phd dang s6ng d cac khu vyc da voi khac: nhom choi tren cd ty Ig cao; nhom choi nira an, nhom chdi Sn cd ty Ig thip. Nen nhiet tuong doi thap, dg am khdng khi cao va nen da vdi thiSu Idp phii dk chilm phin Idn dien tich quy djnh moi quan he nay. - — Yeu to dia iy phan anh mdi quan he giira cac loai hien cd d mgt dia phuang vdi cac loai d khu vyc xung quanh. Dya vao qua phan tich 923 tren sd 960 loai, kk qua tdng hop vh y§u t6 dja ly dugc the hien d bang 2. Bang 2 Yeu to dia ly cua khu bao ton loai Vufm cao vit Trung Khdnh

Yen to dja ly K^ hl?u So loii Ty If % Dac hiJu Viet Nam la 61 6,3 Dac hiru BSc Viet Nam lb 55 5,7 Dong Ducmg 2 112 11,7 Nam Trung Hoa 3 157 16,4 Hai Nam, Dai Loan, Phi-Iip-pin 4 40 4,2 Himalaya 5 14 1,5 An Dp 6 157 16,4 Ma-lai-xi-a 7 5 0,5 Ma-lai-xi-a - In-do-ne-xi-a 8 33 3,4 Ma-lai-xi-a - In-do-ne-xi-a - Chau Uc 9 7 0,7 Chau A nhi?t ddi 10 153 15,9 Co nhi?t ddi 11 28 2,9 Tan nhi?t ddi va lien nhi?t ddi 12 20 2,1 E3ong A 13 26 2,7 On dai Bac 14 3 0,3 Chau A 15 29 3,0 Phan bo rpng 16 11 1,1 Yeu to di cu va nhap ngi hi?n dai 17 13 1,4 Chira xac dinh 37 3,9 Tong so da xac dinh 923 96,1 3. Nguon tai nguyen thye vat Ve gia tri sir dung, da thong ke dugc 10 nhdm cong dyng do tdng so 423 loai, chiem 44% so loai tag nen. Ket qua tdng hgp the hign d bang 3. Co 34 loai dugc ghi danh trong Sach Dd Vigt Nam (2007) gom: 2 loai rat nguy cip (CR): Que bdi Idi (Cinnamomum parthenoxyion). Kim cang pe-ta-16 (Smilax petelotii); 13 loai nguy cap (EN): Hoang lien gai (Mahonia nepalensis), Trai ly (Garcinia fagreoides), Soi dau cimg (Lithocaspus finetii), Nghien (Excentrodendron tonkinense), Kim tuyen da voi (Anoectochilus calcareous), Lan kim tuyen to (Anoectochilus setaceus). Nhin digp ndn (Liparis conopea).

879 HOI NGHI KHOA HOC TOAN QU6C V^ SINH THAI VA TAI NGUYEN SINH VAT L4,N THLf BA

Thanh thien quy (Nervillia fordii). Lan hai vang (Paphiopedilum helenae), Lan hai tia (Paphiopedilum micranthum). Kim hai (Paphiopedilum villosum). Hdng nhung vang xanh (Renanthera citrine), Thit digp nhIt chi hoa (Paris polyphylla ssp. fargestii) va 19 loai se nguy cip (VU): Thdng pa cd (Pinus kwangtungensis). Dgi mil (Mitrephora calcarea), Bach diu na pha luan (Vemonia bonapartei), Dinh thoi (Markhamia stipulate), Tram den (Canarium tramdenum), Dang sam (Conodopsis celebica), Hoe bac bg (Sophora tonkinensis). Soi sim (Quercus glauca), Vii huang (Cinnamomum balansae). Mgc ve nu (Taxillus gracilifolia). Thoa (Acmena acuminatissima). Bac canh (Leptomischus primuloides), Hoang tinh hoa tring (Disporopsis longifolia). Sam cau (Peliosanthes teta). Kim diep (Dendrobium fimbriatum). Tieu hai vang xanh (Paphiopedilum hirsutissimum). Dang sam (Codonopsis javanica), Rau sing (Meliantha suavis), Tran chau xanh (Nervilia aragoana).

Bang 3. Cac nhom cong dyng va ty 1| (%) cua h| thye khu bao ton loai Vu^n cao vit Trung Khanh Nhom cong dyng Ky hifu So loai Tyl? Lam thuoc Me 284 29,6 Luang thuc, thuc pham Ed 111 11,6 Cho go, ciii T 110 11,5 Lam canh Or 55 5,7 Dau beo Oi 21 2,1 Sgi Fi 16 1,7 Tinh dau E 10 1,0 Ta-nanh Ti 8 0,8 Nhuom D 7 0,7 Thirc an cho vat nuoi F 45 10,6 Vat lieu xay dung Ma 4 0,4 Nhira Sa 2 0,2 Tong so loii c6 cong dyng 423 44,1%

ni. KET LUAN Tham thye vat d khu vyc nghien cuu da dugc md ta trong 6 kiSu tham chinh gom: rimg a nhiet ddi thudng xanh cay la rgng d thung liing, rimg tre nua d thung liing, rimg a nhiet ddi thudng xanh cay la rgng d sudn nui, rimg a nhigt ddi thudng xanh hdn giao cay la rgng va hat tran d khu vyc dinh, trang byi nhigt ddi thudng xanh thu sinh va trang cd nhigt ddi thudng xanh thii sinh. He thye vat da thdng ke dugc 960 loai, 541 chi, 144 hg, thuoc 4 nganh; Mudi hg giau loai nhat cd 390 loar chiem 40,6% so loai cua he thye vat; pho dang song da dugc xay dyng bang cong tfflJc: SB = 76,4 Ph + 8,9 Ch + 4,4 Hm + 3,6 Cr + 6,7 Th. Cac yeu to dia ly eo s6 loai nhihu nhit la An Do, Nam Trung Hoa, Chau A nhiet ddi va Dong Duong. Da thong ke dugc 10 nhdm cong dyng do tdng so 423 loai, chiem 44 %> so loai cua khu vyc. Cd 34 loai quy hiem can dugc bao ve, dugc ghi danh trong Sach Dd Vigt Nam (2007).

880 HQI NGHI KHOA HOC TOAN QU6C V£ SINH THAI VA TAI NGUY£N SINH VAT U\N THC" BA

TAI LIEU THAM KHAO 1. Averyanov L.V., Phan Ke Loc, Nguyen Tien Hiep, Pham Van The, Nguyen Tien Vmh, 2004: Preliminary survey of Orchids and Gymnosperms in Trung Khanh district, Cao Bang province, nortliem Viet Nam. In the limits of Ngoe Khe and Phong Nam municipahties. Tai lieu ciia FFI. 2. Nguyen Tien Ban va cgng sy, 2003-2005: Danh luc cac loai thye vat Viet Nam, tap II, III. NXB. Nong nghiep, Ha Ngi. 3. Eg Khoa hgc va Cong nghf, Vi?n Khoa hgc va Cong nghf Vift Nam, 2007: Sach Dd Viet Nam (Phdn II - Thye vat). NXB. Khoa hgc Ty nhien va Cong nghe. Ha Ngi. 4. Brummitt R.K., 1992: Vascular Plant Families and Genera. Royal Botanic Gardens, Kew. 5. Vu Van Dung, Nguyen Huy Dung, 1999: Tai nguyen rimg niii da vdi Cao Bang va phuang hudng bao ve: 103-109. Bao ve va phat trien ben viing rimg va da dang sinh hgc tren viing nui da vdi Vift Nam. Vien Dieu tra Quy hoach rimg, Ha Ngi. 6. Dai hgc Quoc gia Ha Ngi - Trung tam nghien ciru Tai nguyen va Moi trudng, 2001: Danh lye cac loai thye vat Vift Nam. Tap I. NXB. Nong nghiep, Ha Ngi. 7. Pham Hoang Hg, 1999 - 2000: Cay ed Viet Nam, tap 1-3. NXB. Tre, Tp. Hd Chi Minh. 8. Phan Ke Lgc, 1999: Tap chi Lam nghifp, 12/1999, 35-36. Ha Ngi. 9. Nguyen Van Nhan, 1999: Nghien cuu eo sd phuc hoi hf sinh thai rimg tren niii da bang cac loai cay ban dia d Cao Bang : 48-49. Bao ve va phat trien ben vimg rimg va da dang sinh hgc tren viing nui da vdi Viet Nam. Vien Dieu tra Quy hoach rimg. Ha Ngi. 10. Vu Anh Tai et. al, 6. 2006: Update list of flora and making plots for access the forest structure and monitoring the phenology at protected caovit gibbon area, Phong Nam - Ngoc Khe, Trung Khanh district, Cao Bang province. FFI - Indochina programme

DIVERSITY OF FLORA AND VEGETATION AT CAO VIT GIBBON PROTECTED AREA TRUNG KHANH, CAO BANG PROVINCE

NGUYEN HUU TU, VU ANH TAI, PHAM THE VINH TRAN THI THUY VAN, NGUYEN THI THANH NGA

SUMMARY The vegetation of the Cao Vit Gibbon Protected Axea in Trung Khanh, Cao Bang province was sur^'eyed and classified into 6 main types: sub-tropical evergreen broad leaves forest on low mountain limestone valleys, bamboos forest on low mountain limestone valleys, sub-tropical evergreen broad leaves forest on the low mountain limestone slopes, sub-tropical evergreen mixed broad leaves and conifers forest on the lunestone peak area of low mountain, secondary tropical evergreen scrubs and grasses. The study of flora showed 960 species and 541 genera in 144 families and 4 divisions; 10 richest families contain 390 species representing 40,6% of total; life form was calculated as SB = 76.4Ph + 8,9Ch + 4,4Hm + 3,6Cr + 6,7Th. The flora showed phytogeographic elements from Indonesia, South China, Tropical Asia and Indochma. There were 10 groups of plants useful with 432 species representing 44%) of total. There were 34 threatened species of this flora recorded in Vietnam Red Data Book (2007).

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