HQI NGHI KHOA HOC T O A N Q U 6 C V E SINH THAI V A TAI NGUYEN SINH VAT L A N THLf 5
HIEN TRANG THAM THlTC VAT RlTNG TAI HUYEN SONG MA, TiNH SO>i LA
NGUYEN THI QUYEN Vy ban Mat Iran Td quoc Viet Nam huyen Song Md. tinh San La
Huyen Sdng Ma each thanh phd San La 110km ve phia Tay Nam theo tryc quoc Ip 40 vdi tga dp dja ly: 20°39'33"-2l''22' vi do B4C va I03''l4'56"-104°06'00" kinh dp Ddng. Dja hinh trong huyen chu yeu la nui thap va trung binh udn nep theo khdi tang, xen ke cac thung liing va bon dja nhd hep vdi dd cao trung binh tir 1000-1500m so vdi mat nude bien, dac biet cd dinh niii cao tren 1.500m la dinh Facmo 1.772in d phia Bac. Huyen Song Ma nam hoan toan trong vanh dai nhiet ddi va day cung la nai hoi tu ciia cac ludng thuc vat: Luong thuc vat Himalaya- Van Nam-Quang Chau tir phia Bac do xudng; ludng thuc vat Malaysia-Indonesia tir phia Nam len; lu6ng thuc vat khd han India-Myanmar tir phia Tay sang va khu he thuc vat ban dja. Huyen Song Ma cd 4 xa nam hoan toan hoac mot phan trong Khu Bao tdn thien nhien Sop Cgp nen dugc danh gia la khu vuc cd tinh da dang thuc vat phong phii. Dudi tac dpng manh me ciia con ngudi tham th\rc vat rirng ttr nhien da bi suy giam ca ve sd lupng va chat lugng, Hien nay tham th^rc v^t tai day dugc bao ve va khoanh nudi pliuc hdi. Dieu tra hien trang tham thuc vat se cung cap CO sd khoa hgc gii'ip cho viec quan ly, bao tdn trong chien luge quy hoach bao ve va phat trien rirng tai huyen Sdng Ma trong nhirng nam tiep theo.
I. PHUONG PHAP NGHIEN CUU
Sir dung khung phan loai UNESCO (1973) da dugc Phan Ke Lgc ap dung vao Viet Nam (1985) de phan loai tham thuc vat, sir dung phuang phap cua Thai Van Trirng de md ta cau triic tham thuc vat. Ten loai cay dugc xac dinh theo Pham Hoang Hp va cac cdng trinh khac da cdng bd.
II. KET QUA NGHIEN CUU
Theo khung phan loai ciia UNESCO (1973), huyen Sdng Ma, tinh San La cd 4 ldp quan he nhu sau:
/. Ldp quiin he Rii'ng rnm
I.A.la. Qudn he rirng nhiel ddi thudng .xanh nura miia tren niu thdp l.A.Ia (I) Phdn qudn h^ cdy Id rang
Phan quan he nay nam rai rac tren mii va tai cac khu rirng thieng ciia ddng bao dan tgc thieu so. Hi?n nay chiing da bi tac ddng kha nhieu: Khai thae gd, ciii, lay thudc... Cac he sinh thai rirng nguyen sinh cd thanh phan da dang vit phong phii han so vdi rirng phuc hdi sau nuang ray hoac sau khai thae. Cay gd cao trung binh 20-25m, dudng kinh binh quan 20-30cm, doi khi co cay gd to den 50cm, do che phu ciia kieu rirng nay dat 0,7-0^8. Rirng cd cau tnic 4 tang ro ret, thuc vat ngoai tang kha da dang va phong phii. Cac hg cay gd dac trung ciia kieu rirng nay chii yeu thupc hp Vang (Caesalpiniaceae), ho Long nao (Lauraceae), hp Xoan (Meliaceae), hg Trinh nir (Miniosaccac), hp Bira (Clusiaccae), hg Cam quyt (Rulaceae), hp Che (Theaceae). .. Tdng cay b\ii chii yeu la cay chju bdng va la cay con ciia cac loai gd tang tren. Tham tuai mpc rai rac, phan tan, chii yeu la cac loai trang hp Ray (Araceae), hg Ginig (Zingiberaceae), hg Hoa thao (Poaceae), hp Hoang tinh (Marantaccae), cac loai trong nganh Duong xi (Polypodiophyta).,.
1535
HQl NGH! KHOA HQC T O A N Q U O C V E SINH T H A I V A TAI N G U Y £ N SINH VAT L A N THU' 5
Thuc vat ngoai t5ng kha da dang va phong phii vdi cac loai trong hp Phong lan (Orchidaceae), day leo trong hp Cii nau (Dioscoreaceae), ho Nho (Vitaceae), hg Dau (Fabaceae)...
LA. I a (2) Phdn quan he hon giao cdy Id rgng-cdy Id kim
Do tac dpng manh me ciia con ngudi nen phan quan he nay chi phan bd rai rac d mpt vai diem (nhu d ven sudi Nam Cdiig thugc xa Hudi Mgt). Trong phan quan he nay cac cay go dat chilu cao trung binh 18-25m, dudng kinh dat 25-30cm, dp che phii tir 0,7-0,8. Rirng cd cau true 4 tang kha rd ret. Tdng cay gd chii yeu la cac loai cay la rdng thugc hg De (Fagaceae), hg Long nao (Lauraceae), hg Che (Theaceae), hp Ngpc lan (Magnoliaceae), hp Trinh nir (Mimosaceae), hp Vang (Caesalpiniaceae),.. mpc hdn giao vdi mpt sd loai cay la kim nlur Thong nang {Dacrycarpus imbricatiisj, Du sam niii dat {Keteleeria evelyniana) .. Trong do loai Du sam mpc vdi t6 thanh cao gan nhu thuan ioai tai thae Nam Cdng nhung vdi dien tich khdng dang ke, Dudi tan rirng, ting cay bui chu y^u gdm cac loai trong hg Cam quyt (Rutaceae), hp Clie (Theaceae). hg Ca phe (Rubiaeeae)... Tiing tham tuai tuang ddi phat trien. Day leo chu yiu trong hp Dau (Fabaceae), hp Nho (Vitaceae), hg Cu nau (Dioscoreaceae), hp Khoai lang (Convolvulaceae)..
LA. lb. Qudn he rirng nhiet ddi thurriig xanh nura miia tren nui trung binh LA. lb (I) Phdn cptdn he cdy Id rgng
Phan bd tap trung chu yeu tai cac xa Mudng Cai, Hudi Mot, Mudng Hung. Nam Man n5m xung quanh vimg dem Khu Bao tdn thien nhien Sop Cgp. Phan quan he nay da bj tac ddng it nhieu, nhung van mang dac trung ciia he sinh thai rirng nguyen sinh. Dp tan che dat 0,8, chieu cao trung binh cay gd lir 20-25m, dudng kinh tir 20-30cm. Thuc vat tao rirng kha phong phii, phd bien la cac loai trong hp Dau (Dipterocarpaceae), hp Xoan (Meliaceae), ho Trinh nir (Mimosaceae), hp Vang (Caesalpiniaceae), hg Thau dau (Eupharbiaceae), hg Dau tam (Moraceae), hg De (Fagaceae), hg Long nao (Lauraceae), hg Nggc Ian (Magnoliaceae), hg Na (Annonaceae), hg Sim (Myrtaceae), hp Thi (Ebenaceae), hg Bira (Clusiaceae)... Rirng phan thanh 5 tang rd ret, thuc vat ngoai tang rat phong phii vdi nhieu loai thuc vat phy sinh va kl sinh cung nhu day leo than gd va than thao chang chjt tang them sir r^m rap ciia h? sinh thai rirng. Cac loai pho bien thupc hg Phong lan (Orchidaceae), hg Na (Annonaceae), hg Kim cang (Smilacaceae), hp Nho (Vitaceae), hp Cii nau (Dioscoreaceae), hp Cau (Arecaceae),...
Tham tuoi cd thanh phan loai kha da dang va phong phu vdi nhieu loai kich thudc ldn trong hg Hoa thao (Poaceae), hp Chudi (Musaceae), hp Ray (Araceae)... Ngoai ra cdn nhieu loai duang xi khac.
LA. lb (2) Phdn qudn he hon giao cdy Id rgng-cdy la kim
Phan bo chii yk\ khu vuc niii Phu Cam (Mudng Cai) thupc Khu Bao tdn thien nhien Sop Cgp. Phan qu§n he nay it bj tac ddng nhat, dang dugc bao ve nghiem ngat vi vay cdn giii dirge tinh nguyen sinh ciia rirng. Do tan che ciia tan rirng thudng dat 0,8 cd nai dat 0,9. Rirng chia thanh 5 tang rd ret. He thuc vat trong rirng rat phong phii va da dang, chii yku la cac loai cay la rdng thudc cac hp De (Fagaceae), hg Long nao (Lauraceae), hp Che (Theaceae), hg Ngpc lan (Magnoliaceae), hp Thich (Aceraceae), hg Cdm (Eleocarpaceae), hp Chiim dt (Bignoniaceae), hp Vang (Caesalpiniaceae), hp Xoan (Meliaceae)... mgc hdn giao vdi mgt sd Ioai cay la kim nhir Sam bong {Amenlolaxus argolaenia). Bach xanh {Calocedrus macrolepis), Thong nang {Dacrycarpus imbricatus), Du sam mii dit {Keteleeria evelyniana) Trong phan quan he nay gan nhu hoan toan ving mat cac loai cay thugc hp Dau (Dipterocarpaceae;. Thuc vat ngoai tangc6 cac loai day leo thiln thao va than gd trong hp Day gim (Gnetaceae;. hp Kim cang (Smilacaceae;. hg Nho (Vitaceae;, hg Cau (Arecaceae;, hg Lan (Orchidaceae)...
HQl NGHI KHOA HOC T O A N Q U O C V ^ SINH THAI VA T A I NGUYEN SINH VAT LAN THlJ 5
LA.lc. Qudn he rtrng nliiet ddi thudng xanh niu-a miia tren dd voi a ndi thap Thanh phan thuc vat tao rirng trong quan he nay cd nhung loai mang tinh chi thi cao, dac trung nhu Nghien {Burretiodendron tonkinense), Trai {Garclniafagraeoides), May teo {Slreblus macrophyllus), Lat hoa {Chukrasia tahularis), Nang trirng {Hydnocarpus kurzii). Sang {Pomelia pinnata), Dinh {Fernandoa sp.), Vang anh {Saraca dives), Trudng {Pavieasia annamensis)....
Tuy nhien cac loai Nghien, M?y teo thudng xuat hien vdi sd lugng it ia mgt dac diem rieng biet cho kieu rirng nay. Nhin chung d nhirng nai it bj tac dgng, rirng chia thanh 4 tang vdi do che phii d^t 0,6.
Rirng tren dieu kien lap dia nay kha phiic tap. Tren nhirng dien tich cd nhieu dat va da qua canh tac nuong ray thudng xuat hien rirng phuc hdi vdi cac Ioai chiu khd hiin chiem uu the nhu Voi thudc {Schima walUchii), Thanh nganh {Cratoxylumpolyanthum)... Cdn noi la khdi da ldn, doc dirng, thudng xuit hien nhu'ng loai cay nhu Huyet giac {Dracaena cambodiana). Sung da {Ficiis sp.;, May teo {Slreblus macrophyllus),... vdi chieu cao thap nhu trang cay bui.
Thuc vat ngoai tang cung kha phong phu, chii yeu la cac loai day leo thude hg Na (Annonaceae), hg Cii nau (Dioscoreaceae), hg Dau (Fabaceae), hp True dao (Apocynaceae), hp Khoai lang (Convolvulaceae)...
LA.ld. Quan be rirng tre (Bainbusoideac) nhiet ddi a dia hinh ihiip vd niu thdp Day la quan he dugc hinh thanh sau nuang ray hoac rirng cay gd bj khai thae trang phan bd til dia hinh thap den mit thap,
l.A. Id (!) Rimg ire nira thudn logi
Thuc vat tao rirng chii yeu loai May sot {Schizoslachyum sp.), Vau {Indosasa sp.), M?y hdc {Dendrocakiimis hamilumii), Tre gai {Bambusa bambos)... mpc thanh quan he thuan loai. Tham tre nira thudng mgt ting, mat do ciiy kha day (400-600 bui/ha va 50.000-60.000 cay/ha) vdi dudng kinh binh quan 5-6cm, chieu cao binh quan 7-8m tuy thudc vao tirng loai cu the. Dudi tan rimg tham tuai phan bd khdng deu, nhirng nai trdng trai thudng gap cac loai cay thudc hp Hoa thao (Poaceae), hg Cdi (Cyperaceae), mgt sd loai hg Ca phe (Rubiaeeae)... Day leo phd bien thupc hp Thien ly (Asclepiadaceae) va hg Tiet de (Menispermaceae)..,
l.A. Id (2) Phdn qudn he Ire nira hdn giao vdi cdy go Id riing
Rirng clui yeu 1 tang vdi lang tim ddi khi khdng deu tao ra bdi ciic loai ciy gd mpc xen.
Chieu cao binh quan ciia tre nira tir 6-7in, mat do cay khoang 30.000-40.000 cay/ha, dirdng kinh tir 6-7cm. Loai cay la rgng cd kha nang chiu han phd bien thudc hg Long nao (Lauraceae), hg Sau sau (Hamamelidaceae), hg Vang (Caesalpiniaceae), hg Ca phe (Rubiaeeae), hg Thau dau (Euphorbiaceae), hp Dau (Fabaceae), ho Ban (Hypericaceae).,. vdi chieu cao trung binh tir 5- 6m, dudng kinh tir 6-7cm, do che phii cay gd dat 0,3. Tham tuai thua thdt vdi nhieu loai co kha nSng chju hgn cao. Day leo gdm cac loai trong hg Thien ly (Asclepiadaceae), hp Dau (Fabaceae)...
//. Ldp quun he rirng thua
ILA.la. Qudn he rirng thua thtrdng xanh cfiy Id rang a niii thdp
Day la rinig lai sinh sau nuong ray hoac khai thae trang. Tang cay go chi dat dp kliep tan khoang 40%, thudng khdng rd tang lap quan. Kicli thudc cay rirng bien dpng manh, phu lliupc vao thdi gian phuc hdi dai hay ngan ciing nhu dieu kien lap dia. Nhung nai cd thdi gian phyc hoi dai, chieu cao cay trung binh khoang 15in, dirdng kinh 18-20cni, dirai tan ning xuit hien mot so loai ca> ciia rirng nguyen sinh nhu Re huang {Cinnamomum parlhenoxyhim).
HQI NGHI KHOA HQC TOAN QUOC V£ SINH THAI VA TAI NGUY£N SINH VAT LAN THQ- 5 Thanh phin loai va cau true rirng kha dan gian, rirng chi cd mpt tang cay gd cd tan diu nhung kha thua nen dudi tan rirng tham cay bui va tang tham tuai kha phat trien vdi uu thi thugc ve cac loai cd caa trong hg Hda thao (Poaceae) va hp Ciic (Asteraeeae). Thuc vat tao rirng chii yeu trong hg Che (Theaceae), hp Xoai (Anacardiaceae), hg Thau dau (Euphorbiaceae), hp Dau tim (Moraceae), hp Trinh nu (Mimosaceae), hp Ban (Hypericaceae), hg Xoan (Meliaceae), hp Long nao (Lauraceae), hp Vang (Caesalpiniaceae)... vdi cac loai tien phong ua sang, chju khd ban, mpc nhanh nhu Vdi thudc {Schima wallichiij, Cheo trang {Engelhardria spicata), Thanh nganh {Cratoxylum polyanthum), Man dia {Archidendron sp.;, Ngai (Ficiis hispida)...
Day leo thudng gap trong hg Thien ly (Asclepiadaceae), hp 0au (Fabaceae), hp Bau bi (Cucurbitaceae), hg Khoai lang (Convolvulaceae)...
///. Ldp quan he cay bui
III.A. la Qudn he cdy bid nhiet dai thiimig xanh cdy Id rr'mg tren dat dia di/i IHA. la (I) Cd cdy go mgc rdi rac
Plian quan he nay ilurdng cd ngudn gdc thir sinh, la tien de cho qua trinh piuic hdi rirng Iren nuang ray bd hoa hoac tren nhirng dien tich khai thae triing... Tham thuc vat gdm 2 tang: Tang cay bui thudng khdng lien tuc chii yeu la Mua {Melasloma candidum), Mua rirng nhieu hoa {Blastus imihifloms),... ngoai ra cd mot sd loai cay gd chiu han, tien phong, ua sang dang byi trong hg Ciic (Asteraeeae), hg Dau (Fabaceae), hg Dau tam (Moraceae), hp Trinh nir (Mimosaceae), hp Ban (Hypericaceae), hp Xoan (Meliaceae), hg Thau dau (Euphorbiaceae), hp Du (Ulmaceae), hg Long nao (Lauraceae),.,. nhu Vdi thudc {Schima wallichii), Ngai {Ficvs hispida), Thau tau {Aporosa dioica), Mang tang {Litsea ciibeba), Hu day {Trema orientalis). Mo {Cryplocarya sp,). Ngat {Gironniera subaequalis)... Tang tham tuai tuong ddi phat trien. Quan phien day leo chu yeu la cac loai trong hg Khoai lang (Convolvulaceae), hp Thien ly (Asclepiadaceae), hg Dau (Fabaceae), hp Lac tien (Passiflora foetida), hp Bau bi (Cucurbitaceae).,.
Ul.A la (2) Khdng cd cdy go
Day la ket qua ciia nuong riy bd hoa hoac ch^t trang rirng, cac loai cay gd chua mgc trd l^i- Thanh phan Ioai dan gian, cau triic mpt tang cd quyet vdi cac loai chii yeu trong hp Cdc (Asteraeeae), hp Hoa thao (Poaceae)... Thudng gap uu hap Cd lao {Chromolaena odoratd), Ngai ciru rirng {Artemisia japonica). Cut Ign {Ageraliim conyzoide.s); uu hgp Cd tranh {Imperaia cylindrica) va mgt so loai cd cao trong hg Hoa thao (Poaceae). Ngoai ra cdn g3p cac loai cay bui trong hp Ca phe (Rubiaeeae), hp Bdng (Malvaceae), hg Ca (Solanaceae), hp Thiu dau (Euphorbiaceae), nlur Gang gai {Randia spinosa), Bd cu ve {Breynia fruticosa), Coi xay {Abulilon indicum), Ke {Malvastrum coromandelianum), Ca dai {Solanum procuinbens).- Day leo it gap, gdm mpt sd loai trong hp Thien ly (Asclepiadaceae), hp Khoai lang (Convolvulaceae),...
lll.A la (3) Thdm tre triic
Thanh phan Ioai dan gian, chii ylu la cac Ioai Tre nira {Bambusoideae) nhu Nua {Neohouzeoiia diillooa), Tre gai {Bambusa bambos) va mgt so Ioai tre khac. M^t dp cay kha thua, khoang 7000 cay/lia, cao tir 2-4m dudng kinh tir 3-4cm. Dudi tan rirng, tham tuoi khi thua thdt, chii yeu la nhirng loai hoa thao (Poaceae), day leo trong hg Dau (Fabaceae), hp Thifin ly (Asclepiadaceae)... cd kha nang chju han cao.
HQI NGHI KHOA HQC TOAN QUOC V£ SINH T H A I VA TAI NGUYEN SINH VAT L^N THO" 5 IILA.lb Quan he thdm cay bui nhiet dai thudng xanh cdy Id rgng tren dd voi Dugc t?o thanh bdi mgt so loai gd nhd trong hg Thau dau (Euphorbiaceae), hp Dau (Fabaceae), hp Ban (Hypericaceae), hg Long nao (Lauraceae), hp Dau tam (Moraceae),... nhu Soi tia {Sapium discolor), Thau tiu {Aporosa sphaerosperma). Ba soi {Macaranga denticulata), Mang tang {Litsea cubeba). May teo {Slreblus macrophyllus).... Ngoai ra cdn gap nhirng loai than thao trong hg Hoa thao (Poaceae) nhu Lau {Sacchamm sponlaneum). Chit {Thysanolaena maxima), Nira {Neohoiizeaua dullooa),... va mgt sd Ioai trong hg Ciic (Asteraeeae), hg Bdng (Malvaceae), hg Ca phe (Rubiaeeae).... Day leo trong hg Khoai lang (Convolvulaceae), hg Dau (Fabaceae), hg Thien ly (Asclepiadaceae)...
IV. Ldp Quan he trang cd
IV.A.la Quan he thdm co dgng liia cao nhiet ddi, chju han co cdy gd che phu 10-40% co hay khong co cdy bui
Cd ngudn gdc thir sinh sau khai thae rirng hoac nuong ray bd hoang. Cac Ioai cay dang lua cao nhu Lau {Sacchamm sponlaneum). Chit {Thysanolaena maxima), Che ve {Miscanlhus sinensis) va cd cay gd chju han che phii dat 10-40% trong hp Ca phe (Rubiaeeae), hp Dau tam (Moraceae), hp Long nao (Lauraceae), hg Thiu diu (Euphorbiaceae), hg Ban (Hypericaceae),...
nhu Ba soi {Macaranga denliciilata), Bdi ldi {Litsea verticillata), Thanh nganh {Cratoxylum prunijlomni)... Ngoai ra cdn cd cay bui trong hg Ciic (Asteraeeae), hg Trom (Sterculiaceae), hp Bong (Malvaceae).., nhu Cd lao {Chromolaena odoratd), Thau ken {Helicieres angustifoUa)...
IVA.lb Quan he thdm cd dgng lita cao nhiet dai, chiu han co cdy go che phu it han 10%
CO hay khong cd cdy bid
Chii yeu phan bo tren dit sau nuang ray bac mau. Cac loai phd bien la Chit {Thysanolaena maxima), Lau {Sacchamm sponlaneum). Say khd {Phragmites vallatoria), Cd lao {Chomolaena odorata). Cirt Ign {Ageraiuni conyzoidcs) va mot sd loai Hoa thao khac. Cay gd d loai hinh nay rat thua thdt, cd gap mgt sd loai trong hg Thau diu (Euphorbiaceae), hp Dau tim (Moraceae), hp Trinh nif (Mimosaceae), hp Ban (Hypericaceae)...
IV.B.la Quan h£ thdm co dgng lua trung binh nliiet ddi, chiu hcjn cd cdy go che phii 10-40% CO hay khdng cd crly bui
Thudng gap mgt so loai trong hp Hda thao (Poaceae) nhu Cd hoa ire {Apluda mulica), Co long vyc cgn {Echinochloa colonum), Cd tranh {Imperrata cylindrica) va nipt sd loai trong hp Cue Asteraeeae nhu Cirt Ign {Ageraiuni conyzoides), Rau tau bay {Gynura crepidioides), Co lao {Chomolaena odorata),.. Ngoiii ra cdn gap mpt sd loai cay gd trong hg Thau dau (Euphorbiaceae) nhu Me rirng {Phyllanthus emblica), Ba bet {Mallotus barbatiis), Dom ddm {Alchornea rugosa). Thiu tau {Aporosa dirica).. hoac cac loai trong hg Ban (Hypericaceae), Diiu (Fabaceae).,,
IV. B.lb Quan he thdm cd dgng Hut trung binh nhiet d&i, chiu han ci) cdy go che phii it ban 10% CO hay khdng cd cdy bid
Chii yeu la \.^n hgp cac loai Hda thao (Poaceae) nhu uu ligp Cd tranh {Imperrata cylindrica) mpc thanh vat Idn d nhung nai dat bi thoai hoa manh, Ira sdi da. Ngoai ra cdn CO Cd long Ign {Pogonalherium crinilum), Cd chao {P.seudechinolaemi polyslacliya), Tinh
^hao{Eragroslis sp.)...
HQI NGHI KHOA HQC T O A N Q U O C V £ SINH T H A I V A TAI N G U Y E N SINH V A T L A N THLf 5
IV. C. ia Qudn he thdm co khdng dgng lua cao nhiet d&i tliuoc lap Mgt Id mam vd Dicmtg xi song lau nam
IV.C. la (I) Trdng chuoi
Dac trung bdi uu hgp chudi rirng, thudng gap d nai am thip, khe sudi. Dudi tan cd cac Ioai chiu bdng trong hp Ray (Araceae), hp Girng (Zingiberaceae) va nhieu loai trong nganh Ducmg xi vdi mat dp khdng cao.
IV.C.2a Qudn he thdm co khong dgng lua (hap nhiet ddi thugc lap Hai Id mam va Duang xi song Idu nam
Thudng gap sau nuang ray bd hda 2-3 nam, thudng gap uu hgp ciia mgt sd loai trong hg Ciic (Asteraeeae), hp Rau den (Amaranthaceae) nhu Cirt Ign {Ageraiuni conyzoides), Rau tau bay {Gynura crepidioides), Mao ga {Celosia argenlea). Den gai {Amaranthus spinosii.-i)....
III. KET LUAN
Theo khung phan loai ciia UNESCO (1973), tham thuc vat tir nhien huyen Song Ma, tinh Son La gdm 4 ldp quan he vdi 13 quan he. Trong dd Idp quan he rirng kin cd 4 quan he, Idp quan he rirng thua cd 1 quan he, ldp quan he trang cay bui cd 2 quan he, ldp quan he trang co c6 6 quan he Rirng kin la Idp quan he mang tinh chat nguyen sinh, cac quan he cdn lai la h|u qua ciia su tac dpng ciia con ngudi va dang trong giai doan phyc hdi.
TAI LIEU THAM KHAO
1 Bo LSm nghifp, 1978. S6 tay dieu tra quy hoach rirng, NXB. NongnghiSp, Ha Npi.
2. Nguyen Tien Ban (chii bien), 2003, 2005. Danh lye cac loai thuc vgt Vi?t Nam, NXB. Nong nghi?p, Ha Noi, tap 1,2.
3. Pham Hoang H9,1999-2000. Cay co Vi?t Nam, NXB. Tre Tp. H6 Chi Minh, Tap 1-3.
t. Phan Kl L§c, 1985, Tgp chi Sinh hoc, 7 (4)
J. Thai Van Trirng, 2000. Cac he sinh thai rimg nhiet ddi d Viet Nam. NXB. KH & KT, Ha Ngi 2000, 6. UNESCO, 1973. International classification and mapping of vegetation, Paris,
CURRENT FOREST VEGETATION IN SONG MA DISTRICT, SON LA PROVINCE
NGUYEN THI QUYEN
According to UNESCO (1973) dassification, modified by Phan Ke Loc (1985), current forest vegetation of Song Ma dislnct. Son La province includes 4 formation classes with 13 formations. Among them, the closed forest fonnation class includes 4 formations, the woodland (open stands of bws) formation class includes 1 formation, the scrub (shmbiand or thicket) formation class includes 2 fonmations, the herbaceous vegetation formation dass includes 6 fonmations.
