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TAI KHU VXrC TRAM DA DANG SINK HQC ME LINH - VINH PHUC
LE D 6 N G TAN
Vien Sinh thdi vd Tdi nguyen sinh vgt TRAN VAN THVY, VU HAI THUAN Truang Dai hoc Khoa hpc tu nhien, Dai hpc Quoc gia Hd Noi
Tram Da dang sinh hgc Me Luih thudc Vipn Sinh thii vi Tii nguyen sinh vit cd tdng dipn tich ty nhien 170,3ha. Gidi ban frong tga dg dia ly N21 23'57" din N 21 23'35" v i E105 42'40" din E 105 46'65". Phia Bic giip huypn Phd Yen, Thai Nguyen, phia ddng va nam giip thdn Ddng Trim, xa Nggc Thanh, Thi xa Phiic Yen, VTnh Phiic, phia tay giip Vudn Qudc gia Tam Dio. Khu vyc nghien cuu cd dia hinh ddc 15-25°, do chia cat sau khi !dn vdi nhieu ddng phu nim gin nhu vudng gdc vdi ddng chinh. Toin bd dien tich nam ggn trong loai hinh khi hau nhiet ddi gid miia, nhipt do trung binh 23,5°C, lugng mua trung binh 1135-1650mm/nim, do im 85%). Diy Ii mpt trong nhtrng nhin td sinh thii chinh phit sinh cic quin hp rimg ram thudng xanh bao phu toan bg khu vyc nghien ciiu trudc khi cd tic dpng cua con ngudi. Do tiep giip vdi ddng bing chau thd sdng Hdng nai cd mat dp din cu ddng nen cic boat ddng cua con ngudi inh hudng siu sac den sy suy thoii cua thim thyc vat nhu khai thic gd, ciii, sin bin ddng vat. Nhtrng tic ddng niy da tao nen cic loat dien the thii sinh nhin tic-phuc hdi vdi cic trang thii khic nhau trong khu vyc dudi dang the khim phiic tap. Diy chinh Ii ddi tugng cua cic hudng nghien ciiu khoa hgc v i cic dy an trien khai nhim tao ca sd khoa hgc sir dung hgp ly vi phit trien ben vung he sinh t h i i .
L PHU'ONG PHAP NGHIEN ClTU
- Phutmg phap ke thira: Ke thira cac tu lipu ve tham thyc vat,thd nhudng ,khi hau...tai khu vyc nghien ciiu., cac cdng trinh khoa hgc cd lien quan den Tram Da dang sinh hgc Me Linh da dugc cdng bd.
- Cac phirong phap thu thap, xir ly so lipu va phan tich danh gia
- Phan tich thim thyc vit - cic trang thii khic nhau cua loat dien the thii sinh: Md ta va phin tich ciu true: Theo phuang phip ciia RoIIet (1974) v i bio cio cua UNESCO ve he sinh thii rimg nhiet ddi (1979). Tuyen khio sit cua chiing tdi thiet lap qua tat c i c a c quin xa thyc vit dai dipn trong khu vyc de thu thip miu, quan sit cic yeu td cau thanh tham thyc vat c i ve ciu tnic khdng gian, ciu true thanh phan loai (Wittaker,1962), cic nhan td mdi trudng hinh thanh v i inh hudng tdi sy phit trien tham thyc vat v i diln thi thim thyc vat.
_ - Phan tich loat dien the thii sinh: Quan diem cua loat diln thi dugc hilu theo nhirng cdng bd cua Schmid (1974), phin tich loat dien thi dugc xay dyng theo timg trang thii eye dinh va cic loat quin xa thay the thii sinh trong ciing mgt nen khi hiu thd nhudng. Chung dugc phan tich theo loat phittrien hoic suy thoii, tire Ii phuang phip liy khdng gian thay thdi gian, phan tich trang thii hipn tai ciia timg quin xa v i sap xep chiing vio loat dien the theo tudi phuc hdi cua quin xa, hoic theo nhan td tic ddng tai cimg mgt vj tri. Nhirng dan lieu niy dugc thyc hipn qua dieu tra thyc dia va theo ddi thyc nghiem tai vimg nghien ciru.
IL KET QUA NGHIEN CUtJ
Loat dien the thir sinh thudc rimg ram thudng xanh nhiet ddi gid miia ciy Ii rgng tren dat feralit vimg ddi niii, thoat nude (do cao dudi 700m), phong hoi tir cac loai da me khac nhau.
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1. Hipn trang cac trang thai ciia loat dien the
1.1. Quan xa rirng it bj tac dpng.- Trong khu vyc nghien ciiu khdng cdn rimg nguyen sinh, de phan tich trang thii cao dinh niy, chung tdi da khio sat nhung minh rimg it bi tic dpng tai nhirng viing sau, xa nai dan cu d xa Khing Nhit, nai cd dieu kien ty nhien tuang ddi gan vdi viing nghien ciru de lam ddi chimg. Cac loii uu the dugc ghi nhan thupc cac hp Diu Dipterocarpaceae, ho Xoai Anacardiaceae, hp Trinh nir Mimosaceae, hg Dau Fabaceae, hg Vang Caesalpiniaceae, hp Trim Burseraceae, hg Cdm Elaeocarpaceae.... Day Ii nhirng di tich sing cho nghien cuu dieu tra thyc trang cung nhu khi ning phuc hdi rimg.
1.2. Quan xa rirng ram bj tac dgng manh va cac trang thai thir sinh do nhan tac. Ting uu the sinh thii it nhieu bi phi vd hoac rat thua thdt, nhtrng cay gd cdn sdt lai chilm ty le khdng nhieu, cd the ghi nhan 3 giai doan chinh ciia trang thii niy nhu sau:
(1) Giai doan bj tic dpng manh uu the Mudi - Rhus chinensis Mill; Vang anh - Saraca dives Pierre; Sang - Pometia pinnata ssp. tomentosa (Blume) Jacobs; Cheo tia - Engelhardtia roxburghiana Wall,' Tram tring - Canarium album (Lour.) Raeush. ex DC. Thudng din xuit tryc tiep tu rimg nguyen sinh, xuit hipn sau chit chpn hoic cd tudi phuc hdi sau 30 nim.
(2) Giai doan thu sinh uu the Thimg mirc ldng - Wrightia pubescens R. Br., De gai an do - Castanopsis indica (Roxb.) A. DC, Lim xet - Peltophorum dasyrrachis (Miq.) Kurz; Ba soi - Macaranga denticulata (Blume) Muell.-Arg., suy thoii tu kieu tren hoic cd tudi phuc hdi 15-20 nim.
(3) Giai doan thir sinh ngheo kiet uu the Sau sau - Liquidambar formosana Hance; Me rimg - Phyllanthus emblica L.; Biim bup - Mallotus barbatus Muell.-Arg.; Dd ngpn - Cratoxylon pruniflorum (Kurz) Kurz., suy thoii tir kieu (2) hoic cd tudi phuc hdi 12-15 nim.
1.3. Quan xa rimg hon giao Tre Nira va cay go la rpng thir sinh thudng xanh. Xuat hien tren nen rimg da bi chit tring dang phuc hdi, dit thudng cdn ting diy, im hoac ven cic duong tu nude. Tren nhtrng dien tich mdi phuc hdi chi thay thuan loai cic loii hp Hda thio nhu Niia - Neohouzeaua dullooa (Gamble) A. Camus,' Giang - Dendrocalamus patellaris Gamble ...
Nhtrng loii ciy gd mgc hdn giao thudng gip la Sau sau - Liquidambar formosana Hance; Ba soi -Macaranga denticulata (Blume) Muell.-Arg.; Buc bac - Mallotus paniculatus (Lamk.) Muell.- Arg., Hu day - Trema orientalis (L.) Blume, Dd nggn - Cratoxylon pruniflorum (Kurz) Kurz.
1.4. Quan xa rirng Tre Nira thir sinh.' Q giai doan suy thoii manh ban, nhtrng loai cay go gin nhu ving mat, quin xa gin nhu thuan loai Nura - Neohouzeaua dullooa (Gamble) A.
Camus; Giang Dendrocalamus patellaris Gamble mgc xen hoic nhilu nai chi cd dan loii cua mpt trong hai loii tren.
1.5. Quan xa cay byi thir sinh thu-dng xanh: Nhtrng loai ciy bui hoac ciy go dang bui chilm uu the, xuit hipn do nhan tic, cd thi ghi nhan ba trang thii ca bin nhu sau:
(1) Giai doan ciy bui thir sinh thudng xanh cd cay gd uu thi Hole quang - Wendlandia paniculata (Roxb.) D C ; Thiu tiu - Aporosa sphaerosperma Gagn.; Phen den - Phyllanthus reticulatus Poir.;, thudng tdn tai tren nIn thd nhudng chua hoic it bi phi vd cau tnic hoic cd tuoi phuc hdi 7-8 nam
(2) Giai doan ciy bui thu sinh thudng xanh khdng cdn cay go uu thi Ging - Randia spinosa (Thunb.) Poir.'; Dd ngon - Cratoxylon pruniflorum (Kurz) Kurz.; Ba chac - Euodia lepta (Spreng.) Merr.; Cd lao - Chromolaena odorata L. , suy thoai manh han hoic cd tudi phuc hoi sau chat tring 4-5 nim.
(3) Giai doan cay bui thip uu the Mua - Melastoma candidum D. Don; Co lao - Chromolaena odorata L.; Thau ken long - Helicteres hirsuta Lour.; Sim - Rhodomyrtus
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tomentosa (Alton) Hassk. Diy la giai doan suy thoii manh nhit, khd phuc hoi nhit, din xuit tir cic quan xa yen, thudng d dipn tich bj tac dgng lap di lap lai hoac bi giam dap manh, thudng xuyen.
1.6. Quan xa cd thir sinh: Cd hai giai doan chinh nhu sau:
(1). Giai doan xen cay bui, cac loii im the gdm Lau - Saccharum arundinaceum Retz.; Lach - Saccharum spontaneum L.; Chit ddt - Thysanolaena maxima (Roxb.) Kuntze; Cd lio - Chromolaena odorata L...cung vdi mgt sd loii cay byi khic nhu Ba chac - Euodia lepta (Spreng.) Merr.; Bu cu ve - Breynia fruticosa (L.) Hook, f; Gugt - Dicranopteris linearis (Burm. f) Underw.; Lau dd - Psychotria rubra (Lour.) Poir.; Cam ngudi - Ardisia helferiana Kurz
(2) Giai doan chua cd cay bui , mdi xuat hipn do nhan tac gdm chi cd cac loai hg Hda thao Poaceae vdi uu the Lau - Saccharum arundinaceum Retz.; Cd yanh - Imperata cylindrica (L.) Beauv.; Lich - Saccharum spontaneum L.; Chit dot - Thysanolaena maxima (Roxb.) Kuntze
1.7. Quan xa cd thap: L i giai doan suy thoai cao nhat trong loat dien the thoai hda, thudng rit khd phuc hdi do bi tic ddng lip di lip lai vi bi giim dap manh do chin thi gia siic. Cic loai uu the Ii Cd may - Chrysopogon aciculatus (Retz.) Trin.; Cd ga - Cynodon dactylon (L.) Pers.
va mgt vii loii khic cua hg Poaceae.
1.8. Rimg trong cay go la rgng: Cay frdng chu yeu gdm Keo Ii trim -Acacia auriculaeformis A. Cunn. ex Benth., Keo tai tugng- Acacia magnum Willd., Bach din cic loai Eucalyptus spp. Mgt sd trong cic loii tren Ii nhting loii ngoai nhap cd bien do sinh thii rgng, khi ning xim nhap manh me. Sy cd mat cua chung lim md nhat, tham chi phi vd cic dipn mao, die trung cua thim thyc vit bin dia, mdi trudng bi bien ddi theo hudng khdng phii hgp vdi qui luat vdn cd.
2.Nhirng dac trirng ca ban ciia loat dien the
Loat dien the thir sinh (chu yeu do nhin tic vi ndi ddng lye phyc hoi) cua rimg ram thudng xanh nhipt ddi gid miia tren dit thip dugc xic nhan bdi 13 trang thii hay cdn dugc ggi Ii 13 pha ciia dien the, trong dd cd 11 trang thii thii sinh ty nhien hinh thinh do nhin tic vi phuc hoi ty nhien, 1 trang thii nguyen sinh phuc hdi gii thiet tren ca sd phin tich quin xa ddi chihig tren cimg mpt nen rimg nguyen sinh cua quin he, 1 trang thii phyc hdi nhin tao (rimg trdng). Loat dien the dugc hinh thinh bdi 9 chudi dien the hgp phin cd die trung nhu sau:
2.1. Chuoi dien the thir sinh nhan tac - phyc hoi: Rimg nguyen sinh *-» Rirng Tre Nura thir sinh: Li chudi dien the chu dao cua loat dien the, tir quan xa rimg nguyen sinh, do tic ddng chit phi, khai thic cua con ngudi din qua cic giai doan rimg bi tic ddng manh, rimg thir sinh, rimg thii sinh kipt. Nhirng tic ddng lap di lap lai din din tao sy xam nhip cho cic loii Tre Nua mgc hdn giao, cudi cimg la rimg Tre Nira thuan loai. Chudi dien thi niy cd 6 pha :
(1) Rimg ram thudng xanh ciy la rgng uu the cic dai dien hg Dau Dipterocarpaceae, hg Xoai Anacardiaceae, hg Trinh nir Mimosaceae, hg Dau Fabaceae, hg Vang Caesalpiniaceae, hg Trim Burseraceae, hg Cdm Elaeocarpaceae
(2) Rimg rim bi tic dgng manh.
(3) Rimg ram thii sinh.
(4) Rimg rim thir sinh ngheo kiet.
(5) Rimg thu sinh hdn giao Tre Nua - cay gd Ii rong.
(6) Rimg Tre Niia thii sinh.
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Trong chudi dien the nay cd hai trang thii ben virng, cd tdc dp phuc hdi cham. Pha thir nhit la quin xa (2) da xuat hien cic loai cay gd tuang ty vdi trang thii nguyen sinh trudc kia, nhung chua hinh thanh rd nhtmg net tucmg ddng ve cau tnic. Day la trang thii thii sinh gin nhit vdi kilu nguyen sinh vdn cd, sy chuyen hda phuc hdi dien ra tir tir, ddi khi khd nhan bilt. Pha thii hai la quan xa (6) d trang thii ben vung ciia hudng phyc hdi vdi sy hien dipn ciia cic loai Tre Nira ua sing, cd khi nang canh tranh manh. Khi ning phyc hdi thanh rimg hdn giao rat chim, qua thdi gian dai dii de cay gd xam nhap, tao ting tin trong dieu kien canh tranh khdc liet cua quin he. Cic pha cdn lai deu d trang thii thir sinh tam thdi, trong dd loai dien the tien phong ciia chuoi dugc xic dinh la Sau sau - Liquidambar formosana Hance
2.2. Chuoi dien the thir sinh nhan tac - phyc hoi: Rirng Tre Nua thu sinh *-* Trang cd thir sinh (phan minh hga dugc in dim trong sa dd): Hinh thanh tiep tuc tir trang thii cudi cimg ciia chuoi dien thi (1) d tren la quin xa Tre Nua thuan loai. Do tiep tuc bi chit, khai thic tring hoic lim nuomg ray, tir rimg Tre Nua chung trd thinh tring cd thir sinh d cic trang thii cd muc dp xam nhip cua Tre Nua vi cay byi khic nhau tiiy thudc vio mirc dp tic dpng hoic phyc hoi.
Chuoi diln thi niy cd 4 pha:
(1) Rimg Tre Nira thii sinh.
(2) Trang cd cao thii sinh xen ciy bui.
(3) Tring cd cao thir sinh khdng cd cay byi.
(4) Tring ciy byi thudng xanh thir sinh khdng cd cay go.
Pha (1) la trang thii dan xuit ciia chudi dien thi, pha (2) vi (3) Ii trang thii thir sinh tam thdi phuc hdi trd lai pha (1) hoic pha (4) trong mpt dang thip han ciia loat dien thi.
2. 3. Chuoi dien the the thir sinh nhan tac - phyc hoi: Rimg thir sinh kipt <-> Trang cay byi thir sinh
Gom 3 pha:
(1) Rimg rim thu sinh ngheo kipt.
(2) Tring cay byi thii sinh thudng xanh cd cay gd.
(3) Tring ciy bui thu sinh thudng xanh khdng cdn cay gd.
Pha (1) Ii pha dan xuat, hi diy hinh thinh pha (2) va (3) do nhan tic khai thac hing, chit pha. Neu cic hoat dgng niy dimg lai, chung se phyc hdi trd lai trang thii ban dau (pha 1) va tiep t\ic trong cic chudi dien thi khic ciia loat.
2.4. Chuoi dien the thir sinh nhan tac: Rimg it bj tac dpng -^ Trang cay bui thu- sinh v i trang cd thir sinh.' La chuoi diln thi suy thoii nhin tic, tir trang thii nguyen sinh ban dau, con ngudi da tic ddng chat hing . Kit qui hinh thinh tring ciy bui thir^sinh thucmg xanh khong con cay gd. Tir cic trang thii thir sinh nay chimg tham gia vio cic chudi dien the khic cua loat dien the.
2.5.Chu5i dien th^ thir sinh nhan tac: Rirng nguyen sinh ^ trang cd thip thu sinh: Xuit hipn tren nhiing dipn tich dugc chit hing, sau dd canh tic lip di lip lai vi chin tha gia sue.
Trang cd thip chiu han, tren dit bi nen chit do dim dap, tdn tai tuang ddi ben vung vai cac loai ini thi chiu han cao, khi ning canh tranh manh nhu Cd may -Chrysopogon aciculatus {Kc\z.) Trin.; Cd ga - Cynodon dactylon (L.) Pers. Tring cd t_hip Ii pha ben vimg ciia chuoi dien the, dong thdi cung la hang thoii suy thoii nhit ciia loat dien the nhin tac phyc hoi.
2.6. Chu5i diBn t h i thiT sinh nhan tac - phyc h6i cham: Trang cay byi thip thu sinh >
tring CO thap thir sinh
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La sy chuyin hda ciia 2 pha:
(1) Tring cay bui thip thii sinh.
(2) Trang cd thip thii sinh.
Ca hai pha tren diu la trang thai bin vung suy thoai cao cua loat diln the. Chiing chuyen hda do chit phi giam dap, lap di lap lai va phyc hdi. Toe do phyc hoi rit cham, phu thudc nhieu vao dg suy thoii cua dit va tic dgng cua con ngudi.
2.7. Chuoi dien the thir sinh nhan tac - phyc hoi cham: Trang cd cao trung binh thir sinh > trang cd thap thir sinh: Tir trang thii thii sinh tam thdi cua cac chudi dien thi khic la trang cd cao thii sinh do nhan tac ddt nucmg riy hoac ddt lua lam bai chin tha gia sue da hmh thanh teing cd thip. Tdc do phyc hdi tra lai trang thai quin xa cd cao rit cham va khd xiy ra,
2.8.Chuoi dien the thir sinh nhan tac - phyc hoi cham: Trang cay bui thur sinh cd cay go
—y trang cay byi thap thir sinh:
Chiing la sy chuyin tilp cua 3 pha trong trang thii tring ciy byi:
(l)Trang cay bui thir sinh thudng xanh cd cay gd.
(2) Tring cay byi thir sinh thudng xanh khdng cdn cay gd.
(3) Tring cay byi thip thii sinh.
Tir pha (1) do nhan tic hinh thanh pha (2) vi (3), chiing cd thi phuc hdi trd lai cac pha din xuit do phyc hdi. Pha (1) va (2) Ii hang thii tam thdi cd kha ning phuc hdi cao, pha(3) la trang thii ben vimg, phyc hdi cham.
2.9. Chuoi dien the thir sinh phyc hoi nhan tao: Cac quan xa thyc vat ty nhien —> rimg trong cac loai: Thuin tiiy do nhin tic, tir cic trang thii suy thoii cao nhu tring cay byi khdng cd ciy gd, tring cay bui thip, trang cd cao khdng cd ciy bui, tring cd thip dugc con ngudi dua cic loai cay gd Ii rgng vio trdng tao lip nen nhtrng dien tich rimg trdng. Rimg thudng cd ciu tnic 1 ting ciy gd vdi cic loai cay trdng chinh Ii Keo Ii trim Acacia auriculaeformis A. Cunn.
ex Benth., Keo tai tugng Acacia magnum Willd., Bach din cic loai Eucalyptus spp.
III. NHAN DJNH CHUNG VA THAO LUAN
Hinh 1 trong bai viet phan inh tong hgp cic moi quan he cua cic chuoi dien the trong loat dien the thii sinh cua rimg rim thudng xanh nhipt ddi gid miia tren dit thip viing ddi mii thoit nude. Trong loat dien the nay, ghi nhan dugc 4 quan xa d trang thai ben viing trong dd cd quin xa rimg thir sinh tiem can vdi trang thii rimg nguyen sinh trudc kia (quan xa 1 trong sa dd) dugc ggi Ii trang thii cao dinh tam thdi (Tiixen, 1956) hoac tien phong dinh eye (M.Shili,1992).
Ba quin xa cdn lai (quan xa 5, quin xa 8, quin xa 11) Ii nhirng quin xa tuong ddi ben vung d trang thii suy thoii cao. Ben canh do loat dien the ciing the hipn sy phyc hdi ty nhien manh me thdng qua 1 quan xa dien the tien phone vdi loii im the Sau sau Liquidambar formosana Hance, day Ii loat dien the phiic tap nhat, nhieu mit xich nhit va chilu hudng dien bien da dang tren dien tich rgng nhat cua vimg nghien curu, tuy nhien cd the tdng hgp trong hai hudng:
1. Hudng suy thoii nhan tic tir trang thii nguyen sinh hoac cic trang thii it suy thoii horn trong loat dien the do chat phi hoic khai thic, ddt lira... dan den sy xuat hien cic quan xa suy thoii manh ban, day cua suy thoii Ii cic frang cd thip tren nen thd nhudng bi thoii hda manh ve ca tinh chit vit ly, hda hgc v i ciu tnic dat.
2. Hudng phyc hdi ty nhien, tir cic trang thii thip trong loat dien the phuc hdi ty nhien trd lai trang thii cao ban trong cic chudi cua loat dien the. Ve nguyen tic tat ca cic quan xa thii
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sinh ciia loat dien the viing nghien ciru van dang chiu sy dan dat ciia ciia kieu nguyen sinh vdn CO va phuc hdi trd lai trang thii nay, tuy nhien tdc do phuc hdi, cudng do phuc hoi phu thupc rit nhilu vao tic dpngcua con ngudi, vao trang thai ciia dat va cac nhan td sinh thai ciia sinh cinh.
Trong loat dien the nay, gii tri da d^ng sinhhoc chi xuat hien rd net nhat trong quan xa rimg ram thudng xanh cay Ii rong. Theo sd lieu thdng ke khao sit thyc dia, neu khong cd sy tic dpng ciia con ngudi, trong vdng 30 nim tdi it nhit cd 50%) dien tich ty nhien ciia Tram Me Linh phyc hii trd lai trang thii rimg ciy gd thudng xanh thir sinh. Day la ca sd khoa hpc quan trpng cho xay dyng cic dy in djnh hudng bao tdn da dang sinh hoc vi tii tao tii nguyen thien nhien.
TAI LI?U THAM KHAO
1. Crist E.P., R. Laurin, R. C. Cicone, 1986: Vegetation and Soil information contained in transformed Thematic mapper data. Proceeding of IGARR' 86 Sym. Zurich, 8-11 Sep.
ESA.Pudivi, Pp. 1465 -1469.
2. Pham Hoang Hg, 1999; Ciy cd Viet Nam. Nxb. Tre, Tp. Hd Chi Minh, (tip I, II, 111).
3. Ma Thj Nggc Mai, Le Dong Tan, 2004: Nghien curu hien trang thim thyc vat tai Tram DDa dang sinh hgc Me Linh - VTnh Phiic vi cac viing phu can. Nhung van de nghien cim ca ban trong khoa hgc sy sdng. Nxb. Khoa hpc va Ky thuat. Hi Ndi, tr. 818.
4. Puri G. S; R. K. Gupta, V. M. Meher-Homji, 1989: Forest ecology. Vol.2. Oxford and IBH. Pub. CO.PVT.LTD. New Delhi, Calcutta, Bombay.
5. Schmid M., 1974: Vegetation du Viet Nam, le massif sud - annamitique et les regions limitrophes. ORSTOM. Paris.
6. Le Dong Tan, 2003: Mgt sd kit qui nghien cim vl dien thi tai khu vyc ddng-nam Vucm Quoc gia Tam Dao vi xa Nggc Thanh - Me Linh - VTnh Phiic. Tap chi Lam nghiep, 4/2003
7. Le Dong Tan, Do Hoang Chung, 2004: " Mpt sd kit qui budc dau nghien cim xiy dyng md hinh phyc hdi rimg bang bien phip trdng bd sung cic loai cay muc dich tai Trani Da dang sinh hgc Me Linh". Nhung vin dl nghien cim ca bin trong khoa hpc sy song. Nxb.
Khoa hgc vi Ky thuat, Ha Npi, ti 525.
8. Thai Van Trirng, 2000: Nhtmg h? sinhthii rimg nhiet ddi d Viet Nam, Nxb. Khoa hgc vi Ky thuat Viet Nam, Chi nhinh TP. Ho Chi Minh.
9. Vipn DDieu tra Qui hoach rimg, 1970-1986: Ciy go rimg Viet Nam, Nxb. Ndng nghiep. Hi Ndi, tip I-VII.
SECONDARY SUCCESSION OF VEGETATION
IN ME LINH BIODIVERSITY STATION, VINH PHUC PROVINCE LE DONG TAN, TRAN VAN THUY, VU HAI THUAN SUMMARY
Secondary succession of tropical monsoon, dense evergreen, broadleaf forest on lowland is characterized by 11 secondary stams, from secondary forest to secondary low grasslands. They are combined into 9 secondary - restoration series and all of them are closely related in development of succession. If the human impacts are stopped, the secondary forest will restore and cover at least 50% of the study area. These scientific data are important for rational utilization of nahiral resources and biodiversity conservation.
HOI NGHI KHOA HOC TOAN Q U O C V £ SINH THAI VA TAI NGUYtN SINH VAT LAN THLf BA CAO DINH: Khi hiu nhiet ddi im gid miia-
dit Feralit thoit nude.
Rimg ram thudng xanh ciy Ii rgng uu the cic dai dien hp Diu Dipterocarpaceae, ho Xoai Anacardiaceae, hp Trinh nir Mimosaceae, hg Dau Fabaceae, hg Vang Caesalpiniaceae, hg Trim Burseraceae, hg Cdm Elaeocarpaceae
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(11) Tring cd thip chiu giam dap uu the Cd may - Chysopogon aciculatus; Cd gi - Cynodon dactylon
1628
NHAN TAO: Rimg trong cay la rgng
Keo Id trdm Acacia auriculaeformis
Keo tai tuang Acacia magnum Bach ddn cdc loai Eucalyptus spp.
(1) Rimg ram bi tic ddng'manh uu the Mudi- Rhus chinensis; Vang anh - Saraca dives; Sang - Pometia pinnata ssp. tomentosa; Chpo tia- Engelhardtia roxburghiana; Trim trang - Canarium album
it
(2) Rimg ram thir sinh uu the Thimg miic ldng- Wrightia pubescens, De gai in do - Castanopsis indica, Lim xet - Peltophorum dasyrrachis; Ba soi - Macarax^ga denticulata
(3) Rimg rim thir sinh ngheo kipt uu the Sau sau - Liquidambar formosana; Me rimg - Phyllanthus emblica; Biim bup - Mallotus
barbatus; Dd nggn - Cratokyk^n pruniflorum
(4) Rimg thii sinh hdn giao Tre Nira - cay gd Ii rgng uu the Nira - Neohouzeaua dullooa; Sau sau - Liquidambar formosana; Ba soi - Macaranga denticulata; Hu day - Trema orientalis
(5) Rimg Tre niia thu sinh uu'the Niia - Neohouzeaua dullooa; Giang - Dendrocalamus patellaris
(6) Tring cay bui thudng xanh thu sinh cd cay gd uu the Hoic quang - Wendlandia paniculata; Thau tiu - Aporosa sphaerosperma; Phen den - Phyllanthus reticulatus I A
(7) Tring cay byi thudng xann thii sinh uu the Gang - Randia spinosa;
Dd nggn - Cratoxylon pruniflorum; Ba chac - Euodia lepta; Cd lao - Chromolaena odorata i ^
(8) Trang cay bui thip uu the Mua-Melastoma candidum; Cd lao- Chromolaena odorata; Thau ken long - Helicteres hirsuta; Sim - Rhodomyrtus tomentosa
(9) Tring cd cao thii sinh xen cay byi uu the Lau - Saccharum arundinaceum; Lich - Saccharum spontaneum; Chit ddt - Thysanolaena maxima; Co lao Chromolaena odorata; Ba chac - Euodia lepta; Bii cu ve | J^reynia fruticosa; Gugt - Dicranopteris
linearis
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(10) Tring cd thii sinh Lau - Saccharum arundinaceum.; Cd tranh -^
Imperata cylindrica; Lich - Saccharum spontaneum; Chit ddt - Thysanolaena maxima
I A
Hinh I: Tdng hgp cac chudi trong loat dien the thir sinh