S U D A DAIMG L O A I V A T O THAIMH T H U C V A T C U A CAC TRAIMG T H A I RUIMG T A I D A O COIM CO,
T I I M H Q U A I M GT R I
Dang Thai Duong' TOMTAT
He thuc vat dao Con Co bao gom he thuc vat tu nhien va he thuc vat dugc gay trong rat da dang; da dieu tra va thong ke dugc 239 loai thuc vat thupc 185 chi, 84 hp, trong do chiem uu the la nganh Ngpc lan voi 227 loai thupc 175 chi, 77 hp. Ty trpng giua hai lop cua nganh Ngpc lan la Magnoliopsida/Liliopsida = 6,09/1. Co 8 nhPm dang than, bao gom dang cay" phu sinh, cay go Ion, cay gp trung binh, cay go nho, cay bui, cay day leo than go, cay day leo than co, cay co dung; trong do, so loai dang cay c6 dimg chiim ty le cao nhat (29,29%), dang cay bui chiim 15,9%, va dang day leo than co chiim 15,06%, it nhat la dang song phu sinh (1,26%) va dang leo than g6 (3,77%). Td thanh cac loai thuc vat c6 su khac biet giua cac trang thai rimg cr cac vi tri khac nhau, mang tinh dac trung rieng cua 4 nh6m, bao gdm: Trang thai rimg ngheo kiet phia Tay, trang thai rimg lib va llla a phia Tay Nam, trang thai rimg kin thuong xanh phuc hdi lib va Ilia b phia Bic, va trang thai rimg trong tren nen dia hinh doi thap 6 phia Dong va Dong Nam.
Tir khoa: Da dang loai, td thanh thuc vat, trang thai rimg, dao Con Co.
dugc thief k l theo dudng trdn ddng tam dya tren dudng ddng mirc vdi 3 tuyln chinh:
Tuyen 1: Vdng quanh dao theo dudng rli nhua vdi chilu dii tuyen II 5 km, xem xlt tdng quan he thyc vat dio, x l c dinh nhiing diem mdc, sy khIc biet vl chuyin tilp he thyc vat dio.
Tuyen 2: Tu" tuyln 1, elt tuyln dilu tra di vIo rimg theo hudng xuyen tam (hudng den dinh 63).
Tuyln 2 se bao gdm nhieu tuyln nhd, cae tuyln nho se di theo he thdng dudng giao thdng h l o tren dao.
Tuyen 3: Tir tuyen 2, xlc dinh d c hudng cd sir khac biet vl chuyen tilp thyc vat tren dio, md tuyen mdi v l tii lap 6 tieu chuln tai vi tri cd sy khIe biet nly.
0 miu dieu tra. Dilu tra 3 6 m i u dac trung, dien tich 6 tieu chuln II 400 m^.
Chi tieu dieu tra: T h i n h phln loai (bao gdm ca cay gd ldn, cay tai sinh, eay day leo, eay bui, tham tuoi), sinh d n h , mat do, hien trang tai sinh.
Chi tieu dinh gii. Dinh gil da dang d e Taxon v l sinh d n h .
III. KET QUA NGHIEN CUU VA THAO LUAN
1. Sy da dang cae loai thyc vat tai dao Cdn Cd Sdloii thuc vat tai dio Cdn Cd
Kit qui dilu tra ban diu da thdng ke duge 239 loli thyc vat thudc 185 chi, 84 hg, co phan bd tir nhien hoac duge gay trdng tai dao Cdn Cd. Mae dii dien tich dilu tra khong ldn (khoang 2,2 km^), nhung sd loli
~ ~ ~ . ^ . ^ ^,. ~ ~ . ^ , . thyc vat d day k h i da dang vl phan bd kh6ng deu LDATVANDE
DIo Cdn Cd thupc tinh Quang Tri ed dien tich khoing 2,2 km^, cd tga dd dia ly II 17"08'15"- 17°10'05" vi Ble, 107''19'50"-107''20'40" kinh D6ng, d c h dlt liln tii 13 - 19 hIi ly. Tuy cd dien tich kh6ng ldn, nhung dio lai cd tinh da dang sinh hgc eao, dac biet II da dang vl he thyc vat do sy giao luu eiia elc ludng thyc vat dlt liln vl hiln dao. Nam 2001, Bg Khoa hpc, C6ng nghe & Moi trudng v l Td chirc Bao ve Thien nhien Qudc t l da eong nhan dao II mot trong 197 khu hlo tdn thien nhien Viet Nam. Nam 2005, dao Cdn Cd dugc dua vIo danh sleh mot trong 15 khu hlo tdn bien se dugc xay dyng dpc ba bien eua 11 tinh, thinh tren d nude. Tuy nhien, cho d i n nay, van chua cd mot nghien ciin cu t h i nIo dugc cong bd vl he thyc vat dio Cdn Cd, trong khi tham thyc vat d day tilp tuc chiu nhirng tac dong manh me cua ty nhien vl con ngudi. Dien tich phan bd ty nhien eua d c loli thyc vat ngly d n g thu hep do anh hudng ciia biin ddi khi hau, k i t hgp vdi boat dong phlt trien kinh t l vl ddi sdng cua ngudi dan noi day.
Chinh vi vay, viec bd sung v l holn chinh d e sd lieu dieu tra ea bin vl d c dang tham thyc vat, dac dilm sinh thii viing II mpt viec llm d p thilt nhlm bao tdn vl phlt triln sy da dang cua he thyc vat bien dao Cdn Cd.
II. PHUONG PHAP NGHIEN CUU
Phuong phip thu thap sd lieu tren hien trudng dupe td chirc theo tuyln dilu tra. Tuyln dilu tra
nhau giua cac hg. Trong tdng sd 84 hg dilu tra dugc thi da CO din 24 hp (28,57%%) chi cd mot loli, 21 hg
(25%) chi cd 2 loli vl hg ed sd loli ldn nhlt II hg Cue (Asteraceae) cung kh6ng qua 12 loai (ehilm ty le
45,24%
1,19%). CIc hg cdn lai cd sd loai biin dong tu 3-9 loai, chiim 45,24%. Day II mot diem dac tnmg ciia da dang sinh hgc nhiet ddi. Kit qua bilu thi sy chenh lech vl sd loai giua d c hg dugc thi hien qua hinh 1 sau:
D Ho chi CO 1 loai 28,57% a Ho chi CO 2 loai
D Ho CO 12 loai n Cac ho con lai
25%
1,19%
Hmh 1. Bieu dd bieu thi su chenh lech ve sd loli giiia d c hg thyc vat tai dao Suphan bdcic taxon thuc vat trong cic nginh
Kit qua thu duge vl sy phan bd d c bac taxon thyc vat trong cle nglnh duge thi hien qua bang 1.
Bang 1. Sy phan bd cle taxon trong d e nganh thue vat STT
1 2 3 4
Nganh Lycopodiophyta - Thong dlt Polypodiophyta - Duong xi Pinophyta - Thong Magnoliophyta - Ngpc lan
Magnoliopsida - Lop Ngpc lan Liliopsida - Lop Loa ken Tong cong
Sdho 1 5 1 77 62 15 84
Sd chi 1 7 2 175 146
29 185
Sd loai 2 8 2 227
195 32 239
Ty 16 % sd loai 0,84 3,35 0,84 94,97
85,9 14,1 100 Kit qua d bang 1 cho thay sy phan bd d c taxon
trong d c nganh thyc vat tai day kh6ng diu nhau.
Phln ldn cle hp, chi vl loli thyc vat deu tap trung d nganh Ngpc lan, vdi ty le % sd loli len din 94,97%.
Nglnh Th6ng dlt ehi bao gdm 1 hg, 1 ehi vl 2 loli QuyIn bl (Selaginella spp).
Trong nglnh Nggc lan, d e taxon chu ylu thugc Idp Ngpc lan (Magnoliopsida): 62 hg, 146 chi, vl 195 loli, vdi ty le % sd loli so vdi toan nglnh Nggc lan la 85,9%. Ty trgng vl sd loli giua Idp Nggc lan va Idp Loa kin la 6,09:1. So vdi cle he thyc vat nhiet ddi khIc thi ti le nay d bac loli tuong iing II 3:1. Nhu vay, he thyc vat d day mang tinh dac trung rlt eao cua he thyc vat nhiet ddi.
Da dang thuc vat theo dang sdng
Kit qui phan tich 239 loai cay d dia bin nghien ciiu theo dang sdng duge the hien d bing 2.
Cd thi nhan thay ngoli da dang vl d c bac taxon, he thyc vat tai dao Cdn Cd cdn rat da dang vl dang sdng. Kit qui phan tich cho fhly ed 8 dang sdng dac tnmg eua d e loai thyc vat noi day, trong dd dang cay ed dung ed nhilu loli nhlt (70 loli, chiim 29,29% tdng sd loai dilu tra dugc). Tilp theo dd II dang cay bui (38 loai, ehilm 15,90%) vl cay dly leo thin ed (36 loai, ehilm 15,06%). Ca ba dang sdng nly la yeu td the hien dac tinh thich nghi vdi dilu kiln sdng kha khac nghiet eua dao. Chinh vi sy ban ehl vl d c loli eay than gd (trong dd hon mdt nira II nhirng loli cay duge trdng) nen d c dang cay phu sinh vl cay day leo than g6 ehilm mpt ty le rlt nhd trong he thyc vat noi nly.
NONG NGHIEP VA PHAT TRIEN NONG THON - SO 4 - THANG 4/2010 121
5ang 2. Phan loai thyc vat tai dao Cdn Cd theo dang sdng Dang song
Cay phu sinh Cay g6 Ion Cay gd trung binh Cay go nho Cay bui
Cay day leo than go Cay day leo than c6 Cay CO dung Tdng sd
So loai 3 22 29 32 38 9 36 70 239
% tong so 1,26 9,21 12,13 13,39 15,90 3,77 15,06 29,29 100 2. Td thanh thyc vat cua cae trang thai rimg tai dao Cdn Cd
Trang thii rimg ngheo kiet Ila phia Tay
Trang thii rung nghIo kiet Ila thudng fhly d mii ddi phia Tay dio vdi dia hinh bing phang, do ddc trung binh tir 2 - 8°, trii dii tren dien tich khoing 4 ha vdi do cao tdi da khoing 10 din 15 m so vdi myc nude biin. Toln bg hudng phoi eua mii ddi nghieng vl hudng luc dia phia Tay nen tham thyc vat mang nit dac trung eiia vung ehuyin tilp tham thyc vat dat lien.
Kit qui dilu tra tren 6 tilu chuan dinh vi cho fhly, td thinh elc loli cay rimg thugc trang thii rimg ngheo kiet Ila phia Tay khi ngheo nIn. Khoang 12 loli eay gd nhd vl trung binh. Trong sd dd, loli Man chd II to (Knema poilanei) ehilm ti le cao (30% tdng sd cl thi dilu tra duge). CIc loli Trudng mat (Amesiodendron chinense), Ggi tia (Amoora gigantea). Tram (Syzygium spp.) mgc rai rac deu tren toln bd dien tich. Dac biet, loli Gy lau (Sindora tonkinensis) dugc phlt hien tai khu vyc nly vdi mat do thIp nhung phan bd kha diu tren toln bg dien tich. Td thinh thyc vat eay than gd nghIo nIn nhung lai mang vlt tich eiia ddng thyc vat dat lien ven bien thugc d c huyen ven bien tinh Quang Tri nhu HIi Lang, Trieu Phong vl Vinh Linh.
Nhdm eay byi ehilm ti le cao, mgc hdn loli vdi nhdm cay gd nhd; trong dd ding ke II loli Dung dinh. Dimg dinh chiim ti le khi ldn va phan bd diu tren toln bg dien tich eua cle 6 tieu chuan. Kit qua thdng ke theo don vi el thi cho thay. Dung dinh ehilm ti le 35% trong td thinh d e loli eay tham gia trong d u tnic rimg.
Nhdm d y tai sinh duge phat hiln bao gdm d e loli Gpi tia, Trim, Trudng vdi mat do thap, tir 1 - 3 ely tai sinh trIn mdt 6 dilu tra tai sinh 4 m^; trong
dd, Ggi tia dugc phlt hien nhieu nhat, sau dd II Trudng mat vl cac loai cay khIe.
Nhdm cay than thao co chilu eao din 1,5 m dupe phat hien voi mat do cao, che phu ban 90% be mat dlt thugc cac loli Son ciic (Wedelia montana).
Gang gai (Randia spinosi), Cd llo (Eupatorium odoratum). Bach bg (Stemona tuberosi) va Sam bdng bdng (Dracaena angustifolii).
Nhdm thyc vat day leo (thyc vat ngoai ting) phat triln khi phong phu vl chung loai vl sd lugng cl the.
Lgi dung tin rimg thua, do che phu ldn nhung ehl dp sing dudi tan ning cao, nhdm thyc vat ngoai ting bao gdm d e loli nhu May (Calamus viminali^, Ray
(Alocasia macrorrhiza), Ma (Paederia foetidi). Vac (Cayratia trifolia), Kim cang kh6ng gai (Smilaxglabri), Lau (Psychotria condorensis)... phlt triln manh. Ben canh dd, d c cl thi tai sinh thugc loli cay uu thi (Diing dinh) cung dugc phlt hien vdi mat do eao.
LI trang thii rimg ngheo kiet phuc hdi cham, d c bien phap tac dong ky thuat lam sinh dugc de nghi cho trang thii rimg nly bao gdm he thdng cai thien ning kit hgp llm gilu ning vdi elc loli cay ban dia nhu Gu lau, Trudng mat, Ggi tia; ddng thdi bd sung them mot sd loli cay nhu Lim xanh (Erythrophoeum fordii), Huynh (Tarrietia javanici), Trim trIng (Canarium albuni) hoac Nang (Alangium rid ley).
Trang thii rimg lib vi Ilia a phia Tay Nam Trang thii rimg lib vl Ilia phia Tay Nam thupc sudn nui phia Tay Nam dao ehilm dien tich khoang 10% tdng dien tich dio.
Tham thyc vat b khu vyc nly thugc loai kieu rimg kin thudng xanh. Tren d dilu tra djnh vi, do tan che trung binh 85%. Loai thuc vat uu the tai dly vIn la Diing dinh, chiem khoang 35% tdng el the tren 6.
Trang thii rimg kin dang ed khuynh hudng phuc hdi tdt. Nhdm d e loli thyc vat ngoai ting giam nhieu d tieu khu nly, thay vao dd, mat do eay than gd kich thudc ldn xult hien khi nhilu. Dgc theo d e tuyln am dugc tao ra do vlt nirt bazan vl nuf trim tich Neogen, chudi rimg va d c loli eay ua am khac nhu elc loai m6n, rIy che phu toln bp mat dlt voi mat dp cao.
Nhdm cay gd nhd vl cay go vira ehilm uu the tai trang thii rimg nly la Tr6m (25%) hdn giao vdi cac loli Chay trung bg (Palaquium annamense), Tnrdng, Ggi tia, Khao (Machilus thunbergi var. condorensii), Quao (Stereospermum spp.) vl Mau chd la to
(Knema poilanei) voi ti le thIp, k i t dai tin lien tuc thinh ting uu t h i sinh thai che phu khoang 85% tdng dien tich b l mat.
Cl biet, quin t h i Mil u (Calophyllum inophy lluni) tap trung thanh timg dam rieng biet, tao thanh timg 16 rimg don uu Mu u.. Xen lln vdi Mil u, thIm thyc vat dudi tan gdm d c loli ed Cdi xay (Abutilon indicum), va mpt sd loli RIy trIng phlt triln kha manh, che phu ting dlt mat. Tuy nhien, cac dam Mu u xult hien kh6ng nhilu vl kh6ng theo quy luat phan bd nhlt dinh nhu Bing biin (Terminalia cata ppa) va Dira dai (Pandanus tectorriu^. Dim thyc vat don tm tap trung nly ed the fhly lap lai vdi quin t h i cay Lien diep ding (Hemandia nympheaefolia) va cay Bing vu6ng (Barringtonia asiatica) b trang thai ning chuyen tilp dlt bazan nau tim vl d l san h6 vl vd dc tai m l D6ng v l D6ng Nam eiia dio.
Ting eay bui vdi chieu eao d i n khoang 7 m bao gdm td thinh chinh vIn la Dung dinh vdi mat do cao vl phan bd diu theo cym 7 - 9 e l the.
Cle 6 trdng dgc khe can, Chudi rimg (Musa acuminata) vl RIy (Alocasia macrorrhiza) che phu kin b l mat dlt. Chinh quan hgp nly ban e h l tich eye sy phlt triln ciia thyc vat ngoai ting, day leo v l cd dai nhu thudng thay d trang thii rimg nghIo kiet Ila da m6 t a d tren.
Ting tham tuoi dudi tin bao gdm eay tii sinh eiia d c loli eay me tang tren nhu: Trudng mat, Ggi tia vl Diing dinh tii sinh vdi mat do kha eao, che phii gan kin be mat dat.
Nhdm thyc vat ngoai tang nhu Kim cang kh6ng gai, day Ma... ehi phlt trien vdi mat do thap d d c 6 trdng kh6ng dugc che phu.
Td thinh cay tii sinh dudi tan kh6ng da dang, nhdm loli cay tii sinh dudi tin dugc thdng ke II nhdm cay gd vira, ua bdng giai doan dau vl ira sing giai doan sau nhir Gpi tia, Trudng mat vdi mat do eao. Cay tii sinh phan bd diu tren toln bg dien tich vdi mat do tir 20 - 30 c l the tren 6 dilu tra tai sinh 4 m^.
Bien phap lam sinh tac dong trong thdi gian tdi ddi vdi elc trang thii nay II tilp tuc khoanh nu6i bao vl, chat nu6i duang md rong tan rimg cho eay tai sinh phlt trien, k i t hgp trdng dam cay tai sinh dudi tan d l dilu chinh mang hinh phan bd. Do tang dlt k h i dly vl kh6, nhdm eay chiu ban ua sang nen dugc trdng bd sung d d e 6 trdng dudi tin, d c loli eay bui chiu bdng nen duge trdng bd sung nhlm tang kha nang giu nude cho dlt vl d i thien dilu kien dlt dai.
Trang thii rung kin thudng xanh phuc hdi lib va Ilia a phia Bic
Trang thai rimg kin thudng xanh phuc hdi phia Ble phlt triln tren nIn d l me phun trio bazan d do sau tir 40 - 140 cm, tren nIn dia hinh k h i bing phIng vdi do ddc dudi 8**. CIc dai tham thyc vat da dang va phirc tap bit diu the hien dan xen nhau theo chilu eao va khoing each tir dinh ddi din b a biin phia Bic.
Do dilu kien lap dia cd khuynh hudng chuyen tilp tir dlt bazan vIng dd nang sang dlt bazan vIng dd pha d t thit nhe nen td thinh thyc vat cd t h i duge mo ta thinh 2 nhom nhu sau:
Nhdm 1: Td thinh thuc vat trang thii rimg chuyen tiep a sudn ddi phia Nam.
Td thinh thyc vat d day vIn cdn chiu Inh hudng cua d e trang thii rimg mang tinh luc dia phia Tay.
CIc loli eay gd nhd va vira dien hinh eua dao nhu, elc loli Miu chd (Knema spp.), Ldng mang
(Pterospermum diversifolium), Tr6m, Gpi tia, Quao, Trudng, Huynh nuong (Temstroemia penangiani) xen lln vdi cay byi Dung dinh tao thinh kilu rimg phuc hdi sau tie dong. Dac biet, d trang thii rimg nly xuat hien mot sd lugng nhd elc loli cay khIe vdi cle trang thii rimg khIc b dao, nhu Ldng mang xult hien vdi mat do vl tan suit trung binh, Q u i rimg duge phlt hien rai rac tren toln bg dien tich cua trang thii rung chuyen tiep. Nhdm d c loai thude ehi Ficus dugc phlt hien nhieu ban lam cho td thanh thyc vat a day da dang ban. Tham thyc vlt dugc chia thinh 2 tang ro ret, tang gd nhd v l vira ehilm tang cao thinh dii lien tuc d do cao 4 - 8 m so vdi mat nude bien, dang trong tinh trang phuc hdi kh6ng ed sy tie dong.
Cay tii sinh dudi tin kit thinh ting thyc vat thir hai. Nhdm c l the eay con vl cay non thugc d e loai Trudng mat, Tr6m, Miu chd, Ldng mang tai sinh vdi mat do cao (50 - 80 e l t h e / 6 dilu tra tai sinh 4 m^).
Cay bui chii ylu phd hiln d dao Cdn Cd II Dung dinh dugc phlt hien vdi ting suit thap hon, ehilm ti le td thinh dudi 15% va mat do tai sinh tiiap. Bin canh eay eon va ely non eua nhdm thyc vat tang tren, Idp thyc vat tham tuoi cdn cd mat cle loai eay than thio xuat hien vdi tin suit ldn nhu Sam bdng bdng (Dracaena angustifohi). Thyc vat ngoai tang it phlt trien vl sd lupng loli nhung tin suit bit gap cao hon bao gdm cle loli May (Calamus viminahs), Ray bd (Pothos repens)...
NONG NGHIEP VA PHAT TRIEN NONG THON - SO 4 - THANG 4/2010 123
Nhdm 2: Td thanh thuc vat ven bien.
CIc dai thuc vat sinh trudng dac thu cua vung hai dio din dugc thay t h i bdi c l e dai rimg don uu Bing hiln. Bing bien sinh trudng thinh d c dii rung dan un mdt ting vdi ehilu rpng tu' 15 - 50 m phia chan ddi, tren nIn dlt cat pha b i n g phlng. Bing biin dan uu cd chilu cao trung binh tu' 9 - 15 m, dudng kinh than tir 20 - 25 cm tao thinh dai tin lien tyc co do che phii tren 90%.
Dpc theo bd biin, tham Bing biin gilm mat dp dupe thay thi bing dai Dua dai co chilu rdng d i n 10 m trii dii ra din m l p nude bien phia Bac. Cung nhu Bing bien, dat dai II nhan td chu ylu gay tac dong din hien tugng phan bd cue bg dai thyc vat don uu ciia loli Du'a dai. Quin the Dira dai ehilm toln bd dien tich dlt tao thinh dai don uu kh6ng ed loli cay xen ke.
Dpc theo bd nude, d c loli Tra hiln, Phong ba, Bing nude vl Hep thay t h i din tao thinh dai hep khoing 2 m sit m l p nude.
Bien phip tie dong ky thuat lam sinh d l xult II tang cudng tia thua vl nuoi duong d c khoanh rimg chuyen tilp nhlm nang eao sd lugng loli cay, tang tinh da dang vung chuyin tilp, ddng thdi d i thien dilu kien nude nglm nhlm hd trg viec phlt trien dien tich dlt canh tic n6ng nghiep. Mot sd kholnh dat trdng do Idiai thIc trong thdi gian trudc day cd t h i d i tao thinh dlt vudn hoac dlt n6ng nghiep cho cu dan dio.
Trang thii rimg trdng tren nen dia hinh ddi thap a phia Ddng vi Ddng Nam
Dang dia hinh ddi thIp vl ddc hudng D6ng v l Dong Nam tap tmng din d khu vyc ddi 63 g i n trung tam dio. Day II khu vyc dlt Idil ddc nhung lai tao ra d c dai bdi tu cat san h6 doe bd bien do Inh hudng eiia gid biin tir hudng D6ng. Dai thIm ven hiln cd b l mat k h i bing phlng tao thanh d c bai d t san h6 ldn.
N i n dlt chinh II da san h6 Xen lln vd dc k l o thinh dai dii khoing 2,5 km dgc bd bien tir mep bd Ble cua dio (Bai Huong Giang) den h i t Bin Nghi.
Tham thyc vat ty nhien a day cd t h i dugc chia thinh 3 nhdm chinh:
Nhdm 1: Thirc vat trang thii rimg nghIo lib phat triln tren dat bazan nau tim II trang thii rimg hai ting vdi tang cao dugc k i t d u dai tan liln tuc d do cao 10 m bdi td thinh d c loli cay Ggi, Quao, Slu, Miu chd, Tru'dng mat, Huynh nuong, Cui bien.
Nhom 2: Trang thai tham thyc vat Ilia phlt triln tren dlt chuyin tilp bazan nau tim, da san h6 vl vd dc tao sy phan bd eua nhdm thyc vat dac biet tai me dio phia Dong v l D6ng Nam. Nhdm cay dac thii vung hIi dio nhu Bang vu6ng. Lien diep ding sinh trudng thinh dam voi mat dp kha eao v l tap trung tao thinh cac d i m rimg don uu timg loai cay.
Nhdm 3: Trang thai tham thyc vat lib phlt trien tren d l san h6 va vd dc ven hiln tao dac thii rieng cho nhdm cay vung biin nhilu gid v l man. Tra biin, Bing nude. Hip, v l Phong ba mpc hdn loai tao thinh thIm cay bui cd ehilu cao duoi 4 m. Ngoli d c loli tren, Tu' bi bien (Vitex rotundifoha) dugc phlt hien thinh d i m mgc rieng 11 tren d e vung kh6 ban hon.
Trang thii ning trdng Keo II trim chiim dien tich khoing 9 trdng nam 1995 vl Mudng den (Cassia sianiei). Sau 10 nam, chat lugng rung trdng cho kit qua phii xanh k h i tdt, tilu khi hau vl tilu sinh thai rimg dugc kiln tao vdi tham thyc vat dudi tin gdm d c loli day leo, Ngu sic, Bg chd, Bg may vl mon rIy. Dac biet, Ray trang phlt trien rlt manh, dly dac vl eay eao to, ed cay cao 2 m.
Tdm lai, tham thyc vat phia D6ng va D6ng Nam dao diln hiln phirc tap v l t h i hien tinh tuong thich vdi dilu kien lap dia dac biet ciia dao. Ba tham thuc vat cd d u tnic td thinh holn toln khIc nhau phat triln tren 3 dang dat khIe nhau t h i hien tinh dac thii nly. M l phia D6ng va D6ng Nam dao cd k i t clu dia hinh ddc tren 20°, sau dd thoai din theo d c bai cit san h6 gay hien tugng xdi mdn manh. Viec tii Ididi phuc vl md rpng elc quin the dac biet cua hIi dao la d n thilt. Khoanh nu6i ed t i e dong II bien phip lam sinh dugc de nghi thyc hien.
CIc loli cly Lien diep ding, Bing vu6ng. Hip, Phong ba v l Tra bien da duge thir nghiem gieo tao cay eon va uom hom thinh e6ng d dat liln. Viec phat trien khoi phuc cle nhdm thyc vat nay II kha thi. Bin canh dd, kh6i phuc canh quan rung dudi tin Keo la trim II c6ng viec cin thilt. Nhdm d e loli eay ban dia nen dugc trdng thir nghiem d l lam gilu rung vl kli6i phuc d n h quan.
IV. KET LUAN VA KIEN NGH|
1. Kit luan
1. Kit q u i dilu tra da thdng ke dugc 239 loai thyc vat thugc 185 chi, 84 ho, co phan bd tir nhiln hoac dugc gay trdng tai dao Cdn Cd. Phln ldn d c hp, chi v^ ) d i thyc vat diu tap trung a nganh Nggc lan, vdi ty le % sd loli len din 94,97%. Ty trgng ve sd
loli giua lop Ngpc lan vl lop Loa k i n trong nglnh Ngpc lan la 6,09:1.
2. Trong sd 8 dang sdng dac trung eiia cac loai thyc vat noi day, dang cay cd dung co sd loai ehilm 29,29% tdng sd loai dilu tra, tilp sau la dang cay bui (15,90%) va dang eay day leo than ed (15,06%). Dang cay phu sinh ehilm ty le thIp nhat (1,26%).
3. Td thinh d c loli thyc vat cd sy khIe biet giua d c trang thii rung d d c vi tri khac nhau. Trang thii rimg nghIo kiet Ila phia Tay mang dac trung cua vung chuyin tiep thIm thyc vat dlt liln. Trang thii rimg lib vl Ilia d phia Tay Nam thugc loai kieu rimg kin thudng xanh vdi mat do eay than gd kich thuac ldn xult hien k h i nhilu. Trang thai rimg kin thudng xanh phye hdi lib v l Ilia d phia Bac thupc loai kilu rimg kin thudng xanh voi hai nhdm td thanh thyc vat bao gdm: Nhdm td thinh thyc vat trang thii rimg chuyin tilp d sudn ddi phia Nam chiu Inh hudng eua d c trang thai rimg mang tinh luc dia phia Tay; nhdm td thinh thyc vat ven hiln vdi d c dai ning don uu Bing biin vl Du'a dai. Trang thii rung trdng tren nIn dia hinh ddi thap d phia Dong v l D6ng Nam vdi ba nhdm tham thyc vat ty nhien ed d u tnic td thinh holn toln khIc nhau phlt triln tren 3 dang dlt khIc nhau thi hien tinh tuong thich vdi dilu kien lap dia dac biet cua dao. Trang thii ning trdng Keo la trim vl Mudng den cho k i t qua phu xanh k h i tdt, tieu khi hau vl tieu sinh thii rimg dugc d i thien ro ret.
2. Kiln nghi
1. Cin tilp tuc dilu tra n h l m bd sung them danh luc cle loli thyc vat ed phan bd ty nhien vl dupe gay
trdng tren dio.
2. Thir nghiem d c giii p h i p ky thuat lam sinh da dugc kiln nghi sir dyng phu hgp voi timg trang thii rimg. ^
TAI UEU THAM KHAO
1. Nguyin Tiln Ban- Chu bien (2003). Danh luc cic loii thuc vat Viet Nam tap 2. NXB N6ng nghiep, HI Ngi.
2. Nguyin Tiln Ban - Chii bien (2005). Danh luc cic loii thuc vat Viet Nam tap 3. NXB Nong nghiep, HI Ngi.
3. Vo Van Chi, TrIn Hgp (2002). Cayed cd ich a Viet Nam. NXB Gilo dye, HI Ngi.
4. Cue thdng ke QuIng Tri (2007). Nien giim thdng ke tinh Quing Tri 2006. NXB thdng ke HI Ngi, 7/2007.100 tr.
5. Nguyin Huy Dung (2005). Tii nguyen rimg d-en nui di vdi vi van de quin ly. Trich xult tii: Khoa hgc e6ng nghe N6ng nghiep vl phlt hiln n6ng thon 20 nam ddi mdi. NXB Chinh Tri Qudc Gia. Tr: 106-107.
6. Pham HoIng Hg (2000). Caycd Viet Nam tap 3 NXB tre, HI Ngi.
7. Pham HoIng Hd (2000). Caycd Viet Nam tap L NXB tre, HI Ngi.
8. Pham HoIng Hg (2000). Caycd Viet Nam tap 2 NXB tre, HI Ngi.
9. Trung tam T i i nguyen va M6i trudng, Dai hgc Qudc gia Ha Ngi (2001). Danh luc cic loii thuc vit
Viet Nam tap 1. NXB N6ng nghiep, HI Ngi.
THE DIVERSITY OF PLANTS AND THE PLANT SPECIES COMPOSITION OF F O R E ^ T Y P E S IN CON CO ISLAND, QUANG TRI PROVINCE
Dang Thai Duong Summary
The Con Co island flora, including wild flora and cultivated flora, has been very diverse. According to preliminary surveys, 239 plant species belonging to 84 families and 185 genera have been already identified, of which the Magnoliophyta predominates with 227 species belonging to 77 faminies and 175 genera. The species ratio between Magnoliopsida and Liliopsida is 6.09/1. There are 8 stem forms including epiphytic plant, big tree, average tree, small tree, bush tree, woody climber, climbing herbaceous, and standing herbaceous groups, of which the standing herbaceous groups occupy the highest number of species (29.29%), the bush tree groups occupy 15.29%, and the climbing herbaceous groups occupy 15.06%; the epiphytic plant woody climber groups occupy the lowest ratio, corresponding with 1.26% and 3.77%. The plant species composition is different between the forest types in different locations and has the own characteristics, including: the poor forest on the west of island; the forest type lib and Ilia on the southwest of island; the forest type lib and Ilia on the north of island; and the cultivated forest on the lower terrain in the east and southeast.
Keywords: Diversity of species, forest composition. Con Co island Ngudi tham dinh: PGS.TS. Tran Minh Hgi
NONG NGHIEP VA PHAT TRIEN NONG THON - SO 4 - THANG 4/2010
125