KHOA HOC C6NG NGH£ D I E D T R A CAc Y E U TO HilVH THAIVIH RUIVG IXIGAP IVIAIV TREM IVEIV CAT 5A!\I HO Q V U l l M QUOC GIA CdlXI D A O L A I U CO S O D E X U A T IVIO ROIVG GAY TROrVIG Ki^u T u ^ Dat\ Ph^m Th^ DttngS H o ^ g Van Thoi^ T6MTAT Tong dien tich rung ngap man tai VQG Con Dao gom 32 ha, phan bd tai 12 bai trim tich ven biin thupc hon dao chinb la Hon Con Son, Hon Ba va H6n Bay Canh Thuc vat than g6 RNM tai VQG Con Dao co tong cong 46 loai, co 28 loai ngfip man thuc su va 18 loai tham gia vko RNM Rung ngap man a Con Dao chiu anh buong ciia nhom nhSn td hinh thanh, nhung cac yeu to tac dpng chinh la: (1) Ylu to dia hinh dia mao duoc che cbSn cac vinh; (2) dac dilm cua thi nin la da, cat iSn manh vun san ho la nhung bai tram tich ven biin thoai thoai, co hb biin nong va tinh ch^t ca ly boa ciia dat diu la gioi ban tdi thieu de cay rung phat triln duoc; (3) ddng hai luu la nh^n to chinh mang lai su phong phu va da dang cdc loai thuc vat; (4) thuy trilu ngSp th5[p, sdng biin va man nuoc biin nSm pham vi thich ling cua nhilu loai cliy RNM Ngoai dilu kien hSu n6ng am, bi€n dO dao dOng nhi^t thip va lucmg mua nhilu cung la cac yeu td thuSn Igi tao dilu kien cho cay RNM sinh truong va phat triln Cdc loai uu the co triln vong duoc de xu^t mo rpng gSy bao gom loai: Duoc doi, Dung, DSng, Duoc lai, Da Voi va Sii Do Tir khda: Vudii Qudc gia Con dao, rung ngap man, yi'u tdhinh thanh, thSnin da cat va vun san ho, loai uu thSco triSn vong I DAT VAN BE gia Cdn Dao cd he sinh thai dien hinh cua vung bien nhiet ddi vdi hon 1.300 loai sinh vat da duoc thdng ke va dinh danh Vudn Qudc gia Cdn Dao la mot quan dao nam tren viing bien phia Ddng Nam cua nude ta, gom 14 Trong nhimg nam qua, Vudn Qudc gia Con Dao hon dao cd quy mo dien tu nhien 19.990,7 ha, bao gom: 5.990,7 rimg nui ciia 14 dao thupc quan dao da nd luc phdi hpp vdi cac to chiic khoa hoc, bao ton Con Dao va 14.000 mat bien Vudn Quoc gia Con de nghien ciiu cac he sinh thai rung, cac he sinh thai Dao cd tinh da dang sinh hoc cao vdi nhieu he sinh bien va san ho Nhung rieng ve nghien ciiu he sinh tiiai dac trung va nhieu loai sinh vat quy, hiem, d$c thai rung ngap man va cac he sinh thai ven bd bien hiiu Cd kieu rung chinh phan bd tai day la kieu chua dupe thuc hien mpt each day du Gan day, cac rung kin thuong xanh mua am nhiet ddi va kieu rimg nha khoa hpc da phat hien b day cd mpt kieu rimg kin nua rung la mua am nhiet ddi Cd cac he sinh thai ngap man nguyen sinh phan bd tren nen dat cat iSn chinh: he sinh thai rung tren vung doi mii thap; he soi va manh vun san ho, dd cd nhiing loai thuc sinh thai rung tren doi cat va bai cat khd, ban ven vat quy hi^m cd sach Viet Nam Kieu rung bien; he sinh thai RNM va he sinh thai rung ngap ngap man chua thay dupe de cap cac tai phen Nhimg he sinh thai duoc phan bd k^ tuc lieu nghien ciiu vi rung ngap man da dupe cong bo b tren mot khong gian nho hep tai Con Dao Day Viet Nam Khac vdi cac RNM khac or Viet Nam la mot net doc dao, co y nghia vk m$t tu nhien, diln thudng phan bo tren dien tich nin dat biin lang dpng, the va khoa hoc Tham thuc vat ciia VQG Cdn Dao v^ nhung rimg ngap man nguyen sinh tai Con Dao la CO ban vtn mang nhung dac di^m dac trung v^ cau mpt ki^u dac thii phan bo tren th^ n^n la da, cat ISn tnic tang thii, ngoai mao va canh quan cua h$ sinh manh vun san hd hau nhu chua dupe quan tam thai rung tu nhien nhiet ddi, hai dao Rung ciia Vudn nghien ciiu mpt cdch d^y dii Vi vay, viec dieu tra cac Qudc gia Con Dao co phan thuc vat phong phii y^u td hinh len rung ngap man tren nen dat cat va da dang voi tren 1.077 loai thuc vat bSc cao va 135 san ho tai VQG Con Dao, lam co so de xuat ky tiiuat loai dong vat cd xuong sdng da dupe dinh danh ma rpng gay that su can tiiiet va cd y nghia rat (Nguyen Chi Thanh va ctv, 2004) Bifo Vudn Quoc ldn ddi vdi thuc tien dat hien Phan vien NC KHLN Nam Bp N C N G NGHIEP VA PHAT TRIEN N N G THON - KY - THANG 3/2012 81 KHOA HOC C u NOI DUNG VA PHUONG PHAP NGHIEN ciiu Muc tieu d^ tM Thu thap nhimg sd lieu va tiiong tin nham xdc dinh cac y^u to hinh tiianh len rimg ng$p man nguyen sinh tren n^n cdt lan soi vd manh vun san hd a hon Bay Canh va hon Bd tiiupc Vudn Quoc gia Cdn Dao, tii lam co sd di xuat nhimg lodi co tri^n vpng de md rpng gay rimg d^ nhiing noi cd di^u kien lap dia tuong tu NOi dung nghien ciiu Dilu tra su phdn bd cOia kilu rimg ngdp mdn nguyen sinh tren nIn cdt ldn soi vd manh vun san hd b hon Bay Canh vd 13 hdn ddo khdc cua VQG Cdn Dao Dieu tra ddnh gid.cdc ddc dilm 1dm sinh hpc ciia kilu rimg ngap mdn tren nIn cdt soi vd vun san hd d hon Bay Canh vd hon Bd - Dl xuat cdc lodi cd triln vpng dl md rOng gdy Phuong phdp thuc hien Thu thdp cdc tdi Ueu vd thong tin lien quan: bao gom ban cdc loai, dieu kien tu nhien, dat dai, che dp ngap trilu, che dp gid, tham thuc vat vd cdc nghien ciiu cd lien quan - Phuong phdp dilu tra thuc dia Khao sdt so bp todn bp 14 hdn ddo vd dilu tra tuyen diln hinh dl xdc dinh phan bo cCia trang thdi rimg ngap mdn tren nIn dat cdt ldn soi vd mdnh vun sanhd 6NG NGH£ tinh ch^t nude vd cdc y^u td ngoai canh tdc dpng « Phuong phdp phdn tich xii ly sd lieu n6 nghiep Sir dyng cdc phin m^m di tinh todn va xu ly sc li^u g6m: Primer VI, Excel vd Maplnfo Xdc djnh lodi chiim uu thi thdng qua chi so quai trpng (IVI%) aia m6i lodi dupe tinh bang cdngtiiiirccuj Mishra (1968): IVI % = (RD% + RF% + RBA%)/3 Xdc djnh td thdnh lodi thdng qua xdc dinh t^ xudt brong ddi (RI),%) Phdn tich hpp phdn chinh PCA (Principal Component Analysis) dl xdc dinh mdi quan he ciia cdc lodi RNM qudn xa - Phdn tich miu dS't va nude: Mau ddt gom 10 chi tiiu 0)0 mdn, pH Al*^ Fe*^ ^0^\ Ca*^^ U^\ N, Pva thdnh phdn ca gidi) Mdu nude gom cdc chitieu:pH, mdn, dO due, Al*^ Fe*l Lua chpn lodi di xudt ma rpng gdy trong: Lira chpn lodi dua tren s6 lieu ddnh gid vl sinh truong, tai sinh, cdc chi tieu cud quan xd thuc vat vl lodi uu th^ (rVI%) vd dua tren sd lieu dilu tra quan sdt vl vat hau ciia cdc lodi H-KETQUAvAniAOLUAN Phdn bd vd thdnh phdn lodi ciia rimg ngSp m ^ tai VQG Cdn Dao a Phan bdcua rimg ngap m$n Kit qua khdo sdt tren todn bO 14 hon dao cho thay su phdn bd ciia rimg igdp man tai Vudn Quoc gia Con Ddo tai 12 khu vuc khdc nhau, cd tong dito - Dilu tra ti mi: Su dung phuong phdp dilu tra tich Id 32 tdp trung a bon dao ldn Id Hon Con diln hinh, dai dien d cdc trang thdi rimg trSn nIn dat Son, Hon Bay Canh vd Hon Bd Dien tich rimg ngSp cdt ldn soi va manh vun san hd or hon Bay Canh vd mdn phdn bd rai rdc b nhilu khu vue, moi khu vuc co Hon Bd vdi tong cong 60 tieu chudn diln hinh di diin tich khong ldn, khu vuc ldn nhat cd dien tich ddnh gid cdc ddc diem lam sinh hpc ciia RNM, dilu vd khu vuc nho nhat co dien tich 0,2 ha, cu the dupe thi hien qua bang kien lap dia, dat dai, dia hinh dia mao, dp ngap trilu, Bdng V| tri phdn bd ciia RNM thinh d^ing cdc dao Sdng biin or ddy cd anh hudng (thang 5), tiidng cd nhiet binh qudn tiidp nhdt rdt ldn din RNM, ddc biOt Id miia qua chin 25,4^C (tiiang 1), bien dp nhiet giira tiidng lanh vd sdng biin manh 1dm cudn troi trdi vd tru mam nfen tdc dOng tieu cue din khd ndng gieo gidng ciia cay thdng ndng nhat Id 3"C + Dp am: Dp am khong trung binh ndm Id RNM vd 1dm dnh hudng din chdt lupng cua cay tai 80,7%, bien dp biin tiiien ciia dO ^ khong ti-ong sinh + Ddng hid luu: Ddng hdi luu Id nhdn td chinh ndm khoang 5% Thdng cd dd am cao nhdt vdo tiidng giup phdt tdn qud, tru mdm vd hat dpc theo cdc viing 10 (83,4%) vd dp amtiidpnhdt vdo thdng 12 (78,4%) + Chd dp gid: Cdn Dao cd hai hudng gid chinh: ven biin Trong dd, Cdn Ddo Id dilm giao luu ciia miia mua la gio Tay, miia kho Id gid Tdy - Bdc, Dong - cdc ddng hai luu tir An DO Duong qua Indonesia va Bdc vdi cuong dp cap 6, cdp Toe dO gid ldn nhdt Malaysia, kit hpp vdi gid miia Tdy Nam vdo thang trung binh cua cd ndm Id 17 m/s, tdc dp gid cd su din thdng 10, (ung trimg vdi miia chin ciia qua va tru chenh lech rat ldn: thdp nhat Id m/s vd cao nhdt Id mdm cua cdc lodi cdy RNM Do vdy, ddy Id nhan to 26 m/s Tdc dp gid manh nhdt tdp trung vdo tiidng quan trpng dl viing vinh cdc dao tilp nhdn cac vjit - vd miia gid chudng tir thdng 11- thdng ndm sau liiu phdt tdn nhu qud, hat vd tru mdm tir cdc viing + Lupng mua: Lxiqng mua trung binh ndm Id 2.200 cua sdng ven biin tir Indonesia, Malaysia, Thdi Lan mm, so ngdy mua trung binh ndm 166 ngdy,tiidngcd vd cd dai ven biin Nam bO- Ddy Id nguyen nh^n lupng mua cao nhat (thdng 10) Id 348 mm Chi dp chinh hinh thdnh su da dang vl qudn hj lodi ciia mua phdn thdnh miia, miia mua tij tiidng din RNM tai Co.! Dao VI khia canh khdc, thong qua cac tiidng 11, miia khdtirthdng 12 dentiidng4 ndm sau ddng hai luu dd dnh hudng ldn din su di cu vd ton tai ciia nhCmg cdy RNM ddu tien He sinh thdi RNM a c Chd dp thuy v^ + Che dp ngap triSu: Bien dp trilu cd tdc dOng ddy dd cd cdc biin dj vl kilu hinh theo huong tdng len str phong phu, cau tnic vd su phdn bd cOia cdc khd ndng chong lai gid to, sdng ldn vd nIn da, cat quan xa RNM Che dO thiiy trilu vimg biin Cdn Dao ngheo dinh dudng, Thdng qua su phdt triln ciia he tiiupc loai trilu hon hpp thien vl bdn nhdt trilu rl theo hudng trdi rOng, phdt triln nhilu cdnh, than khdng diu Vdi muc nuoc trilu cao nhat 3,5 - 4,0 m, ndm ngang vd giam dO cao cua thdn dl thich ling voi thap nhat 0,5 m; biin dOng bien dp trilu tir 2,5 - 3,5 dieu kien tu nhien vd ddy Id ylu to ca ban tao m Bien dp trilu rpng, di ddi vdi dia hinh khu vuc dd RNM hien cCa Con Dao tao dilu kien cho RNM phdt triln theo bl rOng vd + Nude bien: Theo so lieu thuy vdn ciia tram thdnh phan lodi cdy RNM phong phu Cdn Ddo cd tupng Con Ddo ndm gan ddy thi dp mdn cua cdc ddc dilm vl dilu kien thuy trilu or cdc vinh, khd nude biin tai Con Ddo trung binh Id 32,6^/oo, cao thich hpp cho su ton tai vd phdt triln ciia cdy RNM nhat Id 33,8°/oo vd thap nhat Id 28,3Voo, ^dy Id nguong (tiieo sd ueuti-ong5 ndm tir 2003 - 2007) thich hpp cho nhilu lodi cay chiu mdn bdt buoc + Sdng biSn: Hudng vd dO cao sdng phu thuOc Ngodi ra, RNM a cdc bdi trdm tich ven bien tai cac vdo gid miia Gid Dong - Bdc sdng thinh hdnh vdi tan vjnh or Con Dao cd dilu kien tilp nhdn nude ngot tir xuat dat 60%, dp cao trung binh tir 0,3 -1,5 m Dong tren cdc viing mii cao ven bdr da 1dm cho man chay chu ylu chiu chi phdi ciia dong trilu, nhien nude biin giam, tao dilu ki^n cho cdc lodi co kha gid cd tdc dpng ddng kl lam thay doi dong chay bl ndng chiu mdn thdp vd nhiing lodi tham gia vdo RNM mat a viing biin VI miia Ddng, ddng chay cd hudng sinh trudng vd phdt triln Kit qua phdn tich vl mot Ddng Bdc - Tay Nam trung binh tir 0,7-1,5 m/s, ddng sd tinh chat cua nude biin dudi tan RNM dupe the chay ven ddo phu thudc chii ylu vdo dia hinh bdr dao hien qua bang Bdng Turn chat cua nuoc bien tai diem nghic^ncuu Oaykhi thiiy trieu nit, Vi tri lay mau Hon Bay Canh HonBd Tilp gidp Tiep giap Dudi tdn Tilp gidp Dudi tdn Tiep gidp Chi tieu ngoai mii rimg ngodi rimg mil 6,82 pH (H,0) 7,27 8,31 _ 8,46 7,46 6,94 28,0 _ 8,0 %0 Do mdn 27,0 25,0 28,0 16,0 2393,0 _ 36,0 mg/1 2255,0 2753,0 SO/ 2053,0 785,0 0,24 _ 0,41 0,27 Fe % 0,22 0,11 0,33 84 NONG NGHIEP VA PHAT TRIEN N C N G TH6N - KY - THANG KHOA HOC C N G NGH£ tren nen dia chat tram tich ven cac dao dugc tao cd nguon goc tir bien va su doc tu tir mii cao dem lai tao nen cdc bai thai dai cd dp ngap trieu nong ven cdc dao Viing trilu dugc hinh b cac noi lom cua ba bien, todn quan dao cd 24 bai, nhin chung d tat ca cdc dao diu co, nhung bai bien va bai trieu Ion thi tap trung d- hon dao chinh Id Hon Con Son, Hon Ba va Hon Bay Canh Viing trilu dugc tao boi cat nho, dd lan va manh vun san ho The Lupng SO42 nuoc deu rat cao RNM nen b Con Dao khong ndm phan chia dang lap nguyen sinh d day da hdng ti-dm nam tiioi co lop dia cua RNM tai Viet Nam gom: Biin loang, biin chat, tham muc dugc phdn buy manh duoi tan rimg lai bi set mIm, set chat va dat rdn (theo Dang Cong Buu, anh hudng cua nguon nude mdn vd ngdp trieu d muc 2005) Dat tai cdc khu vuc co dien ti'ch RNM gom thap den trung binh nen trang thdi yem dang chu yeu la: Da + Cat + San ho chet vd nen cat + vdy chung chiia nhieu gdc luu huynh vun san ho chiem tdi 97,5% Cac dang the nIn cd d Dat dai thdnhuong RNM tai Con Dao rat ddc thii vd dpc dao d Viet Nam + Dac diem nen dat RNM Con Dao dugc hinh Tinh chat ciia dat dugc the hien qua bang Bang Tinh chdt ca ly hda ciia ddt tai Hdn Bay Canh vd Hdn Bd Qua ket qua d- bang cho thay: Dp man ciia nude dudi tan rimg ngdp man thap ban so vdi dp man cua nude bien Dac biet d nhimg vi tri tiep gidp vdi rimg nui cao cd dp ngap it vd dupe su bo sung nguon nude ngpt tiii dp mdn khoang tii - I6V00 Loai tiiuc vat RNM xuat hien d day chii yeu Id nhimg loai tiiam gia vao RNM vdi cdc loai nhu: Gia, Ban, Xu 6i, Bang bien, Mudp xdc huong Go biin Mil U va Lpc Vimg Vitri ay mSu Chi tieu pH (H,0) pH (KCl) Do man N ts P,0^ts K,0_ts Fe^^ SO/- D.V.T %0 % % % mg/lOOg mg/lOOg Ca2* meq/lOOg Mg2^ meq/lOOg < 0,002 mm * Thanh Set ' phan ca Thit 0,002 -0,02 mm • gioi (%) Cat > 0,02 mm Hon Bay Canh (Bai Ba Dap) Hon Ba (Dam Quoc) Diem tiep giap Diem giOra Di^m tiep giap Diem ti^p giap Di^m giua Diem tiep RNM ngoai RNM giap ngoai Tangc at, cm Tang c at, cm Tangc at, cm Tangc at, cm Tangc at cm Tang dat, cm 0-10 30-50 0-10 30-50 0-10 30-50 0-10 30-50 0-10 30-50 0-10 30-50 6.64 7,95 7,37 7,87 6.56 8.01 6,65 5,98 7.97 8.08 8.26 7,89 5,54 7,15 6.04 7,26 7.24 7,12 6,19 5,54 7.12 7.20 7.62 6,90 1,00 2,00 2.00 4.00 4,00 4,00 2.00 4,00 4,00 5,00 4.00 5,00 0,17 0.07 0,06 0,34 0.10 0,03 0.14 0,11 0,15 0,10 0,06 0,11 0,01 0,01 0.01 0,01 0,06 0,02 0,03 0.01 0,03 0,03 0,02 0,04 0,07 0,07 0.06 0,06 0,41 0,09 0.11 0.11 0,20 0,15 0,22 0.12 120,39 68,27 205,01 65,51 151,76 327,82 130,37 204,51 49,83 46,27 40,57 28,45 31,00 252.00 92,00 117,00 194,00 246,00 293,00 300,00 271,00 146,00 74,00 109.00 2,25 3,50 3,75 4,00 3,25 1,50 1,25 4.00 3,00 1,50 2,00 4,50 4.25 6,50 7,25 7.75 4,35 4,50 2,50 7.50 4,50 3,25 3,50 7,25 16,00 16,00 14,58 16.00 24,00 8,26 6,18 20,00 12,56 18,53 16.00 32,74 7.18 20.44 14,88 15,27 6.05 6,57 13,72 9.55 11,01 7.64 25,46 16.09 76.82 55.56 69,12 70,15 85.69 87,25 66.28 76,36 76,43 74.45 65.38 41,80 Dat RNM or Con Ddo a miic hoi chua din kilm ' pH(H20) tii 5,98 - 8,26; pH(KCl) tir 5,54 7,62 Dat ngheo dam, ldn vd kah tinh chat cua dat vd ' phan ca gidi nhilu soi da vd san ho it phong hda md • nia troi nhilu chi dO ngdp trilu Ham lupng Ca^*, ' Mg2% ^Ot diu cao tir (1,5-7,5 meq/lOOg) tinh chat ciia dat man Do qua trinh phong hda cua san ho , vd tinh chat cua dat man dilu kien yem ciia , tang tiiam muc dudi rimg ngdp mdn thuong chiia : nhilu thdnh phan gdc luu huynh (S) nen ham lugng I SO/- rat cao Thdnh phan ca gidi cat vd soi (> 0,2 mm) chiim uu till > 40%, set chiim 32%, tiiit j; chiim - 25% Do ham lupng cat chiim uu till, tiidnh iphan ca gidi chac vd tiiodng khi, khd ndng gitr nude kem nen khong tdt cho rimg ngdp man Day la dang lap dia mdi d Con dao, khdc vdi lap dia ciia rimg ngap mdn d Ca Mau vd Can Gid Dilu ciing phii hgp vdi ddnh gid ciia Ldng Vdn King, ndm 1997 Ddc dilm 1dm sinh hpc ciia h i sinh thdi RNM tai Hdn Bay Canh vd Hdn Bd a Dac diem lam sinh hpc cua tang cay cao Thdnh phan loai Khu vuc RNM cua Hon Bay Canh cd 16 loai thuc vdt tiiupc 10 hp khdc nhau, dd so lodi ngap mdn tiiuc su la 15 lodi vd sd loai tham gia vdo RNM Id 01 loai Khu vuc Hon Bd cd 18 loai thuc vat thupc 10 hp khac nhau, dd 17 lodi ngap man thuc su va •jNONG NGHIEP VA PHAT TRIEN NONG THON KY - THANG 3/2012 85 KHOA HQC CbNG N G H £ 01 loai tham gia vao RNM Trong tdng sd 10 hp tbi hg Dude cd so loai cao nhat la 08 loai, day cung la hp TT Loai Dang Duoc doi Coc Tning Cui bien Su Da voi Duoc lai Vetdu 10 11 12 Coc Dung Vet hainesii Ban trSng 13 Vet tru 14 Go bien 15 Tra lam vo 16 Gia- 17 B4ngphi 18 Xu sung 19 20 Xuoi Vudt hiim 21 Xu mmphii cd mdt dO cd thi cao nhdt Sd lieu tdng hgp dupe th hien b hang Bang Tdng hgp tiidnh phdn lo^dciiaR N M t ^ hdnBd vdhdn BdyCjinh HdnBd Bay canh Ten khoa hoc RF% RBA% IVI RD% RF% RBA% RD% Rhizophora stylosa Griff Rliizopliora apiculata Blunie Lumnitzera racemosa Willd Heiitiera littoralis Dryand Aegiceras lloiidum Roem & Scbult Ceriops tagai (Perr) C.B Rob Rhizophora x lamarckii CAii Bruguiera gymnoirbiza (L.) Lamk Lumnitzera littorea Qack) Voigt Rhizophora niucronata Lamk Bruguiera hainesii C.G Rogers Sonneratia alba] Sm Bruguiera cylindrica (L.) Blume Intsia bijuga (Colebr) Ktze Tbespesia populnea (L) Soland ex Lorrea Excoecaria agallocha L Pemphis acidula] R Forst & G Forst Xylocarpus moluccensis (Lam) M Roem Xylocarpus granatum Koening Caesapinia honduc (L) Roxb Xylocarpus rumphii (Kostel) Mabb Tong b Cdng thuc td 36,80 13,75 25,45 12,73 37,10 7,64 33,12 11,37 0,37 1,82 0,18 15.61 10,91 4.46 4,09 IVI 21,74 15,22 2,17 1,09 27,42 0,79 24,38 18,52 0.31 0,15 9,01 11,85 6,33 6.52 3.04 5.30 7,27 3,64 2,71 5,64 4,82 4.45 22,07 4,78 15,22 5,43 14.60 4,60 17.30 4.94 4.83 5,45 3,24 4.51 10,80 13,04 0.07 7.97 1,49 12,64 1,86 0,74 3,64 12,73 1,82 1,82 7,82 14,78 4,04 3,19 4.32 13,38 2,58 1,92 0,15 0,15 1.09 1,09 0.01 0.30 0.42 0,51 1.12 1,82 2,20 1.71 0,37 1,82 0,16 0,78 0,37 1.82 0,14 0.78 3,40 3.26 3,63 3,43 0,37 1.82 0.13 0.78 2.78 3,26 4.38 3,47 4.32 5,43 10,77 6,84 1.54 0,15 3,26 1,09 15.15 0.30 6,65 0,51 100 100 100 100 0.37 1,82 0,36 0.85 0,37 1,82 1,16 1.12 0,37 1,82 0,49 0,89 100 100 100 100 14,84 0.31 0.52 24,5] le.ij 0,93 0,59 ddy bao gom: Ddng, Duoc ddi, Dung, Vet dii, Sii vd Dude lai Id cdc lodi quan trpng dl hinh thdnh nen RNM trin nIn dd, cdt ldn manh vun san ho tai VQG Con Dao Khu vuc Hon Bay Canh: Trong 40 dim dd thdng ke dupe 817 cay cho thdy cdc lodi thuc vdt RNM CO edng thiic to thdnh nhu sau: 2,17 Ddng + c Mdi quan higiOa cac loai thuc vat RNM 1,52 Duoc ddi + 1,52 Dd vdi -i-1,3 V?t dii + 0,65 Sii Mdi quan he giOta cdc lodi thuc vdt RNM -(- 0,64 Dude lai + 0,64 Bdng phi -i- 0,33 gid + 0,33 Tra quan xd tai Hon Bay Canh dupe chia 1dm nhom 1dm vo H-0,33Xu di + sau: Nhdm 1: Ddng, Coc vd Mam trdng; nhom 2; Khu vuc Hon Bd: Trong 20 dim da thdng Dude doi Dude lai, V?t dii, Cui va Dung; nhom 3: Da ke dugc 277 cdy cdc loai, cho thay cdc lodi thue vdt vol, Gid vd Xu 6i; nhdm 4: Coc trdng, Su do, Tra ISm RNM cd cdng thiic to thdnh nhu sau: 2,55 Ddng + vo, Bdng phi vd Vudt hiim 1,27 Duoc Ddi -i-1,27 Dung + 1,09 Su + 0,73 Dd voi Moi quan h i giiia cac lodi thuc vat RNM tai hon + 0,55 Vet dii + 0,36 Dude lai -i- 0,36 Cdc -i- 0,18 Vet Bd dugc chia lam nhdm sau: Nhom 1: Dang, D«* hainesii -i- lai Banti-dngva Xu 6i; nhom 2: Du6c doi, Dung.V?' Tir congtiiiieto thdnh cua cdc lodi thuc vat RNM dii Vet till, Da voi, Xu sung, Go bien vd Tra ISm v^; tai Hon Bay Canh vd Hon Ba cho thdy lodi uu thi or nhdm 3: Su do, Coc dd, Vet hainesu, Gia, Xu rumphi 86 NONG NGHIEP VA PHAT TRIEN NONG T H C N - KY - THANG 3/ 12 KHOA HOC d Cac chi tieu sinh trudng cua cac loai d tang cay cao Tdng hgp so lieu dim cac chi tieu sinh trudng C6NG NGH£ ciia 60 tieu chuan dien hinh tai hon Bd va Hon Bay Canh dugc thi hien or bang cang 101i g h p T »cdc chltiei i i s m l itruor igtdngcd^f cao tai Hdn iBdvd H6nl 3dy CaJib T\: Loai cay DKtan (m) D:,3(cm) Hvn (m) Tai Hon Ba TB ; Max TB Max TB Max 13 25,7 2,2 6,5 5,9 12 9,4 22,6 1.8 2,5 5,8 N/ha (cay/ha) DKtan (m) D,3 (cm) Hvn (m) N/ha (cay/ha) Tai Hdn I3ay Canh TB Max TB Max TB Max 495 12,9 27 1.8 5,5 6,2 11 393 195 10,9 30 1.5 6,4 11 298 10,1 15 2,1 2,5 4,7 5 230 8,3 21,6 1,8 3,5 6,3 105 170 9,9 42,9 1.7 4,5 4,3 355 6,1 7.5 11.7 30 1,8 3,5 4,9 80 6,2 65 10 39,1 5,5 5,9 12 175 6,5 10 19 19 3 4 7,6 4 5 14,1 24,8 2,9 5,9 10 53 13,5 32,1 3,3 4,5 48 18,2 34.4 2,4 5,5 4,2 78 55 12 13 2,5 5,5 5 22,2 22.2 1.7 1,5 6 60 38 93,6 2,7 7.5 4,9 25 11 20 17 17 4,8 5,5 5,5 3.5 6,2 25 2,1 2.5 8,3 15 14.9 2 5 12,7 12.7 1.5 1.5 7 8,6 8.6 1 Dang Duoc Doi Coc trang Sii Do 9.4 34 1.4 3,5 4,2 7.2 Da Voi 10,1 17,5 1,2 1.5 5.6 Duoc lai 12.5 19.1 2,5 Vet dii 10.6 15.3 1.4 Coc Do 29,7 69 3,6 Mam TrSng 10 Gia 7.6 7,6 1.2 1.3 5 11 Tra lam vo 7.9 7,9 1 6 12 Bang phi 13 Dimg 14 24.2 1.9 7,6 14 Xuoi 22.9 22,9 2.5 2,5 15 Cui bien 8.9 8,9 1.5 1.5 16 Ban tring 26.8 38,3 3,5 17 Vet hainessi 19.1 26,1 2,1 18 Vet tru 18,2 35,3 19 Xu sung 14.9 20 Xu mmphii 21 Go bien 11 Tong Kit qua d bang cho thay: RNM tai Hon Bay Canh cd chilu cao vut nggn binh qudn ciia rimg Id 5,21 met vd a Hon Bd Id 6,2 I met Dude ddi Ban trdng, Ddng, Gid, Vet dii vd Dung cd chilu cao viit ngpn cao nhat vd thap nhat Id Sii dd vd Coc trang 5 1.375 1.632 Mat dp cay (N/ha) chiim ty le nhilu nhat la Ddng, Dd Vdi Duoc Ddi, Su Dung va Vet Dii cac lodi cdn lai cd mat dp diu nho hon 100 cdy/ha - So sanh rimg ngdp mdn d Cdn Ddo vd cdc RNM khdc d Viet Nam thi chilu cao cua rimg thap hon rat nhilu, dnh huong manh me cua dilu kien hau thiiy vdn vd thi nIn khdc nghiet Duong kinh tai vi tri 1,3 met binh qudn cua i rimg tai Bay Canh Id 8,9 cm vd hon Bd Id 14,3 cm, cdc e Danh gia phan bd cua cac loai cay RNM d cac loai cd dudng kinh lan Id Tra 1dm vo vd Ddng, Ban dieu kien sinh canh khac ti-ang, Cdc do, Duoe lai, Gid vd Dung cdc lodi ed Kit qud ddnh gid cdc ylu td hinh thdnh nen j dudng kinh nho la Su vd Dd vdi RNM tren nIn dd cdt lan manh vun san ho d VQG 'i Duong kinh tan ciia cdy rimg binh qudn tir 1,9 Cdn Ddo vd sd lieu tdng hpp tir 60 d dim dupe den 2,4 met, cdc lodi cd duong kinh tdn lan Id Tra tong hpp d bang 5»ldm vo Bang phi Ban vd Dang J1N6NG NGHIEP VA PHAT TRIEN NONG THON - KY - THANG 3/2012 87 KHOA HOC CbNG N G H £ Bang Tdng hgp sir xudt hiin cdc lodi thyc vdt RNM dyra trin cdc ylu td hinh thdnh Do man dat Dp man nuoc ("/J Tir den < Tir - 16 Tir den < Tir 16 - 25 Tren Tir 25 - 30 Dp ngap trilu Tliap < 50 cm Tir 50-100 cm Tr^n >100cm Tbc^nh phdn lodi thuc vM tren cdc thi nIn khdc Dc-i -1- cAt + san h6 Cdt + san h6 Set + biin Gi.-i, Bang phi, D^ vdi, Xu 6i, Du6c ddi, Ddng, V?t dii, Gi^,V?tdu v^t tru, Coc Dd vdi, Xu 6i Cdc DAng Dung Dude ddi, Dude Dang, Duoc lai Dung, Bdn,V?t lai.Siidd, DAv6ivdV?tdii Dude d6i vd V?t dii Ddng, Dung, Su do, Sii dd, D.ing, Du6c lai vh Dd Khong Du6c lai voi Qua sd lieu d bang cho thdy: + Voi the nIn la set pha biin d cap mdn it va dp ngap trieu thap thi phan lodi thuc vat kha don gian, chii yeu la: Gia, Vet dii va cdc loai cay tham gia vao RNM chiim uu thi Id Ddng, Su dd Dung, Dd vol Vet d va Dude doi b Mat dp, sue khoe, ngudn gdc vatiiSnVQL cay tai sinh cua cay tai sinh Tdng hgp cdc so lieu sinh truong tdi sinh rim + O cap dp ngap tir 50 - 100 cm, dp mdn dat tir - tai hai khu vuc Hon Bay Canh vd Hon Bd dupe th 4°/oo va dp mdn nude tir 16 25V{)o thi su xudt biin bien d bang cdc lodi cd su da dang ban viing tilp giap vdi nui cao Kit qua tong hgp d bang cho thdy: va viing tilp gidp ngodi - Cdy tdi sinh chi cd 14 lodi xudt hien Mdt ca + Tren dang till nen Id dd, cdt ldn vun san ho d miic dp man cao, dp ngdp trilu ldn thi thdnh phan loai chi cd Su dd Dung, Dang, Dude lai vd Da vol chiim uu thi Ddy cdng chinh Id cdc lodi cd kha ndng chiu dung cao vdi dilu kien khdc nghiet Tdi sinh rimg a Tdtiianhloai cay tai sinh - Khu vuc Hon Bay Canh (Bd Dap - Bai Duong) tdi sinh d khu vuc Hdn Bd la 1.295 cdy/ha vd dBa Canh Id 1.978 cdy/ha Trong dd Ddng, Dung co s lugng cdy tdi sinh cao nhat Id tilp theo den Sii Dd vol Dude doi vd Vet tru Ddy la nhiing lodi co ca; tdi sinh chiim uu thi Cdc lodi: Bdn trdng Vet dii Dude lai cd sd lugng cdy tdi sinh it Cdc lodi khdc nhi Tra 1dm vo, Vudt hiim, Mdm trdng, Xu sung, Ve hainesii, Gd biin, Gid, Xu rumphii Cdc khonj thay xuat hien tdi sinh Tir kit qua dilu tra 40 d tdi sinh, thi tap dodn cdy So lupng cdy tdi sinh cd sue khoe chiem ty 1( tai sinh khu vuc Hon Bay Canh gom cd 11 lodi To tren 90% tong sd cdy tdi sinh Cdy tdi sinh cd nguor thdnh loai cay tdi sinh dugc xdc dinh bdi cdng thiic gdc tii hat/tiTj mam chiim tren 70% vd cdtiienvonj sau: 2,4 Vet dii + 2,4 Dd vdi + 1,3 Ddng -i-1,9 Dude ddi sdng cao + 0,5 Xu di -I- 0,4 Dude lai -i- 0,2 Su + 0,2 Cui biin -iChilu cao cdy tdi sinh cua cdc lodi tap bimg c 0,2 Mam biin -i- 0,2 Gid + 0,2 Bdng phi dp cao < m Cdc loai nhu Dung, Sii do, Ddng va Di Khu vuc Hon Bd ^ a m Qudc) voi cd so lupng cay tai sinh dat chilu cao > m Tir kit qua dilu tra 20 tai sinh khu vuc Hon Bd, chiim ty le cao hon cdc lodi khdc; dilu ndy cho thaj thi tap dodn cay tai sinh d day gom cd lodi To day la cac lodi cay tdi sinh co tilm ndng cd the tham gia vdo tdng cdy kl can ciia rimg loai cdy tai sinh dugc xdc dinh boi cong thu'c Cdn eii vdo sd lieu tdi sinh nhdn tiiay: Cac loai sau: Dang + 1,3 Sii -i-1,9 Dung + 1,1 Dd vol -i- 0,8 cdy neu tren diu cd tilm ndng de tao giong phucvu Vet dii -I- 0,6 Duoe lai -t- 0,5 Duoe doi -i- 0,3 Vet ti\i + cho rimg ciia bao gom cdc phuong phdp: nhan 0,3 Ban trang gidng tir tru mam va bung cay tdi sinh dem Qua cong thiic to thdnh cdc lodi cdy tdi sinh tai hai dia dilm nghiin ciiu cho thay, cay tai sinh 88 rimg true tilp Tuy nhien, cdc bien phdp tao gi6 tren can dupe nghien ciru thii nghiem lai NONG NGHIEP VA PHAT TRIEN NONG THON - KY - THANG 3/^^ KHOA HOC C N G N G H I TT Loai 10 11 Dang Duoc doi Sii Duoc lai Da voi Dung Vet tru Ban trang Vet dii Xu 6i Cui bien Mam 12 bien 13 Gia 14 Bang phi Bang Tong hgp cdc chi tieu tdi sinh rimg tai Hdn Bdy Canh vd Hdn Bd Tai Hon Bay Canh Tai Hon Ba N Tai sinh Cay CoTr Cay Tai sinh Uu N (cay/ha) CTr.mam) khoe vpng khoe (Tr.mam) (cay/ha) tien 753 748 448 728 160 170 170 156 150 88 153 30 30 30 16 15 15 240 245 230 233 33 28 33 15 25 636 635 310 442 160 155 155 0 0 485 485 485 160 160 160 5 15 15 15 23 23 23 23 3 25 3 1.978 CoTr vpng 170 30 245 25 160 485 160 15 Uu tien 11 10 0 14 3 3 13 12 IV KET LUAN V A K e i NGHI l.Kltludn Tdng dien tich rimg ngdp man tai VQG Con Dao gom 32 ha, phdn bd tai 12 bdi tram tich ven biin thupc hon ddo chinh Id Hon Con Son, Hon Bd va Hdn Bdy Canh Thuc vdt tiidn gd RNM tai VQG Con Ddo cd tong cdng 46 lodi, dd cd 28 lodi ngdp man thuc su vd 18 lodi tham gia vdo RNM Rieng d khu vuc Hon Bay Canh vd Hon Bd khd da dang cd 21 lodi thupc 10 hp khdc vdi mat dp dao dpng khoang tii 2.000 din 3.000 cdy/ha Trong dd cdc lodi uu till Id: Ddng, Duoe doi Dung, Dd voi Vet dii, Su vd Duoe lai Rimg ngdp man a Con Dao chiu anh hudng ciia nhdm nhdn td hinh thdnh nhung cdc ylu to tdc dpng chinh Id: (1) Ylu td dia hinh dia mao dupe che chan cdc vinh; (2) ddc diem ciia till nen Id dd, cat ldn manh vun san ho Id nhimg bdi tram tich ven biin ldi thoai, ed ba bien nong vd tinh chat ca ly hda cua dat diu Id gidi ban tdi thilu d l cdy rimg phat tiien dupe; (3) dong hdi luu Id nhdn td chinh mang lai su phong phii vd da dang cdc lodi thuc vdt; (4) tiiuy tiilu ngdp tiidp, sdng bien vd dp mdn nuoc biin ndm ti-ong pham vi thich ling eua nhilu lodi cdy RNM Ngodi dilu kien hdu ndng am, bien dp dao dpng nhiet tiiap vd lugng mua nhilu cung Id cdc ylu to tiiudn igi tao dilu kien cho cay RNM sinh trudng va phdt trien 1.295 To thdnh loai cay tai sinh tap trung chu yeu vao hp Dude, mot so loai khong thay xuat hien cay tai sinh Cac loai cay tai sinh chiim uu the c6 mat dp tai sinh cao Id: Dung, Su dd, Ddng Da voi, Duoc lai, Duoc doi vd Vet dii Mat dp cdy tdi sinh tren ca hai dia diem nghien ciiu khoang tir 1.200 - 1.900 cdy/ha Nguon gdc cdy tdi sinh chu yeu tir tru mam Sire khoe cdy tai sinh vd trien vpng cay tai sinh chiem ty le cao - Cdc lodi uu thi co trien vpng dupe de xuat md rpng gdy bao gom lodi: Duoc doi, Dung Ddng, Duoc lai Da Voi va Su Do Cac lodi diu cd tilm ndng tao gidng de rimg vd cd thi thuc hien bdng phuong phdp Id: (1) Thu hdi tru mam vd rimg true tilp; (2) san xuat cdy giong bii bau; (3) biing cay tdi sinh ti-ong rimg true tilp Kiln nghi Can nghien ciiu tilp dl dua vdo thir nghiem cdc lodi cd triln vpng tren hien trudng nIn dat cdt lan vo sd vd manh vun san ho tai VQG Con Dao nhdm kilm chiing vd hodn thien hon hudng ddn ky thudt rimg cho viing sinh thdi dac thii ndy Kit qua se 1dm ca sd nhdn rpng cac viing biin ddo cd dilu kien tuong tu TAI UEU THAM KHAO Nguyin Chi Thdnh, Le Xuan Ai, Le Xuan Canh, Tran Hgp, Nguyin Ngpc Kieng, Nguyin Dire NONG NGHIEP VA PHAT TRIEN NONG THON - KY THANG 3/2012 89 KHOA HOC C N G NGHl Ngdn, 2004 Tai nguyen ddng, thirc vat Vuim ()iidc gia Cdn Dao Nha xuat ban Ndng nghiep, trang 35; trang 233 - 268 Luong van Tai 2007 Nghien cim a\u tnic rimg ngap m^i tir nhien dhdn Bav Canh Vuon Qudc gia Cdn Dao, tinh Ba Ria - Viing Tau Ludn van lot nghiep ky su lam nghiip Dai hgc Ndng 1/ini Ihanb Hd Chi Minh Vict Nam ti-ang 2 - Phdn bd thuc v$t rimg ng$p mdn tai Vudn Qudc gi Cdn DAo, tinh B^ Ria - Vung Tau (Trong cuon phu hdi rimg ngdp mdn img phd vdi biin ddi khi, ^irdng tdi phdt triln bin vung Phan Nguyfe "^'"S- ^K'uyln Thj Kim Cue vd Vu Thuc Hiin bifi] «"^"- ^hd xudt ban Ndng nghiip trang 21 - 331) Wim Ciiesen, Stephan Wulffraat, Max Zierei and Licsbeth Scholten, July 2007 Mangrov Phan Nguyen Hdng 2003 Phinmg ph.ip dieu tia rimg ngap man Nha xuat ban Klioa hgc Ky thuat, trang 27-30 guidebook for Soutiieast Asia FAO and Wetiandi International (page 685 - 722) ^ ^^^^^ y^ ^^^^^^^ ^^ Amalyos C, anc Tran Dinh Hue 2008 Nghien ciiu da dang tiiiic vat tiian gd rimg ngap man till Vmm Qudc gia Cdn Dao, tinh Ba Ria Viing Tau Luan van tdt nghiep thac sy lam hoc Dai hoc Ndng l^^m Hd Chi Minh shigeyuki B., 1997 Handbook of Mangroves ii /,,^^^^,,^, -phe Development of Sustainabk Vien Ngoc Nam va Tran Dinh Hue 2007 Mangroves Management Project Forestry Indonesia and Japan Cooperation Agency (119 pages) Ministry o: International THE STUDY OF GENECOLOGY OF MANGROVE ON THE GROUND OF CORAL SAND IN CON DAO NATIONAL PARK AS THE BASE FOR EXTENDING MANGROVE PLANTATION Kieu Tuan Dat, Pham The Dung, Hoang Van Thoi Summary Total area of mangroves at Con Dao National Park is of 32 encompasses 12 sediment sea-swamps in the coast of three islands, those are Con Son, Hon Ba and Hon Bay Canh There are in the mangroves of Con Dao National Park 46 woody plant species, including 28 true mangrove species and 18 subordinate ones The four edaphic factors exert influences on mangroves of Con Dao Island, amongst which the main are: (1) topographic and landscape factors of tbe gulf, which has protecting impacts on the island; (2) the underlying rocks consist mainly of limestone and sand mixed with broken coral, forming tbe sediment seaswamps with the shallow and slopping bank The soils of the swamps are river-bome clays with the physical properties and chemical composition responding to tbe least requirements for the growing of mangrove vegetation; (3) tbe sea current is the main factor that brings about the abundance with biodiversity; (4) the low tidal amplitude, sea waves and salinity are in the range of tbe tolerance of many tree species of mangrove vegetation In addition to tbe tropical climate, the low amplitude of temperature variation as well as high precipitation is also the favorite conditions for tbe development of mangroves in Con Dao National Park The prominent species proposed for extending the mangrove plantations are: Rhizophora apiculata, Rhizophora stylosa, Rhizophora mucronata, hybrid Rhizophora, Ceriops tagal, Aegiceras comiculatum Keywords: Con Dao National Park, mangrove, edaphic factors, promising species Ngudi phan biin: TS Trdn Quang Bao 90 NONG NGHIEP VA PHAT TRIEN NONG THON - KY - THANG 3/2012 ... igdp man tai Vudn Quoc gia Con Ddo tai 12 khu vuc khdc nhau, cd tong dito - Dilu tra ti mi: Su dung phuong phdp dilu tra tich Id 32 tdp trung a bon dao ldn Id Hon Con diln hinh, dai dien d cdc trang... Thue vdt rimg ngap mdn tai Vuon Quoc gia vd tdc dpng neotectonic, dd yeu to dia mao Con Ddo cd tong cOng 46 lodi, dd cd 28 lodi cdy dupe coi Id quan trpng nhat hinh thdnh nen RNM RNM ngap mdn thuc... cd ylu to chinh; dl gia vdo RNM thupc 13 hp Hp cd nhilu lodi nhat nghi ndy da dupe Chapman (1977) bd sung them khu vue Id hp Dude vdi lodi, hp Bdng lodi, yeu to niia thdnh ylu td Bdy yeu to ndy