Rung ngap man a Con Dao chiu anh buong ciia 4 nhom nhSn td hinh thanh, nhung cac yeu to tac dpng chinh la: 1 Ylu to dia hinh dia mao duoc che cbSn trong cac vinh; 2 dac dilm cua thi nin
Trang 1KHOA HOC C 6 N G N G H £
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
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 3
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, trong do co 28 loai ngfip man thuc su va 18 loai tham gia vko RNM Rung ngap man a
Con Dao chiu anh buong ciia 4 nhom nhSn td hinh thanh, nhung cac yeu to tac dpng chinh la: (1) Ylu to
dia hinh dia mao duoc che cbSn trong 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 do man nuoc biin nSm trong pham vi thich ling cua
nhilu loai cliy RNM Ngoai ra dilu kien khi 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 trong bao gom 6 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
Vudn Qudc gia Cdn Dao la mot quan dao nam
tren viing bien phia Ddng Nam cua nude ta, gom 14
hon dao cd quy mo dien tu nhien 19.990,7 ha, bao
gom: 5.990,7 ha rimg nui ciia 14 dao thupc quan dao
Con Dao va 14.000 ha mat bien Vudn Quoc gia Con
Dao cd tinh da dang sinh hoc cao vdi nhieu he sinh
tiiai dac trung va nhieu loai sinh vat quy, hiem, d$c
hiiu Cd 2 kieu rung chinh phan bd tai day la kieu
rung kin thuong xanh mua am nhiet ddi va kieu rimg
kin nua rung la mua am nhiet ddi Cd cac he sinh thai
chinh: he sinh thai rung tren vung doi mii thap; he
sinh thai rung tren doi cat va bai cat khd, ban ven
bien; he sinh thai RNM va he sinh thai rung ngap
phen Nhimg he sinh thai nay duoc phan bd k^ tuc
nhau tren mot khong gian nho hep tai Con Dao Day
la mot net doc dao, co y nghia vk m$t tu nhien, diln
the va khoa hoc Tham thuc vat ciia VQG Cdn Dao v^
CO ban vtn mang nhung dac di^m dac trung v^ cau
tnic tang thii, ngoai mao va canh quan cua h$ sinh
thai rung tu nhien nhiet ddi, hai dao Rung ciia Vudn
Qudc gia Con Dao co thanh phan thuc vat phong phii
va da dang voi tren 1.077 loai thuc vat bSc cao va 135
loai dong vat cd xuong sdng da dupe dinh danh
(Nguyen Chi Thanh va ctv, 2004) Bifo Vudn Quoc
gia Cdn Dao cd 3 he sinh thai dien hinh cua vung bien nhiet ddi vdi hon 1.300 loai sinh vat da duoc thdng ke va dinh danh
Trong nhimg nam qua, Vudn Qudc gia Con Dao
da nd luc phdi hpp vdi cac to chiic khoa hoc, bao ton
de nghien ciiu cac he sinh thai rung, cac he sinh thai bien va san ho Nhung rieng ve nghien ciiu he sinh thai rung ngap man va cac he sinh thai ven bd bien chua dupe thuc hien mpt each day du Gan day, cac
nha khoa hpc da phat hien b day cd mpt kieu rimg
ngap man nguyen sinh phan bd tren nen dat cat iSn soi va manh vun san ho, trong dd cd nhiing loai thuc vat quy hi^m cd trong sach do Viet Nam Kieu rung ngap man nay chua thay dupe de cap trong cac tai
lieu nghien ciiu vi rung ngap man da dupe cong bo b
Viet Nam Khac vdi cac RNM khac or Viet Nam
thudng phan bo tren dien tich nin dat biin lang dpng,
nhung rimg ngap man nguyen sinh tai Con Dao la mpt ki^u dac thii phan bo tren th^ n^n la da, cat ISn manh vun san hd hau nhu chua dupe quan tam nghien ciiu mpt cdch d^y dii Vi vay, viec dieu tra cac y^u td hinh thanh len rung ngap man tren nen dat cat san ho tai VQG Con Dao, lam co so de xuat ky tiiuat
ma rpng gay trong that su can tiiiet va cd y nghia rat ldn ddi vdi thuc tien dat ra hien nay
Phan vien NC KHLN Nam Bp
Trang 2K H O A H O C C 6 N G N G H £
u NOI DUNG VA PHUONG PHAP NGHIEN ciiu
1 Muc tieu d^ tM
Thu thap nhimg sd lieu va tiiong tin nham xdc
dinh cac y^u to hinh tiianh len rimg ng$p man
tinh ch^t nude vd cdc y^u td ngoai canh tdc dpng « Phuong phdp phdn tich xii ly sd lieu n6 nghiep
Sir dyng cdc phin m^m di tinh todn va xu ly sc
nguyen sinh tren n^n cdt lan soi vd manh vun san hd li^u g6m: Primer VI, Excel vd Maplnfo
a hon Bay Canh va hon Bd tiiupc Vudn Quoc gia Cdn
Dao, tii do lam co sd di xuat nhimg lodi co tri^n vpng
de md rpng gay trong rimg d^ nhiing noi cd di^u kien
lap dia tuong tu
2 NOi dung nghien ciiu
Dilu tra su phdn bd cOia kilu rimg ngdp mdn
nguyen sinh tren nIn cdt ldn soi vd manh vun san hd
b hon Bay Canh vd 13 hdn ddo khdc cua VQG Cdn
Dao
Dieu tra ddnh gid.cdc ddc dilm 1dm sinh hpc
ciia kilu rimg ngap mdn tren nIn cdt soi vd vun san
hd d hon Bay Canh vd hon Bd
- Dl xuat cdc lodi cd triln vpng dl md rOng gdy
trong
3 Phuong phdp thuc hien
Thu thdp cdc tdi Ueu vd thong tin lien quan:
bao gom ban do cdc loai, dieu kien tu nhien, dat dai,
che dp ngap trilu, che dp gid, tham thuc vat vd cdc
nghien ciiu cd lien quan
- Phuong phdp dilu tra thuc dia
Khao sdt so bp todn bp 14 hdn ddo vd dilu tra
tuyen diln hinh dl xdc dinh phan bo cCia trang thdi
rimg ngap mdn tren nIn dat cdt ldn soi vd mdnh vun
sanhd
Xdc djnh lodi chiim uu thi thdng qua chi so quai trpng (IVI%) aia m6i lodi dupe tinh bang cdng tiiiirc cuj Mishra (1968): IVI % = (RD% + RF% + RBA%)/3 Xdc djnh td thdnh lodi thdng qua xdc dinh t^ xudt brong ddi (RI),%)
Phdn tich hpp phdn chinh PCA (Principal Component Analysis) dl xdc dinh mdi quan he ciia cdc lodi RNM trong qudn xa
- Phdn tich miu dS't va nude: Mau ddt gom 10 chi tiiu 0)0 mdn, pH Al*^ Fe*^ ^0^\ Ca*^^ U^\ N, Pva
thdnh phdn ca gidi) Mdu nude gom cdc chi tieu: pH,
do mdn, dO due, Al*^ Fe*l
Lua chpn lodi di xudt ma rpng gdy trong: Lira
chpn lodi dua tren s6 lieu ddnh gid vl sinh truong, tai sinh, cdc chi tieu cud quan xd thuc vat vl lodi uu th^ (rVI%) vd dua tren sd lieu dilu tra quan sdt vl vat hau ciia cdc lodi
H-KETQUAvAniAOLUAN
1 Phdn bd vd thdnh phdn lodi ciia rimg ngSp
m ^ tai VQG Cdn Dao
a Phan bdcua rimg ngap m$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 6 dilu tra tich Id 32 ha tdp trung a 3 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 6 tieu chudn diln hinh di diin tich khong ldn, khu vuc ldn nhat cd dien tich 6
ddnh gid cdc ddc diem lam sinh hpc ciia RNM, dilu ha vd khu vuc nho nhat co dien tich 0,2 ha, cu the kien lap dia, dat dai, dia hinh dia mao, dp ngap trilu, dupe thi hien qua bang 1
Bdng 1 V| tri phdn bd ciia RNM t<u VQG Cdn Bdo Viti-i
HonBd
Bay Canh
Con Son
Ten bai Vinh Dam Quoc Vinh Dam The Bai Cat ldn Bai Bd Dap Bdi Duong Vinh Dam Tre
Dien tich (ha)
06
02
01
05 2,3 4.5
Vjtii
Con Son
Tong cOiig
Ten bai Bdi Ddm Trau Hpng Dam Bai 6ng Dung Bai Dat Thdm Bai Ong Cdu Bai Ong Cudng
12 bai
Dien tich (ha)
05
05 0,4 ' 0,3 : 0,3 • 0,2
32 ha
li^
Trang 3KHOA HOC CdNG N G H £
BAN D 6 PHAN B 6 RL/NG NGAP M^N
V l ( l N y l ' ( V (.lA r«'lN IXVn-TlNHUA R|A VON<!T^U /-w~-> - — BAH D 6 PHAN B 6 CAC LOAI CAV od RL/NO NOAP MAN
C 6 TRONG OACH D 6 V I $ T NAM TAI
y-^.^-^'.^.-Vl'ON(J(l')('<:iA rVtNDAO-TlNII HA.KtA VCNfi fAU ^,.— \
" • ^
-Hinh 1 Ban dd phdn bO
b Su da dang thanh phan loai cua RNM
Theo Dd Dmh Sam (2005) a Viet Nam cd 37 lodi
cay ngap mdn tiiuc su vd 72 cay tham gia ngap mdn
Tir kit qud dilu tra khdo sdt tren 14 hon dao, kit qua
ghi nhdn tren cdc tuyen dilu tra vd trong cdc 6 do
dim dien hinh cho thay:
+ Thue vdt rimg ngap mdn tai Vuon Quoc gia
Con Ddo cd tong cOng 46 lodi, trong dd cd 28 lodi cdy
RNM ngap mdn thuc su thupc 14 hp vd 18 lodi tham
gia vdo RNM thupc 13 hp Hp cd nhilu lodi nhat
trong khu vue Id hp Dude vdi 9 lodi, hp Bdng 3 lodi,
hp Ddu 3 lodi, cdc hp con lai cd tir 1 - 2 lodi Nhu vdy,
cay rimg ngap mdn thue su b Vuon Qudc gia Con
Ddo chiem 78% tdng so cay RNM thuc su b Viet Nam
vd cdy tham gia RNM a ddy chiim 26% tong so cdy
tham gia RNM b Viet Nam
+ Cdc lodi ddng vai tro quan trpng chiim uu the
Id Sii do Vet dii, Dd voi Dung vd Duoc doi Tong chi
sd IVI ciia 5 lodi ndy Id 63%, 19 lodi con lai Id Vet den
Ban trang, Bdng phi, Cdc do, Cdc trdng, Cui, Ddng,
Dude lai, Gid, Gd bien Mam bien Mam trdng, Mudp
xac hudng, Quao nude, Tra 1dm vo Vet hainesii Vet
tru, Xu 6i, Xu sung cd tdng chi so IVI thap
+ Lodi mdi phdt hien gom 2 lodi Id: Vet hainesii
(Bruguiera hainesii C.G Rogers) va Xu rumphii
(Xylocarpus rumphii (Kostel) Mabb); ddy Id 2 lodi
dupe phdt hien dau tien tai Viet Nam a VQG Con
Dao vd diu Id 2 lodi cdy gd ngap mdn thuc su
+ Lodi hiem gdp vd it phdn bo tai Viet Nam duoc
phat hien d Cdn Ddo Id Bang phi (Pemphis acidulaj
R Forst & G Forst) va Dude lai (Rhizophora x
lamarckii GiS)
+ Lodi cd trong sdch do Viet Nam Id: Duoc doi
(Rhizophora apiculata Blume), Cdc do (Lumnitzera
littorea (Jack) Voigt) va Quao nude (Doh'chandrone
spathacea (L.)KSch) Cdc lodi ndy hien dang cd
nguy ca tuyet chiing or Viet Nam, tai VQG C6n Dao
cd phdn bo nhung sd lupng cd thi khong nhilu
RNM ciia VQG C6n Ddo
2 Ddc dilm cdc ylu td hinh thdnh riing ngdp mdn
Theo Jenning and Bird ndm 1967 va nhilu tdc gid khdc nghien ciiu thi RNM hinh thdnh vd ton tai dupe phu thudc vdo 6 nhdm nhdn td chinh Id: su kho ban, ndng lupng sdng, thiiy trilu, tram tich, khoang
vd tdc dpng neotectonic, trong dd yeu to dia mao dupe coi Id quan trpng nhat hinh thdnh nen RNM Cdn Wash (1974) lai cho rdng cd 5 ylu to chinh; dl nghi ndy da dupe Chapman (1977) bd sung them 2 yeu to niia thdnh 7 ylu td Bdy yeu to ndy khd gidng vdi 6 nhdn to md Jenning vd Bird dl xuat ndm 1967 Bdy nhdn to Id: nhiet dp khdng khi, nIn biin, su che chdn, nude mdn, bien dp trilu, cdc dong hai luu vd bd bien ndng
Ddc thii cua RNM Con Dao dupe hinh thdnh tong hoa ciia 4 nhdm nhdn to chinh Id: (1) vi tri dia
ly, dia hinh dia mao; (2) dilu kien khi hdu; (3) dilu kien thiiy vdn; vd (4) ddc diem vl dat dai thi nIn
a Vi tri dia ly va dia hinh, dia mao
RNM Con Ddo phdn bd tai nhiing bdi tram tich chay ddi ven biin cd dia hinh dupe che chdn; ddy Id
yeu to rat quan trpng, di giir cdc hat gidng, tru mam,
cdy con khoi bi sdng, gid, nen han chi dupe nhirng anh hudng true tiep ciia sdng biin vd ngdn tdc dpng ciia gid chudng Ylu td dia hinh dia mao d ddy Id nhdn to quan trpng nhat hinh thdnh nen RNM ddc thii tai Con Ddo Dilu ndy ciing phii hpp vdi nhdn dinh ciia Chapman, naml977 cho rdng: nude cdng ndng, ba thoai thodi thi RNM cdng dupe md rOng vd a vimg biin nong nhung hep thi RNM chi hinh tiianh mOt dai hep ven mep nude
b Dieu kiin khi hau + Nhiit dp: VQG Con Ddo ndm trong viing khi
hdu nhiet doi gid mua, cd 2 miia kho vd mua rd ret
Do xung quanh Id bien nen chiu dnh hudng cua khi hdu dai duong nen chi dp khi hdu cua Con Dao on hoa hdn so vdi dat bin Nhiet dp trung binh nam
Trang 4KHOA HQC CONG NGHE
27,3''C, tiiang cd nhiet dp binh qudn cao nhdt 28,8°C
(thang 5), tiidng cd nhiet do binh qudn tiidp nhdt
25,4^C (tiiang 1), bien dp nhiet giira tiidng lanh vd
thdng ndng nhat Id 3"C
+ Dp am: Dp am khong khi trung binh ndm Id
80,7%, bien dp biin tiiien ciia dO ^ khong khi ti-ong
ndm khoang 5% Thdng cd dd am cao nhdt vdo tiidng
10 (83,4%) vd dp am tiidp nhdt vdo thdng 12 (78,4%)
+ Chd dp gid: Cdn Dao cd hai hudng gid chinh:
miia mua la gio Tay, miia kho Id gid Tdy Bdc, Dong
-Bdc vdi cuong dp cap 6, cdp 7 Toe dO gid ldn nhdt
trung binh cua cd ndm Id 17 m/s, tdc dp gid cd su
chenh lech rat ldn: thdp nhat Id 6 m/s vd cao nhdt Id
26 m/s Tdc dp gid manh nhdt tdp trung vdo tiidng 6
- 8 vd miia gid chudng tir thdng 11- thdng 1 ndm sau
+ Lupng mua: Lxiqng mua trung binh ndm Id 2.200
mm, so ngdy mua trung binh ndm 166 ngdy, tiidng cd
lupng mua cao nhat (thdng 10) Id 348 mm Chi dp
mua phdn thdnh 2 miia, miia mua tij tiidng 5 din
tiidng 11, miia khd tir thdng 12 den tiidng 4 ndm sau
c Chd dp thuy v^
+ Che dp ngap triSu: Bien dp trilu cd tdc dOng
len str phong phu, cau tnic vd su phdn bd cOia cdc
quan xa RNM Che dO thiiy trilu vimg biin Cdn Dao
tiiupc loai trilu hon hpp thien vl bdn nhdt trilu
khdng diu Vdi muc nuoc trilu cao nhat 3,5 - 4,0 m,
thap nhat 0,5 m; biin dOng bien dp trilu tir 2,5 - 3,5
m Bien dp trilu rpng, di ddi vdi dia hinh khu vuc dd
tao dilu kien cho RNM phdt triln theo bl rOng vd
thdnh phan lodi cdy RNM phong phu Cdn Ddo cd
cdc ddc dilm vl dilu kien thuy trilu or cdc vinh, khd
thich hpp cho su ton tai vd phdt triln ciia cdy RNM
(tiieo sd ueu ti-ong 5 ndm tir 2003 - 2007)
+ Sdng biSn: Hudng vd dO cao sdng phu thuOc
vdo gid miia Gid Dong - Bdc sdng thinh hdnh vdi tan
xuat dat 60%, dp cao trung binh tir 0,3 -1,5 m Dong
chay chu ylu chiu chi phdi ciia dong trilu, tuy nhien
gid cd tdc dpng ddng kl lam thay doi dong chay bl
mat a viing biin VI miia Ddng, ddng chay cd hudng
Ddng Bdc - Tay Nam trung binh tir 0,7-1,5 m/s, ddng
chay ven ddo phu thudc chii ylu vdo dia hinh bdr dao
vd hinh d^ing cdc dao Sdng biin or ddy cd anh hudng rdt ldn din RNM, ddc biOt Id trong miia qua chin sdng biin manh 1dm cudn troi trdi vd tru mam nfen tdc dOng tieu cue din khd ndng gieo gidng ciia cay RNM vd 1dm dnh hudng din chdt lupng cua cay tai sinh
+ Ddng hid luu: Ddng hdi luu Id nhdn td chinh
giup phdt tdn qud, tru mdm vd hat dpc theo cdc viing ven biin Trong khi dd, Cdn Ddo Id dilm giao luu ciia cdc ddng hai luu tir An DO Duong qua Indonesia va Malaysia, kit hpp vdi gid miia Tdy Nam vdo thang 4 din thdng 10, (ung trimg vdi miia chin ciia qua va tru mdm cua cdc lodi cdy RNM Do vdy, ddy Id nhan to quan trpng dl viing vinh cdc dao tilp nhdn cac vjit liiu phdt tdn nhu qud, hat vd tru mdm tir cdc viing cua sdng ven biin tir Indonesia, Malaysia, Thdi Lan
vd cd dai ven biin Nam bO- Ddy Id nguyen nh^n chinh hinh thdnh su da dang vl qudn hj lodi ciia RNM tai Co.! Dao VI khia canh khdc, thong qua cac 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 ddy dd cd cdc biin dj vl kilu hinh theo huong tdng khd ndng chong lai gid to, sdng ldn vd nIn da, cat ngheo dinh dudng, Thdng qua su phdt triln ciia he
rl theo hudng trdi rOng, phdt triln nhilu cdnh, than ndm ngang vd giam dO cao cua thdn dl thich ling voi dieu kien tu nhien vd ddy Id ylu to ca ban tao ra RNM hien nay cCa Con Dao
+ Nude bien: Theo so lieu thuy vdn ciia tram khi
tupng Con Ddo trong 5 ndm gan ddy thi dp mdn cua nude biin tai Con Ddo trung binh Id 32,6^/oo, cao nhat Id 33,8°/oo vd thap nhat Id 28,3Voo, ^dy Id nguong thich hpp cho nhilu lodi cay chiu mdn bdt buoc Ngodi ra, RNM a cdc bdi trdm tich ven bien tai cac vjnh or Con Dao cd dilu kien tilp nhdn nude ngot tir tren cdc viing mii cao ven bdr da 1dm cho do man nude biin giam, tao dilu ki^n cho cdc lodi co kha ndng chiu mdn thdp vd nhiing lodi tham gia vdo RNM sinh trudng vd phdt triln Kit qua phdn tich vl mot
sd tinh chat cua nude biin dudi tan RNM dupe the hien qua bang 2
Bdng 2
Vi tri lay mau
Chi tieu
pH (H,0)
Do mdn
S O /
Fe
%0
mg/1
%
Turn chat cua nuoc bien tai 2 diem nghic
Hon Bay Canh Tilp gidp
mii 6,82 8,0 36,0 0,41
Dudi tdn rimg 7,27 25,0 2753,0 0,22
Tilp gidp ngodi 8,46 28,0 2053,0 0,11
^ncuu Oaykhi
Tiep gidp mil 6,94 16,0 785,0 0,33
thiiy trieu nit, HonBd Dudi tdn rimg 7,46 27,0 2255,0 0,27
1
Tiep giap ngoai 8,31 _ 28,0 _ 2393,0 _ 0,24 _
Trang 5KHOA HOC C 6 N G N G H £
Qua ket qua d- bang 2 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 8 - 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
Lupng SO42 trong nuoc deu rat cao do RNM
nguyen sinh d day da hdng ti-dm nam tiioi co lop
tham muc dugc phdn buy manh duoi tan rimg lai bi
anh hudng cua nguon nude mdn vd ngdp trieu d muc
thap den trung binh nen trong trang thdi yem khi do
vdy chung chiia nhieu gdc luu huynh
d Dat dai thdnhuong
+ Dac diem nen dat RNM Con Dao dugc hinh
Bang 3 Tinh chdt ca ly hda ciia
thanh tren nen dia chat tram tich ven cac dao dugc tao thanh 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 thanh 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- 3 hon dao chinh Id Hon Con Son, Hon Ba va Hon Bay Canh Viing trilu dugc tao thanh boi cat nho, dd lan va manh vun san ho The
nen b Con Dao khong ndm trong phan chia 5 dang lap
dia cua RNM tai Viet Nam gom: Biin loang, biin chat, set mIm, set chat va dat rdn (theo Dang Cong Buu, 2005) Dat tai cdc khu vuc co dien ti'ch RNM gom 2 dang chu yeu la: Da + Cat + San ho chet vd nen cat + vun san ho chiem tdi 97,5% Cac dang the nIn cd RNM tai Con Dao rat ddc thii vd dpc dao d Viet Nam Tinh chat ciia dat dugc the hien qua bang 3
ddt tai Hdn Bay Canh vd Hdn Bd
Vitri
Chi tieu
pH (H,0)
pH (KCl)
Do man
N ts
P , 0 ^ t s
K,0_ts
Fe^^
SO/-Ca2*
Mg2^
* Thanh
' phan ca
• g i o i (%)
Set
Thit
Cat
ay mSu
D.V.T
% 0
%
%
%
mg/lOOg mg/lOOg meq/lOOg meq/lOOg
< 0,002 mm 0,002 -0,02 mm
> 0,02 mm
Hon Bay Canh (Bai Ba Dap) Diem tiep giap
trong Tangc 0-10 6.64 5,54 1,00 0,34 0,04 0,07 120,39 31,00 4,50 7,25 32,74 25,46 41,80
at, cm 30-50 7,95 7,15 2,00 0,17 0,03 0,22 68,27 252.00 3,00 4,50 18,53 16.09 65.38
Diem giOra RNM Tang c 0-10 6.56 6.04 2.00 0.10 0,01 0,15 205,01 92,00 1,50 3,25 16.00 9.55 74.45
at, cm 30-50 8.01 7.24 4.00 0.07 0.01 0.12 65,51 117,00 2,00 3,50 12,56 11,01 76,43
Di^m tiep giap ngoai Tangc 0-10 7,37 7,12 4,00 0,03 0,01 0,07 151,76 194,00 2,25 4.25 16,00 7.64 76,36
at, cm 30-50 7,87 7,26 4,00 0,06 0,03 0.11 327,82 246,00 3,50 6,50 16,00 14,88 69,12
Hon Ba (Dam Quoc) Diem ti^p giap
trong Tangc 0-10 6,65 6,19 2.00 0.14 0.01 0.06 130,37 293,00 3,75 7,25 14,58 15,27 70,15
at, cm 30-50 5,98 5,54 4,00 0,11 0,01 0,06 204,51 300,00 4,00 7.75 16.00 7.18 76.82
Di^m giua RNM Tangc 0-10 7.97 7.12 4,00 0,15 0,06 0,41 49,83 271,00 3,25 4,35 24,00 20.44 55.56
at cm 30-50 8.08 7.20 5,00 0,10 0,03 0,20 46,27 146,00 1,50 4,50 8,26 6.05 85.69
Diem tiep giap ngoai Tang dat, cm 0-10
8.26 7.62 4.00 0,06 0,02 0,09 40,57 74,00 1,25 2,50 6,18 6,57 87,25
30-50 7,89 6,90 5,00 0,11 0,02 0.11 28,45 109.00 4.00 7.50 20,00 13,72 66.28
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 do tinh chat cua dat vd thanh
' phan ca gidi nhilu soi da vd san ho it phong hda md
• nia troi nhilu do c h i dO ngdp trilu Ham lupng Ca^*,
' Mg2% ^Ot diu cao tir (1,5-7,5 meq/lOOg) do tinh
chat ciia dat man Do qua trinh phong hda cua san ho
, vd tinh chat cua dat man trong dilu kien yem khi 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 6 32%, tiiit
j; chiim 6 - 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 nay ciing phii hgp vdi ddnh gid ciia Ldng Vdn King, ndm 1997
3 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, trong 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, trong dd 17 lodi ngap man thuc su va
Trang 6KHOA HQC CbNG N G H £
01 loai tham gia vao RNM Trong tdng sd 10 hp tbi cd mdt dO cd thi cao nhdt Sd lieu tdng hgp dupe th
hg Dude cd so loai cao nhat la 08 loai, day cung la hp hien b hang 4
TT
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
Bang 4 Tdng hgp tiidnh phdn lo^
Loai
Dang
Duoc doi
Coc Tning
Cui bien
Su do
Da voi
Duoc lai
Vetdu
Coc do
Dung
Vet hainesii
Ban trSng
Vet tru
Go bien
Tra lam vo
Gia-B4ngphi
Xu sung
Xuoi
Vudt hiim
Xu mmphii
Ten khoa hoc
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) 0 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
dciiaR N M t ^ hdnBd vdhdn
HdnBd RD%
36,80 13,75 0,37 15.61 4.46 4,09 4.83 1,49 12,64 1,86 0,74 1.12 0,37 0,37 0,37
0.37 0,37
0,37
100
RF%
25,45 12,73 1,82 10,91 7,27 3,64 5,45 3,64 12,73 1,82 1,82 1,82 1,82 1.82 1.82
1,82 1,82
1,82
100
RBA%
37,10 7,64 0,18 9,01 2,71 5,64 3,24 7,82 14,78 4,04 3,19 2,20 0,16 0,14 0.13
0,36 1,16
0,49
100
IVI
33,12 11,37 0,79 11,85 4,82 4.45 4.51 4.32 13,38 2,58 1,92
1.71
0,78 0.78 0.78
0.85 1.12
0,89
100
BdyCj inh
Bay canh RD%
24,38 18,52 0.31 0,15 6,33 22,07 4,78 10,80 0,15 0,15
3,40 2.78 4.32
1.54 0,15
100
RF%
21,74 15,22 2,17 1,09 6.52 15,22 5,43 13,04 1.09 1,09
3.26 3,26 5,43
3,26 1,09
100
RBA%
27,42 14,84 0.31 0.52 3.04 14.60 4,60 0.07 0.01 0.30
3,63 4.38 10,77
15.15 0.30
100
IVI 24,5] le.ij 0,93 0,59 5.30 17.30 4.94 7.97 0.42 0,51
3,43 3,47 6,84
6,65 0,51
100
b Cdng thuc td thanh
Khu vuc Hon Bay Canh: Trong 40 6 do dim dd
thdng ke dupe 817 cay cho thdy cdc lodi thuc vdt
RNM CO edng thiic to thdnh nhu sau: 2,17 Ddng +
1,52 Duoc ddi + 1,52 Dd vdi -i-1,3 V?t dii + 0,65 Sii do
-(- 0,64 Dude lai + 0,64 Bdng phi -i- 0,33 gid + 0,33 Tra
1dm vo H-0,33Xu di +
Khu vuc Hon Bd: Trong 20 6 do dim da thdng
ke dugc 277 cdy cdc loai, cho thay cdc lodi thue vdt
RNM cd cdng thiic to thdnh nhu sau: 2,55 Ddng +
1,27 Duoc Ddi -i-1,27 Dung + 1,09 Su do + 0,73 Dd voi
+ 0,55 Vet dii + 0,36 Dude lai -i- 0,36 Cdc do -i- 0,18 Vet
hainesii -i-
Tir cong tiiiie to thdnh cua cdc lodi thuc vat RNM
tai Hon Bay Canh vd Hon Ba cho thdy lodi uu thi or
ddy bao gom: Ddng, Duoc ddi, Dung, Vet dii, Sii do
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
c Mdi quan higiOa cac loai thuc vat RNM
Mdi quan he giOta cdc lodi thuc vdt RNM trong quan xd tai Hon Bay Canh dupe chia 1dm 4 nhom sau: Nhdm 1: Ddng, Coc do vd Mam trdng; nhom 2; Dude doi Dude lai, V?t dii, Cui va Dung; nhom 3: Da vol, Gid vd Xu 6i; nhdm 4: Coc trdng, Su do, Tra ISm
vo, Bdng phi vd Vudt hiim
Moi quan h i giiia cac lodi thuc vat RNM tai hon
Bd dugc chia lam 3 nhdm sau: Nhom 1: Dang, D«* lai Ban ti-dng va Xu 6i; nhom 2: Du6c doi, Dung.V?' dii Vet till, Da voi, Xu sung, Go bien vd Tra ISm v^; nhdm 3: Su do, Coc dd, Vet hainesu, Gia, Xu rumphi
Trang 7KHOA HOC C 6 N G N G H £
d Cac chi tieu sinh trudng cua cac loai d tang
cay cao
Tdng hgp so lieu do dim cac chi tieu sinh trudng
ciia 60 6 tieu chuan dien hinh tai hon Bd va Hon Bay Canh dugc thi hien or bang 5
T\:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
cang
Loai cay
Dang
Duoc Doi
Coc trang
Sii Do
Da Voi
Duoc lai
Vet dii
Coc Do
Mam TrSng
Gia
Tra lam vo
Bang phi
Dimg
Xuoi
Cui bien
Ban tring
Vet hainessi
Vet tru
Xu sung
Xu mmphii
Go bien
0 101 i g h p T D:,3(cm)
TB
13 9,4
9.4 10,1 12.5 10.6 29,7
7.6 7.9
14 22.9 8.9 26.8 19.1 18,2 14.9 12,7 8,6
Max 25,7 22,6
34 17,5 19.1 15.3
69
7,6 7,9
24.2 22,9 8,9 38,3 26,1 35,3 14.9 12.7 8.6
»cdc c h l t i e i DKtan (m) Tai Hon Ba
TB 2,2 1.8
1.4 1,2 2,5 1.4 3,6
1.2
1
1.9 2.5 1.5 3,5 2,1 2,1
2 1.5
1
Max 6,5 2,5
3,5 1.5
4
2 6,5
1.3
1
4 2,5 1.5
5 3.5 2.5
2 1.5
1
i i s m l itruor
Hvn (m)
TB 5,9 5,8
4,2 5.6 6,1 6,2
6
5
6
7,6
5
6
9 6,2 8,3
5
7
6
;
Max
12
9
7.2
9 7.5
9
10
5
6
11
5
6
11
8
9
5
7
6 Tong
igtdngcd^
N/ha (cay/ha)
495
195
230
170
5
65
5
5
55
5
60
20
25
15
5
5
5 1.375
f cao tai Hdn
D,3 (cm)
iBdvd H6nl
DKtan (m) Tai Hdn I
TB 12,9 10,9 10,1 8,3 9,9 11.7
10
19 7,6 14,1 13,5 18,2
12 22,2
38
17
Max
27
30
15 21,6 42,9
30 39,1
19
8 24,8 32,1 34.4
13 22.2 93,6
17
TB 1.8 1.5 2,1 1,8 1.7 1,8
2
3
4 2,9 3,3 2,4 2,5 1.7 2,7 4,8
3dy Ca Jib Hvn (m) 3ay Canh
Max 5,5
5 2,5 3,5 4,5 3,5 5,5
3
4
4 4,5 5,5
2 1,5 7.5
3
TB 6,2 6,4 4,7
4 4,3 4,9 5,9
4
5 5,9
6 4,2 5,5
6 4,9 5,5
Max
11
11
5 6,3
9
9
12
4
5
10
8
7
7
6
7 5,5
N/ha (cay/ha)
393
298
5
105
355
80
175
3
3
53
48
78
5
3
25
3
1.632
Kit qua d bang 5 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
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
loai cd dudng kinh lan Id Tra 1dm vo vd Ddng, Ban
ti-ang, Cdc do, Duoe lai, Gid vd Dung cdc lodi ed
j dudng kinh nho la Su do vd Dd vdi
'i Duong kinh tan ciia cdy rimg binh qudn tir 1,9
9 den 2,4 met, cdc lodi cd duong kinh tdn lan Id Tra
5»ldm vo Bang phi Ban vd Dang
Mat dp cay (N/ha) chiim ty le nhilu nhat la Ddng, Dd Vdi Duoc Ddi, Su do 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, do dnh huong manh me cua dilu kien khi hau thiiy vdn vd thi nIn khdc nghiet
e Danh gia phan bd cua cac loai cay RNM d cac dieu kien sinh canh khac nhau
Kit qud ddnh gid cdc ylu td hinh thdnh nen RNM tren nIn dd cdt lan manh vun san ho d VQG Cdn Ddo vd sd lieu tdng hpp tir 60 d do dim dupe tong hpp d bang 6
Trang 8KHOA HOC CbNG N G H £
Bang 6 Tdng hgp sir xudt hiin cdc lodi thyc vdt RNM dyra trin cdc ylu td hinh thdnh
Do man dat
Tir 1 den < 2
Tir 2 den < 4
Tren 4
Dp man nuoc ( " / J Tir 8 - 16 Tir 16 - 25 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 nhau Dc-i -1- cAt + san h6
Gi.-i, Bang phi, D^ vdi, Xu 6i, v^t tru, Coc do DAng Dung Dude ddi, Dude lai.Siidd, DAv6ivdV?tdii
Sii dd, D.ing, Du6c lai vh Dd
voi
Cdt + san h6 Du6c ddi, Ddng, V?t dii,
Dd vdi, Xu 6i Cdc do Dang, Duoc lai Dung, Dude d6i vd V?t Ddng, Dung, Su do, Du6c lai
Set + biin Gi^,V?tdu Bdn,V?t dii Khong
Qua sd lieu d bang 6 cho thdy:
+ Voi the nIn la set pha biin d cap do mdn it va
dp ngap trieu thap thi thanh phan lodi thuc vat kha
don gian, chii yeu la: Gia, Vet dii va cdc loai cay tham
gia vao RNM
+ O cap dp ngap tir 50 100 cm, dp mdn dat tir 2
-4°/oo va dp mdn nude tir 16 25V{)o thi su xudt biin
cdc lodi cd su da dang ban viing tilp giap vdi nui cao
va viing tilp gidp ngodi
+ 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
4 Tdi sinh rimg
a Td tiianh loai cay tai sinh
- Khu vuc Hon Bay Canh (Bd Dap - Bai Duong)
Tir kit qua dilu tra 40 d tdi sinh, thi tap dodn cdy
tai sinh khu vuc Hon Bay Canh gom cd 11 lodi To
thdnh loai cay tdi sinh dugc xdc dinh bdi cdng thiic
sau: 2,4 Vet dii + 2,4 Dd vdi + 1,3 Ddng -i-1,9 Dude ddi
+ 0,5 Xu di -I- 0,4 Dude lai 0,2 Su do + 0,2 Cui biin
-i-0,2 Mam biin -i- -i-0,2 Gid + -i-0,2 Bdng phi
Khu vuc Hon Bd ^ a m Qudc)
Tir kit qua dilu tra 20 6 tai sinh khu vuc Hon Bd,
thi tap dodn cay tai sinh d day gom cd 9 lodi To
thanh loai cdy tai sinh dugc xdc dinh boi cong thu'c
sau: 3 Dang + 1,3 Sii do -i-1,9 Dung + 1,1 Dd vol -i- 0,8
Vet dii -I- 0,6 Duoe lai -t- 0,5 Duoe doi -i- 0,3 Vet ti\i +
0,3 Ban trang
Qua cong thiic to thdnh cdc lodi cdy tdi sinh tai
hai dia dilm nghiin ciiu cho thay, cay tai sinh
chiim uu thi Id Ddng, Su dd Dung, Dd vol Vet d
va Dude doi
b Mat dp, sue khoe, ngudn gdc va tiiSn VQL cay tai sinh cua cay tai sinh
Tdng hgp cdc so lieu sinh truong tdi sinh rim tai hai khu vuc Hon Bay Canh vd Hon Bd dupe th bien d bang 7
Kit qua tong hgp d bang 7 cho thdy:
- Cdy tdi sinh chi cd 14 lodi xudt hien Mdt do ca 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 do
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 do khonj thay xuat hien tdi sinh
So lupng cdy tdi sinh cd sue khoe chiem ty 1( tren 90% tong sd cdy tdi sinh Cdy tdi sinh cd nguor gdc tii hat/tiTj mam chiim tren 70% vd cd tiien vonj sdng cao
Chilu cao cdy tdi sinh cua cdc lodi tap bimg c
dp cao < 1 m Cdc loai nhu Dung, Sii do, Ddng va Di voi cd so lupng cay tai sinh dat chilu cao > 1 m chiim ty le cao hon cdc lodi khdc; dilu ndy cho thaj day la cac lodi cay tdi sinh co tilm ndng cd the tham gia vdo tdng cdy kl can ciia rimg
Cdn eii vdo sd lieu tdi sinh nhdn tiiay: Cac loai cdy neu tren diu cd tilm ndng de tao giong phucvu cho trong rimg ciia bao gom cdc phuong phdp: nhan gidng tir tru mam va bung cay tdi sinh dem trong rimg true tilp Tuy nhien, cdc bien phdp tao gi6 tren can dupe nghien ciru thii nghiem lai
Trang 9KHOA HOC C 6 N G N G H I
TT
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Loai
Dang
Duoc doi
Sii do
Duoc lai
Da voi
Dung
Vet tru
Ban trang
Vet dii
Xu 6i
Cui bien
Mam
bien
Gia
Bang phi
Bang 7 Tong hgp cdc chi tieu tdi sinh rimg
Tai Hon Bay Canh
N (cay/ha)
753
156
16
233
636
0
23
3
6
3
3 1.978
Tai sinh CTr.mam)
748
150
0
33
635
0
23
0
0
0
3
Cay khoe
448
88
15
28
310
0
23
3
0
3
3
CoTr
vpng
728
153
15
33
442
0
23
25
0
3
3
Uu tien
1
3
5
4
2
6
tai Hdn Bdy Canh vd Hdn Bd
Tai Hon
N (cay/ha)
170
30
245
25
160
485
160
5
15
1.295
Tai sinh (Tr.mam)
170
30
230
5
155
485
160
5
15
Ba Cay khoe
160
30
240
15
155
485
160
5
15
CoTr
vpng
170
30
245
25
160
485
160
5
15
Uu tien
2
5
1
6
4
3
7
11
10
9
8
14
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 3 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, trong 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 nhau 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
do vd Duoe lai
Rimg ngdp man a Con Dao chiu anh hudng ciia
4 nhdm nhdn td hinh thdnh nhung cdc ylu to tdc
dpng chinh Id: (1) Ylu td dia hinh dia mao dupe che
chan trong 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 ra dilu kien khi 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
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 trong bao gom 6 lodi: Duoc doi, Dung Ddng, Duoc lai Da Voi va Su Do Cac lodi diu cd tilm ndng tao gidng de trong rimg vd cd thi thuc hien bdng 3 phuong phdp Id: (1) Thu hdi tru mam vd trong rimg true tilp; (2) san xuat cdy giong trong bii bau; (3) biing cay con tdi sinh ti-ong rimg true tilp
2 Kiln nghi Can nghien ciiu tilp d l dua vdo trong thir nghiem cdc lodi cd triln vpng ngay 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 trong rimg cho viing sinh thdi dac thii ndy Kit qua nay se 1dm ca sd nhdn rpng ra cac viing biin ddo cd dilu kien tuong tu
TAI UEU THAM KHAO
1 Nguyin Chi Thdnh, Le Xuan Ai, Le Xuan Canh, Tran Hgp, Nguyin Ngpc Kieng, Nguyin Dire
Trang 10KHOA HOC C 6 N G N G H l
Ngdn, 2004 Tai nguyen ddng, thirc vat Vuim ()iidc Phdn bd thuc v$t rimg ng$p mdn tai Vudn Qudc gi gia Cdn Dao Nha xuat ban Ndng nghiep, trang 5 - Cdn DAo, tinh B^ Ria - Vung Tau (Trong cuon phu
35; trang 233 - 268 hdi rimg ngdp mdn img phd vdi biin ddi khi, ha
2 Luong van Tai 2007 Nghien cim a\u tnic ^irdng tdi phdt triln bin vung do Phan Nguyfe rimg ngap m^i tir nhien dhdn Bav Canh Vuon Qudc "^'"S- ^K'uyln Thj Kim Cue vd Vu Thuc Hiin bifi] gia Cdn Dao, tinh Ba Ria - Viing Tau Ludn van lot «"^"- ^hd xudt ban Ndng nghiip trang 21 - 331)
nghiep ky su lam nghiip Dai hgc Ndng 1/ini Ihanb 6 Wim Ciiesen, Stephan Wulffraat, Max Zierei
pho Hd Chi Minh Vict Nam ti-ang 2 2 - 2 5 and Licsbeth Scholten, July 2007 Mangrov
3 Phan Nguyen Hdng 2003 Phinmg ph.ip dieu guidebook for Soutiieast Asia FAO and Wetiandi tia rimg ngap man Nha xuat ban Klioa hgc Ky thuat, International (page 685 - 722)
trang 27-30 ^ ^^^^^ y^ ^^^^^^^ ^^ Amalyos C, anc
4 Tran Dinh Hue 2008 Nghien ciiu da dang shigeyuki B., 1997 Handbook of Mangroves ii tiiiic vat tiian gd rimg ngap man till Vmm Qudc gia /,,^^^^,,^, -phe Development of Sustainabk Cdn Dao, tinh Ba Ria Viing Tau Luan van tdt
nghiep thac sy lam hoc Dai hoc Ndng l^^m thanh
pho Hd Chi Minh
5 Vien Ngoc Nam va Tran Dinh Hue 2007
Mangroves Management Project Ministry o: Forestry Indonesia and Japan International Cooperation Agency (119 pages)
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 ha 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
sea-swamps with the shallow and slopping bank The soils of the sea-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 1 - THANG 3/2012