KHOA HOC C O N G N G H l
OAC DIEIVI CAU TRIJC RlJIXIG CO PHAM BO LOAI THdlMG IXIAIVI LA [Pinus dalatensis Ferre) Q TAY I\1GUYEI\I
Lfi Canh Nam', Bui Th^ Hodng^, Truong Quang C\sim^, Hodng TTianh Trudng', Luu TTi^ Trung', Bao Huy^
T6MTAT
Quan the Thong 5 la {Pinus dalatensis Ferrre) la dac huu va c6 gia tri quy hiem nhifiu mat ve su dung va bao ton. Nghien cuu nay mo hinh hoa c6 he thdng cau tnic kilu rimg hdn giao cay IA rgng la kim co phan bd loai Thong 5 la a Tay Nguyen lam co so de xuat cac bien phap ky thuat lam sinh va bao tdn loai ciy va cac quan thfi quy hiem nay. Vdi 17 6 tieu chuan co dien tich 2.500 m^ dupc thiet lap 6 cac Vucm Qudc gia:
Bidoup Niii Ba (6 6), Chu Yang Sin (6 6) va Kon Ka Kinh (5 6). Chi sd quan trong bnportance Value Index (IV, %) duoc su dung de xac dinh loai uu the; cau tnic sd cay theo cap Idnb (N/D) va chieu cao (N/H) dugc thii nghiem mo phong theo cac ham Mayer, khoang each - binh hoc va Weibull; cau tnic mat bdng dupc danh gia bdng phan bd U theo khoang each d^n cay gdn nhat. K^t qua cho thay Th6ng 5 \k la loai uu thfi sinh thai voi [V% tir 3,6 - 12,2%; khong ghi nhan cluoc tai sinh tu nhifin Thong 5 la trong cac lam phdn co cay Tlifing 5 la tmong thanh; phan bd N/D voi 53% 6 tuan theo phan bd khoang each co dang giam; phan bo N/H rat bie'n dong co 35% cac 6 mo phong dupc theo phan bd Weibull dang co dinh Ifich trai dfin gdn chuan; phSn bo mat bdng cua lam phan wk rieng Tiiong 5 la chii ylu phan bd cum; phan bo N/D va N/H cOa rifing quan thfi Th6ng 5 la co mpt den nhieu dinh tap trung, do khong co qua trinh tai sinh lifin tuc.
Tii ldi6a: Cau tnic rdng, la rdng, la kim, thong Ba Lat
l.tVHTBAU
, Cac lodi cay Id kim, trong dd cd Tiiong 5 Id (JPtius dalatensis Ferre) - mdt lodi cdy dac hiiu va quy hiem, cung vdi cac lodi cay la rpng tao thanh tdng tan cao cua rung tu nhifin hon giao cay Id rpng Id kim (Nguyfin Tien Hifip va cs, 2004); kieu rung nay tap trung d Tay Nguyfin bao gdm cac cao nguyen Hon Vifin, Ban Mfi Thupt, Pleiku, Ngpc linh (Nguyfin Due Td Luu va Phibp Thomas, 2004). Rung ty nhifin nhifit ddi Id mpt he sinh thdi rat phtic tap, bao gdm nhieu thdnh phan voi cdc qui luat sdp xep phtic tap trong khong gian vd thay ddi theo thdi gian.
Cdc nghifin cuu ve cau tnic rung mua nhifit ddi duoc bdt dau tien hdnh mfi td, sau dd cung vdi su phdt trien cdng nghe thdng tin tiong lam nghifip, mo hinh hda cau true rung la npi dung ca bdn trong nghifin cuu hfi sinh thai rimg gd, ddng gdp vao viec quan ly, xu ly ldm sinh vd bao tdn rung (Nguyfin Van Truong 1983; Nguyfin Hdi Tuat, 1990; Jayaraman, 1999; Tran Van Con, 2001; Zheng vd Zhou, 2010; Vo Dai Hai, 2014; Bdo Huy, 2017).
' Vien Khoa hpc Lam nghiep Nam Trung bp v& Tay Nguyen
' VuonQufic gia Bidoup Niii Bii ' Truong Dai hpc Tay Nguyen
Mac du da cd mpt sd nghifin cuu ve dac diem cau tnic ctia kidu rung hdn giao cay Id rgng Id kim, tuy nhifin cdc nghifin cuu nay chi dugc tifi'n hanh rifing le va chua phan dnh dugc ddy du cau tnic chung va rifing qudn the Thong 5 Id. Nghifin ctru ndy mo hinh hda cd he thdng cdu tnic kieu rung hdn giao cdy Id rdng la kim cd phan bd lodi Thong 5 la d Tay Nguyfin ldm co sd dfi xuat cdc bifin phap ky thu4t ldm sinh vd bdo tdn lodi cay vd cdc qudn the quy hi^m ndy.
2 . B U TUDNG VA PHUONG PHAP lUGMBV CUU 2.1. Ddi tuging nghifin ciiu
Cac lam phdn cd phan bd loai Thfing nam la {Pmus dalatensis Ferre) d Tay Nguyen; trong dd tap tiling d ba Vudn Qudc gia (VQG) Id Bidoup Nui Ba (Ldm Ddng), Chu Yang Sin (Ddk Ldk) vd Kon Ka Kuih (Gia Lai).
2.2. Phuong phdp nghifin cuu 2.2.1. Phuongphap thu thap sd Uiu Su dung phuong phdp nit mdu difin hinh theo d tieu chuan 2.500 m^ (50 m x 50 m) tai cac lam phdn cd phan bd ty nhifin loai Thong 5 la. Tifiu chuan lua chpn vi tri d mdu Id noi it hoac chua bi tdc dpng; da tiiiet lap 6 6 d VQG Bidoup Xui Ba. 6 6 d VQG Chu
NONG NGHIEP VA PHAT TRIEN NONG THON - KY 1 - THANG 5/2020
KHOA HOC C O N G N G H E
Yang Sin vd 5 6 d VQG Kon Ka Kmh; tdng cpng cd 17 fl mdu dupc thu thap sd lifiu.
Tren cdc d mdu dien hinh 2.500 m^ chia thdnh 25 fl 100 m^ (10 m X 10 m), tien hanh thu th^p sd hfiu cua tang cdy gd, hao gdm cdc chi tifiu: tfin lodi cay gd, chieu cao cay (H, m), dudng kinh ngang ngyc (D > 6, cm), do cu ly tu mdt cay gd trong 6 den cay gd gdn nhat, ndu la cdy Thdng 5 la thi cd 2 cu ly: dfin cay Thdng 5 Id gdn nhat khde va cay gd gan nhat, neu la cay lodi khde thi chi do mgt cy ly den cay gdn nhat khac.
Trong cdc d mdu 2.500 m^, tien hanh dat 5 6 phu c 6 d i e n t i c h l d 4 m ^ ( 2 m x 2 m ) , 4 6 d bdn gdc va mgt a tam o de do dem cay tdi smh cd trien vgng (H > 0,5 m va D < 6 cm), xdc dinh tfin loai, do chieu cao cay (H,m).
2.2.2. Phuongphip xac dinh ciu true thanh phan ciygd va cay tai suih
Su dung chi sd quan trpng (Importance Value Index) IV% gdm 3 chi tifiu N%, G% va F% cua Curtis va Mcintosh (1950) dd xdc dinh loai uu the, cau h-uc thdnh phdn loai cay g6 va ty tipng lodi Thdng 5 Id tiong cac lam phan cd phan bd loai nghien cuu (Bao Huy, 2017).
Vdi N% Id % mat dd loai, G% la % tdng tiet difin ngang (G) cua lodi vd F% la % tan suat xuat hifin lodi tifin 6 don vi 10 m x 10 m cua he thdng 6 2.500 m^
cho mdi vung phan bd ddng nhdt sinh thdi. Ddi vdi cay tai sinh thi chi sd IV% tinh theo 2 chi tifiu N% va F%; trong dd F% Id % tdn suat xuat hifin loai trfin 6 do tai sinh 2 m x 2 m cua hfi tiidng 6 2.500 m^.
2.2.3. Phuong phap mo phong cau true sd ciy tiieo cdp kinh (N/D) vi theo cap chieu cao (N/H)
Pham vi cap kinh va cap chieu cao de thidt lap
phan bd N/D va N / H phan anh quy luat chung dn dinh cho cdc 6 mdu; tu dd xdc dinh cap D cd pham vi 10 cm; vdi cap H cd pham vi 2 m.
Kiem ti-a sy ddng nhat cua cac day phan bd N / D hoac N/H cua cdc 6 mdu bdng tieu chuan thdng kfi x2, nhdm xem xet cac day phan bd d eac 6 mdu cd cung chung mpt tdng the de gdp chung tinh todn, mo phdng (Bao Huy, 2017).
Thu nghiem mo phdng cac kifin cdu tnic N/Dva N/H Unto bdn dang hdm chinh Id Mayer, khoang cdch, hinh hpc va Weibull va Idem tra su phu hop cua phan bd ly thuyet so vdi thyc te d muc P < 0,05 theo tieu chuan x^o.o5. do (Wratten vd Fry, 1986, Nguyfin Hdi Tuat va cs, 2006; Bdo Huy, 2017).
2.2.4. Phuang phip nghien cuu cau true mit bing
Ps^ dung phuong phap dua tren phan bd khoang each tu mpt cay chpn ngdu nhifin ddn cay gdn nhdt, vol dung lupng mau n > 30 (sd khoang each do) tinh theo tifiu chuan U cua Clark vd Evans (ddn theo Bdo Huy, 2017).
3. KFT QUA NGHBU COU VA THAO LOAN
3.1. D$c di^m cdu tnic lam phdn cd phdn bd TTidng 5 Id d T^y Nguyfin
3.1.1. Cau true thanh phan loai ciy gd vi ciy tai sinh
- Cau true thinh phan loai caygd
Chi sd IV% dupc tinh theo tung vung phan bd sinh thai tifin co sd ddng nhat cdc yeu td sinh thdi d cdc 0 mdu theo tung vung (Narayan vd Anshumali, 2015). Nghien cuu nay xac dinh loai uu thd vdi IV96 >
3% de nhdm loai uu the dat tu 5 - 10 loai (Thai Van Trung, 1978; Bao Huy, 2017) (Bang 1).
cdc day phdn bd dupc tham dd de cd dupc chu6i
Bang 1. TTidnh phdn lodi uu th^ theo chi so IV% trong cdc ldm phdn cd Thdng 5 Id q ba vung phdn bd Vung phan
bd VQG Bidoup Nui Ba
Thli tuloai mith^
1 2 3 4 5 6 7
Loai
Ngu mac linh Thong 2 la det Thang 514 Tram vo do Kha thu an Cap moc bidoup Hdng timg
N (cay/
ha) 137 42 21 70 68 57 24
N%
10,9 3,4 1,7 5,6 5,4 4,5 1,9
G (mVha)
6,42 10,66 9,18 3.41 1,81 1,91 3,97
G«
10,8 17,9 15,4 5.7 3.0 3.2 6,7
F
54 30 17 43 32 33 20
F%
6,5 3,6 2,1 5,2 3,8 4,0 2.4
IV%
9,4 8,3 6,4 5,5 4,1 3.9 3.7
NONG NGHIEP VA PHAT TRIEN NONG THON - KY 1 - THANG 5/2020 89
KHOA HOC CONG NGHt
Viing phan bd
VQG Chu Yang Sin
VQG KonKa Kinh
Thli tuloai ifu th^
8 9 1 2 3 4 5 6 1 2 3 4 5 6 7 8 9
Loai Cho xdt 99 loai khac Tdng Hdng quang Soi linh Kha thu nhim Tram vd do Thdng 514 125 loai khac Tdng TTidng514 Kha thu Chd xdt Cdm Sen Cap mdc Khao Go dong 119 Loai khac Tdng
N (ciy/
ha) 35 797 1.251
219 83 77 66 11 1.406 1.750 59 138 83 45 55 42 45 40 579 1.087
N%
2.8 63.8 100,0 11.8 4.5 4.1 3.5 0,6 75,5 100 5,4 12,7 7.7 4,1 5.1 3,9 4,1 3,68 53,27 100,0
G (mVha)
1,74 20,34 57,38 4,48 1,75 1.78 1.92 4.11 30.45 42,92 10,39 4,69 6,18 1,11 0.53 0,88 0.34 0,71 14,73 39,55
G%
2,9 34.2 100,0
10,1 3.9 4.0 4.3 9,2 68,4 100,0 26,3 11,8 15.6 2,8 1,3 2,2 0,9 1,78 37,25 100,0
F 28 576 811 38 31 33 33 9 939 951 32 43 48 30 28 24 28 23 416 672
f%
3,4 69.1 100,0 3,5 2,9 3.0 3,0 0,8 86,7 100.0
4,8 6,4 7,1 4,4 4,2 3,6 4,2 3,5 61,9 100,0
IV%
3,0 55,7 100,0 8,4 3.8 3,7 3,6 3,6 76,9 100,0 12,2 10,3 10,1 3,8 3,5 3,2 3,0 3,0 50,8 100,0 Tdng sd loai cay gd la kha cao, bien ddng tu 107 -
130 loai, vdi 61 - 78 chi vd 35 - 42 hp thuc vat Sd loai uu thd tu 5 - 8 lodi; trong dd lodi Thong 5 la luon xuat hifin Id loai uu tiie vdi IV% tir 3,6% - 12,2% (Bang 1).
Nhdm loai uu the d cdc vimg sinh thdi khac nhau la cd sy khde bifit ro ret, kdt qua nay phu hpp vdi ket luan cua Narayan vd AnshumaU (2015) khi nghifin cuu ve chi sd quan tipng cua cac loai uu the trong rung nhifit ddi.
- Ciu true thanh phan loai ciygd tii sinh Tdng sd lodi cay gd tdi sinh bien ddng kha ldn, tu 36 - 97 loai, trong dd sd loai cay go tdi sinh nhifiu nhat Id tai VQG Chu Yang Sin vdi 97 lodi; fliap nhat Id tai VQG Kon Ka Kinh vdi 36 loai. Sd loai cay tai sinh uu flie bien dpng tir 4 - 7 lodi vdi rV% > 3% (Bdng 2).
Trong tat ca cac lodi cay tai smh do dem dupc tai ba vting phan bd deu khdng ghi nhan duoc cay Thong 5 Id tai sinh nao trong cac lam phan cd cay Thdng 5 la timmg thanh, trong khi dd Thdng 5 la cd tai sinh kha nhieu d noi dat trdng (Hinh 1).
Xem xet sy ti-iing khdp hay khong giua cac lodi uu the d tdng cao va tdi sinh trfin co sd so sanh bdng 1 vd 2; ket qua cho thay tiidnh phdn loai cay go uu
thd trfin cdc tang cao va thanh phdn loai cay tdi sinh uu thd tai 3 vung phan bd lodi Thdng 5 Id Id cd su khac biet; dieu nay cho thay ddy Id ket qua ciia kilu tai smh tudn hodn theo vet noi md tdn - mdt dac trung cua phuong thuc tai sinh cua cdc he sinh thai rung mua nhifit ddi (Xhai Van Trung, 1978; Phimg Ngpc Lan, 1986).
Hinh 1. Tdi sinh ti; nhifin Thdng 5 ]k tirfin ddt ti^ng trong VQG Chu Yang Sin
Ket qua ndy ciing phdn dnh khong phai Thdng 5 la khong cd tdi sinh ty nhifin ma chi tai sinh t^
nhiing noi cd dieu kien thuan lpi ve cac didu ki^n smh flidi, dd Id du dnh sang, nhifit dp,... Q nhung 16
KHOA HOC C 6 N G NGHE
trdng trong rimg, bia rung hay cac khu vuc md (Phi cd cay m? Thdng 5 la da can trd tai sinh tu nhien cua Hdng Hai, 2011; Trang, 2011). Tan rimg thanh thuc chinh loai nay.
Bine 2. Tiianh ph Viing ph4n bd
VQG Bidoup Niii Ba
VQG Chu Yang Sin
VQG KonKa Kinh
4n io4i tai sum Thli tuloai
uuthe 1 2 3 4 5 6
1 2 3 4 5
1 2 3 4 5 6 7 8
uu the theo clu so 1 Loai Da huong Didn bach Cdng Sdi Langbiang Cutngua 69 loai khac Tdng Kha thu nhim Ca di la nhd Tram do Khao 93 loai khac Tdng Kha thu Tram Khao Sam Sdi Su long Cdm 29 loai khac
Tdng
v% trong c4i N/ha 1.500 1.083 667 667 750 13.583 18.250 1.300 1.600 1.100 1.000 19.200 24.200 3.500 1.500 1.083 750 500 500 333 3.583 11.750
quan the a N*
8,2 5,9 3.7 3.7 4,1 74.4 100,0
5,4 6,6 4,5 4,1 79,3 100,0 29,8 12.8 9.2 6.4 4,3 4,3 2,8 30,5 100,0
5 Thdng 5 F 750 500 583 333 250 10.500 12.917 600 200 500 300 14.600 16.200 1.333 1.000 417 583 500 500 333 316 7.833
a a b a v i m g F%
5.8 3.9 4.5 2.6 1,9 81.3 100,0 3,7 1,2 3,1 1,9 90.1 100,0 17.0 12,8 5,3 7,4 6,4 6.4 4,3 40,4 100,0
phanbd IV%
7,0 4,9 4,1 3,1 3,0 77,9 100,0
4,5 3,9 3,8 3,0 84,7 100.0 23,4 12,8 7,3 6,0 5.3 5.3 3,5 35,5 100,0 3.1.2. Die diem ciu tnic sdcay theo cap kmh
(N/D) vi cap cbieu cao (N/H) - Cau true sd ciy theo cap kinh (N/D) Day phan bd N/D cua cac lam phdn cd phan bd Thdng 5 la cho ba vung phan bd the hifin tiong hinh 2.
Hinh 2. Phdn bd N / D ciia Idm phdn cd Thdng 5 Id d cdc vting phdn bd
BD: VQG Bidoup Nui Ba. CYS: VQG Chu Yang Sin, KKK: VQG Kon Ka Kuih
Hinh 2 cho thay ngoai tru 2 cap kinh dau (cap kinh 11 va 21 cm) thi tir cap kinh 31 cm ti-d di ca ba
dudng phan bd N/D cua ca 3 vung gdn nhu Id trung nhau. Ket qua nay cung cho thay cdc lam phdn cd phdn bd Thong 5 la khd ddng nhat vfi phdn bd N/D, chi khac bifit nhd d cap kinh nhd do tdc ddng khde nhau cua cdc yeu td moi trudng dudi tdn rung tao nfin su thay ddi mat dp lap cay cd cap kinh nhd.
Ket qua Idem tia ddng nhat cua cac phan bd N/D trong cung vung phan bd va d ca ba vung theo tieu chuan K mdu dut quang bdng tifiu chuan -g d bang 3.
Ket qua cho thay khong cd ddng nhat chung cac day N/D ciia tdt ca 6 mdu d ba vung phan bd, difiu nay cd nghia cd su khac bifit gitia cdc d tiong tung vung hay giira cdc vung.
Da td hpp xep cdc nhdm ddng nhat va ket qud thu dupc cho thay cd 5 nhdm 6 ddng nhdt vdi nhau va 01 d rifing bifit. Cdc nhdm 6 nay cd the gdp lai de mo phdng phan bd N/D chung theo nhdm flieo cdc dang ham phdn bd ly thuyet.
NONG NGHIEP VA PHAT TRIEN NONG THON - KY 1 - THANG 5/2020
KHOA HOC CONG NGHE
Bang 3. Su ddng nhat cic day phta bd N/D cua c4c d tiSu chuin trong cimg v4 khic vimg phin bd theo lieu chuin x^
TT 1 2 3 4 5 6 7
K m i u 17 d
4 d (BD:1.3, 5; CYS: 6) 4 d (CSY: 5; KKKl, 2,4) 3 d (BD: 2, 6; KKR 5) 3 d (BD 4, CYS: 1, 2) 2 d (CYS3; KKK3) CYS 4
X2 474.98
33.12 29.65 9,20 21.27 12.86
X2 (0.05;
df.(m-l)(k-l)) 164,22
36,42 40,11 28,87 26.30 15.51
K&luan Ho Ho*
Ho- H„*
Ho*
Ho*
Ghi chu df.(17-l)(9-l)
df=_(8-l)(4-l) df.(10-l)(4-l) df-(9-l)(3-l) df-(9-l)(3-l) df-(9-l)(2-l)
Ghi chii: BD: VQG Bidoup Nui Bi; CYS: VQG Chu Yang Sin; KKK VQG Kon Ka Kmh; 1(1 = 1,...6) la so thu tud tiiu chuan. Ho*: Cac day phin bd N/D a cac 6 miu la ddng nhat, Ha: Cac day phan bd N/D dcac 6 mau li CO sukhac biet
Bang 4. K^t qui md phong cau tnic dan TT
1
2
3
4
5
6
Nhdm OTC ddng nhat BD (1. 3, 5)
va CYS 6
CYSSva KKK (1. 2, 4)
BD (2. 6) va KKK5
BD4vaCYS (1,2)
CYS 3 va KKK3
CYS 4
Dang ham phan bd Mayer Khoang cich Hinh hoc W^eibuU Mayer Khotagcich Hinh hoc WeibuU Mayer Khoang each Hinh hoc Weibull Mayer Khoang each Hinh hoc WeibuU Mayer Khoang each Hinh hoc WeibuU Mayer Khoang c4ch Hinh hoc Weibull
N/D theor gphtabdls
X
0,074493
0,089615
0,076446
0,098258
0.218218
0,206968
ihdm d ddng nhit va ki&n tra b ^ tifiu chuin x^ theo c4c
^ thuydt dr 3 vung p h t a bd V
0,296425
0,399149
0.32015
0.437016
0.505034
0,555825 a 1513.8 0,47 0.57 0.90 2106,2 0,40 0.28 0,90 1018,3 0.47 0,56 0.90 1014,6 0.34 0.46 0.90 1015.7 0.49 0.49 0.60 1408,9 0,21 0,36 0,90
P 0.074
0.080
0.060
0,070
0.060
0.131 X2 158.78 10,34 145.60 67.56 201,54 8,42 83,15 102,08 112,12 12,02 79,99 61.37 325,69 9,81 163.63 207.06 125.67 50.27 50.31 77.10 68.57 1,93 31.58 3,65
X2 (0,05) 11.07 11,07 14.07 14.07 11,07 11,07 12,59 14,07 11,07 11,07 14,07 14,07 9,49 7,81 12,59 12,59 11,07 11.07 12,59 12,59 5,99 5,99 9.49 7,81
df 5 5 7 7 5 5 6 7 5 5 7 7 4 3 6 6 5 5 6 6 5 2 4 6
KS luan H„- Ho* Ho Ho H„ Ho* Ho Ho Ho Ho H„- H„ Ho Ho H« H«- H, H« Ho Ho Ho Ho* H,- H,* Ghi chu: H^: Khong mo phong dupc theo cac dang phan bd ly thuyeti Ho *: md phdng duoc theo d^ng phan bdly thuyit (m dam).
KHOA HOC CdNG N G H £
Bang 4 cho thay cd 3 nhdm d tidu chuin md phong duoc theo dang phan bd khoang each vdi 9/17 6. chi^m ty 16 (53%) co -g < x^o,os), luat p h t a bd cua c4c lam phin nay cung theo quy luat chung cua cac kilu rimg hdn giao la rdng duoc md phdng bdi NguySn Van Tniong (1983) va Dong Si Hien (1974).
500
-Nqs(c/ha)
Cd 01 (6%) d tieu chuan (CYS 4) vira cd the md phdng theo ham phta bd khotag each va Weibull.
Cac nhdm d tieu chuan cdn lai (7/17 d, 43%) khdng the md phdng theo cac dtag p h t a bd ly thuydt the hien qua x^>x',o.o5).
400 300 200 100 0
Nqs (c/ha)
D(cm)
500 n 400 300 200
„ 100 - z - Nqs
(c/ha) Nit (c/ha)
11 34
34 21 43
42 31 19
20 41 10
95
--
51 35
45 - N q s .
61 20
21 71 11
10 rn 81 10
5 b
)
91 4
2 Nit (c/ha)
Hinh 3. ffi^u d^mg phdn bd tiiuc t^ N / D vd md phdng theo phan bd khoang cdch: a) d^mg gidm; b) cd dinh chir J 6 c ^ kinh nho. Nqs: S6 cdy quan sdt. Nit Sd cdy udc lupng tiieo ham phan bd khodng cdch Ket qua ndy cho thay quy luat chung cua phan
bo N/D cua cdc lam phan cd Thdng 5 la: i) Da sd hian tiieo quy luat phdn bd khoang each cd dang giam ho^c cd 1 dinh chu J d cap D nhd Nguyfin Van Tnrong (1983) (Hmh 3); ii) Phan bd Weibull ve ly diuydt cd khd nang mo ta cho nhidu kieu dang phan bo N/D hiy nhien tiong nghifin ctiu nay chi phti hpp voi 01 6 tieu chuan (6%); ui) Nhdm 6 tieu chuan khong tuan theo quy luat phan bd ly thuyet, nhung nhin chung phan bd N / D tuan theo kieu dang phan bo chung Id giam chu J hoac cd mdt dinh d cap kinh tiiu 2. Tuy nhifin tdc dp giam khac hoac dinh phan bd thap nfin khong phu hpp vdi mdt dang phan bo ly thuydt nao.
Tdm lai kidu phan bd N / D dang giam cho tiiay cdc ldm phdn cd Thong 5 la la ben vung, cdn kieu mpt dinh thd hien su han chd lop cay nhd do ldm phan tiidnh fliuc lam can trd anh sdng, khong gian dinh duong cho Idp cay tdi sinh, kfi can; dieu nay sfi dupc giai tda khi ma thd he cdy gia nga do md ra khdng gian cho the he hdp theo.
- Cau true sdcay theo cap chieu cao (N/H) Phan bd N / H chung cua lam phan cd phan bd Thdng 5 la tai cdc vung phdn bd VQG Bidoup Nui Bd, VQG Chu Yang Sin vd VQG Kon Ka Kmh duoc tiie hi^n tai hmh 4, cho thdy phan bd N / H cua ca 3 vung d^u cd dang cd dinh, tuy nhifin tai hai vung phan bd VQG Chu Yang Sin vd VQG Kon Ka Kmh cd dang m6t dinh Ifich trdi, sd cay tdp trung nhieu d cdp chieu cao tu 8 - 14 m. Rieng tai VQG Bidoup Nui Ba phan
bd cd dang hinh chuong, sd cay tap trung nhieu d cdc cap chieu cao tu 14 - 20 m. Day la mot dac trung cua rung kin nhifit ddi, nhieu loai cay d cap kinh nhd nhung da vuon cao de canh tranh dnh sdng, do dd da tao nfin mpt tdng cd dinh vdi nhidu loai cdy tham gia (Dong Si Hien, 1974; Nguyfin Van Truong, 1983). Do cao cua tang tao dinh tiiy thupc vao muc dp thanh thuc, lap dia cua moi vung sinh thai.
C fl m n 14 lfi 18 20 22 24 2fi 2fl ilO Hinh 4. Phan bd sd cdy theo cap chi^u cao (N/IO
ciia cdc lam phdn cd phdn hd Thdng 5 Id 6 Tay nguyfin
Kfit qua kiem tra su dong nhdt day phan bd N / H giua cac 6 vd vung phan bd bdng tifiu chuan x" mtic y nghia P = 0,05 cho tiiay giua cac d vd cac phuong an td hpp cac nhdm d khong cd su ddng nhat, difiu ndy phan anh phan bd N / H khd nhay cam vd cd su rieng bifit ro ret theo timg vung phdn bd hoac theo cdc dieu kifin hodn canh khac nhau. Vi vay da tien hanh kiem ti-a kha nang mo phdng phan bd N / H cho timg du Ufiu 17 d tifiu chuan theo bdn dang phdn bd ly thuyet, ket qua cd 6/17 6 mo phdng dupc theo ham phdn bd Weibull (Bang 5).
N 6 N G N G H I E P V A PHAT TRIEN NONG THON - KY 1 - THANG 5/2020 93
KHOA HOC CONG NGHt
B t a g 5. KA qua cac d md phdng duoc ciu tnic N / H thpn nhan hii Wmliiill A ha viinf ohin bd TT
1 2 3 4 5 6
0 m t a theo vung phta
bd B D 5 B D 6 CYSl CYS 2 CYS 4 KKKl
Dang ham p h t a b d
Weibull
Cac tham sd X
0,020 0,009 0.187 0.211 0,277 0.049
Y a 1.800 2.000 1.600 1,400 1,500 1,700
P X2 10,36 10.56 1.99 5.12 0,47 0,60
x2 (0,05, dO 14,07 15,51 5.99 7,81 5,99 11.07
DoUl ' Ket do (df) [J
8 2 3 2 5
luan Ho'
H„*
Ho*
Ho- Ho-
H„-
Ghi chii: Ho*: Gia thuydt dupc chip nhan. ham phan VQG Bidoup Nui Ba, CYS: VQGChuYangSm viKKK-
200 -I
:4|26'28 N q s | 4 0 l l 0 | l l | l 8 | 1 6 l l 8 | i : 56 52|12|24|4 Nit i9'l0 I ^ P 16 14 10 "^ 46 26 14 7 Hinh 5. M6 phdng phan bd N / H theo phan bd
WeibuU
Nqs: Sd ciy quan sat/ha; Nit Sd cay udc tinh//ha tiieo Weibull
10 i : 14 16 iSjjiftny --1 -6 28 30 Hinh 6. Cdc day phdn bd N / H 6 cdc 6 mdu ti^n ba vting khdng md phdng dupc tiieo phdn bd t:^ thuydt
bd ly thuydt mo phong tdt cho phin bdquan sat BD:
VQG KonKa Kmh.
Kdt qua cd 6/17 (ty lfi 35%) 6 tifiu chudn cd tii^
md phdng phan bd N / H theo ham phan bd Weibull cd dinh; phdn anh quy luat chung cua phan bd N/H cd dinh lech trdi ddn gan chuan (Hinh 5) va chi thi cho su canh tranh anh sdng cua cdc lodi cd gdng vuon Ifin cdc tdng cao.
Tuy nhifin didu nay cung cho thay phan bd N/H rat bidn dpng, tu dang gidm cho den cd mpt d^n nhidu dinh va thay ddi theo timg vung, timg dilu kifin smh thdi do dd khd tiep can theo mot quy lu^t phan bd chung (ty lfi 6596) (Hinh 6). Vi vay can h?n che sOr dung phan bd ly thuyet de udc tinh day phan bd N/H; chi su dung de mo ta su phan tdng, tang hi tdn nham de xudt gidi phdp lam sinh thich hpp.
- Cau tnic mat bing
Xet vd lam phdn thi cd 8 6 cd phdn bd cum, 7 6 phan bd ngdu nhifin (Bang 6). Cdc kilu phdn bo mat bdng cua cac lam phdn ndy cung theo kieu chung ciia rimg mua nhifit ddi, dd Id chu ydu phan bd cum a giai doan trung men, chuydn ddn sang ngdu nhifin d^n ddu khi bdt dau thdnh tiiuc (Nguyfin Van Truong, 1983; Bao Huy, 2017).
Trong khi dd nfiu xet rifing lodi Thdng 5 Id tiii hau het cd phan bd cum, rifing vung phan bd VQG Kon Ka Kinh, quan the lodi Thong 5 la cd phan bo ngdu nhifin. Ket qua nay phu hpp vdi dac di^m phan bd tai sinh lodi nay, chung chi tai sinh theo Id trdng vd tudn hodn, do do thudng cd phan bd cum cdc cay Thong 5 Id theo vfit vd sau do theo thdi gian sfi tuan hoan trong vung phan bd thich hop tao thdnh kilu phan bd hue kham. Ket qud nay dua den gpi y vi^
xuc tien tdi sinh va bdo tdn Thdng 5 la can tudn tiieo quy luat tudn hodn vd phdn bd cum; trong dd cdn xuc tien tai sinh theo noi Id tidng va bdo ton lodi theo cum, ddm.
NONG NGHIEP VA PHAT TRIEN NONG THON - KY 1 - THANG 5/2020
KHOA HOC CdNG NGHE
BtaK 6. CSu tnic mSt bSng Itai Vimg
phtabd BD
CYS
KKK
Otidu chuta BDI BD2 BD3 BD4 BD5 BD6 6d CYSl CYS2 CYS4 CYS4 4d KKKl KKK2 KKK3 KKK4 KKK5 5d
Lam phta/loai Ltaiphan L t a i p h i n L t a i p h t a Ltaiphan Ltaiphan Ltaiphan Thong 5 la L t a i p h t a Ltaiphan Ltaiphan Ltaiphan Thdng 5 la Ltai phta Ltai phan Lam phta Ltai phta Ltai phta Thdng 5 la
p h ^ theo d X (m) 1.25 1.32 1.44 1,15 1,48 1,28 8.16 0.99 1.07 1,14 1,23 11,13
1,35 1,40 1,67 1,41 1,46 6,19
Udu chuin v4 ridne loMThdneSladtS vimir ohta bd n (tdng
khotag each) 337 331 312 359 271 266 32 569 494 386 413 50 322 303 212 274 248 54
X (sd cay/m^
0,1348 0,1324 0.1248 0.1436 0.L84 0.1064 0.0021 0.2276 0.1976 0.1544 0.1652 0.0011 0,1288 0,1212 0,0848 0,1096 0,099 0,006
U
-2,919 -1.357 0,570 -3.647 -0.808 -5.076 -2.669 -2,624 -2,231 -3,770 -0,108 -3,536 -0,949 -0,866 -0,716 -2,030 -2,376 -0,581
Kieu phta bd
Cum Ngau nhien Ngta nhien Cum Ngta nhien Cum Cum Cum Cum Cum Ngta nhidn Cum Ngta nhien Ngta nhien Ngta nhien Cum Cum Ngta nhien Ghi chu: BD: VQG Bidoup Nui Ba; CYS: VQG Chu
3.2. Ddc dilm cdu tnic rifing lodi Tiidng 5 Id 3.2.1. Cau true N/D neng loai Thdng 5 la Ba day phan bd N / D theo tung vung phan bd rifing loai Thong 5 la cd dang cd dinh tir lech trdi sang gan chuan, tap trung d cap kinh thanh tiiuc vdi D = 5 1 - 9 1 c m ( H u i h 7 ) .
I .-•'•. B D 10 - / ;
|ll,213141 BD 1 0 1 1 CYS i J _ i 1 KKK' -I ! 0 ' 0 I
516iri Si puoiiuEaiiltiji.n 3 5 ' 3 3 3 j 1 ' 1 ' 1 • 1 : 0 11 1 1 iO J 4 !0 1
Hinh 7. Phdn bd N / D ciia lodi Thdng 5 Id d ba vung phanbd
Yang Sin va KKK: VQG Kon Ka Kmh
Tien hdnh xem xet kha nang mo phdng phan bd N/D cua rieng loai Thong 5 la theo cdc dang phan bd ly thuyfit, trong do khong su dung ham Mayer vi cac phan bd deu cd dinh, ket qua dupc trinh bay d bang 7.
Bang 7 cho thdy phan bd WeibuU mo phdng tdt cho phan bd N/D rifing lodi Tiiong 5 la tai hai vung phdn bd VQG Bidoup Nui Ba va VQG Kon Ka Kmh.
Trong dd VQG Kon Ka Kinh cd dang mot dinh chu J, cdn vung VQG Bidoup Nui Ba cd phan bd gdn tifim can chuan (Hinh 8a va 8b).
Nhu vay, khi so sanh phan bd N/D cua lam phdn cd phan bd Thong 5 la (hinh 2) va rieng lodi Thdng 5 la (hinh 7) thi khdng dinh su ben vung ciia cac lam phdn cd phan bd Thong 5 la tren co sd phan bd N/D chu yfiu theo dang phan hd giam; trong khi dd phdn bd N / D neng lodi Thong 5 la cd phan bd cd dinh tap trung do khong cd qud trinh tdi sinh hfin tuc trfin cimg mpt don vi dien tich.
NONG NGHIEP VA PHAT TRIEN NONG THON - KY 1 - THANG 5/2020 95
KHOA HOC C O N G NGHt
Vimg phta bd
BD
CYS
KKK
D a n g h t a i p h t a b d X Khotag each*
Hinh hoc
Weibull 0,00002
Khotag each*
Hinh hpc Weibull*
Khotag ctah*
Hinh hoc
WeibuU 0,00178
7 a
0,85 2,50
0,79
0,77 1,70
Z2
11,68 0,80
8,79
92,31 5,08
X2(0,05,df)
3,84 5,99
3,84
3,84 9,49
Bac m do df-l-r-1
1
1^
1
1 4
Ket luan
Ho Ho-
Ho-
Ho
H„*
Ghi chu: *: Khdng tinh vi sd capDlal<r-l. BD: VQG Bidoup Nui Ba; CYS: VQG Chu Yang Sin vi KKK:
VQG Kon Ka Kmh. In dam la md phdng dupc vol dang ly thuyet (Ho'^)
••Nqs - N i t
11 21 31 41 51 61 ' 1 SI 91 101111121131141151
^ ~ ' • ' ' ~ ^ 3 I 1 ' 1 I 1 I 1 o i l 1 f) 0 fl 'Nqs I 1 I 0 1 I r 3
iNlt n I fl I 12 1 1 1 1 1 VQG Bidoup Nui Ba (a)
2 l l 3 l i 4 1 51 61 " I ' S l 91101111121131141151 9 j 9 |12,1-1 6 1 1 2 2 1 0 lO 0 1
0 i l l in 9 " J 1 2 I 0 I) n n fl VQG KonKa Kmh (b) Hinh 8. Phdn bd N/D loai llidng 5 Id dupc md phong theo phdn bd Weibull cho ttmg vimg phdn bd (a & b).
Nqg Id sd cdy quan sdt /ha ti-ong tOcng vung phdn bd vd N^ Id sd cdy/ha theo phan bd Weibull 3.2.2 Cau titic N/H rieng loii Thong 5 la
Ket qua kidm tra mo phdng phan bd N/H cua qudn the Thong 5 la trfin cdc vung phan bd theo 3 ham phan bd khoang cdch, hinh hpc va Weibull cho thdy khong cd hdm phan bd ly thuyet nao phu hpp vol x2 > x2(o,o5, df)- Hinh 9 cho thay hau hfit cac phan bd N / H deu cd nhieu dinh hoac cd mpt dinh nhung rat tap trung sd cay.
Dieu nay phu hpp vdi kdt qua vfi phan hd N / D vd tdi sinh cua loai Thong 5 la, dd la chung tdi sinh khong lien tiic, hinh thdnh sd cd the tap trung
trong timg giai doan tiidi tao thdnh mpt ddn nhidu ^^^^ g p j ^ b6 sd dly ttieo cdp H cua lodi Thdng 5 dinh. Id cho timg vung phan b6
NONG NGHIEP VA PHAT TRIEN NONG THON - KY 1 - THANG 5/2020
KHOA HOC CONG NGHl
4. KET LUAN
Thong 5 Id phan bd ti-ong kieu rimg hdn giao cay la rOng la kim vdi rV% tir 3,6% - 12,2%. Khong ghi nhgn dupc tai sinh tu nhien Thong 5 la trong cac lam phdn cd cay Thdng 5 la trudng thdnh, tuy nhien vdn bat gap cay tdi sinh Tiidng 5 Id d nhung noi md tan, cho thay Thdng 5 la cd kidu tai suih tuan hodn theo vet nod md tan.
Phan bd N/D, N/H lam phan ddu tuan theo quy luat phan bd chung cila rung hdn loai nhifit ddi. Phan bo N/D vdi da sd (53%) tudn theo phan bd khoang each (cd dang giam hoac cd 1 dinh chu J d cap D nhd); phan bd N/H rat bien d6ng, cd dang mpt ddn nhidu dinh tu Ifich ti-ai sang phai va thay ddi tiieo timg didu kifin sinh thai do do khd tidp can theo mpt quy luat phan bd chung; 35% cdc 6 nghien ctiu cd thd mo phdng N/H theo phan hd Weibull dang cd dinh I6ch tiai den gan chuan.
Phan bd mat bang cua lam phdn theo kidu chung ciia rung mua nhifit ddi, dd la chu yeu phan bd cum d giai doan trung nien, chuyen dan sang ngau nhifin ddn deu khi bdt dau thanh thuc; trong dd xet neng loai Thong 5 la thi hau hdt cd phan bd cum, cd nghia Thfing 5 la chi tai sinh theo Id trdng vd tuan hoan, do do thudng cd phan bd cum theo vfit.
Phan hd N/D va N / H cua rieng quan the Thfing 5 la cd mpt ddn nhieu dinh tap trung, do khong cd qua tai sinh hfin tuc ma chi tdi smh ti*ong tung giai dogn thuan lpi nhat dinh trfin cung mot don vi difin tich.
TAI UEU THAM KHAO
1. Bao Huy, 2017. Tm hoc tiidng ke trong lam nghiep. Nxb Khoa hpc va Ky thuat, TP. Hd Chi Minh, 282 tiang.
2. Curtis, J. T. and Mcintosh, R. P., 1950. The Interrelations of Certain Analytic and Synthetic Phytosociological Characters. Ecology 31 (3): 434- 455.
3. Ddng Si Hien, 1974. Lap bieu the tich va bieu dp tiion cay dung cho rung Viet Nam. Nxb Khoa hpc va Ky thuat. Ha Npi.
4. Jayaraman, K., 1999. A Statistical Manual for Forestry Research. FAO, Bangkok. Thailand.
5. Narayan, C , and Anshumali, 2015. Diversity indices and importance values of a tropical deciduous forest of Chhotanagpur plateau, India. Joumal of Biodiversity and Environmental Sciences 7 (1): 358 - 367.
6. Nguyfin Due Td Luu, Philip Ian Thomas, 2004. Cay la kim Viet Nam: 55-57. Nxb Thd gidi, Hd Ndi.
7. Nguyfin Hai Tudt, 1990. Qua trinh Poisson va ting dung trong nghifin cuu cau tnic quan th^ ning.
Thong tm Khoa hpc Ky thuat, Trudng Dai hpc Lam nghiep, s o l (1990); 1-7.
8. Nguyfin Hai Tuat, Vu Tidn Hinh, Ngd Kim Khoi, 2006. Phan tich thdng ke ti-ong lam nghifip.
Nxb Nong nghiep.
9. Nguyfin Tien Hiep, Phan Kd Lpc, Nguyfin Due Td Luu, Philip Ian Thomas, Aljos Farjon, Leonid Averyanov va Jacinto Regalado, 2004. Thong Viet Nam: Nghien ctiu hien trang bao tdn cay la kim Vifit Nam. Nxb Lao dong.
10. Nguyfin Van Truong, 1983. Quy luat cdu tnic rung hdn loai. Nxb Khoa hpc va Ky thuat. Ha Noi, 107 tiang.
11. Phi Hdng Hdi, 2011. Nghifin cuu bao tdn ngudn gen cay rung. Nxb Nong nghifip, Ha Npi.
12. Phung Ngpc Lan, 1986. Lam sinh hpc. Nxb Nong nghifip. Ha Npi, 120 trang.
13. Thai Van Trung, 1978. Tham tiiuc vat rung Viet Nam. Nxb Khoa hpc va Ky thuat, 276 trang.
14. Tran Van Con, 2001. Nghien cuu cau true rung tu nhifin d Tay Nguyfin va kha nang ting dung trong kinh doanh rung tu nhien - Nghifin cuu rung tu nhifin, 2001. Dd Dmh Sam, Nguyfin Hoang Nghia (chu bifin). Nxb Thdng kfi.
15. Trang, T. T. T., 2011. Spatial distilbution and historical dynamics of threatened conifers of the Dalat plateau, VietNam. A thesis Presented to The Faculty of the Graduate School at the University of Missouri, the US.
16. Vo Dai Hai, 2014. Nghifin cuu mdt sd dac diem cau tnic tang cay cao rung IIA tai khu vuc rimg phdng hp Yfin Lap. tinh Quang Ninh. Tap chi Khoa hpc Lam nghiep, sd 3 (2014): 3390 - 3398.
17. Wratten, S. D. and Fry, G. L. A,, 1986. Thuc nghiem sinh thai hoc. Ngudi dich: Mai Duih Vien, Le Huy Hoang va Nguyfin Viet Tung. Nxb Khoa hpc vd Ky thuat. Ha Noi, 159 tiang.
18. Zheng, L F. and Zhou, X. N., 2010. Diameter distnbution of tiees ui natural stands managed on polycycUc cutting system. For. Stud. China, 2010, 12(1): 21-25 DOI 10.1007/sl 1632-010-0009-2.
NONG NGHIEP VA PHAT TRIEN NONG THON - KY 1 - THANG 5/2020 97
KHOA HOC C 6 N G N G H £
FOREST STRUCTURE WHERE Pinus dalatensis Ferrt DISTOIBUIED IN THE CENTRAL HIGHLANDS OF VIETNAM
Le Canh Nam', Bui The Hoang^. Truong Quang Cuonff', Hoang Thanh Truong^, Luu Tlie TrungS Bao Huy'
^Forest Sciences bistitiite of Central Highlands and Soutii of Central VietNam
^Bidoup Nui Ba National Park
^Tay Nguyen University Summary
The forests where Pmus dalatensis Ferrre (Dalat Pine) distributed are endemic and high value in many aspects of use and conservation. This study was to systematically model the mixed broad4eaved and coniferous forest structure with the distribution of Dalat Pine in the Central Highlands of Vietnam as a basis for silvicultural measures and conservaUon of the valuable species and its populations. 17 sample plots 2500 m^were set in three National Parks Bidoup Nui Ba (6 plots), Chu Yang Sin (6 plots) and Kon Ka Kmh (5 plots). Importance Value Index (IV, %) was used to identify dominant species; the structure of the diameter distnbution (N/D) and height (N/H) was simulated by the Mayer. Distance, and Weibull functions; the structure of trees coordination on the ground was assessed by the U test according to the distance from a tree to the nearest tree. The results showed that Dalat Pine is an ecological dominant species with rV% from 3.6 to 12.2%; no natural regeneration of Dalat Pine was found under forest canopy; N/D simulation had 53%
of the plot follows the distance fiinction; N/H distribution with 35% was simulated by the Weibull; the trees coordination on the ground mainly was a cluster distribution.
Keywords: Broad-leaved forest, congerous forest, Da Lat pine, forest structure.
Ngudi phan bi^n: TS. Ph?im Tli^ Anh Ngay nhan bdi: 6/3/2020 Ngdy tiidng qua phdn bi^n: 8/4/2020 Ngdy duyet dang: 15/4/2020
98 NONG NGHIEP VA PHAT TRIEN NONG THON - KY 1 - THANG 5/2020
