HQI NGHj KHOA HQC T O A N Q U O C V E SINH THAI V A TAI N G U Y E N SINH VAT LAN T H U ' 5
DANH GIA SI>fH KHOI CUA THAM CAY BUI THAP TAI KHU BAO TON THIEN NHIEN NA HANG
TINH TUYEN QUANG
BUI THANH HUYEN Truang THCS Trung Mdn. Yen San, Tuyen Quang LE DONG TAN Vien Nghien ciru Khoa hgc Tdy Bdc, Viin Hdn ldm Khoa hgc vd Cong nghe Vi?l Nam
Nghien cuu sinh khdi va ting cudng trdng rimg tren cac dien tich dit trdng ddi nui trgc d cac viing nhiet ddi tir liu da dugc thira nhan li mdt giai phip hQu hi^u trong viec giim ty I? gia ting ciia khi CO2 trong khi quyIn (Dyson, 1977). Khi cay sinh trudng va phat triln, chiing hip thy carbon trong cic te bao va ddng nghTa vdi viec gia ting sinh khdi cua ciy (trong rimg hoac trong cac san phim tu rimg), nhu vay ndng do khi CO^ trong khi quyIn se giam di. Khi ning hap thy khi CO2 ciia rirng la vin de tien quylt trong viec thiic diy cic du an hip thu carbon d cic nude dang phat trien, cac qudc gia nay cd the nhan diu tu tir cac cdng ty, chinh phii cd mong mudn bu dip Iai lugng phat thii khi nha kinh cua hg theo co chl phat triln sach ciia Nghj dinh thu Kyoto (Feamside, 1999).
0 Viet Nam, cac nghien cuu co sd ve sinh khdi va trir Iugng carbon ciia rirng dang dugc quan tam nghien cuu tir mgt vii nim gan day va da dat dugc nhirng thinh tyu dang kl. Cac nghien cdu dien hinh bao gdm nghien ciiu trir lugng carbon trong cic thim thyc vat nhu cd tranh, lau lach va cay byi (Vii Tin Phucmg vd cs.. 2005); trir Iugng carbon ciia rirng trdng Keo tai tugng, Keo Ii tram, Bach dan urophylla (Ngd Dinh Qui vd cs., 2006; Vii Tin phuang vd cs., 2007); Thdng (Nguyen Nggc Lung vd cs., 2004; Vo Dai Hii vd cs.. 2009).
Na Hang la mgt huy?n vimg cao ciia tinh Tuyen Quang nam d phia Bac ciia tinh. Chinh sach bao ve vi phit tien rimg cua Tuyen Quang ndi chung vi huyen Na Hang ndi rieng dugc xep vao loai tdt nhat trong c i nude. Nh|in thirc sdm tam quan trgng ciia cdng tie bio tdn thien nhien ngay 9/5/1994 Uy ban Nhan dan tinh Tuyen Quan^ da ra quylt dinh thinh lap Khu Bao tdn thien nhien Na Hang. Ting di?n tich ty nhien theo Quyet dinh sd 247 ngiy 5/9/1994 ciia UBND tinh Tuyen Quang la 41.930ha. Ngoii y nghTa vl bio tdn da dang sinh vit thi sinh khdi vi trii' lugng carbon tich luy trong cac he sinh thai rimg d Khu Bio tdn thien nhien Na Hang dugc cho Ii khi Idn, cd tiem nang cao trong viec hap thy va luu giir carbon. Chinh vi vay vi?c nghien ciru sinh khdi va trir lugng carbon d tham cay byi ciia rung thugc Khu Bao tdn thien nhien Na Hang se cung cap co sd khoa hgc quan trgng trong vi?c kiem ke khi nha kinh va thuang mai gia tri carbon cua rirng, nham bd sung din li?u ve cau tnic sinh khdi va kha nang tich luy carbon ciia thim thyc vat lam co sd xac djnh Iugng carbon ca sd trong du an trdng rimg theo ca che sach d Viet Nam, gdp phin thyc hi?n chinh sich chi tra djch vy mdi trudng rimg d Tuyen Quang dang dugc bit diu xiy dyng dl an theo Nghj djnh sd 99/20I0/ND-CP ngay 24/9/2010 ciia Chinh phii.
I. PHU'aNG PHAP NGHIEN CUtJ
1. Dieu tra ve cau true va thanh phin loai trong tham cay bui ngoai thuc dja
Dugc thyc hi?n theo tuyen vi d tieu chuin (OTC). Tren tuyIn dilu tra bo tri OTC lOOm^ (lOm X 10m) dl thu thap sd li?u. Trong OTC thiet ke h? thdng 9 d dang bin (ODB) 2m^
(2m X 2m) tai 4 gdc, tren dudng cheo vi t?i dilm trung tam cua OTC.
HQI NGHI KHOA HQC T O A N Q U Q C V E SINH T H A I V A T A I N G U Y E N SINH V A T L A N THlJ 5
Thu thap sd lieu ve hien trang tham cay bui: Tren tuyen dieu tra ghi chep tit ci cay gip trong pham vi 2m dgc theo hai ben tuyen, trong OTC thu thap sd lieu ve thinh phan vi m§t dp loai ciy. Trong ODB danh gia dg che phu cua cay byi. Nhihig loii cay chua bilt ten thu miu de giam djnh ten loai.
2. Thu thap so lieu ve sinh khoi
Chgn 3 dja diem trong thim cay byi thap, mdi dia diem Igp 3 d tieu chuin (OTC) cd dien tich lOOm^ (10m X 10m)dlthu thap so li?u. Trong OTC chgn 5 d ODB ( d 4 gdc vi trung tim) de thu thap sd lieu. Trong ODB chit toan bg ciy byi d vj tri sit dat, dao liy toan bg re, phan chia thanh cic cic bd phin: Thin, rl, canh, la sau dd cin de xac dinh trgng lugng tuoi. Doi vdi cac loai uu thi, sd lieu thu thap dugc ghi rieng cho timg loai; cac Ioai cdn Iai ghi chung theo timg bg ph|n.
Trgn deu miu trong 5 ODB, cin lay mdi bg phan it nhat 500g de phoi xic djnh sinh khoi kho.
Trong ODB thu toan hg thim khd cin de xac djnh trgng lugng trong mdi d. Sau dd trgn deu mlu thu dugc cua 5 ODB trong OTC, cin liy 500g de phai khd xac djnh trgng Iugng khd.
3. Xic dinh sinh khoi khd
Sir dung phuang phap say miu bang tu say d nhiet do 75''C trong khoang thdi gian tir 6-8h, Trong qui trinh siy, kiem tra trgng lugng eua miu sau 2,4, 6 va 8h siy. Nlu sau 3 lin kiem tra thiy trgng lugng khdng ddi thi dd chinh la trgng lugng khd ciia mau. Trgng lugng khd ciia tham muc dugc xic djnh theo cdng thirc sau:
MC (%) = (FW-DW/FW) X 100.
Trong do: MC la dg am tinh bang%, FW Ii trgng Iugng tuoi cua mau, DW la trong iugng khd ki^t ciia mau.
Sinh khdi khd dugc tinh theo cdng thdc sau:
TDM (I) = TFW (L) X (1-MC (I)) TDM (tc) = TFW (tc) X (l-MC (tc)) TDM (r) = TFW (r) x (l-MC (r)) TDM (c) = TFW (c) X (i-MC (c)) TDM (tm) = TFW (tm) x (l-MC (tm))
Trongdd: TDM (I), TDM (tc), TDM (r), TDM (c), TDM (tm) la tong sinh khoi khd tren 1 ha tinh bing tan cua la, than canh, rl, cd va thim myc. TFW (I), TFW (tc), TFW (r), TFW (c), TFW (tm) la tdng sinh khdi tuoi ciia la, than cinh, re, cd v i tham muc do dem trong OTC tinh bing tin. MC (I), MC (tc), MC (r), MC (c), MC (tm) la dg im tinh bing % cua Ii, than cinh, rl, cd va thim muc. Tdng sinh khdi khd (TDB) dugc tinh nhu sau:
TDB tin/ha = TDM (I) + TDM (tc) + TDM (r) + TDM (c) + TDM (tm) II. KET QUA NGHIEN CUtJ VA THAO LUAN
1. Mot so die diem tham cay bui viing nghien cuu
Tdng hgp sd ligu dieu tra theo tuyIn va d tieu chuin cho thiy d viing nghien ciiu cd hai tni hgp thuc vat trong thim cay bui thip la uu hgp Mua {Melasloma candidum) + Don nem {Maesa balansae) + Ba chac {Euodia lepta) + Thau ken {Helicieres angustifoUa) va uu hgp Cd lao {Eupalorium odoratum) + Mua {Melasloma candidum) + Md tring {Clerodendron chinensis).
(I) Uu hgp Mua {Melasloma candidum) + Dan nem {Maesa bahnsae) + Ba chac {Euodia lepta) + Thau ken {Helicieres angustifoUa) cd dien tich Idn va pho biln, thudng gap d chan doi vi dugc hinh thanh tren dit sau nuang ray bd hoang. LTU hc^ cd chieu cao trung binh 0,8-lin, 1404
HQI NGHI KHOA HQC T O A N Q U Q C V £ SINH T H A I V A T A I N G U Y E N SINH VAT L A N THLf 5 dp tan che cua ciy bui 0,5-0,6. Thanh phin chii yeu cic loai cay bui mgc phd biln tren viing ddi d mien Bac Viet Nam nhu: Cd lio {Eupalorium odoratum), Md {Clerodendron chinensis), Liu {psychotria monlana), Budm bac {Mussaenda frondosa), Don nem {Maesa balansae), Tai tugng {Acalypha australis)...
(2) Uu hgp hgp Cd lio {Eupalorium odoratum) + Mua {Melasloma candidum) + Md tring {Clerodendron chinensis) phan bd rai ric va dugc hinh thanh tren dit sau nuang riy. Trgng thii tham thuc vat nay thudng xuit hien tren dat mdi dugc bd hoang. Thanh phin loai cay dan gian va cd dg tin che thap.
Chiing tdi chgn uu hgp Mua + Dan nem + Ba chac + Thiu ken dl nghien ciru tich luy sinh khdi trong tham cay bui tai Khu Bio tdn thien nhien Na Hang
2. Tdng sinh khoi tham cay bui 2.1. Sinh khoi tuai
Sinh khdi tuoi la toan bd trgng Iugng tuai cua tham thuc vat bao gom c i phin sinh khdi cay dimg va tham muc tren mdt don vi dien tich xic dinh. Sinh khdi tuoi ciia tham cay bui tai 3 dia diem nghien ciru duae trinh bay trong bing 1.
Tdng sinh khdi tuai ciia tham ciy bui tai Khu Bao tdn Na Hang, tinh Tuyen Quang cd sy khac nhau giiia cic diem nghien cim. Dia diem 1 cd tdng sinh khdi Idn nhit li 34,74 tin/Iia, sau do Ii dia diem 3 (19,36 tin/ha) va thip nhit li dia diem 2 (16,60 tin/ha), hung binh li 23,56 tin/ha.
Ve thinh phan sinh khdi ciia tham cay byi gdm cd 3 nhdm chi'nh: Cay bui, cd va tham myc.
Trong dd, nhdm cd va thim myc dugc tinh chung khdng phin biet cac bg phin nhu than va rl (cic Ioai cd) va canh, la (ddi vdi tham myc). Cic sd li?u cho thay tiiy theo timg vi tri va mat dg hay do che phii ciia Idp cay bui ma cd trgng Iugng khac nhau. O dja diem 1, khoi tugng tuai cua cay byi li 25,54 tin/ha (79,27%), ciia cay than thao (cd) li 2,0 tin/ha (5,76%) vi tham muc la 5,2 tin/lia (4,97%). Tuang tu, d dja diem 2 khdi lugng tuoi ciia cay byi la 8,1 tan/ha (48,79%), ciia ciy than thao (cd) Ii 6,0 tin/ha (36,14%) vi tham myc Ii 2,5 tan/ha (15,06%J; d dja dilm 3 khdi lupng tuai ciia ciy bui la 11,62 tan/ha (60,02%^, cua ciy than thio (cd) la 4,5 tan/ha (23,24%) vi thim' myc la 3,2 tan/Iia(l6,53%). Trung binh khdi Iugng tuai ciia cay bui li 15,75 tin/ha (66,89%), ciia cay thin thao(cd) la 4,16 tin/ha (17,69%) vi tham myc la 3,63 tan/ha (15,43%).
Bdng 1 Sinh khoi tuoi (tan/ha) cua tham cay bui tai cac diem nghien cuu E>ia dilm
Dja diem 1
Dja dilm 2
Dja dilm 3
Trung binh C l i i s d nghien cu'u
Kh6i lu-vng (tan/ha) Khoi \wyng
%
(tan/ha) Khoi iuvng
%
(tan/ha) Khoi liro'ng
%
(tan/ha)
%
Cay bi^i Than
18,27 52,59 4,57 27,53 6,44 29,28
9,76 41.44
U 2,93 8,43 1,28 7.71 1,50 5,71 1,90 8.08
Rl 6,34 18,25 2.25 13.55
3.68 12,27 4,09 17,37
Tong 27,54 79,27 8.10 48.79 11.62 60,02 15,75 66,89
Co 2,00 5,76 6.00 36.14
4,50 23,24 4,16 17,69
Tham myc 6,20 14,97 2,50 15,06 3,20 16,53
3.63 15.43
Tong CQng 34,74 100,00 16.60 100,00
19,36 100,00 23,56 100.00
HQI NGHI KHOA HQC TOAN QUQC VE SINH THAI VA TAI NGUYEN SINH VAT LAN THO" 5 2.2. Sinh khoi khd
Sinh khoi kho (tan/ha) cua tham cay bui tai cac diem nghien cihi Bdng 2
Dja diem
Bja dilm 1
Dja dilm 2
Dia diem 3
Tnjng binh
Chisd nghien ci>u
Khoi lifiyng (tSn/ha)
%
Khoi iu-iyng (tan/ha)
%
Khoi luo'ng (tan/ha)
%
Khoi lu'O'ng (tan/iia)
%
Cay bgi Than
7,67 68.36 2.04 64.84
2,69 57.60 4,13 63,20
La 1,12 9,98 0,45 12,10 0.58 12,42
0.72 10.96
R i 2,43 21.66 1.23 33,06
1.40 29,98
1.69 25.79
l o n g 11,22 66,04 3,72 37,42 4,67 46,06 6,54 52,89
Co
1,22 7,18 3,81 38.33 2,75 27.12 2.59 20,98
Tham mgc 4,55 26.78 2,41 24.25 2.72 26.82 3,23 26,11
Ting c$ng 16.99 100.00 9,94 100,00 10,14 100,00 12,36 100,00 Sinh khoi khd ciia thim cay bui dugc trinh bay trong bang 2 cho thiy tong sinh khoi kho chi bing tren dudi 50% so vdi sinh khdi tuoi. Tai dja diem 1 tdng sinh khoi khd la 16,99 tan/ha, dja diem 2 la 9,94 tan/ha vi dja diem 3 Ii 10,14 tin/ha, trung binh la 12,36 tan/ha.
Ve CO cau, ty I? sinh khdi trong cay bui, cay thao (cd) va tham muc tuong ling la 66,04%, 7,18% vi 26,78%; d dia dilm 2 Ii 37,42%, 38,33% va 24,25%; dja dilm 3 la 40,06%, 27,12%
va 26,82%; trung binh Ii 52,89%, 20,98% va 26,11%. Nhu vay, tiiy theo trang thai mi Iugng sinh khdi tich luy trong quan xa khac nhau Ii khdng gidng nhau.
Rieng vdi cay hui, ty Ie sinh khdi tich luy trong phin thin, Ii vi rl d dja dilm 1 la 68,36%, 9,98% va 21,66%; dja dilm 2 !i 54,84%, 12,10% vi 33,06%; dja dilm 3 la 57,60%, 12,42% va 29,98%; trung binh la 63,20%, 10,96% va 25,79%.
Hinh 1. Ty 1$ trung binh vi khoi kho theo cdc nhdm cdy trong thdm cdy bui tgi Khu Bdo ton thien nhien Na Hang, tinh Tuyen Quang 1406
HQl NGHj KHOA HQC T O A N Q U Q C V £ SINH T H A I V A T A I N G U Y E N SINH VAT L^N THO" 5 3, PbSa bo sinh khoi theo loai
3.1. Phan bSsinh kh6i tuai theo loai
Sinh khdi tuoi bien dgng rit khac nhau giira cic loai cay bui. Mua {Melasloma candidum) CO khoi Iugng tuoi cao nhit 6,75 tin/ha (chilm 24,52%), tilp den la Don nem {Maesa balansae) 6,38 tin/ha (3,17%), Ba chac {Euodia lepta) 2,84 tin/ha (0,32%), Thau ken {Helicieres angustifoUa) 2,69 tan/ha (9,77%), Thau tau {Aporosa sphaerosperma) 1,61 tin/ha (9,52%), Cd lio {Aporosa sphaerosperma) 2,16 tin/ha (7,85%), Sim {Memecylon sp.^ 1,63 tin/ha (5,92%) va 8 loai khic Ii 2,46 tin/ha (8,92%). Sinh khdi tuoi ciia tirng bg phan cung rit khic nhau, tap trung chii ylu vao phin than canh va rl. Sinh khdi tren mat dat (than canh va la) chilm ty If ding kl so vdi tdng sinh khdi, cao nhit la Vd dyt chilm 88%, tilp din la Sim chilm 84,66%, Mgc tring chiem 84,21%, 8 loai khac chilm 70% vi thip nhit la Ke la hinh trdn chilm 68,04%.
Sinh khoi tu'oi (tan/ha) cua cac loai cay bui or khu vuc nghien cu'u Bdng 3
Ten lo^i cay
Mua Don nem
Ba chac Thau ken Thiu tiu Co tao Sim 8 loai khac
Ting
ThSn Khdi luo'ng
5,00 3,75 1,76 1,81 1.87 1.59 1.19 1,31 18,27
Tyl?
(%)
74,07 55,56 25,93 26.81 27,70 23.66 17.63 19.4 66,36
La Khoi lu'O'ng
0,5 1.00 0,31 0,07 0,31 0,04 0,19 0.50 2,926
T y l f
(%)
7,41 14,81 4.59 1.04 4.69 0,59 2,81 7,48 10,63
R i Khai liro'ng
1,25 1,63 0,78 0,81 0,44 0,63 0,25 0,64 6,33
Tyle 18.62 24.15 11,56 12,00 6.52 7,85 3.70 9,55 23,01
T6ng K h i i liro'ng
6,75 6.38 2,84 2.69 2,62 2,16 1,63 2,46 27,50
TylJ 24,52 23,17 10,32 9,77 9,52 7.85 5.92 8.92 100,00 3.2. Phdn bo sinh khoi klid theo lodi
Bdng 4 Sinh khoi khd (tan/ha) cua cac loai cay bui 6* khu vuc nghien ciru Ten
lodi cay Mua Don nem
Bachac Thiu tiu Thau k6n C6lao Vodut 8 loai khSc
Ting
Than Kh6i lu'O'ng
2.07 1,73 0,76 0.84 0,70 0,64 0,60 0.87 8,21
Tyl?
76.38
(%)
64,31 63,33 73,68 67.31 71,91 96,77 73,02 70.08
U Khoi liro'ng
0.2 0.35 0,12 0,12 0,03 0,017
0,01 0,269 1,116
Tyl?
7.38 13.01 10.00 10.53 2,88 1,91 1,61 22,47 9,52
R l Khdi luo'ng
0,44 0.61 0.32 0.18 0,31 0.23 0.01 0.054 2,154
Tyl?
(%)
16,24 22,68 26,67 15,79 29,81 25,84 1.61 4,51 18,37
T i n g Kh6i lifi^ng 2.71 2.69 1,2 1,14 1,04 0,89 0.62 1,19 11,72
Tyl?
23,12 22,95 10,24 9,73 8,87 7,59 5,29 12,21
100
HOI NGHI KHOA HQC T O A N Q U 6 C V E SINH THAI V A TAI N G U Y S N SiNH VAT LAN THlj 5
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//in/j 2. Ty I? trung binh ve sinh khdi kho trong thdn, la, re ciia thdm cdy biii lgi Khu Bdo ton thien nhien Na Hang, linh Tuyen Quang III. KET LUAN
Sinh khoi tuoi cua thim cay bgi thip tai Khu Bao tdn thien nhien Na Hang dat trung binh 23,56 tan/ha, trong do ciy bui la 15,75 tan/ha, chiem 66,89% tong sinh khdi; Cd (cay thao) 4,16 tin/ha, chilm 17,69% va tham myc 3,63 tan/ha, chiem 15,43%. Rieng ddi vdi cay byi, sinh khIi ciia phin than la 9,76 tan/ha, chilm 41,44%; la 1,90 tin/ha, chilm 8,08% va rl la 4,09 tin/ha, chilm 17,37%.
Sinh khdi khd ciia c i quin xa dat 12,36 tin/ha, trong dd cay byi la 6,54 tan/ha chiem 52,89%, cay thio (cd) la 2,59 tan/ha chilm 20,98% va thim muc la 3,23 tin/ha chiem 26,11%.
Phin than ciy byi Ii 4,13 tin/ha chilm 63,20%, la cay bui Ii 0,72 tin/ha chilm 10,96% va rl cay byi la 1,69 tin/ha chiem 25,79%.
Theo Ioai, Mua {Melasloma candidum) cd sinh khdi cao nhat 2,271 tan/ha (chiem 23,12%), Don nem {Maesa balansae) 2,69 tin/ha (22,95%), Ba chac Euodia lepta) 1,20 tin/ha (10,24%), Thiu tiu {Aporosa sphaerosperma) 1,14 tin/ha (9,73%i), Thau ken {Helicieres anguslifolia) 1,04 tan/ha (8,87%), Cd lao {Eupalorium odoratum) 0,89 tan/ha (7,59%) va Vd dyt {Ilex rotunda) 0,62 tin/ha (5,29%), cac loai khac 1,19 tin/ha (12,21%).
TAI LIEU THAM KHAO
1. Nguyen Ngpc Lung, Nguyen Tudng Vin, 2004. Thii nghi?m tinh toin gii trj bang tiln ciia rimg h-lng trong co che phit triln sach. Tgp chl Ndng nghiep vd PTNT, 12/2004: 1747-1749.
2 Vii Tan Phuong, 2006. Nghien ciiu trO Iugng carbon ciia thim tuoi vi ciy bui: Ca sd xic djnh dudng carbon ca sd trong cic dy in tring rirng/tii trdng rimg theo ca che phit trien sach d Vi|t Nam.
Tap chi Ndng nghi4p vd Phdt trien ndng thdn, 8/2006: 81-84.
3 Vii Tan Phuong va cs., 2007. Bao cao tone kit dl tii "Nghien cuu Iirgng gid kinh te gid tri '^°[
trudng vd DVMT ciia mgt s6 logi rirng chu yeu a Viet Nam". Trung tim NghiSn ciiu Sinh thii vi Mfli tmdng rirng (RCFEE). Ha Noi
4. Vu Tan Phuffng vd cs., 2008. Bio cio ting kit dl tai ^'Nghien ah djnh gid rirng a Vi?l Nam".
Trang tam Nghien ciiu Sinh thai vi M6i trudng rimg (RCFEE), Hi Ndi.
5. Ngo Dinh Que va cs., 2006. Khi ning hip thy CO2 cua mpt sd lo?i rimg tr6ng chu ylu d Vi|t Nam.
Tap chl Ndng nghiep ya Phdt triin ndng thon, 7/2006: 67-73.
HQl NGH! KHOA HQC T O A N Q U 6 C V £ SINH T H A I V A T A I NGUYEN SINH VAT L A N THU' 5 BIOMASS ASSESSMENT OF THE SCRUB VEGETATION IN NA HANG NATURE RESERVE,
TUYEN QUANG PROVINCE
BUI THANH HUYEN, LE DONG TAN SUMMARY
Fresh biomass of scmb vegetation in Na Hang Nature Reserve accounted to 23.56 tons/ha, of which 15.75 tons/ha of shmb (66.89%), 4.16 tons/ha of grass (17.69%) and 3.63 tons/ha of litter (15.43%). Dry biomass of this vegetation accounted to 12.36 tons/ha, of which 6.54 tons/ha of shrub (52.89%), 2.59 tons/ha of grass (20.98%) and 3.23 tons/ha of litter (26.11%). The dry shrub biomass has following distribution: 4 13 tons/ha of stem (63.20%), 0.72 tons/ha of leaves (10 96%) and 1.69 Ions/ha of roots (25.79%). The dry shrub biomass has the following species distribution: 2.271 tons/ha of Me/astoma candidum (23.12%), 2.69 tons of li/laesa balansae (22.95%), 1,20 tons/ha of Euodia lepta (10.24%), 1.14 tons/ha of Aporosa sphaerosperma (9.73%). 1.04 tons/ha of Heiicteres angustHolia (8.87%). 0.89 tons/ha of Eupatorium odoratum (7.59%). 0.62 tons/ha of Ilex rotunda (5.29%). 1.19 tons/ha of other species (12.21%).