31(4): 68-73 Tap chi SINH HOC 12-2009
NHUNG BIEN DOI VE TINH CHAT VAT LY VA HOA HOC CUA DAT TRONG QUA TRINH DlIlN THE DI LEN CUA THAM THljC VAT
TAI TRAM DA DANG SINH HOC ME LINH, TINH VINH PHUC
MA THI NGOC MAI
Tncdng dgi hgc Su phgm - Dgi hgc Thdi Nguyen LE DONG TAN
Vien Sinh thai vd Tdi nguyen sinh vdt
Tram Da dang sinh hpc Me Linh thupc Vien Sinh thai va Tai nguyen sinh vat, cd dia diem tai xa Ngpc Thanh, thi xa Phuc Yen, tinh VInh Phuc l i dia diem dupc chung toi thuc hien cic nghien ciiu ve qua trinh didn the' phuc hoi he sinh thii rimg nhiet ddi tQ nim 2001 de'n nay.
Nhirng kef qua nghien ciiu tren dia ban da dupc trinh biy trong mdt sd cdng bd gin day [4-6].
Trong bii vie't nay, chung tdi trinh bay mpt sd kef qua nghien ciiu ve qui trinh bie'n ddi cung nhu kha nang cai tao dat cua tham thtrc vat trong qua trinh didn the' di len.
I. PHUONG PHAP NGHIEN CUU 1. Ddi tupng
Dd'i tupng nghien cQu l i dat dudi 4 trang thii tham thuc vat dang trong qui trinh diin the' di len nhu sau: tham co (thim gupt - Dicranopteris linearis); thim cay bui (phuc hdi 7-8 nam); rQng non (rQng phuc hdi 12-14 nam) va rQng gia (rQng phuc hdi tren 30 nam).
2. Phuong phap
a. Phuang phdp dieu tra vd thu mdu
Thu thip sd lieu ve tham thuc vat: trong mdi trang thii, thief lap 3 6 tieu chuan tam thdi 400 m^ (20 m X 20 m). Trong d tieu chuan, dieu tra thu thap sd lieu ve thuc vat theo cic phuong phap thdng thudng dang dupc ap dung hien nay.
Thu thip miu dat: Mdi d tieu chuan dio 1 phiu dien cd kich thudc I m x I m x 2 m tai trung tim la diem giao-nhau cua 2 dudng cheo.
Md ta phiu dien theo sich hudng din dieu tra ngoai thuc dia [I]. Trong 6 tidu chuin, chpn 5
diem tai trung tam va 4 goc de thu miu. Mdi diem thu 3 miu d dp sau 0-10 cm, 15-30 cm va
> 50 cm, mdi miu 1,5 kg. Trpn ddu 5 miu d cung dp siu trong cung mot 6 tidu chuan, chia thinh 5 phin bing nhau lay 1 phin de lim miu nghien ciiu.
b. Phuang phdp phdn tich
Dp im, dp chat, dp da lin dinh gii ngoai thuc dia theo hudng din trong "Sd tay quy hoach rung nam 1978"; Thanh phan co gidi dat:
phuong phip dng hut; Dung trpng: phuong phap dng dung trpng; Dp xdp: theo cdng thQc Xt% = ( 1- D/d) X 100; Dam tdng sd (N%): phuong phip Kjeldhl; Mun tdng sd (M%): phuang phap Tiurin; Lin (P2O5): theo phuong phip so miu:
Kali (K2O5): phuong phip quang ke ngpn lua:
PHKO,: bing pH met; Dp chua thuy phan (Al'"^):
phuang phip Sokolop; Canxi trao ddi (Ca^'^):
phuong phip Complexon v i Magie trao ddi (Mg^"^): phuong phip Complexon.
n . KET QUA NGHIEN CUU
1. Dieu kien tu nhien va tham thuc vat cua viing nghien cQa
NhQng dac diem ve dieu kien tu nhien vi hien trang thim thtrc vat d khu vuc nghien ciiu da dupc md ta khi chi tie't trong mpt sd cdng bd gin day [4-6]. Rieng cic ddi tupng nghien cQu, kef qui dieu tra cho thi'y:
Tham co: la thim gupt - Dicranopteris linearis (Burm. f.) Undow phuc hdi 4-5 nim trdn dat riing sau khai thic va xu ly tring de trdng rQng nhung khdng thanh rQng. Day li kieu
thim thuc vat phd bie'n va chie'm dien tich ldn trong vung nghidn cQu d dp cao so vdi mat bien tQ 200 m trd xudng.
Tham cdy bui: phuc hdi 7-8 nam tren dit rQng sau khai thic kiet va xQ ly tring de trdng riing; chieu cao cua cay trung binh 2-3 m, dp tin che 0,6-0,7. Thanh phin loii gdm sim - Rhodomyrtus tomentosa (Ait.) Hassk., ba chac - Euodia lepta (Spreng) Merr., me rimg - Phyllanthus emblica L., thiu tiu - Aporosa sphaerosperma Gagnep., Aporosa dioica (Roxb.) Muell.-Arg., bpt e'ch - Glochidion eriocarpum Champ., ba dau - Croton tiglium L., phen den - Phyllanthus reticulatus PoQ., gang - Randia spinosa (Thunb.) Poir....
Ricng non: l i rimg thQ sinh mdi phuc hdi 14- 15 nam trdn dat rimg sau khai thic va xu ly tring de trdng rQng. Rimg cd can true gdm I ting ciy gd cao 8-9 m, doi khi cao de'n 10-12 m (bd de), dudng kinh cua than trung binh 10-12 cm, mat dp 650-700 cay/ha, dp tin che 0,6-0,7.
Thinh phin loii gdm sau sau - Liquidambar formosana Hance, bd de - Styrax tonkinensis
(Pierre) Craib. ex Hartwiss, de gai - Castanosis sp., son - Toxicodendron succedanea (L.) Mold., bum bup nau - Mallotus paniculatus (Lamk.) Muell.-Arg., re - Phoebe sp., dung - Symplocos sp., thanh nganh - Cratoxylum prunifiorum (Kurz.) Kurz. Ting ciy bui cao 2-4 m gdm cd ba chac - Euodia lepta (Spreng) Merr., hoic quang - Wendlandia paniculata (Roxb.) D C , thiu tiu - Aporosa sphaerosperma Gagnep., sim - Memecylon edule Roxb., com nguoi - Ardisia aciphylla Pit., lau - Psychotria rubra (Lour.) PoQ., Psychotria silvestris Pitard.... Thim tuoi thua, dp gap Sp - Cop3, thinh phan gdm cic loii thupc hp Cdi (Cyperaceae), hp Lua (Poaceae), hp Gutng (Zingiberaceae), cic loai duong xi thupc cic hp Adiantaceae, Dennstaedtiaceae, Aspleniaceae...
Ritng gid: la rQng thQ sinh phuc hdi sau khai thic trdn 30 nim. Rung cd ciu true gdm 1 ting cay gd cao 10-15 m (ddi khi de'n 20 m), dudng kinh cua than trung binh 20-25 cm, mat dp 400- 500 cay/ha, dp tin che 0,8-0,9. Thinh phin loai chu ye'u l i nhdi - Bischofia javanica Blume, de gai - Castanopsis sp., ving anh - Saraca dives Pierre, che rCmg - Adinandra bockiana Pritz. ex Diels, cdm - Elaeocarpus sp., tram - Syzygium
sp., re - Phoebe sp.... Ting ciy bui cao 3-4 m, thinh phan gdm ndng - Sauraida tristyla DC, mua leo - Medinilla assamica (Clarke) C. Chen, com nguoi - Ardisia aciphylla Pit., lau Psychotria rubra (Lour.) Poir., Psychotria silvestris Pitard, cic loii thupc hp Ord (Acanthaceae), hp Gai (Urticaceae).... Thim cd cd dp diy rim Copl-Cop2, thinh phin gdm cac loai thupc thupc hp Ray (Araceae), hp GQng (Zingiberaceae), hp Hanh (Liliaceae), hp Cd (Poaceae), hp Cdi (Cyperaceae) va cic loai duong xi thupc cic hp Adiantaceae, Polypodiaceae, Dennstaedtiaceae, Aspleniaceae.
2. Dac diem cua phiu dien dat
Tham co: Tang A diy 22 cm; dat miu nau vang; ca'u true cue goc canh vQa, kho, cQng;
thanh phin co gidi thit; cd nhidu rS cay nhd;
chuyen ldp ro theo miu sic. Tang B day 40 cm, mau ving nhat; ca'u true tang cd lin da, hoi kho.
Cling; thanh phin co gidi thit nang; cd It re cay nhd; chuyen ldp r5 theo mau sic. Ting C day trdn 50 cm, miu ving sim; ca'u true cue, ciing, mit, im; cd nhieu san sdi; thanh phin co gidi thit.
Tham cdy hui: Ting A diy 28 cm, mau nau;
cau true vidn cue, hoi khd, hoi ciing; thanh phan CO gidi thit; cd Id hdng cua dpng vat dat; cd nhieu re cay nhd va vua; chuyen ldp ro theo miu sic. Ting B day 35 cm, miu ving; cau true cue vQa v i nhd, mit, am; thinh phin co gidi thit trung binh; cd nhieu Id hdng cua dpng vat dat;
cd It re cay vQa va nhd; chuyen ldp tQ tQ theo mau sac. Ting C day trdn 50 cm, miu vang nhat; can true vien cue vQa va nhd; vin cdn id hdng cua dpng vat dat; thanh phin co gidi thit;
cd It r l cay nhd.
Ritng non: Ting AQ diy 2,5 cm, mau mau;
cau true toi bd, mit, cd lin It mun; nhidu rS cay nhd. Tang A diy 38 cm, mau nau sim; cau true vien cue nhd, mat, hoi cQng; thinh phin co gidi thit nhe. It san sdi; cd nhieu rd cay vQa va nhd;
chuyen ldp ro theo man sic. Ting B day 40 cm, mau nau; cau true vidn cue nhd, mit, hoi cQng;
thanh phan co gidi thit nhe; cd It r i cay nhd vi vQa; chuyen ldp r5 theo man sic. Ting C diy tren 45 cm, mau niu nhat; cau true vidn cue, cd nhieu d i lin, mit, im, hoi cQri'g; cd it ri cay;
thanh phin co gidi thit nang.
Ricng gid: Ting A^, day 6,0 cm, mau nau, co
lin nhiiu mun, ri cay; cd Id hdng cua dpng vat di't; cau true toi xdp; mat, thanh phin co gidi thit pha cit. Ting A day 32 cm, miu niu ving;
cau true vien cue, hoi ciing, mat, lin it san sdi (10%); cd nhieu id hdng nhd va vQa cua ddng vat daf; nhieu ri cay vQa v i nhd; thanh phin co gidi thit nhe; chuyen ldp rd theo miu sic. Ting B day 40 cm, mau vang nhat; cau true cue vQa va nhd; cd nhiiu hang Id nhd cua ddng vat dat;
cd nhiiu r i cay; thanh phin co gidi thit; chuyen ldp tQ tQ theo mau sic. Tang C day tren 50 cm, mau vang; ciu true ctic tang vQa va nhd, ty le da lin cao (60-70%), cQng, mat; cd It r i cay; thinh phin CO gidi thit nang.
3. Thanh phan co gidi cua da't
Sd lieu trinh bay trong bing 1 cho thay:
Cap hat > 2 mm chiem ty le thap nhat, tQ 0,21% (d dp sau > 50 cm cua tham cd) de'n 6,44% (d dp sau > 50 cm cua rimg non); sau dd la cap hat < 0,002 mm, tQ 7,53% (d dp sau 0-10 cm cua tham cd) de'n 24,11% (d dp sau > 50 cm cua rimg non); tie'p de'n la cip hat 0,05-0,002
mm tQ 23,62% (d dp sau 0-10 cm cua rung non) de'n 37,1% (d dp sau 15-30 cm cua thim ciy bui); cip hat 2,1-0,05 mm chie'm ty le cao nhat, tQ 41,13% (d dp sau > 50 cm cua rQng non) den 60,59% (d dp sau 0-10 cm cua tham cd).
Theo chiiu sau cua phiu dien: Cip hat <
0,002 mm tang din theo dp sau. Cip hat 0,05- 0,002 mm d rung non va rQng gii cung cd chiiu hudng tuong tu, nhung d tham cd va thim cay bui thi 0 dp sau 15-30 cm cd ty le cao hon so vdi d dp sau 0-10 cm va > 50 cm. Cip hat 2,1-0,05 mm d dp siu 0-10 cm diu cao hon so vdi d dp sau 15-30 cm va dp sau > 50 cm. Cip hat > 2 mm tang din d rQng non va rQng gii, giam din d thim cd, ridng thim cay biii tang tQ 0,71% dp sau 0-10 cm len 1,90% d dp sau 15-30 rdi sau dd giim xudng cdn 1,32% d dp sau > 50 cm.
Theo qui trinh diin the: ty le cap hat
< 0,002 mm diu cd xu hudng tang theo giai doan phit trien tQ thim cd den thim cay bui va rQng non d cQng mpt dp sau lay miu. Cic cap hat khac khdng the hien ro chiiu hudng thay ddi nay.
Bdng 1 Thanh phan co gidi ciia dait trong cac trang thai tham thuc vat phuc hoi tu nhien
tai Tram Da dang sinh hpc Me Linh Trang thai
Thim cd
Tham cay bui
RQng non
RQng gia
Dd sau (cm) O-IO 15-30
> 5 0 0-10 15-30
> 5 0 0-10 15-30
> 5 0 O-IO 15-30
> 5 0
Ty le (% ) cap hat
> 2 mm 1,30 0,80 0,21 0,71 1,9 1,32 2,64 3,21 6,44 1,27 1,86 2,72
2,1 - 0,05 mm 60,59 48,03 49,26 57,16 44,01 45,53 60,33 52,03 41,13 56,64 43,15 44,05
0,05-0,002 mm 30,58 36,34 31,40 32,62 37,10 33,82 23,62 26,67 28,32 27,66 32,12 30,66
< 0,002 mm 7,53 14,83 19,13 9,51 16,99 19,33 13,41 18,09 24,11 14,43 22,87 21,57 4. Dung trpng va dp xdp cua da't
Chung tdi da phan tich dung trpng va dp xdp trong ting dat mat (O-IO cm). Ket qua dupc trinh bay trong bang 2.
Cac sd lieu cho thiy, dp xdp cua dat tang len
qua cic giai doan diin the khi ro rang: d thim cd la 46,7% sau dd ting ldn 49,8% (d thim cay bui), tie'p de'n la 54,0% (d rQng non) va 57,2% (d rQng gii). Dung trpng cd xu hudng giim theo qui trinh diin the, nhung khdng nhiiu, dao dpng trong khoang 0,01-0,03 g/cm\
Bdng 2 Dung trpng va dp xdp cua tang dat mat (0-10 cm) trong cac trang thai tham thuc vat
phuc hoi tu nhien tai Tram Da dang sinh hpc Me Linh Trang thai
Tham cd Tham ciy bui RQng non RQng gia
Dung trpng (g/cm') 1,33
1,32 1,28 1,25
Dp xdp (%) 46,7 49,8 54,0 57,2 5. Ham lupng mun va cac chat dinh dudng cua da't
Cac sd Ueu phin tich vi ham lupng mun vi cic chit dinh dudng cua di't dupc trinh biy trong bang 3.
Bdng 3 Ham lupng mun va chat dinh dudng cua da't trong cac trang thai tham thuc vat phuc hoi
tu nhien tai Tram Da dang sinh hpc Me Linh Trang thai tham
thuc vat Tham cd
Tham cay bui
RQng non
Rting gia
Dp sau (cm) O-IO 15-30
> 5 0 0-15 15-30
> 5 0 0-15 15-30
> 5 0 0-15 15-30
> 5 0
Mun (%) 1,66 0,77 0,53 1,86 1,11 0,59 3,81 1,98 1,09 4,38 2,31 1,79
Dam (%) 0,12 0,09 0,08 0,16 0,13 0,07 0,21 0,17 0,12 0,31 0,19 0,18
Tong sd (%) P7O, 0,15 0,13 0,11 0,16 0,16 0,14 0,15 0,13 0,17 0,21 0,19 0,19
K2O 1,32 1,27 1,24 1,62 1,61 1,58 1,52 1,56 1,70 1,00 1,02 1,00
D l tieu (mg/100 g di't) P , 0 ,
2,06 0,14 0,13 2,56 0,64 0,50 2,66 2,20 0,41 5,68 3,16 2,16
K2O 1,93 0,96 0,96 2,53 1,93 0,96 14,22
2,77 3,37 16,39
8,13 5,54 TQ kef qua thu dupc chung tdi cd mpt sd
nhin xet sau:
Ham lupng mun: ham lupng mun d dd siu 0-10 cm, 15-30 cm va > 50 cm cua tham cd tuong ling li 1,66%, 0,77%o vi 0,53%. Tuong tu cua thim cay bui la 1,86%, 1,11% va 0,59%;
rQng non la 3,8i%, 1,98% va 1,09%; va rung gii li 4,38%, 2,31% va 1,79%. Nhu vay, ham lupng mun diu cd chiiu hudng tang qua cac giai doan phat triin cua tham thuc vat trong qui trinh diin the.
Ham lupng dam: ham lupng dam cua ting dif mat (O-IO cm) cua tham cd li 0,12%, sau dd ting len d tham cay bui va riing non, den riing gii dat mQc trung binh (0,31%). Ham lupng dam giam theo chiiu sau cua phiu dien.
Ham lupng lan tdng sd: d ting di't mat (O-IO cm) giao dpng tQ 0,15-0,21%; tuong tu d dp sau 15-30 cm tQ 0,13-0,19% va d dp siu > 50 cm tQ 0,11-0,19%. Theo chiiu sau, him lupng lan tdng sd diu cd xu hudng giam, nhung mQc giam khong nhiiu, trong khoang 0,1-0,2%.
Ham lupng kah tdng sd: 0 tang dat mat tang tQ 1,32% (d tham cd) ldn 1,62% (d tham cay bui) rdi sau dd giim xudng cdn 1,52% (d rimg non) va chi cdn 1,0% (d riing gia). Theo dp siu, thim cd vi tham cay bui cd him lupng kali giam, rimg non cd xu hudng tang cdn riing gia gan nhu dn dinh va duy tti d mQc 1,0%.
Cac chit di tieu:
Lin di tieu: trong ting dit mat tang kha rd 71
rang qua cic giai doan dien the' va dat mQc cao nhit la 5,68 mg/100 g di't d rQng gia. C) dp sau khac (15-30 cm va >50 cm) cung diu cd chiiu hudng tuong ty. Sd lieu cdn cho thi'y ham lupng lan di deu giam din theo chiiu siu phiu dien.
Kali d i tidu: thim cd va tham ciy biii cd lupng kali d i tieu thap: 0,96-1,93 mg/100 g dat d thim cd; 0,96-2,53 mg/100 g dat d thim ciy bui. RQng non va rQng gia cd ham lupng d mQc trung binh v i cao, dao dpng trong khoang tQ
2,77- 14,22 mg/100 g dat d rQng non vi tu 5,54 - 16,39 mg/100 g dit d rQng gii. Ting dat mat cd him lupng kali d i ddu cao nhat, sau dd giam ding ke d cic ting dudi.
pH va ham trong dat
lupng cac cation trao doi Nhung sd lieu phan tich vi PHKCI, cic ion trao ddi, dp chua trao ddi dupc trinh biy trong bing 4.
Bdng 4
PHKCL V^ ham lupng cac cation trao ddi trong da't trong cac trang thai tham thuc vat phuc hoi tu nhien tai Tram Da dang sinh hpc Me Linh
Trang thai
Thim cd
Tham cay bui
RQng non
RQng gii
Dp sau (cm) 0-15 15-50
> 3 0 0-15 16-30
> 5 0 0-15 15-30
> 3 0 0-15 15-30
> 5 0
P H K C I
3,79 3,89 4,07 3,81 3,80 4,11 4,72 4,59 4,59 5,02 5,05 5,05
Ca^% Mg^* trao ddi (dl/lOOgdi't) Ca""
0,48 0,22 0,28 0,30 0,10 0,10 0,14 0,10 0,12 1,84 1,38 0,82
Mg""
0,18 0,02 0,06 0,30 0,06 0,14 0,12 0,06 0,06 2,24 1,46 1,10
Dp chua trao ddi (dl/lOOgdat)
AP"
0,98 0,94 0,66 1,08 1,18 0,53 2,98 2,82 2,20 0,03 0,02 0,06
H"
0,04 0,02 0,02 0,06 0,04 0,03 0,09 0,04 0,03 0,10 0,06 0,05 Dat trong cac trang thii tham thuc vat diu
chua vdi PHKCL dao dpng trong khoang 3,79- 4,07 d tham cd; 3,81-4,11 d tham cay bui; 4,72- 5,59 d rung non v i 5,02-5,05 d rQng gii. Nhu vay, dp chua cua dat giim theo giai doan phat trien cua thim thuc vat. Theo chieu sau cua phiu dien, dp chua giim.
Hdm lugng Ca^*: trong ting dat mat d tham cd cd ham lupng cao nhit (0,48 dl/100 g dat), sau dd giim xudng 0,30 dl/IOO g dat d thim cay bui vi 0,14 dl/IOO g dat d riing non v i tang nhe len 1,84 dl/IOO g dat d rQng gia. Theo chieu sau, ham lupng Ca^" giim, mQc thi'p nhat la 0,1 dl/100 g dit d dp sau 15-30 cm v i > 50 cm tham cay bui va riing non.
Hdm lugng M^^: trong ting dat mat, rung non cd ham lupng thap nhat (0,12 dl/IOO g dit), sau dd la tham cd (0,18 dl/IOO g dit), tiep den l i tham cay bui (0,30 dl/100 g da't) va cao nhat la rung gia
(2,24 dl/100 g di't). Nhin chung, ham lupng Mg^"
diu giam theo chiiu siu cua phiu dien.
Hdm lugng A/^".- tang tQ tham cd den tham cay bui va rQng non, sau dd giim d rung gii. 0 tham cd, rirng non v i riing gii cd xu hudng giim theo chiiu sau cua phiu dien, d thim cay bui cd tang nhe d dp siu 15-30 cm nhung sau dd lai giam d dp siu > 50 cm; d ritog gia giam d dp sau 15-30 cm, sau dd tang len d dp sau > 50 cm.
Hdm lugng H*: diu thip trong tat ca cac giai doan diin the va cd xu hudng giim theo chiiu sau cua phiu dien.
III. KET LUAN
Di't dudi cic trang thai tham thuc vat kha day (tren dudi 1 m); hinh thii cua phiu dien cd su phin di rd rang vi ciu true va mau sic. Tham thuc vat cd tic dung phuc hdi ting A„ d rQng
non va rung gia.
Dudi cic trang thai thim thuc vat, cip hat <
2 mm chie'm ty le thap nhit: tQ 0,21-6,44%; sau dd la cip hat < 0,002 mm (7,53-24,11%) v i cap hat < 0,002 mm (30,58-37,1%); cap hat 2,1-0,05 mm chie'm ty le cao nhat (41,13-60,59%). Theo giai doan diin the, dp xdp cua dit tang cdn dung trpng giam.
Ham lupng mun trong ting da't mat (0-10 cm) cua tham cd va tham cay btii diu d mQc ngheo (dudi 2%), cua rung non mdi phuc hdi va rung gii tang ldn d mQc trung binh (> 3,5%). Ham lupng mun giam theo chiiu siu cua phiu dien.
Ham lupng cac chat dinh dudng trong dat khong cao. Trong ting dit mat (0-10 cm) ham lupng dam giao dpng trong khoing 0,12-0,31%, lan tdng so: 0,15-0,21%; kah tdng sd: 1,32- 1,62%; lan d i tidu: 2,06-5,68 mg/100 g dat va kali di tieu: 1,93-16,39 mg/100 g dat.
Dit trong cic trang thii deu cd phan Qng chua. Tham thuc vat phuc hdi cd tic dung lam giam dp chua cua dat. Him lupng cic ion AP", H", Ca^", Mg^" diu cd xu hudng giam theo chiiu sau cua phiu dien, nhtmg tang theo qua trmh diin the.
TAI LIEU THAM KHAO
1. Bp Lam nghiep, 1978: So tay dieu tra quy hogch ricng. Nxb. Ndng nghiep. Ha Npi.
2. Chuong trinh phat trien Lien Hiep Qudc, du an UNDP/FAO/VIE 96/014, 1998.
3. Ma Thi Ngpc Mai, 2007: Nghien ciiu qui trinh diin the di ldn cita thim thuc vat d Tram Da dang sinh hpc Me Linh, Vinh phuc va vung phu can. Luan i n tie'n sy Sinh hpc.
Ha Npi.
4. Ma Thj Ngpc Mai, Le Dong Tain, 2004:
Nhung van d i nghien ciiu co bin trong khoa hpc sir sdng: 818-821. Nxb. Khoa hpc va Ky thuat. Ha Ndi.
5. Le Dong Tan, Ma Thj Ngpc Mai, 2006:
Tap chl Ndng nghiep & Riat trien ndng thdn: 80- 84. Ha Npi.
6. Le Dong Tan, 2003: Tap chi Lim nghiep, 4: 465-467. Ha Npi.
7. Thai Van TrQng, 2000: Nhung he sinh thai rQng nhiet ddi d Viet Nam. Nxb. Khoa hpc v i Ky thuat. Ha Npi.
THE CHANGES IN PHYSICAL AND CHEMICAL PROPERTIES OF SOIL DURING PROGRESSIVE SUCCESSION OF VEGETATION
AT ME LINH STATION FOR BIODIVERSITY, VINH PHUC PROVINCE
MA THI NGOC MAI, LE DONG TAN SUMMARY
Forest is an ecosystem including factors of climate, soil, flora and human's impacts. Of which, the soil is an importance factor participates in forming type of climate - soil vegetation. In tropical region, the vegetation of forest has an important role for the invirionmetal protection and preservation of soil and water from erosion.
As a result, if vegetation of forest destroy, the land will be regressive, but when it is recovered these vegetation will effect to improve and increase fertility for the soil.
Melinh Station for Biodiversity is an unit of Institute of Ecology and Biological Resources, locates at Ngoe Thanh community, Phuc Yen town, Vinh Phuc province is a site that we have implemented some works on natural rehabilitation succession of forestry ecosystem in 2001. The recorded dates were published in articles recently. To add dates for this studies, in this paper the author presented the results of changes of physical and chemical properties of soil during progressive succession of vegetation. The dates indicated that the soil in stages of vegetation in areas is quite deep (more than 1 meter). The profile form of soil is clearly different in structure and color. There was not layer Ao in grassland and scrub because of erosion, but it restored in the young secondary forest (with 2.5 cm) and old secondary forest (with 6.0 cm). The restored vegetation effected to improve structure, moisture, soft, nature weight, to increase humus, content of nutrition (N, P, K) and to reduce acidity in the soil.
Ngdy nhdn bdi: 12-4-2009
