Cây xanh đô thị

Nude rat can cho cudc sdng cua cay, d dd thi chat lupng va luu lupng nUdc han che, bdi hau het be mat san vudn dudng phd deu la be tdng, mat dp xay dung cdng trinh trong dd thi Idn,[r]

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Q U Y H O A C H KIEN TRUC & HA TANG

C a y x a n h

d o t h i

Nguyen Th) Thai Thanh

ABSTRACT

Urban verdure is the requirement for environment and living quality

improvement for urban citizens Arrangement of verdure lines for streets and urban green spaces such as green public gardens, parks, isolating verdure lines is for maximum devel-opment of urban natural beauty, to make the city specific images and to serve the living essential needs The factors that affecting to urban verdure are climate, water, earth environment, light, insects Research for choosing plant varieties in city and necessary solutions for plant caring, is to cope with the effects of hard urban environ-ment

KTS Nguyen Thj Thai Thanh TrUcrng Cao dang Xay dimg Cong trinh Do thj

Yen Thudng - Gia Lam - Ha Noi Oi dong 0983782833

001 OIEU VE CAY XANH DO THI Cay xanh dd thi dtfpc ndi den nhieu nhU: Td chdc cay xanh cho cac tuyen phd, cdng vien, vudn hoa, nhu the se khai thac dupe tdi da ve dep canh quan thien nhien dd thi

Trong quy hoach, cac khdng gian xanh dupe coi nhu la phdi cua phd, la mdt khdng gian chdc nang phd ban tang cho cU dan dd thi de hp cd co hdi ddi khdi nhUng khdi be tdng den de tha minh hdn dao xanh cua thien nhien, tan hudng khdng lanh hiem hoi cua dd thi

Trong kien true, cay xanh dupe thiet ke lam phdng nen cho cdng trinh nhd mau sac sinh ddng va cac Idp cay tao khdng gian cd chieu sau giup cdng trinh hda nhap vdi thien nhien

Bd tri cay hpp ly se che nang tdt ma van dam bao chieu sang ttf nhien cho cdng trinh va ddn dtfpc gid mat vao mua he, chdng dtfpc gid lanh vao mua ddng

Thanh cdng viec khai thac va td chdc cay xanh dd thj tao nen sac thai rieng cua khdng gian, gdp phan lam tang ve dep canh quan va tao dupe hinh anh rieng cua phd

BAN BIET GIVE CAY XANH? Theo nghien ctfu cua vien nghien ctfu cay xanh Canada (FCA),

mdt cay khde manh cd the hap thu khoang 2,5 kg C02/nam, mdt cay trUdng cd the hap thu ttf 3000 den 7000 hat bui/m3 khdng Mdt cay trtfdng cd the cung cap Itfpng 02 can thiet cho ngtfdi

Theo nghien ctfu cua Dai hpc Michigan State University, Urban Forestry, stf hien dien cua mpt cay d gan nha giam 30% Itfpng khdng d nhiem Mdt cay trtfdng hut mat 450 lit ntfdc da't rdi lai tra ve khdng dtfdi dang hoi ntfdc de lam mdi khdng Mdt cay phong cd dtfdng kinh 30cm, mdt mua nd cd the hut dtfpc Itfpng chat kim loai nang dat nhtf 60mg cadmium, 140 mg chrome, 820mg Nickel, va 5200mg chi

Theo mpt nghien ctfu cua My ve gia trj dat d thi stf hien dien cua mdt cay lam tang them 18% gia trj mdi trtfdng

Cay co ldi ich gi?

Trong bdi canh toan cau ndng len va mdi trudng thj dang tao nhtfng dao nhiet, thi cay xanh la stf can thiet de cai thien mdi trtfdng va chat luong cudc sdng nhU: cay xanh lam giam Itfpng C02, nhu ngan bui, giam tieng on, giam nhiet bang each tao bdng mat va chdng gid bao Co the tiet

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kiem chi phi dieu hoa va sudi am nhd trdng cay xung quanh cdng trinh xay dpng Cay giup chdng xdi mdn va gitf da't Cay tao nen phong canh, cung cap noi cd tru, thdc an cho cac loai chim va bao ve cd dan phd

Ly cay thi Cdy cd tdc dung vdi tdm ly

Mau sac cua cay lam giam bdt hanh vi cudc sdng Chung ta nhan thay rang, cay trdng d benh vien giup benh nhan hdi phuc sdc khde nhanh han

2 Cdy cd tdc dung vdi khdng

Cay hap thu C02 va thai 02 giup khdng lanh

Cay hut nddc dddi Idng da't va tra lai khdng dddi dang hai nuac lam khdng mat me han

La cay va than cay can giu bui va lam giam am thanh, tieng on phd Nha't la loai cay cd vd san sui va la thd rap, bui bam lai cay mUa xudng "cat bui lai trd ve vdi cat bui"

Trdng cd tren san da't hoac bai da't trdng se ngan bui sinh td da't vao mdi trudng

3 Cdy cd tdc dung Idm sach mdi trUdng ddt

Mdt so loai cay than gd cd kha nang hap thu dupe cac chat kim loai nang da't d nhiem nhu chat Pb, Cd, Co, Zn, Cu nen cay cd

Arbre-Paris the lam giam dupe cac chat ddc hai xam nhap tdi ngudn nddc ngam khu vUc dan cU

4 Cdy cd tdc dung ngdn tieng on

Am phan xa qua lai nhieu lan qua cac tan cay se giam lupng am dang ke Vi vay, thiet ke cac Idp cay trdng xen ke cay bui, cay tha'p tang va cay cao de giam bdt am den cac cdng trinh

5 Cdy cdi thien he sinh thai

Tao dieu kien cU tru cho chim, cdn trung, va cac ddng vat khac ThUc te la so lupng cac loai chim khac thudc vao cay trdng Cac yeu td anh hudng den cay xanh thj

7. Khi hdu

Do la nhiet dp va dp am khdng

Mua he, anh nang chieu xudng be mat be tdng (cdng trinh, san, dudng, he phd' ) va phan xa len than va la cay lam cay ndng han nhu'ng cay trdng d khu vpc ndng thdn

Mua ddng, thdi tiet khd hanh, gid lua thudng xuyen, dp am khdng it nen cay thie'u nUdc, dat khd lam giam kha nang hut khoang chat cua re cay Vi vay, cay xanh dd thi thoat hoi nude manh han cay xanh khu vuc lam nghiep tu nhien

2 Mdi trUdng nUdc

Nude rat can cho cudc sdng cua cay, d dd thi chat lupng va luu lupng nUdc han che, bdi hau het be mat san vudn dudng phd deu la be tdng, mat dp xay dung cdng trinh dd thi Idn, nen mUa xudng khdng chay tran tren mat da't va tham xudng da't nhu d mdi trudng tu nhien, ma phan Idn nude mUa se thoat vao he thdng cdng cua dd thi, chi cd mdt phan rat nho dupe tham xudng Idng dat de nuoi cay

3 Mdi trUdng dat

Chat lupng cua dat rat quan cho cay trdng:

- Da't nhieu se dam bao sU gan ket va try vUng cua cay de chdng lai gid bao

- Da't gitf nUdc, gid dupe chat dinh dudng can thiet cho su tang trudng va sU sdng cua cay

- Da't cho phep he thdng re cay hd hap nhd vao dp tai xdp

NhUng cac khu vUc thj, dat ngheo chat dinh dudng, chat hep va bi nen chat bdi cac mang khdi be tdng cua cac tda nha, san, dudng va via he, Van de da ngan can re cay di chuyen vao Idng da't, va khd khan de hut cac khoang chat

Ben canh dd, d nhiem moi trudng da't dang la van de, cac chat ddc hai td cac cdng trinh nha d, nha may, cd the la thai true tiep cung co the chi rd ri da cd nhu'ng anh hudng den sU sdng cua cay nhU rung la, benh, chet

4 Anh sdng

Cay ludn true tiep tiep xuc vdi cac tia cdc tim ngoai trdi, ddi tac ddng cua thdi gian chieu nang ca cdn gay nguy hiem cho cay khdng kem tac hai cua cudng dp chieu nang

Ngoai mdt anh hudng tren mdc binh thudng den sir phat trien cua cay xanh tren dudng phd chinh la anh sang nhan tao tu cac cdt den cao ap dpc theo duang giao thdng, cdng vien va cac khu vUdn dao khac

5. O nhiem khong

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TL/ NHIEN

Thoat ho'i nifdc binh thudng

Re cay phat trien tot

DO THI

Thoat ho'i nu'o'c manh

• i_7 i

Re cay kho phat trien

0 nhiem khong cung la yeu to anh hudng nghiem den sdc song cua cay Nhucac NO va N02, CO, S02

Khu vdc thi, nhiem dpc hai chu yeu la thai td to (N02), nhdng dac biet la nganh cong nghiep (S02) Bui khdi den bam vao than, la cay ngancanspquang hpp

6 Sau benh

Hien cd cac loai cdn trung, ray nau va cac benh nam vi khuan tan cdng cay trdng Cdn trung va sau benh khdng nhu'ng an pha cay ma cdn truyen tai cac benh nam den cay

CHAM SOC NHUNG CAY XANH TRONG DO TH| NHI/THE NAO?

Dd thi khdng phai la mdi trifdng

ly tddng de cay cdi phat trien nhien, tham chi cdn la mdi trddng khac nghiet va day nhdng han che ton tai, vi vay cay trdng phai chpn de cd the dd'i phd vdi thdi tiet, vdi chat Idpng mdi trddng sdng dd thi de phat trien khde manh

Tru'dc het phai chon gidng cay cho thj

Gid mdi trddng tu nhien yeu hon nhd vao sU san sui va ram rap cua cay cdi, nhung dd thj lai thudng xuyen cd gid lua, sdc gid Idn nha't la mua mUa bao, vi vay cay trdng dd thi, dac biet la cay tren dudng phd phai cd re bam sau, than cay trudng phai Idn va cay phai khde manh

CS Phap, yeu cau cua thiet ke, nen nhdng cay bdng mat trdng hang thudng xuyen dupe chinh sda hinh dang, la ngudn gdc dan den tinh trang sdc khde cua cay xa'u di VI vay, de tranh anh hudng den sdc khde va giam bdt kinh phi cho viec cat tia tao hinh cho nhung cay phat trien qua khd,

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chung ta nen chpn nhu'ng loai cay co sure khoe, thich nghi vdi moi trudng cu the td gidi han kich thudc, den kha nang hda nhap hau mdi trudng giup cay phat trien dupe d dia hinh chat hep khdng cho phep cay phat trien qua kho dd thi

Cham sdc cay xanh thj

Ddi phd vdi nhu'ng anh hudng cua mdi trUdng dd thj khac nghiet, cay xanh khdng tranh khdi su can cdi va tam vdc cua cay be nhd hon rat nhieu so vdi cay xanh mdi trudng tu nhien

1 Cham sdc theo cdc chu ky phat

trien cua cdy xanh thi

Trong mdi trudng dd thi, Cac chu ky phat trien cua cay van cdn tuong tu nhu mdi trudng tu nhien Vi vay, sU cham sdc va nhdng tac ddng cua ngudi van tri tuan thu vdi cac chUc nang sinh hpc va dap dng cho mdi giai doan phat trien cua cay

• Hau het cay xanh phd dupe sinh td cac vddn uam, cay thudng luu lai vudn uam khoang td den 20 nam va quang thdi gian do, re va hinh dang cay dupe tdng budc hinh

• NhUng cay chua trddng dupe trdng phd, la ly no dupe cham sdc dam bao phuc hdi td't de phat trien hai hda: No dupe tudi nude thudng xuyen, cd cpc dd gid cho cay ludn thang khdng bi nghieng, dam bao vdc dang dudng net yeu cau den cay trudng Trung binh mdi nam, cay cao them 50cm, va den trudng cay cd so tudi khoang 30 - 40 nam (tuy vao loai cay)

• Mdt vai nam sau do, cay trudng va khdng ddi hdi bat ky cham sdc dac biet nao

• cudi chu ky, chat lupng go suy giam, va cd rat nhieu phan gd chet, cay bat dau thu hut ray nau va trd len nguy hiem dd'i vdi cU dan dd thi Luc cay ddi hdi phai dupe cham sdc dac biet vdi

kinh phi Idn de got bd phan go chet, cat bdt canh la qua gia, va trang bj he thdng day bao ve de phdng trUdng hop gay canh mda gid tranh gay nguy hiem cho cd dan dd thj

2. Trdng vd chdm sdc cdy xanh

do thi

m Dd'i vdi dudng phd, cay trdng phai gid mdt khoang each nha't djnh dd'i vdi lan dudng xe chay nhu each diem giao cat dudng khoang 6m den 10m; each bd via 0,3 den 0,5m Khdng nhung de tranh che tam mat ngudi tham gia giao thdng, khdng che khua't bien chi dan tren dudng phd ma cdn giup cay tranh thuang tich, tranh va dap • Khoang each td't nhat giifa hai cay gan vao dac diem cua tdng loai cay va thudng each xa hon 3m

• GiQ am cho dat, bang each tan dung nude mua, nude thai sinh hoat da qua xd ly tudi cho cay xanh theo djnh ky hoac hang nhd vao he thd'ng tudi cay tu ddng hoac cac vdi phun cua cac xe bdn chuyen nganh

• Phun thudc trd sau benh dinh ky, nhung phai dam bao khdng anh hudng den sdc khde ngudi dan

• Cat tia nhung canh la d dp cao dddi 7m; nhu'ng canh cd anh hudng den cac cdng trinh xay dung, den he thd'ng dudng day dien va cat bd nhu'ng canh cd kha nang bj gay (muc, mpt, sap gay)

• Thay cay mdi cd kich cd tuong dng vdi cay bi chet hoac mat

• Duy tri va phat trien nhu'ng cay di san

• Cay ludn phai dd'i phd vdi he thd'ng dudng dng tang ky thuat dd thj nhU: cap dien thoai, dudng ong cap, thoat nude va rat nhieu nhu'ng yeu to khac, vi vay trudc trdng can phai tinh toan dp tru cho cay trdng d dung nai va cd tinh toan den kha nang phat trien va chiem hdu khdng gian tuong lai nhd nghien cdu tudi thp, tudi ngung phat trien va hinh dang cua cac loai cay

3 Bdo ve cdy xanh thi: m To chdc tuyen truyen ve vai trd, tac dung ciia cay xanh dd thi ddi vdi ddi sdng, van hda cua dan cu dd thi

• Thiet lap cac nhdm cdng tac bao quan va gin gid cay xanh dd thi thudng xuyen theo ddi tinh trang sdc khde cay xanh

• Mpi ngudi deu cd trach nhiem giir gin va bao quan cay xanh thj

• Trang bj nhu'ng cdng cu de bao ve su tan cdng ciia ngudi, phUOng tien giao thdng va ddng

vat den cay •

TAI LIEU THAM KHAO

1 Bourgery, C et Mailliet, L 1993 L'arboriculture urbaine Collection mission du paysage Institut pour le Developpement Forestier

2 Buntinx, B.1998 Methodes non-destruc-tives d'estimation de la vitalite des arbres urbains Travail de fin d'etudes ULB

3 http://www.cg94.fr/node/11049 Garance.voyageuse.free.fr/botanique/ programme2006.pdf