Popularize these 2 kinds of cultivated trees in great quantities in the country before, want to prohibited cultivating now, if the farmer was disobeyed, still can be faced with by amerce, so farmer friend must notice!
The reforming and opening that is in China is earlier, it is the time of a corporeal lack, as social development, country is bigger and bigger to the demand of lumber, because domestic tree grows slow, satisfy this one requirement very hard. In last centuries then branch of forestry of 80 time nation was introduced from abroad many fast unripe tree cultivates promotion, north basically is poplar, and south basically is ash. Through very old development, home's ceaseless to the demand of lumber amplification, to satisfy the requirement of the market, fast the tree that gave birth to a tree to become a country to popularize is planted.
As the elapse of time, this kind fast unripe forest the problem that creates more and more reflected come out: Because big thrust of the country is wide, plus market economy revulsive bring about our country fast unripe forest main tree is planted the construction is very single, south basically is give priority to with ash, and north is to cultivate poplar, the structure is simple the stability of zoology is very poor, resist very hard the problem; such as plant diseases and insect pests still had to throw into confusion namely local ecosystem, cause bad situation play havoc with. Below two simple kinds this fast unripe tree.
1, ash
Why can be ash belonged to fast give birth to a tree? Because its rising action is very quick, because huge rising action draws many water share toward underground,ash is met inside the 8 growth period that reach 10 years, and its root absorbs the ability of water portion exceedingly powerful, bring about the other tree all round it to plant thereby cannot draw water share and die, and because grow rate is very rapid, it meets ash race to control is other and arboreous feudal, he resembles an aggressor what the tree of same embezzlement this locality plants is feudal. Cause local tree to plant onefold, structure of silvan plant community is not stable, plant diseases and insect pests is sent easily more, destroy local zoology environment badly.
2, poplar
Respecting poplar, the friend that believes north affirms special profundity to its impression, be in especially annual arrived in April May when, when walking into poplar forest, resembling is the picture that enters a winter, the Yang Xushi that poplar trail comes to affects a the biggest question to people. The Yang Xuhou of person bring into contact with of those allergic constitutions, cause easily snorty, sneeze, breath is hurried wait for a symptom, sufferred from irritability rhinitis and asthmatic crowd to should notice more. As the national attention to the environment, this kind of poplar also was prohibited cultivating.
