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In its native China, the Tree of Heaven isn' t a problem, but in a different habitat like Britain, the insects and diseases that normally keep its growth in check aren' t here. How old is this one, then? Well, that is. The leaves you can see there is a year' s growth, well less than a year' s growth, several months. These things can grow three, four metres in a year, so this is not a particularly big one. In just less than a year, this is how high it can grow or higher? Yes. That' s incredible. And there' s baby down there, so that' s just really in its first season. Okay. What kind of damage can it cause to our native plants? It just forms a thicket and actually just covers them. It also has a capacity to do something called allelopathy, which means that it produces chemicals from its leaves, and when rain falls onto it, the chemicals wash out of the leaves and soak into the ground. These chemicals actively inhibit the growth of other plants, so it' s got a double whammy in that it' s shading out other plants and then effectively poisoning its competitors as well, a very effective strategy if you' re a Tree of Heaven, but pretty bad news for our native plants. Okay. It' s a bit of a horror. I' ll never look at one of these again in the same way. I have to. |
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zài tiān táng shù de gù xiāng zhōng guó, tā cóng bù lìng rén cāo xīn, dàn zài huán jìng jiǒng yì de yīng guó, méi yǒu xiāng yìng de kūn chóng hé bìng hài, lái yì zhì tā men de shēng zhǎng. zhè kē shù duō dà le dà gài shì kě jiàn de yè zǐ dōu shì yī nián zhī nèi shēng de, bú dào yī nián, jǐ gè yuè ba. zhè zhòng zhí wù yī nián zhī jiān jiù néng zhǎng sān sì mǐ, suǒ yǐ zhè zhū hái bù suàn dà. bú dào yī nián, tā jiù kě yǐ zhǎng zhè me gāo, shèn zhì gèng gāo méi cuò. bù kě sī yì ya zhè xià miàn hái yǒu kē shù miáo, hái bú dào sān ge yuè dà, zhèi xiē tā men duì běn dì zhí wù yǒu shén me wēi hài ne? tā men xíng chéng cóng lín, zhē dǎng zhù běn dì zhí bèi, tā hái yǒu" zhí huà xiāng kè" de wēi lì. zhè zhòng shù de yè zi huì fēn mì huà xué wù zhì, dāng yǔ shuǐ luò dào shù yè shàng, huà xué wù zhì bèi chōng diào, bèi tǔ dì xī shōu. zhèi xiē huà xué wù zhì néng yǒu xiào yì zhì, qí tā zhí bèi de shēng zhǎng, yǐ tā de zhē bì duì qí tā zhí wù de dǎ jī shì shuāng chóng de, zhēng qiǎng yáng guāng de tóng shí hái dú hài tā men. zhè shì tiān táng shù de yǒu lì shēng cún shǒu duàn, dàn duì yú běn tǔ zhí wù, zé shì è hào, què shí kě pà, wǒ yào duì tā men lìng yǎn xiāng kàn le. |