Интегрированное письмо TOEFL

📖 Текст для чтения

The introduction of non-native species into new environments is often viewed with alarm, but a growing body of evidence suggests that such introductions can actually be beneficial to local ecosystems. Three key arguments support this view. First, non-native species can fill ecological niches that have been left vacant due to habitat degradation or the extinction of native species. For example, in Hawaii, the introduction of the Japanese white-eye bird has helped pollinate native flowers whose original pollinators had disappeared, thereby aiding in plant reproduction. Second, non-native species can increase biodiversity at the local level. In many urban and agricultural landscapes, native species are already scarce, and non-native species add to the total number of species, creating more complex food webs and increasing overall ecosystem resilience. Third, non-native species often bring economic and practical benefits to humans. For instance, non-native crops and livestock, such as corn and cattle in the Americas, have provided reliable food sources, and non-native trees like eucalyptus have been used for timber and erosion control. These advantages suggest that the blanket rejection of non-native species is misguided, and that careful management could turn these introductions into ecological and economic assets.

🎧 Лекция

The reading argues that non-native species can be beneficial, but this view is flawed. Firstly, the claim that non-native species fill vacant ecological niches is misleading. In reality, the absence of native pollinators in Hawaii was caused by habitat destruction, and the Japanese white-eye, while pollinating some flowers, also competes with native birds for insects and spreads invasive plant seeds, leading to a net negative impact on native flora and fauna. Secondly, while non-native species may increase species count, this does not equate to genuine biodiversity. True biodiversity includes the abundance and health of native species, and non-native species often become invasive, outcompeting natives and reducing their populations. For example, in many lakes, introduced fish species have caused native fish to decline, thus decreasing overall native biodiversity even if total species numbers remain high. Thirdly, the economic benefits of non-native species are often short-term and come with hidden costs. Eucalyptus trees, for instance, are highly flammable and have increased wildfire risks, while also depleting water resources, which has led to enormous economic losses in fire suppression and water management. Therefore, the supposed benefits of non-native species are outweighed by their long-term ecological and economic harms, casting serious doubt on the reading's claims.