5 sentences

1. 食物链维持了生态系统的平衡。

   shí​wù​liàn wéi​chí le shēng​tài xì​tǒng de píng​héng.

   The food chain maintains the balance of the ecosystem.

   Source: Dong Chinese Dictionary

2. 生物多样性对生态系统至关重要。

   shēng​wù duō​yàng​xìng duì shēng​tài xì​tǒng zhì​guān​zhòng​yào.

   Biodiversity is vital to the ecosystem.

   Source: Dong Chinese Dictionary

3. 这位生物学家致力于研究海洋生态系统。

   zhè wèi shēng​wù​xué​jiā zhì​lì yú yán​jiū hǎi​yáng shēng​tài xì​tǒng.

   This biologist is dedicated to studying marine ecosystems.

   Source: Dong Chinese Dictionary

4. 海藻在海洋生态系统中起着非常重要的作用。

   hǎi​zǎo zài hǎi​yáng shēng​tài xì​tǒng zhōng qǐ zhe fēi​cháng zhòng​yào de zuò​yòng.

   Seaweed plays a very important role in the marine ecosystem.

   Source: Dong Chinese Dictionary

5. 沙漠里各种动植物构成了一个脆弱的生态系统。

   shā​mò lǐ gè zhǒng dòng​zhí​wù gòu​chéng le yī gè cuì​ruò de shēng​tài​xì​tǒng.

   The various plants and animals in the desert constitute a fragile ecosystem.

   Source: Dong Chinese Dictionary