Chen Yanfeng, Zhang Lingwei, Shi Xiang, Liu Huiliang, Zhang Daoyuan
Key Laboratory of Biogeography and Bioresource in Arid Land, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urümqi, Xinjiang, China.
University of Chinese Academy of Sciences, Beijing, China.
PeerJ. 2019 Jan 11;7:e6158. doi: 10.7717/peerj.6158. eCollection 2019.
Precipitation change and nitrogen deposition are not only hot topics of current global change but also the main environmental factors affecting plant growth in desert ecosystems. Thus, we performed an experiment of increased precipitation, nitrogen, and precipitation plus nitrogen on the ephemeral annual species and in the Gurbantunggut Desert. We aimed to determine the life history responses of and to environment changes, and the germination percentage of the offspring (seeds) was also tested in the laboratory. The results showed that increased nitrogen and precipitation plus nitrogen increased the growth of both plant species, whereas increased precipitation inhibited the growth of but increased the growth of . This differential response of these two species to precipitation and nitrogen also affected the germination of their offspring. In response to increased nitrogen and precipitation plus nitrogen, the germination percentage of the offspring produced by two species decreased in conjunction with the plants exhibiting high reproduction, which may prevent overcrowding during the following year; however, the plants produced more nondormant offspring in conjunction with low reproduction under relatively greater amounts of precipitation, and offspring could occupy their habitat via rapid germination in suitable environments. Therefore, with increased precipitation and nitrogen deposition, these differences in offspring dormancy may affect their ecological niche in the community.
降水变化和氮沉降不仅是当前全球变化的热点话题，也是影响沙漠生态系统中植物生长的主要环境因素。因此，我们在古尔班通古特沙漠对一年生短命植物进行了增加降水、施氮以及降水加施氮的实验。我们旨在确定该植物对环境变化的生活史响应，并且在实验室中还测试了其后代（种子）的萌发率。结果表明，施氮以及降水加施氮均增加了两种植物的生长量，而增加降水抑制了一种植物的生长，但增加了另一种植物的生长。这两种植物对降水和氮的这种差异响应也影响了它们后代的萌发。对于施氮以及降水加施氮的情况，两种植物产生的后代萌发率随着植株表现出高繁殖率而降低，这可能会避免来年出现过度拥挤的情况；然而，在降水量相对较多的情况下，一种植物在低繁殖率时产生了更多非休眠后代，并且其后代能够通过在适宜环境中快速萌发来占据其栖息地。因此，随着降水增加和氮沉降，后代休眠的这些差异可能会影响它们在群落中的生态位。
