Life history responses of two ephemeral plant species to increased precipitation and nitrogen in the Gurbantunggut Desert
Life history responses of two ephemeral plant species to increased precipitation and nitrogen in the Gurbantunggut Desert
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古尔班通古特沙漠中两种短命植物对降水和氮增加的生活史反应
DOI：
10.7717/peerj.6158
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发表时间：
2019-01-11
期刊：
影响因子：
2.7
通讯作者：
Zhang, Daoyuan
中科院分区：
文献类型：
--
作者：
Chen, Yanfeng;Zhang, Lingwei;Zhang, Daoyuan
降水变化和氮沉降不仅是当前全球变化的热点话题，也是影响荒漠生态系统植物生长的主要环境因子。因此，我们对古尔班通古特沙漠中的一年生短暂物种荆芥和 Eremopyrum distans 进行了增加降水、氮和降水加氮的实验。我们的目的是确定微甘菊和远距菊的生活史对环境变化的反应，并在实验室测试了后代（种子）的发芽率。结果表明，氮素增加和降水加氮肥促进了两种植物的生长，而降水量增加则抑制了微甘草的生长，但促进了远景桉的生长。这两个物种对降水和氮的不同反应也影响了它们后代的发芽。由于氮的增加和降水加氮，两个物种产生的后代的发芽率下降，同时植物表现出高繁殖力，这可能会防止来年的过度拥挤；然而，在相对较多的降水量下，金甘菊植物产生了更多的非休眠后代，且繁殖率较低，并且金甘菊后代可以通过在合适的环境中快速发芽来占据其栖息地。因此，随着降水和氮沉降的增加，后代休眠的这些差异可能会影响它们在群落中的生态位。
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 Nepeta micrantha and Eremopyrum distans in the Gurbantunggut Desert. We aimed to determine the life history responses of N. micrantha and E. distans 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 N. micrantha but increased the growth of E. distans. 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 N. micrantha plants produced more nondormant offspring in conjunction with low reproduction under relatively greater amounts of precipitation, and N. micrantha 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.