PDF(Pubmed)
Abstract：
Tall clonal grasses commonly display competitive advantages with nitrogen (N) enrichment. However, it is currently unknown whether the height is derived from the vegetative or reproductive module. Moreover, it is unclear whether the height of the vegetative or reproductive system regulates the probability of extinction and colonization, and determines species diversity. In this study, the impacts on clonal grasses were studied in a field experiment employing two frequencies (twice a year vs. monthly) crossing with nine N addition rates in a temperate grassland, China. We found that the N addition decreased species frequency and increased extinction probability, but did not change the species colonization probability. A low frequency of N addition decreased species frequency and colonization probability, but increased extinction probability. Moreover, we found that species reproductive height was the best index to predict the extinction probability of clonal grasses in N-enriched conditions. The low frequency of N addition may overestimate the negative effect from N deposition on clonal grass diversity, suggesting that a higher frequency of N addition is more suitable in assessing the ecological effects of N deposition. Overall, this study illustrates that reproductive height was associated with the clonal species extinction probability under N-enriched environment.
摘要：
高克隆草通常具有氮（N）富集的竞争优势。然而,目前尚不清楚身高是来自植物还是生殖模块。此外，尚不清楚植物或生殖系统的高度是否调节灭绝和定殖的可能性，并决定物种多样性。在这项研究中,对克隆草的影响在田间试验中进行了研究，采用两种频率(每年两次与每月)在温带草原中以9个氮添加率穿越，中国。我们发现氮的添加降低了物种频率，增加了灭绝概率，但并没有改变物种定殖的概率。低频率的N添加降低了物种频率和定殖概率，但增加了灭绝的可能性。此外，我们发现，物种繁殖高度是预测富氮条件下克隆草灭绝概率的最佳指标。低频率的氮添加可能高估了氮沉积对克隆草多样性的负面影响。表明较高的N添加频率更适合评估N沉积的生态效应。总的来说,这项研究表明，在富氮环境下，生殖高度与克隆物种灭绝概率有关。
