Soil nutrient supply modulates temperature-induction cues in mast-seeding grasses.
Soil nutrient supply modulates temperature-induction cues in mast-seeding grasses.
复制标题
土壤养分供应调节肥大播种草的温度诱导信号。
DOI：
10.1890/11-1750.1
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发表时间：
2012
期刊：
影响因子：
4.8
通讯作者：
D. Coomes
中科院分区：
文献类型：
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作者：
Andrew J. Tanentzap;William G. Lee;D. Coomes
长寿植物的同步和间歇繁殖，即所谓的桅杆播种，是由气候信号诱导的，但解释相邻但土壤隔离的物种之间桅杆播种差异的机制尚不清楚。土壤养分可以促进开花，因此，在营养丰富的土壤上的种群可能需要不太适宜的生长温度才能开花。我们通过预测新西兰南岛五种高山Chion ochloa草37年来开花对气温的响应，并将我们的预测与土壤N供应(NH4(+)+NO3(-))联系起来，验证了这一假设。夏季气温比春季气温更能预测开花，春季气温与土壤氮素矿化相关。富氮土壤上的物种需要较低的平均温度来诱导开花和/或在气温梯度上做出更一致的反应，从而导致它们的分蘖和草袜在夏季温度较低时开花的可能性更高。我们的结果表明，开花主要是对温暖的夏季温度做出反应，但富含N的土壤上的物种需要不那么有利的生长条件，因为它们在种子中投入的N相对较少。因此，预测丰产需要考虑气候、植物内部资源和矿质养分吸收之间的相互作用。
Synchronous and intermittent reproduction in long-lived plants, known as mast seeding, is induced by climatic cues, but the mechanism explaining variation in masting among neighboring but edaphically segregated species is unknown. Soil nutrients can enhance flowering, and thus, populations on nutrient-rich soils may require less-favorable growing temperatures to flower. We tested this hypothesis by predicting the probability of flowering in response to air temperature for five species of alpine Chionochloa grasses in South Island, New Zealand, over 37 years and relating our predictions to soil N supply (NH4(+) + NO3(-)). Summer air temperatures better predicted flowering than spring air temperatures, which were correlated with soil N mineralization. Species on N-rich soils required lower mean temperatures to induce flowering and/or responded more consistently across a gradient of air temperatures, contributing to the higher probability of their tillers and tussocks flowering at low summer temperatures. Our results suggest that flowering primarily occurs in response to warm summer temperatures, but species on N-rich soils require less favorable growing conditions because they invest relatively less N in seeds. Thus, predicting masting requires a consideration of the interactions among climate, the internal resources of plants, and mineral nutrient uptake.