Germination requirements and seed mass of slow- and fast-colonizing temperate forest herbs along a latitudinal gradient
Germination requirements and seed mass of slow- and fast-colonizing temperate forest herbs along a latitudinal gradient
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DOI：
10.2980/16-2-3234
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发表时间：
2009-01-01
期刊：
影响因子：
1.3
通讯作者：
Baskin, Carol C.
中科院分区：
文献类型：
--
作者：
Graae, Bente J.;Verheyen, Kris;Baskin, Carol C.
关于气候变化导致适宜栖息地迁移的预测表明，定居能力较差的植物物种可能无法足够快地移动，以适应预测的气候引起的栖息地分布变化。然而，对早期全新世植物迁徙的研究表明，许多植物物种在今天是糟糕的定居者，它们快速迁徙。我们假设，全新世早期较暖的温度产生了更高的种子质量，这有助于解释快速迁徙。我们研究了沿1400公里纬度梯度采集的11种具有不同定殖力的森林草本植物的种子质量、发芽率和打破种子休眠的要求这3个种子质量变量的变化。在种内，种子质量与纬度呈正相关，而发芽力与温度(采种时获得的生长度小时数)呈较强的正相关。只有慢定殖型物种的发芽率随温度的升高而增加，而只有快速定殖型物种的发芽率随纬度的增加而增加。这些相互作用只有在分析种子的发芽力时才能检测到，即使这一性状与种子质量相关。打破休眠的需要与纬度或温度无关。结果表明，气候变暖可能有利于缓慢移居者的种子发育，进而可能对它们的迁徙能力起到重要作用。
Predictions on displacement of suitable habitats due to climate change suggest that plant species with poor colonization ability may be unable to move fast enough to match forecasted climate-induced changes in habitat distribution. However, studies on early Holocene plant migration show fast migration of many plant species that are poor colonizers today We hypothesize that warmer temperatures during the early Holocene yielded higher seed quality, contributing to explaining the fast migration. We studied how the 3 seed quality variables, seed mass, germinability, and requirements for break of seed dormancy, vary for seeds of 11 forest herb species with varying colonization capacity collected along a 1400-km latitudinal gradient. Within species, seed mass showed a positive correlation with latitude, whereas germinability was more positively correlated with temperature (growing degree hours obtained at time of seed collection). Only slow-colonizing species increased germinability with temperature, whereas only fast-colonizing species increased germinability with latitude. These interactions were only detectable when analyzing germinability of the seeds, even though this trait and seed mass were correlated. The requirement for dormancy break did not correlate with latitude or temperature. The results indicate that seed development of slow colonizers may be favoured by a warmer climate, which in turn may be important for their migration capacity.