作者：
Xiao-Hui Zhou1,2 and Wei-Ming He1,2*
单位：
1State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
2College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, China
Abstract
植物的性能通常依赖于温度，因此这种性能可能随着气候变暖而变化。种子是植物最重要的繁殖体之一，种子性状对植物入侵的成功与否有很大影响。因此，了解气候变暖条件下的种子性状对预测入侵风险具有重要意义。为此，我们利用红外辐射器进行了增温实验，并研究了5年增温（比环境温度高约2℃）对加拿大一枝黄花种子质量和随后萌发的影响，这些一枝黄花分别来自北美（24个本土种群）和中国（29个入侵种群）。温度制度（即环境vs.变暖）与种群源（即本地vs.入侵）相互作用显著影响种子萌发，但对千粒重没有影响。增温显著提前了加拿大土生植物种群的种子萌发时间，提高了其种子发芽率；增温对入侵加拿大一枝黄花的萌发时间没有影响，但降低了其萌发率。在两种温度组合下，24个本土加拿大一枝黄花种群的种子体积较小，萌发时间较晚，发芽率低于29个入侵加拿大一枝黄花种群。这些发现表明，气候变暖可能促进本地而非入侵种群的种子发芽。我们的数据还强调，由于种子质量更好，种子萌发速度更快，入侵种群可能比本地种群更成功。
TABLE 1.Field sites where seeds were collected for the experiment.
TABLE 2.Effects of population sources (source) and temperature regimes (temperature), both of which were treated as fixed factors, on the thousand-seed mass (seed mass), first germinating time (first germination), half germinating time (half germination), and germination rate.
FIGURE 1.Effects of population sources and temperature regimes on the thousand-seed mass of Solidago canadensis populations. Data are means + 1 SE (n = 5). The line indicates the average value of the thousand-seed mass for populations grown under a given temperature regime. Detailed statistical analyses are presented in Table 2.
FIGURE 2.Effects of population sources and temperature regimes on the first germinating time of Solidago canadensis populations. Data are means + 1 SE (n = 5). The line indicates the average value of the first germinating time for populations grown under a given temperature regime. Detailed statistical analyses are presented in Table 2.
FIGURE 3.Effects of population sources and temperature regimes on the half germinating time of Solidago canadensis populations. Data are means + 1 SE (n = 5). The line indicates the average value of the half germinating time for populations grown under a given temperature regime. Detailed statistical analyses are presented in Table 2.
FIGURE 4.Effects of population sources and temperature regimes on the germination rate of Solidago canadensis populations. Data are means + 1 SE (n = 5). The line indicates the average value of the germination rate for populations grown under a given temperature regime. Detailed statistical analyses are presented in Table 2.
综上所述，气候变暖可能对原生生境植物种群的种子萌发产生更强的影响，而对入侵生境植物种群的影响不明显。换句话说，在萌发方面，本地种群可能比入侵种群对气候变暖更敏感。在两种气候条件下，入侵种群可能比本地种群更成功，因为前者有更好的种子质量和更快和更高的种子萌发。研究结果表明:对不同气候带植物种子性状的网络研究对于研究气候变暖下的植物入侵具有重要意义，未来对本土和入侵植物种子的研究将有助于进一步评估全球变化下的入侵风险。
