Decadal changes in masting behaviour of oak trees with rising temperature
Decadal changes in masting behaviour of oak trees with rising temperature
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随着温度升高，橡树的肥大行为发生了十年的变化
作者：
M. Shibata;T. Masaki;T. Yagihashi;T. Shimada;T. Saitoh
在全球气候变化的背景下，播种行为的年代际变化——种子生产随年代际时间尺度波动的方向性变化——引起了广泛的关注。然而，我们对气候对种子生产在年代际尺度上的影响的机制理解并不令人满意，部分原因是对长期数据的统计分析不足。基于日本北上山的长期数据（38年：1980-2017），我们检测了日本栎（Quercus crispula）的吸塑行为的年代代性变化。20年滑动窗内种子产量的移动平均值增大，变异系数减小。小波功率谱和二阶对数线性自回归（AR）模型表明，捕获周期从3年或4年缩短到2年。随着温度的升高，种子产量的移动平均呈线性增加。两种AR模式系数随温度的变化曲线均为凹形曲线。合成。通过对一个长期种子生产数据集进行统计分析，我们获得了日本栎树采伐行为年代际变化的重要证据，并表明采伐间隔的缩短与温度升高有关。会议讨论了资源分配转移和环境否决可能是造成年代际变化的机制。
Decadal changes in masting behaviour—directional changes in seed production with fluctuations on a decadal time‐scale—are attracting widespread attention in the context of global climate change. However, our mechanistic understanding of the effects of climate on seed production on a decadal scale is unsatisfactory, partly because of the insufficient statistical analyses of long‐term data on masting. We detected decadal changes in masting behaviour in the Japanese oak Quercus crispula based on long‐term data (38 years: 1980–2017) from the Kitakami Mountains of Japan. The moving average of seed production in a 20‐year sliding window increased, whereas the coefficient of variation decreased. A wavelet power spectrum, as well as a second‐order log‐linear autoregressive (AR) model showed that masting intervals shortened from 3‐ or 4‐year cycle to a 2‐year cycle. The moving average of seed production increased linearly as the moving average of temperature increased. Temporal variations of the two AR model coefficients as a function of temperature were well described by concave curves. Synthesis. By conducting the statistical analyses of a long‐term seed production dataset, we obtained significant evidence of decadal changes in the masting behaviour of the Japanese oak and showed that the shortening of the masting interval was associated with rising temperature. A resource allocation shift and an environmental veto were discussed as possible mechanisms underlying the decadal change.