Changes in the timing of hay cutting in Germany do not keep pace with climate warming
Changes in the timing of hay cutting in Germany do not keep pace with climate warming
复制标题
德国割草时间的变化跟不上气候变暖的步伐
DOI：
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发表时间：
2013
影响因子：
11.6
通讯作者：
A. Menzel
中科院分区：
文献类型：
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作者：
A. Bock;T. Sparks;N. Estrella;A. Menzel
研究了一组独特的长期物候数据集，包括超过11万条德国各地第一次割草日期的记录，时间跨度为1951-2011年。此外，我们还分析了近20年来草地狐尾草开花初期的长期数据。我们测试了割草日期(基于人类决定何时割草)是否显示出与这种草原物种的发展相似的趋势、温度关系和空间分布，以及这些趋势是否与气候变化有关。第一次割草的时间受海拔、纬度和经度的影响很大(P<；0.001)，特别是表现出东西向的梯度。在过去的60年里，割草的时间发生了变化，大多数德国联邦州都有显著的进步(P<；0.05)，大约每十年一天。总体而言，对3-5月平均气温的反应非常显著(−2.87d°C−1；P<；0.001)。然而，在过去的20年里，没有一个联邦州经历了显著的进步，有两个甚至显著推迟了。对于大多数联邦州来说，1991年后这段时间的温度反应变得不那么明显或不明显。我们认为，农业土地利用的差异和农业环境计划(AES)的不平等吸收可能是导致地区差异的原因，而农业环境计划(AES)的普遍增加似乎扰乱了过去20年来干草切割的整体趋势。与草甸狐尾草物候相关的趋势和对温度的反应相比，随时间的变化趋势和对温度的反应都较小。该物种在物候上的进步大于割草上的进步，这意味着割草可能没有跟上气候变化的步伐，这可能对草原生态有积极的影响。
A unique long‐term phenological data set of over 110 000 records of 1st cutting dates for haymaking across Germany, spanning the years 1951–2011 was examined. In addition, we analyzed a long‐term data set in the beginning of flowering of meadow foxtail (Alopecurus pratensis) covering the last 20 years. We tested whether hay‐cutting dates (based on a human decision when to cut) showed trends, temperature relationships and spatial distribution similar to the development of this grassland species, and if these trends could be related to climate change. The timing of 1st hay cut was strongly influenced (P < 0.001) by altitude, latitude and longitude, revealing in particular an east‐west gradient. Over the past 60 years, there have been changes in the timing of hay cutting, with the majority of German federal states having significant (P < 0.05) advances of approximately 1 day per decade. Overall, the response to mean March–May temperature was highly significant (−2.87 days °C−1; P < 0.001). However, in the last 20 years, no federal state experienced a significant advance and two were even significantly delayed. The temperature response in this post‐1991 period became less or non‐significant for most of the federal states. We suggest that differences in agricultural land use and unequal uptakes of Agri‐Environment Schemes (AES, which encourage later cutting) were likely to be responsible for the regional differences, while the general increase in AES appears to have confounded the overall trend in hay cutting in the last 20 years. Trends over time and responses to temperature were small relative to those associated with the phenology of meadow foxtail. The advance in phenology of this species is greater than the advance in hay cutting, implying that hay cutting may not be keeping pace with a changing climate, which may have a positive effect on grassland ecology.