Erdős László, Ónodi Gábor, Ho Khanh Vu, Tanács Eszter, Akinyi Rabuogi Quinter, Török Péter, Tölgyesi Csaba, Bátori Zoltán, Kröel-Dulay György
HUN-REN Centre for Ecological Research Institute of Ecology and Botany Vácrátót Hungary.
HUN-REN-DE Functional and Restoration Ecology Research Group Debrecen Hungary.
Ecol Evol. 2024 Sep 2;14(9):e70244. doi: 10.1002/ece3.70244. eCollection 2024 Sep.
Repeated surveys of vegetation plots offer a viable tool to detect fine-scale responses of vegetation to environmental changes. In this study, our aim was to explore how the species composition and species richness of dry grasslands changed over a period of 17 years, how these changes relate to environmental changes and how the presence of spring ephemerals, which may react to short-term weather fluctuations rather than long-term climatic trends, may influence the results. A total of 95 plots was surveyed in 2005 and resurveyed in 2022 in dry grasslands of the Kiskunság Sand Ridge (Hungary, Eastern Central Europe), where there has been a significant increase in mean annual temperature during the last decades, while no trends in precipitation can be identified. Db-RDA was performed to reveal compositional changes. The changes in environmental conditions and naturalness state were assessed using ecological and naturalness indicator values. We also compared per-plot richness of all species, native species and non-native species of the old and the new relevés. All analyses were repeated after removing all spring ephemerals. We found clear temporal changes in species composition. Mean temperature indicator values increased, while mean soil moisture indicator values decreased during the 17 years. Also, decreasing per-plot richness was detected both for all species and for native species, while mean naturalness increased. After the removal of spring ephemerals, the compositional changes were less obvious although still significant. The increase in the temperature indicator values remained significant even without the spring ephemerals. However, the decrease in the moisture indicator values, the decrease in the number of all species and native species, as well as the increase in naturalness indicator values disappeared when spring ephemerals were excluded from the analyses. Our study demonstrates that between-year weather differences and long-term environmental trends both contribute to observed vegetation changes.
对植被样地进行重复调查为检测植被对环境变化的细微尺度响应提供了一种可行的工具。在本研究中，我们的目的是探究干旱草原的物种组成和物种丰富度在17年的时间里是如何变化的，这些变化与环境变化有何关系，以及春季短命植物的存在（其可能对短期天气波动而非长期气候趋势做出反应）如何影响结果。2005年在匈牙利中东部基什孔沙格沙脊的干旱草原上共调查了95个样地，并于2022年进行了重新调查，在过去几十年里，该地区年平均气温显著升高，而降水量没有明显趋势。进行去趋势对应分析（Db-RDA）以揭示组成变化。利用生态和自然度指标值评估环境条件和自然状态的变化。我们还比较了旧样方和新样方中所有物种、本地物种和非本地物种的每个样方的丰富度。在去除所有春季短命植物后，重复进行所有分析。我们发现物种组成存在明显的时间变化。在这17年中，平均温度指标值增加，而平均土壤湿度指标值下降。此外，所有物种和本地物种的每个样方丰富度均下降，而平均自然度增加。去除春季短命植物后，组成变化虽然仍然显著，但不太明显。即使没有春季短命植物，温度指标值的增加仍然显著。然而，当从分析中排除春季短命植物时，湿度指标值的下降、所有物种和本地物种数量的减少以及自然度指标值的增加都消失了。我们的研究表明，年间天气差异和长期环境趋势都对观察到的植被变化有贡献。
