Biodiversity effects on seasonality, trends, and events in highly resolved long-term time series of the N and P cycles: a synthesis

生物多样性对 N 和 P 循环的高分辨率长期时间序列中的季节性、趋势和事件的影响：综合

• 批准号: 289418115
• 负责人: Professorin Dr. Yvonne Oelmann
• 金额: --
• 依托单位: Institut für Geographie und Geoökologie (IFGG)
• 依托单位国家: 德国
• 项目类别: Research Units
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2020-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/289418115?language=en
• 关键词: Biodiversity; effects; seasonality; trends; events

Plant diversity influences many ecosystem variables, such as productivity and nutrient cycling. However, only a few studies differentiated between initial (short-term) and longer-term effects of plant diversity. In the few existing longer-term studies including the Jena Experiment, the relationship between plant diversity and ecosystem variables, mostly productivity, became stronger with time suggesting that short-term experiments underestimated biodiversity effects. Plant diversity effects on productivity can be expected to feed back on element cycling, and even more so with ongoing experimental duration. This may cause differently pronounced temporal trends along the plant diversity gradient and also may modify the size of (seasonal) variability and the effects of extreme events on ecosystem functioning. Our objectives are to test (i) whether the strength of plant diversity effects on element concentrations, fluxes, and (stoichiometric) ratios changes with season; (ii) if plant diversity controls variability in element concentrations, fluxes and ratios; (iii) whether the temporal course of monthly-resolved element concentrations, fluxes and ratios (as reflected by linear and non-linear trends, seasonal amplitudes, and breaking points) depend on plant community composition. Furthermore, we assess which role other plot properties and environmental conditions including particularly wet and dry phases, extreme temperatures, and cumulative meteorological indicators such as sum of precipitation or temperature during key periods in the vegetation period play; (iv) whether the plot-specific soil or plant histories in the delta-BEF experiment influence the biodiversity-nutrient cycling relationship. Our analyses will rely on time series of water fluxes and element concentrations, fluxes, and ratios in fortnightly resolution since 2003. To cope with measurement gaps, we will use Bayesian modeling for gap filling. The completed data sets will then be treated with methods of the mathematical time series analysis.

植物多样性影响许多生态系统变量，例如生产力和营养循环。但是，只有少数研究区分了植物多样性的初始（短期）和长期影响。在包括Jena实验在内的少数现有长期研究中，随着时间的流逝，植物多样性与生态系统变量之间的关系大多是生产力，这表明短期实验低估了生物多样性的影响。植物多样性对生产率的影响有望以元素循环为基础，而随着持续的实验持续时间的影响。这可能会导致沿植物多样性梯度沿着植物多样性梯度的时间趋势不同，并且也可能会改变（季节性）变异性的大小以及极端事件对生态系统功能的影响。我们的目标是测试（i）植物多样性对元素浓度，通量和（化学计量）比率的影响是否随季节变化； （ii）如果植物多样性控制元素浓度，通量和比率的变异性； （iii）每月分辨元素浓度，通量和比率的时间介绍（如线性和非线性趋势所反映的，季节性幅度和断裂点）取决于植物群落的组成。此外，我们评估了尤其是潮湿和干燥相，极端温度以及累积气象指标的其他情节特性和环境条件的角色，例如植被期间的关键时期降水量或温度之类的累积气象指标； （iv）DELTA-BEF实验中特定的土壤或植物历史是否会影响生物多样性循环关系。我们的分析将依赖于自2003年以来每两周分辨率的水通量和元素浓度，通量和比率的时间序列。为了应对测量空白，我们将使用贝叶斯建模来进行间隙填充。然后，完整的数据集将使用数学时间序列分析的方法处理。