Abstract To assess the competitive ability of plant species, ecologists describe many species from contrasting habitats with traits that are proxies of ecophysiological functions whereas agronomists describe few species from similar habitats with process-based parameters. Here, we combined both approaches and compared many contrasting crop and weed species of temperate European arable crops in terms of competition for light, to understand weed response to shading by crop canopies and to choose light-competitive crop species and varieties. We (1) measured species parameters that drive light-competition processes in 26 crop and 35 weed species of temperate European arable cropping systems, (2) related the parameter values to species features that are easier to measure or available in databases. Early plant-growth parameters (relative growth rate RGR, initial leaf area) were measured in optimal light and nutrient conditions in a greenhouse with automatic non-destructive measurements. Potential plant morphology in unshaded conditions (specific leaf area SLA, leaf biomass ratio LBR, plant height and width per unit biomass HM and WM, vertical leaf distribution) was measured in garden plots in optimal light and nutrient conditions and harvested at 4–5 stages. Shading response was measured by comparing potential morphology to that of plants grown under shading nets. We confirmed well-known relationships (lower SLA and LBR in legumes vs non-legumes…), included new species features (base temperature, photosynthetic pathway…), and established relationships for the new shading-response parameters (weeds respond more to shade than crops, by increasing LBR, SLA, HM and WM…). Some correlations reported in ecology (RGR vs SLA…) were not verified on our species pool from arable temperate fields. Shade-response parameters explained species responses to habitat described by Ellenberg indexes, e.g., when shaded, shade-loving species (low Ellenberg-L values) increased SLA and HM to increase light interception.

中文翻译：

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杂草和作物物种对遮荫的反应。如何从物种性状和生态指标预测其形态和可塑性？

摘要 为了评估植物物种的竞争能力，生态学家从对比生境中描述了许多物种，这些生境具有代表生态生理功能的特征，而农学家用基于过程的参数描述了来自相似生境的少数物种。在这里，我们结合了这两种方法，并在光竞争方面比较了温带欧洲可耕作物的许多对比作物和杂草物种，以了解杂草对作物冠层遮荫的反应，并选择光竞争性作物物种和品种。我们 (1) 测量了在欧洲温带耕作系统的 26 种作物和 35 种杂草中驱动光竞争过程的物种参数，(2) 将参数值与更容易测量或在数据库中可用的物种特征相关联。早期植物生长参数（相对生长率 RGR，初始叶面积）在温室中的最佳光照和营养条件下通过自动无损测量进行测量。在最佳光照和营养条件下，在园地中测量未遮荫条件下的潜在植物形态（比叶面积 SLA、叶生物量比 LBR、每单位生物量 HM 和 WM 的植物高度和宽度、垂直叶分布）并在 4-5 个阶段收获. 通过将潜在形态与在遮荫网下生长的植物的形态进行比较来测量遮荫响应。我们确认了众所周知的关系（豆科植物与非豆科植物的 SLA 和 LBR 较低……），包括新物种特征（基础温度、光合作用途径……），并建立了新遮荫响应参数的关系（杂草对遮荫的反应比作物，通过增加 LBR、SLA、HM 和 WM……）。生态学中报告的一些相关性（RGR 与 SLA ……）未在我们温带耕地的物种库中得到验证。遮荫响应参数解释了物种对 Ellenberg 指数描述的栖息地的反应，例如，当有阴影时，喜荫物种（低 Ellenberg-L 值）增加 SLA 和 HM 以增加光拦截。