Analysis of root traits to test for environmental filtering and niche complementarity in grassland communities

虽然前面的项目是根据地上特征从整个区域物种库中预测接受群落的物种表现，但如果预测结果较低，将改变人们的观点，从新来者的角度出发，旨在预测新来者可能在哪个当地社区表现最好。我们将特别强调与地下过程有功能联系的特征，从而分析根特征和分泌物，包括植物分泌的一系列低分子有机化合物。我们将检验这样的假设：(H1)生存和表现可以通过物种在特定地区的共同出现的统计概率来预测；(H2)群落加权平均性状和功能多样性与土地利用强度有关；(H3)叶经济学谱与根经济学谱相关。此外，我们将测试(H4)在特定环境设置中，存在定义的与居民社区的特征相似程度，在该程度上，通过限制相似性来平衡环境过滤和竞争，从而使性能最大化。此外，我们假设(H5)根特征值和根分泌物模式被调整以适应当地的邻居和土地利用，(H6)某些根特征值和分泌物导致土壤条件随时间的变化，(H7)根分泌物的组成是植物特有的，特别是草本植物不同于草本植物。我们计划使用菌根和非菌根各10种以及草本植物和草本植物各10种，共计20种，在田间和温室中进行研究。对于其中的10个，我们将分析根分泌物。该项目将由四个工作包组成，其中包括培育植物和分析当地邻里关系(WP1)，在54个草地地块(3个探索室，3个土地利用类型，6个重复)中种植20个物种的植物温度计，监测它们的生长，并在最终收获时评估它们的解剖、形态和化学根特征，并使用这些数据预测组装规则(WP2)，进行温室盆栽实验以进行根特征分析(WP3)，以及分析分泌物和根用于基于质谱仪的非靶标代谢物分析(WP4)。综上所述，我们汇集了功能生物多样性研究，群落生态学和功能根研究，以填补地上和地下过程之间的重要空白。

While the preceding project BE RICH predicted species performance in a recipient community from the whole regional species pool based on aboveground traits, BE LOW will change the perspective and take on the newcomers' perspective, aiming at predicting in which local neighbourhood a newcomer might perform best. We will have a particular emphasis on traits with a functional link to belowground processes, and thus analyse root traits and exudates, including a broad spectrum of low molecular organic compounds exudated by plants. We will test the hypotheses that (H1) survival and performance can be predicted from the statistical probability of co-occurrence of a species in a specific local neighbourhood, (H2) community-weighted mean traits and functional diversity is related to land use intensity, (H3) the leaf economics spectrum is related to the root economics spectrum. In addition, we will test that (H4) in a specific environmental setting there is a defined degree of trait similarity to the resident neighbourhood community at which performance is maximized, caused by a balance of environmental filtering versus competition by limiting similarity. Furthermore, we hypothesize that (H5) root trait values and root exudation patterns are adjusted to the local neighbourhood and to land use, (H6) certain root trait values and exudates result in a change in soil conditions with time and (H7) that root exudate composition is plant species-specific, and in particular grass species differ from herb species. We plan to use ten species each of mycorrhizal and non-mycorrhizal species as well as ten species each of grass and herb species, in total 20 species, studied both in the field and in the greenhouse. For ten of them we will analyse root exudates. The project will consist of four work packages, which will comprise raising plants and analysis of the local neighbourhood (WP1), planting phytometers of the 20 species into a selection of 54 grassland plots (3 exploratories, 3 land use types, 6 replicates), monitoring their growth and assessing their anatomical, morphological and chemical root traits at the final harvest and using these data to predict assembly rules (WP2), conducting glasshouse experiments in pots for root trait analysis (WP3), and analyzing exudates and roots for mass spectrometry-based non-targeted metabolite analysis (WP4).In summary, we bring together functional biodiversity research, community ecology and functional root research to fill an important gap between above- and belowground processes.