Applying concepts from natural ecosystem ecology, particularly through diversified cropping systems that integrate woody crops with other crops, can enhance agrobiodiversity and significantly contribute to multifunctional agriculture. The ecological and, more recently, the agronomic literature have indicated that functional trait aspects of diversity offer a more comprehensive explanation for ecosystem functions compared to species richness alone. In this study, we apply the trait-based approach during experimental agroforest succession in subtropical Southern Brazil to investigate the main factors of crop functional structure, differentiating the effects of functional diversity (FD) from functional identity (CWM - community weighted mean), on Nature's Contributions to People (NCP). The experiment was designed varying crop FD, based on leaf nitrogen concentration, while maintaining crop species richness constant across all treatments. To assess FD and CWM, we measured six crop traits; maximum plant height, leaf area, specific leaf area, leaf nitrogen content, leaf dry-matter content, and stem-specific density. Additionally, we evaluated four material NCP (green manure, forage, germplasm, and food) based on data collected during the initial four years of the experiment (2017–2020). To analyze the data, we employed principal component analysis to reduce the number of variables and subsequently fitted linear mixed-effect models. Our findings provide support for the hypothesis that crop functional structure, particularly in relation to leaf traits (leaf area and leaf nitrogen content) and vegetative height, significantly influences material outputs and predicts above-ground biomass production that can be utilized as green manure and animal feed in agroforestry and silvopastoral systems. Both FD and CWM were important drivers of NCPs, showing that both niche complementarity and selection effects contribute to explain agroecosystem functioning. By utilizing functional traits, we reached valuable insights for generating agronomical recommendations and enhancing cropping system diversification through effective trait-based management.

中文翻译：

---

作物功能结构预测多样化农林业中自然对人类的物质贡献


应用自然生态系统生态学的概念，特别是通过将木本作物与其他作物相结合的多样化种植系统，可以增强农业生物多样性，并对多功能农业做出重大贡献。生态学和最近的农艺文献表明，与单独的物种丰富度相比，多样性的功能性状方面为生态系统功能提供了更全面的解释。在本研究中，我们在巴西南部亚热带的农林演替实验中应用基于性状的方法来研究作物功能结构的主要因素，区分功能多样性（FD）与功能同一性（CWM - 群落加权平均值）的影响，大自然对人类的贡献（NCP）。该实验根据叶片氮浓度设计了不同的作物 FD，同时在所有处理中保持作物物种丰富度恒定。为了评估 FD 和 CWM，我们测量了六种作物性状；最大株高、叶面积、比叶面积、叶氮含量、叶干物质含量和茎比密度。此外，我们根据实验最初四年（2017-2020）收集的数据评估了四种材料 NCP（绿肥、饲料、种质和食品）。为了分析数据，我们采用主成分分析来减少变量数量，并随后拟合线性混合效应模型。 我们的研究结果支持了以下假设：作物功能结构，特别是与叶子性状（叶面积和叶子氮含量）和营养高度相关的结构，显着影响物质产出并预测可用作绿肥和动物的地上生物量产量为农林业和林牧系统提供饲料。 FD 和 CWM 都是 NCP 的重要驱动因素，表明生态位互补性和选择效应都有助于解释农业生态系统的功能。通过利用功能性状，我们获得了宝贵的见解，可以通过有效的基于性状的管理来生成农艺建议并增强种植系统的多样化。