Breitschwerdt Eva, Jandt Ute, Bruelheide Helge
Institute of Biology/Geobotany and Botanical Garden Martin Luther University Halle-Wittenberg Halle Germany.
German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig Leipzig Germany.
Ecol Evol. 2019 Jan 28;9(4):1691-1701. doi: 10.1002/ece3.4818. eCollection 2019 Feb.
The way functional traits affect growth of plant species may be highly context-specific. We asked which combinations of trait values are advantageous under field conditions in managed grasslands as compared to conditions without competition and land-use. In a two-year field experiment, we recorded the performance of 93 species transplanted into German grassland communities differing in land-use intensity and into a common garden, where species grew unaffected by land-use under favorable conditions regarding soil, water, and space. The plants' performance was characterized by two independent dimensions (relative growth rates (RGR) of height and leaf length vs. aboveground biomass and survival) that were differently related to the eight focal key traits in our study (leaf dry matter content (LDMC), specific leaf area (SLA), height, leaf anatomy, leaf persistence, leaf distribution, vegetative reproduction, and physical defense). We applied multivariate procrustes analyses to test for the correspondence of the optimal trait-performance relationships between field and common garden conditions. RGRs were species-specific and species ranks of RGRs in the field, and the common garden were significantly correlated. Different traits explained the performance in the field and the common garden; for example, leaf anatomy traits explained species performance only in the field, whereas plant height was found to be only important in the common garden. The ability to reproduce vegetatively, having leaves that are summer-persistent and with high leaf dry matter content (LDMC) were traits of major importance under both settings, albeit the magnitude of their influence differed slightly between the field and the common garden experiment. All optimal models included interactions between traits, pointing out the necessity to analyze traits in combination. The differences between field and common garden clearly demonstrate context dependency of trait-based growth models, which results in limited transferability of favorable trait combinations between different environmental settings.
功能性状影响植物物种生长的方式可能具有高度的情境特异性。我们探究了与无竞争和土地利用的条件相比，在管理草地的田间条件下，哪些性状值组合是有利的。在一项为期两年的田间实验中，我们记录了93个物种移植到德国不同土地利用强度的草地群落以及一个共同花园中的表现，在共同花园中，物种在土壤、水和空间有利的条件下生长，不受土地利用的影响。植物的表现由两个独立维度表征（高度和叶长的相对生长速率（RGR）与地上生物量和存活率），这两个维度与我们研究中的八个关键性状（叶干物质含量（LDMC）、比叶面积（SLA）、高度、叶片解剖结构、叶持久性、叶分布、营养繁殖和物理防御）有不同的关联。我们应用多元普氏分析来检验田间和共同花园条件下最优性状 - 表现关系的对应性。RGR是物种特异性的，并且田间和共同花园中RGR的物种排名显著相关。不同的性状解释了田间和共同花园中的表现；例如，叶片解剖结构性状仅解释了田间的物种表现，而植物高度仅在共同花园中很重要。营养繁殖能力、具有夏季持久的叶片以及高叶干物质含量（LDMC）在两种环境下都是重要性状，尽管它们的影响程度在田间和共同花园实验之间略有不同。所有最优模型都包括性状之间的相互作用，指出了综合分析性状的必要性。田间和共同花园之间的差异清楚地表明了基于性状的生长模型的情境依赖性，这导致有利性状组合在不同环境设置之间的可转移性有限。
