Biology subjects

Schöb, C.

Publications and source records attributed to Schöb, C..

6 recordsLinked to original sources

bioRxiv2023

Coadaptation of coexisting plants enhances productivity in an agricultural system

O_LIGrowing crops in more diverse crop systems (i.e. intercropping) is one way to produce food more sustainably. Even though intercropping, compared to average monocultures, is generally more productive, the full yield potential of intercropping might not yet have been achieved as modern crop cultivars are bred to be grown in monoculture. Breeding plants for more familiarity in mixtures, i.e. plants that are adapted to more diverse communities (i.e. adaptation) or even to coexist with each other (i.e. coadaptation) might have the potential to sustainably enhance productivity. C_LIO_LIIn this study, the productivity benefits of familiarity through evolutionary adaptation, where one species adapts to its neighbourhood, and coevolutionary coadaptation, where two or more species adapt to each other, were disentangled in a crop system through an extensive common garden experiment. Furthermore, evolutionary and coevolutionary effects on species-level and community-level productivity were linked to corresponding changes in functional traits. C_LIO_LIWe found evidence for higher productivity and trait convergence with increasing familiarity of the plants composing the community. Furthermore, our results provide evidence for coevolution of plants in mixtures leading to higher productivity of coadapted species. However, with the functional traits measured in our study we could not fully explain the productivity benefits found upon coevolution. C_LIO_LIOur study is, to our knowledge, the first study that investigated coevolution among randomly interacting plants and was able to demonstrate that coadaptation through coevolution of coexisting species in mixtures promote ecosystem functioning (i.e. higher productivity). This result is particularly relevant for the diversification of agricultural and forest ecosystems, demonstrating the added value of artificially selecting plants for the communities they are familiar with. C_LI

ecology↗

bioRxiv2023

Transgenerational coexistence history attenuates negative direct interactions and strengthens facilitation

BackgroundInteractions among species are a fundamental aspect of biodiversity and driving ecosystem functioning and services. Species interactions include direct (pairwise) interactions among two species and indirect interactions that occur when a third species interacts with the two others and changes the direct interactions between the two. In a three-species interaction network, these interactions can be transitive (where one species outperforms all others) or intransitive (where each species outperforms another). How direct and indirect interactions influence ecosystem functions in crop systems, and how diversification and evolutionary adaptation can influence those interactions and therefore ecosystem functions has not been studied. MethodsA common garden experiment was conducted with crop communities in monocultures, 2- and 3-species mixtures that had either a common or no coexistence history (i.e. community adaptation) for three years. Net, direct and indirect interaction intensities were estimated and compared between the diversity levels and coexistence histories. Furthermore, species interaction networks were inspected for transitive/intransitive interactions. ResultsWe found evidence for lower competition in mixtures and for reduced negative direct interaction intensity and enhance facilitative effects upon community adaptation. We could further show that indirect interactions were generally less important for community adaptation than direct interactions. Additionally, we showed that community adaptation has the potential to shift interactions in the species interaction networks from competitive intransitive into pairwise competitive interactions where interactions occurred mainly between two species. SynthesisCo-adapted crop species with reduced negative interactions might have the potential to enhance productivity especially in more diverse cropping systems. This supports the notion that intercropping is a vital part towards a more sustainable agriculture and one with further yield potential when developing cultivars adapted to grow in mixtures.

ecology↗

bioRxiv2023

How do different functional groups of crop perform in temperate silvoarable agroforestry systems? A case study

Agroforestry systems provide a number of ecosystem services and are frequently considered as a promising diversification strategy for more sustainable and climate resilient primary production. Still, less than 1% of the agricultural land in the European Union is silvoarable agroforestry. Most agroforestry field trials compare one crop type with a control in open field with no additional environmental treatments such as nutrient and water availability, thereby limiting our understanding of the ecological processes underlying the potential benefits of agroforestry for food production. The present experimental study addresses three factors (shade, fertilisation, irrigation) on three functionally different crop species (field bean, summer barley, summer rapeseed) and a C4-grass (Echinochloa crus-galli) in a Swiss agroforestry system. The objective of this study was to assess if and how crop performance (physiological traits, yield) between functional groups varies and if and how shade-induced crop yield reductions diverge between treatment combinations, aiming to provide general functional crop species and management recommendations as a guideline for a successful agroforestry practice in temperate Europe. Summer barley (-44%) and field bean (-38%) showed significant yield declines, similar to summer rapeseed with a significant biomass decline (-35%). Shade significantly increased the occurrence of lodging in barley. Rapeseed in particular performed better when fertilised (+40% biomass). Our results enable to estimate the range of potential yield losses in the competitive zone near mature trees for functionally different crop types and serve as a decision-support for species selection in temperate European agroforestry systems.

plant biology↗

bioRxiv2022

Crops grown in mixtures show niche partitioning in spatial water uptake

O_LIMore diverse plant communities generally produce more biomass than monocultures. This benefit of plant diversity is supposed to stem from resource partitioning of species in mixtures. Different plant species might use the resources spatially, temporally, or chemically in different ways. Along the same lines, for agricultural production crop mixtures outperform monocultures. Differences in vertical root distributions of crop species in mixtures could explain such higher yield. C_LIO_LIHere we used the stable isotopes of water and a Bayesian model to investigate the spatial water uptake patterns of six different crops species and how these patterns differ depending on the crop diversity. In addition, we calculated niche overlaps of water uptake as an indicator for belowground spatial niche partitioning, compared them among the different diversity levels, and linked them to productivity. C_LIO_LIThe spatial water uptake pattern differed among crop species. The effect of crop diversity had a minor effect on water uptake but varied strongly depending on the crop species. Niche overlap in spatial water uptake was highest in monocultures and decreased strongly in mixtures. Furthermore, productivity in mixtures was higher compared to monoculture. Additionally, we showed that increased competition intensity leads to stronger changes in water uptake patterns. C_LIO_LISynthesis. We found evidence for niche partitioning of spatial water uptake, and therefore complementary spatial root distribution, and higher productivity in crop mixtures compared to monocultures. Consequently, a more efficient use of soil resources in intercropping systems might explain their yield benefits. C_LI

ecology↗

bioRxiv2020

Facilitation and biodiversity jointly drive mutualistic networks

O_LIFacilitation by nurse plants increases understorey diversity and supports ecological communities. In turn, biodiversity shapes ecological networks and enhances ecosystem functioning. However, whether and how facilitation and increased biodiversity jointly influence community structure and ecosystem functioning remains unclear. C_LIO_LIWe performed a field experiment disentangling the relative contribution of nurse plants and increasing understorey plant diversity in driving pollination interactions. Both the presence of nurse shrubs as well as increased understorey plant diversity increased pollinator diversity and visitation rates. While nurse and understorey diversity effects on pollinator visitation rates did not interact, the effects of increasing understorey plant diversity on pollinator diversity were stronger in the absence than in the presence of shrubs, meaning that nurse shrubs attenuated the effects of high understorey diversity and buffered the effects of low understorey diversity. C_LIO_LIWe also found positive complementarity effects among understorey species as well as complementarity between nurse plants and understorey species at high diversity. Results also indicate negative selection effects, suggesting that species with generally few pollinators benefit the most in the polyculture, while a species (possibly the nurse plant) with generally lots of pollinators does not. The corresponding changes in pollination networks with the experimental treatments were due to both changes in the frequency of visits and turnover in pollinator community composition. C_LIO_LISynthesis Plant-plant facilitative systems, where a nurse plant increases understorey plant diversity, are common in stressful environments. Here, we show that these facilitative systems positively influence mutualistic interactions with pollinators via both direct nurse effects and indirect positive effects of increasing plant diversity. C_LIO_LIConserving and supporting nurse plant systems is crucial not only for maintaining plant diversity but also for supporting ecosystem functions and services. C_LI

ecology↗

bioRxiv2017

Facilitation between plants shapes pollination networks

SignificanceAlthough it is known that plant-plant and plant-pollinator interactions can strongly influence biodiversity and its effects on ecosystem functioning, the details of how competition and facili-tation among plants scale up to mutualistic interactions with pollinators and thus affect pollina-tion networks are poorly understood. We introduce a simple experimental system in which we control local plant interactions, measure pollinator responses and characterize plant-pollinator networks. We find that facilitation among plants produces synergistic and antagonistic effects on the pollinator community affecting the architecture and robustness of plant-pollinator net-works. Our results provide evidence for bottom-up non-additive effects of plant interactions on pollination networks and have implications for the way we study and manage ecosystems.

ecology↗