#Plants #2020 – 2023 #2017 – 2020 #2014 – 2017 #Soil seed bank #Species enrichment/ Species loss #Species biodiversity #Functional diversity #Grassland #Ecosystem processes #Soil #Nutrients #Land use #Plant diversity #Ecosystem services #Species communities #Herbs #Disturbance

SADE (Contributing project)

Effects of disturbance and seeding on the reformation of plant communities and ecosystem functions

Background

The disturbance and seeding experiment aims to explore different questions that are highly relevant from a scientific, agricultural, and conservation perspective. On the one hand, it is about resilience, that being the resistance of the ecosystem to disturbances. Resilience is an important component of the stability of an ecosystem. Here we are studying how quickly the ecosystem ‘grassland’ with all its functions can return to its original state after a drastic disturbance, and how much resilience depends on the former diversity of the vegetation and the current land use. On the other hand, research is being conducted into the extent to which the species richness of a grassland can be increased by seeding in plant species that are not yet present and how strongly different ecosystem services are promoted as a result. This refers, for example, to the positive effects of certain species on yield and forage value, but also to other functions like pollination or carbon fixation. Seeding also allows us to assess the extent to which the current diversity of grasslands of different land uses is limited by the species’ restricted ability to disperse. At the same time, the experiment represents an attempt to make agricultural grassland potentially less vulnerable to climate and weather fluctuations, because the experimental increase in species could in turn also have a positive effect on the resilience of the system.

Hypotheses

How does the resilience of the grassland ecosystem relate to plant diversity and land-use intensity?
How long do grassland areas with and without seeding need to fully recover their entire functionality?
How much is the current vegetation of the grasslands limited by lack of spread and lack of germination sites?
Which biotic, abiotic and land-use species filters influence the composition of grassland vegetation?
Does experimentally increased plant diversity have positive effects on key ecosystem functions such as resilience, nutrient cycling, and drought tolerance?

Experiment

On the total of 73 grassland plots along the land use gradient in the three exploratories, a Seeding and Disturbance Experiment (SADE) has been set up, combining the use of regional (autochthonous) seeds and topsoil disturbance in a fully factorial way. Through the cooperation of numerous working groups of the Biodiversity Exploratories in the SADE experiment, numerous aboveground as well as belowground parameters and processes can be collected for joint analysis in the coming years.

Design

On each grassland plot, the experiment consists of four 7 m × 7 m subplots on which the factors ‘disturbance’ and ‘seeding’ are explored, including a control plot (Figure 1). In order to separate the individual effects, not only the combination but also the separate implementation of the treatment variants is necessary. Seeding is carried out with regionally sourced and regionally specific seed. The available vegetation surveys from the exploratories were taken as the basis for the species pool to be introduced. The same species mixture, consisting of grasses, herbs and legumes, is used on each area of a region. The species mixtures differ between the exploratories depending on the regional species pool and contain 47 to 66 plant species. Disturbance by tilling or harrowing the topsoil to a depth of 10 cm resets the current vegetation and creates open germination sites. Thus, the regeneration of the ecosystem can be observed with and without the introduction of additional plant species. Further information and initial results can be found in the publication Klaus et. al 2017 (doi: 10.1093/jpe/rtw062).

Picture: The photo shows a green meadow on a cloudy day, with two partial areas of dug-up topsoil in the foreground. Two young female scientists are busy sowing on the areas. A row of unfoliaged trees stretches along the horizon.

Seeding in Hainich-Dün

Picture: The photo shows a tractor with trailed implement tearing up the meadow surface to cause a disturbance.

Disturbance on the Schwäbische Alb

Picture: The diagram shows the design of the seeding and disturbance experiment SADE. The square arrangement of four square subplots, each measuring 7 by 7 meters, is shown. The horizontal and vertical distance between the fields is 2 meters each. For each of the 4 plots, a different combination of treatment variants is indicated. For the subplot on the upper left: no seeding and no disturbance. For the subplot on the lower left: seeding and no disturbance. For the subplot on the upper right: no seeding and with disturbance. For the subplot on the lower right: seeding and with disturbance.

Fig. 1: Design of the seeding and disturbance experiment SADE

Project participants

Working groups involved in SADE to date and in the future:

Botany, Uni Bern
ESCAPE II, Uni Münster
Crustfunction, Uni Rostock
RootHerb II, FU Berlin
SEBA-RS, FU Berlin
SCALEMIC, Uni Hohenheim
AntAphid, Uni Bayreuth
Microorganism, UFZ Halle
ForNit, Helmholtz Zentrum München

Publications

Increasing plant species richness by seeding has marginal effects on ecosystem functioning in agricultural grasslands

Freitag M., Hölzel N., Neuenkamp L., van der Plas F., Manning P., Abrahão A., Bergmann J., Boeddinghaus R., Bolliger R., Hamer U., Kandeler E., Kleinebecker T., Knorr K.-H., Marhan S., Neyret M., Prati D., Le Provost G., Saiz H., van Kleunen M., Schäfer M., Klaus V. H. (2023): Increasing plant species richness by seeding has marginal effects on ecosystem functioning in agricultural grasslands. Journal of Ecology 111 (9), 1968-1984. doi: 10.1111/1365-2745.14154

Microbial drivers of plant richness and productivity in a grassland restoration experiment along a gradient of land use intensity

Abrahão A., Marhan S., Boeddinghaus R. S., Nawaz A., Wubet T., Hölzel N., Klaus V. H., Kleinebecker T., Freitag M., Hamer U., Oliveira R. S., Lambers H., Kandeler E. (2022): Microbial drivers of plant richness and productivity in a grassland restoration experiment along a gradient of land use intensity. New Phytologist 236 (5), 1936-1950. doi: 10.1111/nph.18503

Restoration of plant diversity in permanent grassland by seeding: Assessing the limiting factors along land-use gradients

Freitag M., Klaus V. H., Bolliger R., Hamer U., Kleinebecker T., Prati D., Schäfer D., Hölzel N. (2021): Restoration of plant diversity in permanent grassland by seeding: Assessing the limiting factors along land-use gradients. Journal of Applied Ecology 58 (8), 1681-1692. doi: 10.1111/1365-2664.13883

Linking land use and plant community assembly to understand ecosystem processes in temperate grasslands

Freitag M. (2021): Linking land use and plant community assembly to understand ecosystem processes in temperate grasslands. Dissertation, University of Münster

Dark diversity as a tool to predict the establishment success of plant species in grassland restoration

Närmann, S. (2021): Dark diversity as a tool to predict the establishment success of plant species in grassland restoration. Master Thesis, University of Münster, Münster.

Auswirkungen von Störung auf den Trockenheitsstress in der Vegetation und die Stickstoff-Ausnutzung der Pflanzen

Schröder S. K. (2021): Auswirkungen von Störung auf den Trockenheitsstress in der Vegetation und die Stickstoff-Ausnutzung der Pflanzen. Technical report, University Münster

Recovery of ecosystem functions after experimental disturbance in 73 grasslands differing in land‐use intensity, plant species richness and community composition

Erholung von Ökosystemfunktionen nach experimenteller Störung in 73 Grünlandflächen mit unterschiedlicher Landnutzungsintensität, Artenvielfalt und Zusammensetzung der Pflanzengesellschaft

Schäfer D., Klaus V. H., Kleinebecker T., Boeddinghaus R. S., Hinderling J., Kandeler E., Marhan S., Nowak S., Sonnemann I., Wurst S., Fischer M., Hölzel N., Hamer U., Prati D. (2019): Recovery of ecosystem functions after experimental disturbance in 73 grasslands differing in land‐use intensity, plant species richness and community composition. Journal of Ecology 107 (6), 2635-2649. doi: 10.1111/1365-2745.13211

The Biodiversity Exploratories: a large-scale framework project for functional biodiversity research

Klaus V. H., Fischer M., Hamer U., Hölzel N., Kleinebecker T., Prati D., Schäfer D., Allan E. (2018): The Biodiversity Exploratories: a large-scale framework project for functional biodiversity research. European Grassland Federation 2018, Vol. 23, 610-612

Diversity-stability relationships in temperate grasslands and forests of differing land-use intensities

Diversitäts-Stabilitäts-Beziehungen in temperaten Grünländern und Wäldern von unterschiedlicher Landnutzungsintensität

Schäfer D. (2018): Diversity-stability relationships in temperate grasslands and forests of differing land-use intensities. Dissertation, University Bern

Die Resilienz von arbuskulärer Mykorrhizakolonisierung gegenüber Störungs- und Einsaateffekten entlang eines Landnutzungsgradienten in Grasländern

Tolkmitt L.-T. (2018): Die Resilienz von arbuskulärer Mykorrhizakolonisierung gegenüber Störungs- und Einsaateffekten entlang eines Landnutzungsgradienten in Grasländern. Bachelor thesis, FU Berlin

Resilienz von arbuskulärer Mykorrhizakolonisierung in Grünländern gegen Störungs- und Einsaateffekte entlang eines Landnutzungsgradienten

Streuer I. (2018): Resilienz von arbuskulärer Mykorrhizakolonisierung in Grünländern gegen Störungs- und Einsaateffekte entlang eines Landnutzungsgradienten. Bachelor thesis, FU Berlin

Störungs- und Ansaateffekte auf arbuskuläre Mykorrhizakolonisation entlang eines Landnutzungradienten

Kaminska A. (2018): Störungs- und Ansaateffekte auf arbuskuläre Mykorrhizakolonisation entlang eines Landnutzungradienten. Bachelor thesis, FU Berlin

Resilienz von arbuskulärer Mykorrhiza gegenüber Einsaat und Störung entlang eines Landnutzungsgradienten

Thurow H. (2018): Resilienz von arbuskulärer Mykorrhiza gegenüber Einsaat und Störung entlang eines Landnutzungsgradienten. Bachelor thesis, FU Berlin

Einfluss von Ansaat und Störung auf die Pflanzendiversität landwirtschaftlich genutzter Grünländer

Knabe C. (2017): Einfluss von Ansaat und Störung auf die Pflanzendiversität landwirtschaftlich genutzter Grünländer. Bachelor tesis, University Münster

Zur Artenvielfalt im Grünland

Hölzel N., Klaus V. H. (2017): Zur Artenvielfalt im Grünland. Natur in NRW 2/2017, 35-39

Grasslands soil seed banks: composition, diversity and its response to disturbance

Grünlandbodensamenbanken: Zusammensetzung, Artenvielfalt und der Einfluss von Störungen

Hoever C. J. (2016): Grasslands soil seed banks: composition, diversity and its response to disturbance. Master thesis, University Münster

Untersuchungen zur Bodensamenbank im Grünland: Effekte experimenteller Oberbodenstörung

Mertens D. (2015): Untersuchungen zur Bodensamenbank im Grünland: Effekte experimenteller Oberbodenstörung. Bachelor thesis, University Münster

Resilience of grassland in the Biodiversity Exploratories

Reichling R. P. (2015): Resilience of grassland in the Biodiversity Exploratories. Bachelor thesis, University Münster