Effects of disturbance and seeding on composition and ecosystem functions of plant communities

Picture: The photo shows, photographed from above, two young female scientists on the right and left of the picture, lying on a sunlit meadow and busy with the determination of seedlings. The female scientist on the right is noting something on paper in a clipboard lying on the ground in front of her. In front of the head of the female scientist on the left, a thin marking stick is stuck in the ground, next to her lies an unfolded folding ruler.

Background

Biodiversity experiments have often shown positive relationships between plant species numbers and various ecosystem functions such as productivity, biomass quality, nutrient cycling, stability and resistance to disturbances and invasions. Nevertheless, there is a scientific debate on whether the results of these rather controlled experiments can be transferred to real ecosystems. In our project, the effects of land use intensity, pre-disturbance diversity, soil seed bank and seeding on the resilience of ecosystem functions after a disturbance event are investigated. The focus is particularly on the role of the permanent seed bank as part of the invisible diversity as well as the effects of additionally introduced seeds from regional seeds on plant communities and ecosystem functions.

Hypotheses

Within the full factorial disturbance seeding experiment SADE, we will explore how the targeted introduction of plant species influences the regeneration of vegetation and its essential ecosystem functions after a severe disturbance. This will be done along a real diversity and land use gradient. Special attention is also paid to the resilience of the plant community and important productivity-related ecosystem functions. In a complementary mesocosm experiment, we will test whether and how plant diversity modifies effects of experimental fertilisation and drought on, for example, nutrient cycling. We will test the following hypotheses:

In disturbed areas, subordinate and transient species emerging from the diaspora bank will play an important role in maintaining numerous ecosystem functions, especially at the beginning of revegetation.
In species-rich stands, plant diversity and many ecosystem functions will be restored more quickly without seeding than in stands with low diversity, as regeneration in these stands is severely limited by a lack of diaspores.
Species enrichment through seeding with Regio seed will positively influence various ecosystem functions such as yield, forage quality, desiccation resistance and nutrient uptake.
High plant diversity will positively influence nutrient retention and reduce losses of nutrients to groundwater or deeper soil layer

Methods

Our project will explore the diaspora bank on all 75 plots of the SADE experiment in all three study areas to investigate the relevance of plant diversity for the recovery of the vegetation community after the disturbance event. The main indicators for maintaining ecosystem functions are productivity, nutrient storage in the vegetation, and abundances of stable isotopes of nitrogen (N) and carbon (C) as integrative measures of N cycling and drought stress. In addition, mineralisation rates of N and phosphorus (P) in the soil are measured on all plots using exchange resins (so-called resin bags) to record nutrient availability and surplus in relation to the diversity and land use intensity gradient. Interactions between plant diversity, drought stress and fertilisation on nutrient cycling will be investigated in a separate ex-situ mesocosm experiment with the aim of isolating controlling factors and identifying key mechanisms.

Picture: The diagram titled "Fifteen replicates from the Alb Exploratory" divided into parts A, B and C presents information on the seeding and disturbance experiment SADE. Part A on the grass experiment shows four circles representing the following parameters: circle 1 fertilizer, circle 2 drought, circle 3 fertilizer plus drought, circle 4 control. Part B on the soil experiment shows four circles representing the following parameters: circle 1 mature soil, circle 2 potting soil, circle 3 mature soil with fertilizer, circle 4 potting soil with fertilizer. Part C shows an illustration of a thirty centimeter diameter cylindrical core drill consisting of forty centimeters of sand in the lower part and twenty centimeters of soil in the upper part. Grasses and flowers are shown on top of the cylinder.

Picture: The photo shows a large, green, unmown meadow with a forest in the background. Two people are standing in the middle of the meadow.

Picture: The photo shows the transition area from arable soil to a meadow with tall grass and yellow flowers.

Picture: The photo shows a large blue tractor with attached mower mowing a meadow on a sunny day.

Publications

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

Drought boosts risk of nitrate leaching from grassland fertilisation

Trockenheit erhöht die Gefahr der Stickstoffauswaschung stark

Klaus V. H., Friedritz L., Hamer U., Kleinebecker T. (2020): Drought boosts risk of nitrate leaching from grassland fertilisation. Science of The Total Environment 726, 137877. doi: 10.1016/j.scitotenv.2020.137877

Will I stay or will I go? Plant species‐specific response and tolerance to high land‐use intensity in temperate grassland ecosystems

Werde ich bleiben oder werde ich gehen? Artspezifische Reaktionen und Toleranzen von Pflanzen auf und gegenüber hoher Landnutzungsintensitäten in temperaten Grünland-Ökosystemen

Busch V., Klaus V. H., Schäfer D., Prati D., Boch S., Müller J., Socher S. A., Chisté M., Mody K., Blüthgen N., Fischer M., Hölzel N., Kleinebecker T. (2019): Will I stay or will I go? Plant species‐specific response and tolerance to high land‐use intensity in temperate grassland ecosystems. Journal of Vegetation Science 30 (4), 674-686. doi: 10.1111/jvs.12749

Land-use intensity shapes kinetics of extracellular enzymes in rhizosphere soil of agricultural grassland plant species

Tischer A., Sehl L., Meyer U.-N., Kleinebecker T., Klaus V., Hamer U. (2019): Land-use intensity shapes kinetics of extracellular enzymes in rhizosphere soil of agricultural grassland plant species. Plant Soil 437 (1–2), 215–239. doi: 10.1007/s11104-019-03970-w

Contribution of the soil seed bank to the restoration of temperate grasslands by mechanical sward disturbance

Die Bodensamenbank hilft nicht bei der Renaturierung von artenarmem Wirtschaftsgrünland

Klaus V. H., Hoewer C. J., Fischer M., Hamer U., Kleinebecker T., Mertens D., Schäfer D., Prati D., Hölzel N. (2018): Contribution of the soil seed bank to the restoration of temperate grasslands by mechanical sward disturbance. Restoration Ecology 26 (2), 114-122. doi: 10.1111/rec.12626

Effects of mowing, grazing and fertilization on soil seed banks in temperate grasslands in Central Europe

Die Effekte von Düngung, Mahd und Beweidung auf die Bodensamenbank im Grünland

Klaus V. H., Schäfer D., Prati D., Busch V., Hamer U., Hoewer C. J., Kleinebecker T., Mertens D., Fischer M., Hölzel N. (2018): Effects of mowing, grazing and fertilization on soil seed banks in temperate grasslands in Central Europe. Agriculture, Ecosystems and Environment 256, 211-217. doi: 10.1016/j.agee.2017.11.008

And the winner is …! A test of simple predictors of plant species richness in agricultural grasslands

Kleinebecker T., Busch V., Hölzel N., Hamer U. , Schäfer D., Prati D., Fischer M., Hemp A., Lauterbach R., Klaus V. (2018): And the winner is …! A test of simple predictors of plant species richness in agricultural grasslands. Ecological Indicators 87, 296–301. doi: 10.1016/j.ecolind.2017.12.031

Land use intensity, rather than plant species richness, affects the leaching risk of multiple nutrients from permanent grasslands

Die Intensivierung der Nutzung und der Umbruch von Grünland steigern das Risiko der Nitratauswaschung

Klaus V. H., Kleinebecker T., Busch V., Fischer M., Hölzel N., Nowak S., Prati D., Schäfer D., Schöning I., Schrumpf M., Hamer U. (2018): Land use intensity, rather than plant species richness, affects the leaching risk of multiple nutrients from permanent grasslands. Global Change Biology 24 (7), 2828-2840. doi: 10.1111/gcb.14123

Early stage litter decomposition across biomes.

Die Anfangsphase des Streuabbaus in unterschiedlichen Biomen

Djukic I., Kepfer-Rojas S., Schmidt I. K., Larsen K. S., Beier C., Berg B., Verheyen K., et al., TeaComposition (2018): Early stage litter decomposition across biomes. Science of the Total Environment 628-629, 1369 - 1394. doi: 10.1016/j.scitotenv.2018.01.012

Enriching plant diversity in grasslands by large-scale experimental sward disturbance and seed addition along gradients of land-use intensity

Die floristische Anreicherung von Grünland unterschiedlicher Landnutzungsintensität mittels Störung und Ansaat

Klaus V. H., Schäfer D., Kleinebecker T., Fischer M., Prati D., Hölzel N. (2017): Enriching plant diversity in grasslands by large-scale experimental sward disturbance and seed addition along gradients of land-use intensity. Journal of Plant Ecology 10 (4) 581–591. doi: 10.1093/jpe/rtw062

Grassland management in Germany: effects on plant diversity and vegetation composition

Grünlandnutzung in Deutschland: Auswirkungen auf Pflanzendiversität und Vegetationszusammensetzung

Gilhaus K., Boch S., Fischer M., Hölzel N., Kleinebecker T., Prati D., Rupprecht D., Schmitt B., Klaus V. H. (2017): Grassland management in Germany: effects on plant diversity and vegetation composition. Tuexenia 37, 379-397. doi: 10.14471/2017.37.010

Zur Artenvielfalt im Grünland

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

Effects of seed addition and sward disturbance on species diversity and herbivory in grasslands

Craemer A. (2017): Effects of seed addition and sward disturbance on species diversity and herbivory in grasslands. Master thesis, University Münster

Temporal and small-scale spatial variation in grassland productivity, biomass quality, and nutrient limitation

Zeitliche und kleinräumige Schwankungen von Aufwuchs, Aufwuchsqualität und Nährstofflimitierung von Pfl anzen im Grünland

Klaus V. H., Boch S., Boeddinghaus H., Hölzel N., Kandeler E., Marhan S., Oelmann Y., Prati D., Regan K. M., Schmitt B., Sorkau E., Kleinebecker T. (2016): Temporal and small-scale spatial variation in grassland productivity, biomass quality, and nutrient limitation. Plant Ecology 217 (7), 843–856. doi: 10.1007/s11258-016-0607-8

Plant diversity moderates drought stress in grasslands: Implications from a large real-world study on 13C natural abundances

Pflanzenartenvielfalt beeinflusst den Trockenstress des Grünlands: Erkenntnisse einer umfangreichen Studie in Pflanzen und Böden

Klaus V. H., Hölzel N., Prati D., Schmitt B., Schöning I., Schrumpf M., Solly E., Hänsel F., Fischer M., Kleinebecker T. (2016): Plant diversity moderates drought stress in grasslands: Implications from a large real-world study on 13C natural abundances. Science of The Total Environment 566–567, 215–222. doi: 10.1016/j.scitotenv.2016.05.008

Carbon dioxide and nitrous oxide emissions under supervised treatments along a land use gradient – a mesocosm study

Craemer A., Steffen P. (2016): Carbon dioxide and nitrous oxide emissions under supervised treatments along a land use gradient – a mesocosm study. Technical report, University Münster

Mesokosmen-Experiment 2015 – Ergebnisbericht

Wolanska K. (2016): Mesokosmen-Experiment 2015 - Ergebnisbericht. Technical report, University Münster

Germination success of grassland-species on soils of different land-use intensity

Plumbaum K. (2015): Germination success of grassland-species on soils of different land-use intensity. Bachelor thesis, University Münster

Grazing and its ecological effects: A new index for grazing intensity in grasslands

Beweidung und ihre ökologischen Auswirkungen: Ein neuer Index zur Beweidungsintensität im Grünland

Smiatek M. (2014): Grazing and its ecological effects: A new index for grazing intensity in grasslands. Bachelor thesis, University Muenster