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

Aims The relationship between biodiversity and ecosystem functioning is among the most active areas of ecological research. Furthermore, enhancing the diversity of degraded ecosystems is a major goal in applied restoration ecology. In grasslands, many species may be locally absent due to dispersal or microsite limitation and may therefore profit from mechanical disturbance of the resident vegetation. We established a seed addition and disturbance experiment across several grassland sites of different land use to test whether plant diversity can be increased in these grasslands. Additionally, the experiment will allow us testing the consequences of increased plant diversity for ecosystem processes and for the diversity of other taxa in real-world ecosystems. Here we present details of the experimental design and report results from the first vegetation survey one year after disturbance and seed addition. Moreover, we tested whether the effects of seed addition and disturbance varied among grassland depending on their land use or pre-disturbance plant diversity. Methods A full-factorial experiment was installed in 73 grasslands in three regions across Germany. Grasslands were under regular agricultural use, but varied in the type and the intensity of management, thereby representing the range of management typical for large parts of Central Europe. The disturbance treatment consisted of disturbing the top 10 cm of the sward using a rotavator or rotary harrow. Seed addition consisted of sowing a high-diversity seed mixture of regional plant species. These species were all regionally present, but often locally absent, depending on the resident vegetation composition and richness of each grassland. Important findings One year after sward disturbance it had significantly increased cover of bare soil, seedling species richness and numbers of seedlings. Seed addition had increased plant species richness, but only in combination with sward disturbance. The increase in species richness, when both seed addition and disturbance was applied, was higher at high land-use intensity and low resident diversity. Thus, we show that at least the early recruitment of many species is possible also at high land-use intensity, indicating the potential to restore and enhance biodiversity of species-poor agricultural grasslands. Our newly established experiment provides a unique platform for broad-scale research on the land-use dependence of future trajectories of vegetation diversity and composition and their effects on ecosystem functioning.

[Map of Brown & Fullers addition to Ann Arbor, Michigan surveyed by J.F. Stratton, 1832

Oriented with north to the upper left; sheet 42 x 51 cm.

Couzens Hall addition

Also known as Nurses Residence. Built 1925. Albert Kahn, architect. Addition 1954-1956. R.A. Calder, architect. On verso: Women's Housing 3

Couzens Hall addition

Also known as Nurses Residence. Built 1925. Albert Kahn, architect. Addition 1954-1956. R.A. Calder, architect. On verso: Women's Housing. Couzen Hall Addition 4

Angell Hall--Addition

Smith, Hinchman & Grylls, architects. Bryant & Detwiler, contractor. In 1951/1952 Haven Hall (south side) and Mason Hall (north) were added to the east or diagonal side of Angell Hall. View from south.

Unified action armed forces (UNAAF) November 1959.

Includes Changes 1,3,4,6,7,8 and addendum to change 8, 1961-1964.

The manner of securing all sorts of buildings from fire, or, A treatise upon the construction of arches made with bricks and plaister, called flat-arches, and of a roof without timber called a bricked-roof : with the addition of some letters that have passed between the Count of Espie and Peter Wyche Esq. on this subject : adorned with two copper-plates serving to illustrate the whole work /

Publication date from ESTC.

Church melodist: a collection of sacred music, comprising, in addition to most of the old standard tunes, a great variety of new and original tunes, sentences, chants, anthems, &c. Adapted to social and religious worship, societies, singing schools, &c.

For chorus (SATB), principally with figured bass.

Institutes of natural philosophy, theoretical and practical. With some corrections; change in the order of the branches; and the addition of an appendix to the astronomical part, selected from Mr. Ewing's Practical astronomy.

"Appendix to the astronomy. Containing solar and lunar tables, with their explanation and use, and the projection of eclipses, selected from 'Ewing's Practical astronomy'": [233]-297.

Soap-bubbles, their colours and the forces which mould them ; being the substance of many lectures delivered to juvenile and popular audiences with the addition of several new and original sections /

Mode of access: Internet.

An experiment on a unified control construct /

Bibliography: p. 34.

MUMS, a modular unified microprocessor system /

Originally presented as the author's thesis, University of Illinois at Urbana-Champaign.

Unified modified divided difference implementation of Adams and BDF formulas /

"March 1980."