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Semi-natural meadows in southern Sweden - changes over time and the relationship between nitrogen supply and management.

Berlin, Gudrun A I LU (1998)
Abstract
In this thesis, I have studied continuously managed semi-natural meadows in south-central Sweden. The purpose was 1) to make a survey of meadow vegetation in the region 2) to compare two investigations of the vegetation, one from 1963-1966 and one from 1990 3) to investigate experimentally in the field how increased nitrogen supply rate as well as changed management intensity effects the nitrogen economy and species richness in two meadow communities.



In the regional survey of meadows nine plant communities were recognised; five wet-moist plant communities, and four mesic-dry plant communities. The most obvious differences between the plant communities in the two data sets from 1963-66 and 1990 was that the range of... (More)
In this thesis, I have studied continuously managed semi-natural meadows in south-central Sweden. The purpose was 1) to make a survey of meadow vegetation in the region 2) to compare two investigations of the vegetation, one from 1963-1966 and one from 1990 3) to investigate experimentally in the field how increased nitrogen supply rate as well as changed management intensity effects the nitrogen economy and species richness in two meadow communities.



In the regional survey of meadows nine plant communities were recognised; five wet-moist plant communities, and four mesic-dry plant communities. The most obvious differences between the plant communities in the two data sets from 1963-66 and 1990 was that the range of plant communities had become smaller, particularly among the wet-moist meadows. Also, within the plant communities changes in the vegetation were revealed in a comparison of eight semi-permanent plots between the two investigations. They indicate considerable species dynamics in the seemingly stable vegetation of these meadow communities. Furthermore, several general characteristics of the vegetation differed between the two investigations, e.g., increase in cover of vascular plants, increases both in number and cover of graminoid species, as well as an increase in the potential vegetation height in most of the plots. Also, species supposed to be favoured by mowing decreased in relative cover and the meadows trend towards an increase in number of species of non-grassland origin.



In the field experiment the effects due to fertilisation were greatest at the less productive site, while the effects due to cessation of management was largest at the more productive site. General trends for both sites due to fertilisation were an increase in the share of graminoids in biomass and higher nitrogen concentrations in the above-ground biomass. At both sites, a decreased number of species was found with excluded management, forb species in particular disappeared, whereas no differences in species number were found in the fertilised plots with mowing. At the more productive site above-ground biomass decreased, while at the less productive site an opposite effect was found due to cessation of management. Finally, the ratio (litter + dead biomass) / green biomass was higher at the less productive site, which may indicate differences in decomposition rates. (Less)
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author
opponent
  • Prof Zobel, Martin, Dept of Botanical Ecology, Tartu Univesity, 40 Lai St., Tartu EE2400, Estonia.
organization
publishing date
type
Thesis
publication status
published
subject
keywords
Plant community dynamic, Nitrogen, Mowing, Meadows, Management, Long-term study, Landscape changes, Field experiment, Community diversity, Fertilisation, Species changes, Species turnover, Plant ecology, Växtekologi
pages
76 pages
publisher
Department of Ecology, Lund University
defense location
Blå Hallen, Ecology Building, SE-223 62 Lund, Sweden
defense date
1998-05-15 13:15
external identifiers
  • Other:ISRN: SE-LUNBDS / NBBE-98 / 1048 + 76 pp
ISBN
91-7105-100-7
language
English
LU publication?
yes
id
d4aa0be3-a986-4f02-a4cf-ab77159ddd9b (old id 38632)
date added to LUP
2007-06-20 11:56:06
date last changed
2016-09-19 08:45:08
@misc{d4aa0be3-a986-4f02-a4cf-ab77159ddd9b,
  abstract     = {In this thesis, I have studied continuously managed semi-natural meadows in south-central Sweden. The purpose was 1) to make a survey of meadow vegetation in the region 2) to compare two investigations of the vegetation, one from 1963-1966 and one from 1990 3) to investigate experimentally in the field how increased nitrogen supply rate as well as changed management intensity effects the nitrogen economy and species richness in two meadow communities.<br/><br>
<br/><br>
In the regional survey of meadows nine plant communities were recognised; five wet-moist plant communities, and four mesic-dry plant communities. The most obvious differences between the plant communities in the two data sets from 1963-66 and 1990 was that the range of plant communities had become smaller, particularly among the wet-moist meadows. Also, within the plant communities changes in the vegetation were revealed in a comparison of eight semi-permanent plots between the two investigations. They indicate considerable species dynamics in the seemingly stable vegetation of these meadow communities. Furthermore, several general characteristics of the vegetation differed between the two investigations, e.g., increase in cover of vascular plants, increases both in number and cover of graminoid species, as well as an increase in the potential vegetation height in most of the plots. Also, species supposed to be favoured by mowing decreased in relative cover and the meadows trend towards an increase in number of species of non-grassland origin.<br/><br>
<br/><br>
In the field experiment the effects due to fertilisation were greatest at the less productive site, while the effects due to cessation of management was largest at the more productive site. General trends for both sites due to fertilisation were an increase in the share of graminoids in biomass and higher nitrogen concentrations in the above-ground biomass. At both sites, a decreased number of species was found with excluded management, forb species in particular disappeared, whereas no differences in species number were found in the fertilised plots with mowing. At the more productive site above-ground biomass decreased, while at the less productive site an opposite effect was found due to cessation of management. Finally, the ratio (litter + dead biomass) / green biomass was higher at the less productive site, which may indicate differences in decomposition rates.},
  author       = {Berlin, Gudrun A I},
  isbn         = {91-7105-100-7},
  keyword      = {Plant community dynamic,Nitrogen,Mowing,Meadows,Management,Long-term study,Landscape changes,Field experiment,Community diversity,Fertilisation,Species changes,Species turnover,Plant ecology,Växtekologi},
  language     = {eng},
  pages        = {76},
  publisher    = {ARRAY(0xab31b30)},
  title        = {Semi-natural meadows in southern Sweden - changes over time and the relationship between nitrogen supply and management.},
  year         = {1998},
}