Created grassland diversity afrer 12years of mowing in Southern Sweden
Abstract
Understanding the relationship between soil fertility and species richness in grasslands is
important for conservation of species rich grasslands particularly for habitat creation. In this
study, species composition and species number was examined on a meadow constructed in 1997
on formerly agricultural soil in Scania, southern Sweden. The site consisted of a 1,600 m long
and about 10m wide strip. On this, 3 different seed treatments were created; one grass mixture,
one simple herbal-grass mixture, and one rich grass and herb mixture. The rich herb-grass
mixture consisted of a mixture of 75% herbaceous species seeds and 25 % grass species seeds
while the simple herb-grass mixture contained 25% herbaceous species seeds and 25% grass
species seeds. For this study only the rich grass-herb and the grass mixture sites were used since
the simple grass-herb mixture site had no significant difference in composition when compared
to the rich grass-herb site. The species number was determined using 10m transects on each plot
which had 6 replicates for each treatment. The same was done in 3 independent plots which were
the reference sites of this study. The biomass and soil samples were collected and subsequently
analysed for each plot. The soil chemistry including the extractable N (KCI), extractable P (Bray
I) and soil pH (KCI) was determined. Total foliar Nand P levels (after digestion in sulphuric
acid), were also determined from the leaves of the dominant species. The species diversity was
also calculated.
A significant negative relationship was observed between species richness and soil fertility
especially with extractable soil phosphorous which had an influence on species richness
(F3,1=6.462, p=O.018).There was also a moderate influence on biomass by the distance from the
forest edge where the meadow was constructed adjacent a planted forest. It was concluded that
soil P has an influence on species diversity. The interactions between available nitrogen and
phosphorus and their influence on the vegetation play an important role in the control of the
grassland plant diversity. Thus, for both conservation and restoration of species rich grasslands,
it is necessary to maintain low levels of soil P and to carefully sow seed mixtures which are
appropriate for the area to ensure establishment and succession. This study shows that species
richness is related to soil P.
Citation
Master of Science in Biology of ConservationSponsorhip
University of NairobiPublisher
University of Nairobi School of Biological Sciences