dc.contributor.advisor | Isselstein, Johannes Prof. Dr. | de |
dc.contributor.author | Petersen, Ute | de |
dc.date.accessioned | 2012-05-04T15:10:23Z | de |
dc.date.accessioned | 2013-01-18T10:12:04Z | de |
dc.date.available | 2013-01-30T23:51:17Z | de |
dc.date.issued | 2012-05-04 | de |
dc.identifier.uri | http://hdl.handle.net/11858/00-1735-0000-000D-EF38-3 | de |
dc.identifier.uri | http://dx.doi.org/10.53846/goediss-1777 | |
dc.description.abstract | In den letzten Jahren wurde der
Zusammenhang von Biodiversität und | de |
dc.format.mimetype | application/pdf | de |
dc.language.iso | eng | de |
dc.rights.uri | http://creativecommons.org/licenses/by-nc-nd/3.0/ | de |
dc.title | Effects of agricultural management and manipulated plant species composition of permanent grassland on productivity and sward structure | de |
dc.type | doctoralThesis | de |
dc.title.translated | Auswirkungen von landwirtschaftlichem Management und manipulierter Pflanzenartkomposition auf Produktivität und Narbenstruktur im Dauergrünland | de |
dc.contributor.referee | Isselstein, Johannes Prof. Dr. | de |
dc.date.examination | 2012-09-02 | de |
dc.subject.dnb | 580 Pflanzen (Botanik) | de |
dc.subject.gok | YEU 300 | de |
dc.subject.gok | WNI 000 | de |
dc.subject.gok | YEH 000 | de |
dc.description.abstracteng | The relationship between biodiversity and
ecosystem functions of grasslands has received increasing attention
in recent years. Scientists have sought to disentangle this complex
relationship by sown biodiversity experiments and observational
studies. However, both methods have their advantages and
shortcomings. Hence, by using a complementary approach, namely a
removal experiment involving manipulation of established
vegetation, we might gain new and interesting insight into the
effects of biodiversity on productivity and other ecosystem
functions. In this study, a removal experiment was set up in the
Solling Uplands in 2008 where a permanent grass sward was
manipulated by herbicides to obtain either pure grass swards (dicot
reduced) or swards with relatively high amounts of forbs and
legumes (moncot reduced), on top of untreated control swards.
Species numbers were larger than 10/m2 and thus covered
the upper part of the usually examined logarithmic scale. They were
comparable to average spechies richness on European grassland. The
manipulated swards were then examined under different environmental
conditions, i.e. we created a gradient in management intensity,
regulated by both the cutting regime and the nutrient supply. Three
main aspects were investigated. At first, we were interested to see
how the herbicide application changed the grass swards and if we
could create an appropriate biodiversity gradient on our
experimental area. The regrowth of swards after herbicide
application was also monitored, focusing on plant functional traits
(growth height, reproductive strategy) of colonizer plants. The
second aspect was the productivity and quality of the manipulated
swards under different management treatments. We hypothesized that
a more diverse sward would yield more and higher quality forage
than one with a lower diversity in terms of species richness,
functional diversity (proportions of grasses, forbs and legumes) or
biodiversity indices. Finally, we analyzed whether the functional
diversity, the amounts of graminoid and dicot species influenced
the sward structure in terms of leaf area index and vertical
biomass distribution. Compared to the baseline data before
treatment implementation, the combination of treatments, especially
the herbicide application, led to a broad variety of swards with
the sward type alone accounting for more than 25% of all variance
in composition. The functional composition of the sward changed
slightly, since mainly vegetatively reproducing species were able
to expand after herbicide application. In grass rich swards these
were mainly the smaller grasses, leading to a slightly lower
canopy. We conclude that this kind of sward manipulation was
successful because the swards differed significantly in species
number, evenness and composition of functional groups. Neither the
biodiversity nor the distribution of functional groups influenced
the yield in this experiment. However, in fertilized plots, larger
amounts of tall grasses and tall species altogether increased
yields significantly. The swards rich in legumes and forbs tended
to have a better quality than the control and grass-rich swards.
Consequently, part of the forage quality parameters showed
correlations with biodiversity indices since these increased with
increasing forb content. Although the yields did not differ among
the swards, the sward architecture showed different vertical
patterns between moncot reduced and dicot reduced swards. The
latter also had converted more of the fertilized nutrients into
leaf area. Species richness did not influence sward structure, the
main source of variation lay – apart from the management – in the
grass:dicot ratio. Compared with artificial biodiversity
experiments, in our experiment, biodiversity only had moderate
effects on examined ecosystem functions probably due to the shorter
and more natural range of biodiversity levels realized in our
experiment. | de |
dc.contributor.coReferee | Leuschner, Christoph Prof. Dr. | de |
dc.contributor.thirdReferee | Tscharntke, Teja Prof. Dr. | de |
dc.subject.topic | Agricultural Sciences | de |
dc.subject.ger | Grünland | de |
dc.subject.ger | Biodiversität | de |
dc.subject.ger | Produktivität | de |
dc.subject.ger | Futterqualität | de |
dc.subject.ger | Struktur | de |
dc.subject.ger | Vegetation | de |
dc.subject.ger | Monokotyle | de |
dc.subject.ger | Dikotyle | de |
dc.subject.eng | permanent grassland | de |
dc.subject.eng | biodiversity | de |
dc.subject.eng | productivity | de |
dc.subject.eng | forage quality | de |
dc.subject.eng | structure | de |
dc.subject.eng | vegetation | de |
dc.subject.eng | monocots | de |
dc.subject.eng | dicots | de |
dc.subject.bk | 42.44 | de |
dc.subject.bk | 48.16 | de |
dc.subject.bk | 48.50 | de |
dc.identifier.urn | urn:nbn:de:gbv:7-webdoc-3492-6 | de |
dc.identifier.purl | webdoc-3492 | de |
dc.affiliation.institute | Fakultät für Agrarwissenschaften | de |
dc.identifier.ppn | 720321999 | de |