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Lindström, Sandra, 2008. Effects of agricultural intensity and landscape complexity on plant species richness. SLU, Dept. of Ecology, Uppsala. Uppsala: SLU, Dept. of Ecology

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Abstract

During the last decades, raised inputs, changed cultivation measures and changes in the farm layout have been implemented in order to raise crop yields. The result has been an intensification of farming with negative consequences for farmland biodiversity. In this study, the impact of different levels of agricultural intensity on plant species richness in winter wheat (Triticum aestivum L.) production has been examined.

The presence of vascular plant species in 160 fields was examined at 32 farms in Uppsala County in the plain districts of south central Sweden. The sampling was performed between the 19th of June and the 13th of July 2007, during the flowering period of the winter wheat.

The relationship between species richness and eight different variables measuring aspects of intensity was examined: yield, crop cover, nitrogen application, herbicide use, soil cultivation, proportion arable land, field size and perimeter-area ratio. Crop management intensity was quantified using farmers' questionnaires. Landscape data was collected by using the block database from Uppsala County Administrative Board and analysed with GIS. Further, the variation in species richness within the farms and between the farms was examined using additive partitioning.

Increased proportion crop cover decreased species richness of plants in arable fields significantly. This was found on both organic and conventional farming systems. Crop cover reflects intensive agricultural practices with high levels of inputs in combination with the appropriate timing of the cultivation measures, which results in a dense and competitive crop stand. Species richness was generally higher on organic than conventional farms. Variables measuring landscape structure seemed to be of minor importance for weed species diversity in arable fields.

Approximately 70 % of the total diversity within the region could be attributed to differences between farms. Local field diversity, between field diversity and between farm diversity all decreased with crop cover. Hence, agricultural intensification influenced the biodiversity negatively both at the local scale and on the between farms scale in the region.

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Jordbrukets intensitet har under de senaste decennierna ökat genom effektiviserad teknikanvändning och ökade insatser av pesticider och växtnäring. Detta har inte bara lett till ökade skördar utan även till negativa konsekvenser för den biologiska mångfalden i jordbrukslandskapet.
I denna studie inventerades förekomsten av kärlväxter i 160 höstvetefält (Triticum aestivum L.) på 32 gårdar i Uppsala-Enköpingsregionen under sommaren år 2007. Förhållandet mellan artrikedom och åtta olika intensitetsvariabler undersöktes genom linjär regression: skörd, grödans täckningsgrad, kvävetillförsel, herbicidanvändning, jordbearbetning, andel odlad mark, fältstorlek och omkrets-area-kvot. Vidare studerades variationen av artsammansättning inom och mellan gårdarna genom beräkning av betadiversitet.
Ökad täckningsgrad hos grödan medförde signifikant lägre artrikedom bland kärlväxter i fälten, både i ekologiska och konventionella odlingssystem. Hög täckningsgrad hos grödan är ett resultat av intensiv odling med höga insatser av kväve, jordbearbetning och herbicidanvändning, i kombination med rätt tidpunkt för åtgärderna, vilket resulterar i en tät och konkurrenskraftig gröda. Artrikedomen på ekologiska gårdar var generellt högre än på konventionella. Landskapets struktur visade inga tendenser till att påverka antalet arter.
Cirka 70 % av den totala artrikedomen inom i studieområdet kunde förklaras av skillnader mellan gårdar. Artrikedomen på enskilda fält, mellan fält och mellan gårdar minskade alla med ökande täckningsgrad hos grödan. Följaktligen påverkar jordbrukets intensifiering den biologiska mångfalden av kärlväxter negativt både på den lokala skalan och mellan-gårdskalan i regionen.

Main title:Effects of agricultural intensity and landscape complexity on plant species richness
Authors:Lindström, Sandra
Supervisor:Bengtsson, Jan
Examiner:UNSPECIFIED
Series:Självständigt arbete/Examensarbete / SLU, Institutionen för ekologi
Volume/Sequential designation:2008:9
Year of Publication:2008
Level and depth descriptor:Other
Student's programme affiliation:NATMP Natural Resources Programme 240 HEC
Department:(NL, NJ) > Dept. of Ecology
(S) > Dept. of Ecology
Keywords:additive partitioning, agricultural intensity, arable landscape, plant diversity, weeds
URN:NBN:urn:nbn:se:slu:epsilon-s-8604
Permanent URL:
http://urn.kb.se/resolve?urn=urn:nbn:se:slu:epsilon-s-8604
Subjects:SLU > (NL, NJ) > Dept. of Ecology
SLU > (S) > Dept. of Ecology

Weeds and weed control
Language:English
Deposited On:06 Nov 2017 11:42
Metadata Last Modified:06 Nov 2017 11:42

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