Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Governing nature by numbers - EU subsidy regulations do not capture the unique values of woody pastures
Stockholm University, Faculty of Science, Department of Physical Geography.
Stockholm University, Faculty of Science, Department of Physical Geography.
2015 (English)In: Biological Conservation, ISSN 0006-3207, E-ISSN 1873-2917, Vol. 191, p. 1-9Article in journal (Refereed) Published
Abstract [en]

A vast majority of European farmers are dependent on EU subsidies, which makes subsidy regulations through the Common Agricultural Policy (CAP) powerful tools in shaping agricultural landscapes. Unfortunately, steering recommendations are sometimes arbitrary, like in the case of pasture management, where 50 trees per hectare constitute an upper limit to qualify for subsidies. Although pasture biodiversity is well studied and the core of many CAP conservation programmes, it is seldom studied as direct effects of subsidy systems. In this paper, we examine plant diversity in relation to the impact of subsidy systems in Swedish woody pastures along a gradient from 3 to 214 trees per hectare. We selected 64 sites where we recorded vascular plants, soil properties and canopy cover. We found a general increase in γ- and β-diversity along the gradient, whereas α-diversity and the number of grassland specialists remained indifferent along the gradient. Additionally, tree density, organic content and C:N-ratio were the strongest predictors of species composition. Hence, when CAP regulations encourage tree cutting for pastures to qualify for subsidies there is risk of homogenisation of EU grasslands, leading to decreased γ- and β-diversity. If a general target for the subsidies is to increase biodiversity, there is need to scrutinise these regulation details to preserve the high values of woody pastures. We argue that habitat variation, species diversity and low intensity management, rather than a specific number of trees, should be the main incentives for financial support to preserve biodiversity.

Place, publisher, year, edition, pages
2015. Vol. 191, p. 1-9
Keywords [en]
CAP, Diversity, European Union, Plant, Tree Density
National Category
Physical Geography
Research subject
Physical Geography
Identifiers
URN: urn:nbn:se:su:diva-121797DOI: 10.1016/j.biocon.2015.06.007ISI: 000364257100001OAI: oai:DiVA.org:su-121797DiVA, id: diva2:861470
Available from: 2015-10-16 Created: 2015-10-16 Last updated: 2018-04-10Bibliographically approved
In thesis
1. Woody or treeless pastures? Effects of EU tree density limitations on biodiversity in woody pastures
Open this publication in new window or tab >>Woody or treeless pastures? Effects of EU tree density limitations on biodiversity in woody pastures
2015 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

The high biological and cultural values of traditionally managed rural landscapes are threatened by habitat change and degradation due to homogenisation through modern agricultural practices and abandonment. Woody pastures are important for many different taxa, and hence crucial for biodiversity conservation in these agricultural landscapes. To mitigate biodiversity loss, agricultural policy recommendations and subsidies are important tools, but if not implemented properly they may have the opposite effect. To keep agricultural landscapes open and to preserve biodiversity, the Common Agricultural Policy (CAP) of the European Union (EU) regulates how many trees farmers are allowed to have on their pastures to receive subsidies from the EU. A seemingly arbitrary limit was set to 50 trees/ha in 2003, which changed recently to 100 trees/ha. However, woody pastures are environments where high nature values often arise from the trees themselves, whereas there is little evidence on how biodiversity is directly affected by tree density in woody pastures. In this study, the tree density limit is targeted to investigate the effects on plant and bird diversity in 64 Swedish woody pastures along a gradient from 0 to 200 trees/ha. The results show that tree density is one of the major drivers of plant diversity, by favouring shade tolerant species without having a negative effect on less shade tolerant grassland specialists. Tree density positively affect bird diversity, an effect saturating at medium dense pastures but large species turnover rates along the gradient point at a variety of species found within woody pastures. Woody pastures with high tree densities in this study contribute substantially to biodiversity as heterogeneous environment enables high species richness. This thesis demonstrates a mismatch between subsidy systems and biological values that need to be further scrutinised to preserve biodiversity of agricultural landscapes.

Place, publisher, year, edition, pages
Stockholm: Department of Physical Geography, Stockholm University, 2015. p. 31
National Category
Physical Geography
Identifiers
urn:nbn:se:su:diva-121799 (URN)
Presentation
2015-11-06, Högbomsalen, Geovetenskapens hus, Svante Arrhenius väg 8, Stockholm, 10:00 (English)
Opponent
Supervisors
Available from: 2016-01-25 Created: 2015-10-16 Last updated: 2018-01-11Bibliographically approved
2. Wooded or treeless pastures?: Linking policy, farmers' decisions and biodiversity
Open this publication in new window or tab >>Wooded or treeless pastures?: Linking policy, farmers' decisions and biodiversity
2018 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Worldwide, biodiversity conservation is one of the key challenges for a sustainable future of nature and society. It is particularly important to preserve high quality habitats within otherwise intensively managed agricultural landscapes. Within the European Union (EU), farmers are highly dependent on agricultural subsidies through the Common Agricultural Policy (CAP), which hence have a strong influence on management and biodiversity. In European agricultural landscapes, wooded pastures form important habitats that contribute to landscape level heterogeneity and high local biodiversity, values which are often closely linked to trees. Unfortunately, many of these values were put at risk when a tree density limitation was introduced within the CAP, encouraging farmers to keep pastures open and ensuring grazing management. However, limiting tree density to a specific number to increase biodiversity finds little basis in the scientific literature. The main objective of this thesis is therefore to investigate how different measures of biodiversity across multiple taxa are affected by tree density and to study the farmers' perspective on this CAP regulation. Wooded pastures in the biosphere reserve Östra Vätterbranterna in southern Sweden were used as study sites. This thesis shows that encouraging farmers to cut trees to receive subsidies weakens the link between social and ecological values of wooded pastures, with potential subsequent losses in biodiversity. Trees were almost exclusively positive for biodiversity within this study system, increasing the species richness of plants, birds and bats. However, functional diversity across these taxa were mainly affected by other vegetation attributes within and around the pastures, such as shrub density and surrounding forest cover. A seed sowing experiment showed how trees partly shape plant communities already at the germination stage. Further, responses of functional diversity was mainly driven by resource use related traits among plants and birds, whereas bat functional diversity responses were mainly determined by their ability to manoeuvre through the micro-habitats of wooded pastures. Based on this thesis, I conclude that the tree density limit proposed by the EU has failed to capture the unique biological values of continuously managed wooded pastures and that the social-ecological links between policy, management and biodiversity are threatened by number specific governance of nature. It is therefore promising that the EU in November 2017 announced to open up for excluding the tree density focus in the CAP. Further development of the CAP can benefit from the findings of this thesis, revealing important knowledge gaps on biodiversity patterns in relation to trees in pastures.

Place, publisher, year, edition, pages
Stockholm: Department of Physical Geography, Stockholm University, 2018. p. 53
Series
Dissertations from the Department of Physical Geography, ISSN 1653-7211 ; 71
Keywords
bat, biodiversity, bird, canopy cover, Common Agricultural Policy, European Union, farmer, functional diversity, germination, grassland, multi-taxa, pasture, plant, policy, seed sowing, tree density, trees
National Category
Physical Geography
Research subject
Physical Geography
Identifiers
urn:nbn:se:su:diva-154373 (URN)978-91-7797-161-0 (ISBN)978-91-7797-162-7 (ISBN)
Public defence
2018-05-25, De Geersalen, Geovetenskapens hus, Svante Arrhenius väg 14, Stockholm, 13:00 (English)
Opponent
Supervisors
Funder
Swedish Research Council Formas, 2011-977
Note

At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 3: Manuscript. Paper 4: Manuscript.

Available from: 2018-05-02 Created: 2018-03-26 Last updated: 2018-04-16Bibliographically approved

Open Access in DiVA

No full text in DiVA

Other links

Publisher's full text

Search in DiVA

By author/editor
Jakobsson, SimonLindborg, Regina
By organisation
Department of Physical Geography
In the same journal
Biological Conservation
Physical Geography

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 2427 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf