Land‐use intensity and the effects of organic farming on biodiversity: a hierarchical meta‐analysis

By Sean L. Tuck, C. Winqvist, F. Mota, Johan Ahnström, Lindsay A. Turnbull, J. Bengtsson. Journal of Applied Ecology, 2014

784 citations recorded by the source corpus.

Summary The benefits of organic farming to biodiversity in agricultural landscapes continue to be hotly debated, emphasizing the importance of precisely quantifying the effect of organic vs. conventional farming. We conducted an updated hierarchical meta‐analysis of studies that compared biodiversity under organic and conventional farming methods, measured as species richness. We calculated effect sizes for 184 observations garnered from 94 studies, and for each study, we obtained three standardized measures reflecting land‐use intensity. We investigated the stability of effect sizes through time, publication bias due to the ‘file drawer’ problem, and consider whether the current literature is representative of global organic farming patterns. On average, organic farming increased species richness by about 30%. This result has been robust over the last 30 years of published studies and shows no sign of diminishing. Organic farming had a greater effect on biodiversity as the percentage of the landscape consisting of arable fields increased, that is, it is higher in intensively farmed regions. The average effect size and the response to agricultural intensification depend on taxonomic group, functional group and crop type. There is some evidence for publication bias in the literature; however, our results are robust to its impact. Current studies are heavily biased towards northern and western Europe and North America, while other regions with large areas of organic farming remain poorly investigated. Synthesis and applications. Our analysis affirms that organic farming has large positive effects on biodiversity compared with conventional farming, but that the effect size varies with the organism group and crop studied, and is greater in landscapes with higher land‐use intensity. Decisions about where to site organic farms to maximize biodiversity will, however, depend on the costs as well as the potential benefits. Current studies have been heavily biased towards agricultural systems in the developed world. We recommend that future studies pay greater attention to other regions, in particular, areas with tropical, subtropical and Mediterranean climates, in which very few studies have been conducted.

Subfields: Ecology, Evolution, Behavior and Systematics, Nature and Landscape Conservation, Plant Science

View Paper: https://www.semanticscholar.org/paper/3ae3c8112ff56b4e21e7bd6206e7589538680e64

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Citations in the corpus

Evidence that organic farming promotes pest control (2018, methodology): “We screened the bibliography from related reviews 16,46–48 .”
Organic Agriculture, Food Security, and the Environment (2018, background): “The “land sharing” versus “land sparing” debate is complex and requires site-specific solutions, which is why simplistic global prescriptions are inappropriate (Phalan et al. 2011, Tuck et al. 2014).”
Landscape configuration, organic management, and within‐field position drive functional diversity of spiders and carabids (2018, background): “Organic farming increases biodiversity according to a recent meta- analysis (Tuck et al., 2014).”
Assessing the integrated effects of landscape fragmentation on plants and plant communities: the challenge of multiprocess–multiresponse dynamics (2014, methodology): “To reflect the multilevel structure of the analysis of ES as a function of response type nested within each fragmentation process, we used a hierarchical Bayesian framework for the analysis (Gelman & Hill 2007; Stevens & Taylor 2009; Tuck et al. 2014).”
Deciphering the associations between soil microbial diversity and ecosystem multifunctionality driven by long‐term fertilization management (2018, background): “However, agricultural soils usually have a lower level of soil biodiversity compared to natural ecosystems (Tsiafouli et al., 2015; Tuck et al., 2014), suggesting a lack of multifunctional redundancy in these soils.”
An Underground Revolution: Biodiversity and Soil Ecological Engineering for Agricultural Sustainability. (2016, background): “Conservation agriculture and organic farming approaches attempt to reduce negative impacts on biodiversity and soil biota [4,37,55].”
Safeguarding pollinators and their values to human well-being (2016, neutral): “include organic farming practices 49,54,55 and planting flower strips that provide floral resources 56 .”
The role of agri-environment schemes in conservation and environmental management (2015, methodology): “We addressed 2 specific issues by merging the data sets of 3 recent meta-analyses on the effects of AES on species richness (Batáry et al. 2011; Scheper et al. 2013; Tuck et al. 2014).”
Crop–livestock integration beyond the farm level: a review (2016, background): “Organic agriculture also favors natural enemy diversity at the field and/or farm and/or landscape levels (Crowder et al. 2010; Gosme et al. 2012; Tuck et al. 2014; Puech et al. 2015).”