Biodiversity and yield trade-offs for organic farming

Organic farming supports higher biodiversity than conventional farming, but at the cost of lower yields. We conducted a meta-analysis quantifying the trade-off between biodiversity and yield, comparing conventional and organic farming. We developed a compatibility index to assess whether biodiversity gains from organic farming exceed yield losses, and a substitution index to assess whether organic farming would increase biodiversity in an area if maintaining total production under organic farming would require cultivating more land at the expense of nature. Overall, organic farming had 23% gain in biodiversity with a similar cost of yield decline. Biodiversity gain is negatively correlated to yield loss for microbes and plants, but no correlation was found for other taxa. The biodiversity and yield trade-off varies under different contexts of organic farming. The overall compatibility index value was close to zero, with negative values for cereal crops, positive for non-cereal crops, and varies across taxa. Our results indicate that, on average, the proportion of biodiversity gain is similar to the proportion of yield loss for paired field studies. For some taxa in non-cereal crops, switching to organic farming can lead to a biodiversity gain without yield loss. We calculated the overall value of substitution index and further discussed the application of this index to evaluate when the biodiversity of less intensified farming system is advantageous

Relationship between landscape complexity and ecosystem services from the perspective of smallholder agroecosystems in China—A review

Ecosystem services such as pollination and natural pest control are crucial for sustainable agriculture and affected by landscape complexity. Landscape complexity is associated with field size; therefore, studies in re- gions with large field sizes and regions with small field sizes are required for a comprehensive understanding of the landscape complexity-ecosystem service relationship. We conduct a systematic review, which shows that a majority of the studies are conducted in the US and Europe. Among the top 10 countries with the highest num- ber of publications, China is the only one with extensive agricultural areas with very small fields (<0.64 ha). Then, we review all studies in China. Scattered studies show that landscape complexity enhances biocontrol, but not necessarily pollination, whereas results are likely dependent on the measuring methods. Finally, we highlight a future research agenda and recommend that future studies use standardized and multiple matrices to measure landscape context and associated ecosystem services

Dataset on blood flow and instantaneous wave-free ratio in normal and stenosed coronary arteries

Instantaneous wave-free ratio (iFR) has been proposed as a hemodynamic parameter that can reliably reflect the blood flow in stenosed coronary arteries. Currently, there are few investigations on the quantitative analysis of iFR in the patients regarding the variation of microcirculatory resistance (MR). The data aim to provide geometric (cross-section area of branches) and hemodynamic (flow rate and iFR of branches) parameters of normal and stenosed coronary arteries derived from CFD simulation. The CFD simulation was performed on the three-dimensional artery models reconstructed from computed tomography (CT) images of four subjects. The hemodynamic parameters were obtained in six situations of MR to simulate coronary microvascular dysfunction (CMD). This dataset could be used as the reference to estimate the iFR and flow rate in patients with CMD and stenosis in coronary arteries. The geometric parameters could be used in the modelling of coronary arteries