Dataset DOI: 10.5061/dryad.9ghx3ffwg

Description

This repository contains the dataset and R scripts used in the manuscript submitted to Ecology Letters. The analysis explores how landscape composition directly and indirectly influences crop yield mediated through natural enemies, biological control, and pests across multiple studies using a structural equation model.

Contents

• Data_SEM.csv: Excel file containing the compiled dataset from 116 studies across 28 countries. The original data from which this dataset is derived is presented in the supplementary material from Karp et al. 2018, where the data were already standardized: https://www.pnas.org/doi/abs/10.1073/pnas.1800042115#supplementary-materials
• SI_3_Data_Exploration.r : R script that performs preliminary analyses to determine needs for data transformation and selects the landscape variables that need to be included in the structural equation model. This Analysis was performed using R version 4.4.2 (2024-10-31 ucrt) -- "Pile of Leaves” with packages ‘nlme’, ‘MuMIn’ and ‘dplyr’.
• Analysis_SEM.R: R script that performs data transformation, structural equation model analysis, and analysis of spatial autocorrelation and multicollinearity. This Analysis was performed using R version 4.4.2 (2024-10-31 ucrt) -- "Pile of Leaves” with packages ‘piecewiseSEM’, ‘nlme’, ‘dplyr’, and ‘writexl’.

Dataset interpretation

Below, we will explain the content of each of the columns found in the dataset:

Nr: Unique identifier for each row of data

Study_ID: Unique identifier for each study

Site: Site name given by the authors of each study

Study_Year: The year in which the study was performed. Some studies repeat the experiment in several years, and more than one year will appear for that given study.

X: Longitude

Y: Latitude

NAT_250: Proportion of natural area at the 250 decay rate

NAT_750: Proportion of natural area at the 750 decay rate

NAT_1250: Proportion of natural area at the 1250 decay rate

AG_250: Proportion of agricultural area at the 250 decay rate

AG_750: Proportion of agricultural area at the 750 decay rate

AG_1250: Proportion of agricultural area at the 1250 decay rate

Crop: Latin or common species name of the crop, based on what was reported by the authors of each study

Poll_depend: Pollinator dependency of the crop. For details on the classification see Supplementary Information 5 of the paper. “poll” means that the crop is pollinator dependent and “no_poll” means that the crop is not pollinator dependent.

Enemy: Standardized abundance of all natural enemies (for standardization methods, refer to the paper).

Predator: Standardized abundance of all predators.

Parasitoid: Standardized abundance of all parasitoids.

Biological control: Standardized measure of biological control

pest: Standardized abundance of all pests.

specialist: Standardized abundance of all specialist pests. For more information see Supplementary Information 1 of the paper.

generalist: Standardized abundance of all generalist pests. For more information see Supplementary Information 1 of the paper.

Marketable_or_Total: Yield measure done by the authors of each study that distinguished between marketable (that can be sold in the market) and total (where there is no distinction if the produce is of marketable quality or not).

Stand_yield: Standarized yield measurement.

Cells with an ‘NA’ value mean that the data are not available, because they were not collected in the field by the research team that did this work.

Data was derived from the following source:

• Supplementary information of Karp et al. 2018, Crop pests and predators exhibit inconsistent responses to surrounding landscape composition, Proc. Natl. Acad. Sci. U.S.A. 115 (33) E7863-E7870, https://doi.org/10.1073/pnas.1800042115 (2018).