Cropland expansion in the United States produces marginal yields at high costs to wildlife

Tyler J Lark,Holly K Gibbs,Matthew Bougie,Seth A Spawn

doi:10.1038/s41467-020-18045-z

Tyler J Lark, Holly K Gibbs + Show 2 more

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https://doi.org/10.1038/s41467-020-18045-z

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Abstract

Recent expansion of croplands in the United States has caused widespread conversion of grasslands and other ecosystems with largely unknown consequences for agricultural production and the environment. Here we assess annual land use change 2008–16 and its impacts on crop yields and wildlife habitat. We find that croplands have expanded at a rate of over one million acres per year, and that 69.5% of new cropland areas produced yields below the national average, with a mean yield deficit of 6.5%. Observed conversion infringed upon high-quality habitat that, relative to unconverted land, had provided over three times higher milkweed stem densities in the Monarch butterfly Midwest summer breeding range and 37% more nesting opportunities per acre for waterfowl in the Prairie Pothole Region of the Northern Great Plains. Our findings demonstrate a pervasive pattern of encroachment into areas that are increasingly marginal for production, but highly significant for wildlife, and suggest that such tradeoffs may be further amplified by future cropland expansion.

Highlights

Recent expansion of croplands in the United States has caused widespread conversion of grasslands and other ecosystems with largely unknown consequences for agricultural production and the environment
We find that cropland expansion has continued at a rate of over 1 million acres per year while generating belowaverage yields and supplanting high-quality habitat
Our results are similar in direction and spatial pattern to other, coarser estimates of cropland expansion and abandonment, a b

Summary

Introduction

Recent expansion of croplands in the United States has caused widespread conversion of grasslands and other ecosystems with largely unknown consequences for agricultural production and the environment. The impacts of recent land conversion on both agricultural production and natural habitat are largely unknown These information gaps limit our ability to compare the consequences of cropland expansion around the world or against other means of increasing production such as agricultural intensification, thereby clouding navigation of the intertwined global challenges of improving food and fuel production while maintaining the integrity of ecosystems. New croplands in the US tend to occupy areas with marginal biophysical characteristics such as erosive soils, poor drainage, nutrient or moisture deficiencies, or climatic stress[9] While these limitations could constrain crop yields and diminish the returns from expansion, the magnitude of their impact is unknown. A recent United Nations report identified agricultural land use change as a primary driver of global biodiversity loss[11,12], but detailed analyses of crop expansion impacts in the US have not yet been conducted

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