当前位置: X-MOL 学术Glob. Change Biol. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Recent collapse of crop belts and declining diversity of US agriculture since 1840
Global Change Biology ( IF 11.6 ) Pub Date : 2020-10-16 , DOI: 10.1111/gcb.15396
Michael S. Crossley 1 , Kevin D. Burke 2 , Sean D. Schoville 3 , Volker C. Radeloff 4
Affiliation  

Over the last century, US agriculture greatly intensified and became industrialized, increasing in inputs and yields while decreasing in total cropland area. In the industrial sector, spatial agglomeration effects are typical, but such changes in the patterns of crop types and diversity would have major implications for the resilience of food systems to global change. Here, we investigate the extent to which agricultural industrialization in the United States was accompanied by agglomeration of crop types, not just overall cropland area, as well as declines in crop diversity. Based on county‐level analyses of individual crop land cover area in the conterminous United States from 1840 to 2017, we found a strong and abrupt spatial concentration of most crop types in very recent years. For 13 of the 18 major crops, the widespread belts that characterized early 20th century US agriculture have collapsed, with spatial concentration increasing 15‐fold after 2002. The number of counties producing each crop declined from 1940 to 2017 by up to 97%, and their total area declined by up to 98%, despite increasing total production. Concomitantly, the diversity of crop types within counties plummeted: in 1940, 88% of counties grew >10 crops, but only 2% did so in 2017, and combinations of crop types that once characterized entire agricultural regions are lost. Importantly, declining crop diversity with increasing cropland area is a recent phenomenon, suggesting that corresponding environmental effects in agriculturally dominated counties have fundamentally changed. For example, the spatial concentration of agriculture has important consequences for the spread of crop pests, agrochemical use, and climate change. Ultimately, the recent collapse of most agricultural belts and the loss of crop diversity suggest greater vulnerability of US food systems to environmental and economic change, but the spatial concentration of agriculture may also offer environmental benefits in areas that are no longer farmed.

中文翻译:

自1840年以来,最近的农作物带崩溃和美国农业的多样性下降

上个世纪,美国农业大大集约化并工业化,投入和单产增加,而农田总面积却减少了。在工业部门,典型的是空间集聚效应,但是这种作物类型和多样性模式的变化将对粮食系统对全球变化的适应力产生重大影响。在这里,我们调查了美国农业产业化在何种程度上伴随着农作物类型的集聚,而不仅仅是农地的总面积,以及农作物多样性的下降。基于1840年至2017年美国本土的单个农作物耕地覆盖面积的县级分析,我们发现最近几年大多数农作物类型的空间集中度都非常大。在18种主要农作物中,有13种 20世纪初美国农业所代表的广泛带已经崩溃,空间集中度在2002年之后增加了15倍。从1940年到2017年,每种农作物的生产县数量下降了97%,总面积下降了98%。 %,尽管总产量增加。随之而来的是,县内作物类型的多样性急剧下降:1940年,88%的县种植的农作物> 10种,但2017年只有2%增长,曾经代表整个农业地区的作物类型组合消失了。重要的是,随着耕地面积的增加,作物多样性的下降是最近出现的现象,这表明农业主导县的相应环境影响已发生根本变化。例如,农业的空间集中度对农作物虫害的传播,农用化学品的使用和气候变化具有重要影响。最终,最近大多数农业带的崩溃和农作物多样性的丧失表明美国粮食系统更容易受到环境和经济变化的影响,但是农业的空间集中度也可能在不再耕种的地区带来环境效益。
更新日期:2020-12-09
down
wechat
bug