Gurgel Angelo C, Reilly John, Blanc Elodie
Joint Program on the Science and Policy of Global Change, Massachusetts Institute of Technology, 77 Massachusetts Avenue, E19-411, Cambridge, MA 02139-4307, USA.
iScience. 2021 Jun 24;24(7):102772. doi: 10.1016/j.isci.2021.102772. eCollection 2021 Jul 23.
Land use in the United States (US) is driven by multiple forces operating at the global level, such as income and population growth, yield and productivity improvement, trade policy, climate change, and changing diets. Future land use has implications for biodiversity, run-off, carbon storage, ecosystem values, agriculture, and the broader economy. We investigate those forces and their implications from a multisector, multisystem dynamics (MSD) perspective focused on understanding dynamics and resilience in complex interdependent systems. Historical trends show slight increases in grassland and natural forest areas and decreases in cropland. We project these trends to intensify under higher pressures for agriculture land and reduce under lower pressures, with no evidence of tipping points toward larger agricultural land abandonment or deforestation. However, US sectoral output and trade, fertilizer use, NO and CH emissions from agriculture activities, and CO emissions from land use changes are substantially impacted under land use forcing scenarios.
美国的土地利用受到全球层面多种力量的驱动,如收入和人口增长、产量和生产率提高、贸易政策、气候变化以及饮食结构变化。未来的土地利用对生物多样性、径流、碳储存、生态系统价值、农业及更广泛的经济都有影响。我们从多部门、多系统动态(MSD)视角研究这些力量及其影响,重点是理解复杂相互依存系统中的动态和恢复力。历史趋势表明,草地和天然林面积略有增加,农田面积减少。我们预计,在农业用地压力较高的情况下,这些趋势将加剧;在压力较低的情况下,这些趋势将减弱,没有证据表明会出现向更大规模农业用地弃耕或森林砍伐的临界点。然而,在土地利用强制情景下,美国的部门产出和贸易、化肥使用、农业活动产生的一氧化氮和甲烷排放以及土地利用变化产生的二氧化碳排放将受到重大影响。