Terry Tyson J, Sala Osvaldo E, Ferrenberg Scott, Reed Sasha C, Osborne Brooke, Jordan Samuel, Lee Steven, Adler Peter B
Department of Wildland Resources and the Ecology Center, Utah State University, Logan, UT 84322, USA.
School of Life Sciences, Arizona State University, Tempe, AZ 85287, USA.
Sci Adv. 2024 Jul 26;10(30):eadm9732. doi: 10.1126/sciadv.adm9732.
Variability of the terrestrial global carbon sink is largely determined by the response of dryland productivity to annual precipitation. Despite extensive disturbance in drylands, how disturbance alters productivity-precipitation relationships remains poorly understood. Using remote-sensing to pair more than 5600 km of natural gas pipeline corridors with neighboring undisturbed areas in North American drylands, we found that disturbance reduced average annual production 6 to 29% and caused up to a fivefold increase in the sensitivity of net primary productivity (NPP) to interannual variation in precipitation. Disturbance impacts were larger and longer-lasting at locations with higher precipitation (>450 mm mean annual precipitation). Disturbance effects on NPP dynamics were mostly explained by shifts from woody to herbaceous vegetation. Severe disturbance will amplify effects of increasing precipitation variability on NPP in drylands.
陆地全球碳汇的变化在很大程度上取决于旱地生产力对年降水量的响应。尽管旱地受到广泛干扰，但干扰如何改变生产力与降水量的关系仍知之甚少。利用遥感技术，将北美旱地5600多公里的天然气管道走廊与相邻未受干扰地区进行配对，我们发现干扰使年平均产量降低了6%至29%，并使净初级生产力（NPP）对年际降水变化的敏感性增加了五倍。在降水量较高（年均降水量>450毫米）的地区，干扰影响更大且持续时间更长。干扰对NPP动态的影响主要是由木本植被向草本植被的转变所解释的。严重干扰将放大降水变率增加对旱地NPP的影响。
