Characterizing differences in precipitation regimes of extreme wet and dry years: implications for climate change experiments

Abstract

Climate change is intensifying the hydrologic cycle and is expected to increase the frequency of extreme wet and dry years. Beyond precipitation amount, extreme wet and dry years may differ in other ways, such as the number of precipitation events, event size, and the time between events. We assessed 1614 long-term (100 year) precipitation records from around the world to identify key attributes of precipitation regimes, besides amount, that distinguish statistically extreme wet from extreme dry years. In general, in regions where mean annual precipitation (MAP) exceeded 1000 mm, precipitation amounts in extreme wet and dry years differed from average years by~40% and 30%, respectively. The magnitude of these deviations increased to >60% for dry years and to >150% for wet years in arid regions (MAP<500 mm). Extreme wet years were primarily distinguished from average and extreme dry years by the presence of multiple extreme (large) daily precipitation events (events >99th percentile of all events); these occurred twice as often in extreme wet years compared to average years. In contrast, these large precipitation events were rare in extreme dry years. Less important for distinguishing extreme wet from dry years were mean event size and frequency, or the number of dry days between events. However, extreme dry years were distinguished from average years by an increase in the number of dry days between events. These precipitation regime attributes consistently differed between extreme wet and dry years across 12 major terrestrial ecoregions from around the world, from deserts to the tropics. Thus, we recommend that climate change experiments and model simulations incorporate these differences in key precipitation regime attributes, as well as amount into treatments. This will allow experiments to more realistically simulate extreme precipitation years and more accurately assess the ecological consequences.

Experimental Manipulation of Precipitation Affects Soil Nitrogen Availability in Semiarid Mongolian Pine (Pinus sylvestris var. mongolica) Plantation

“…Fisher's protected LSD (least-significant difference) test was used to compare means for all significant effects (p < 0.05). Pearson's correlation coefficients between MBN (Soil microbial biomass nitrogen) and soil NH 4 + -N, NO 3 − -N, and inorganic N were calculated. Linear fitting was used for the relationship between SWC and NH 4 + -N, NO 3 − -N, and MBN during the growing season for all plots.…”

“…Global climate change is expected to alter precipitation regimes over large regions of the world [1][2][3][4]. A great deal of research has focused on the effects of precipitation on biomass production [5][6][7], with fewer studies examining the effects of precipitation change in the soil properties of arid and semiarid ecosystems [8][9][10][11][12].…”

Water relations and photosynthesis along an elevation gradient for Artemisia tridentata during an historic drought

“…Drought is common and can be persistent in many parts of the United States where synoptic meteorological patterns, topography, local features, and microsite conditions affect precipitation patterns and soil water (Knapp et al 2015b;Loik et al 2004;Sun et al 2015). Long-term drought has affected the central and southeast United States in recent years (Berdanier and Clark 2015;Knapp et al 2015a), and California in 2015 is experiencing a 1-in-1200 year drought (Griffin and Anchukaitis 2014;Williams et al 2015).…”

“…Many plant and ecosystem patterns and processes are affected by precipitation characteristics, which determine soil water availability and vegetation productivity (Knapp et al 2015b;Loik et al 2004;Sala et al 2015). Combined with other stresses such as invasive species, pests, and wildfire, drought affects the distribution and function of key species, populations, and ecosystems (Abatzoglou and Kolden 2011;Anderegg et al 2015).…”

降水格局改变背景下土壤呼吸变化的主要影响因素及其调控过程

“…近年来, 人类活动导致大气中的CO 2 浓度升高, 引起了全球升温和降水格局的改变 (Borken et al, 2002;Chimner et al, 2010;IPCC, 2013)。 多个气候模 型预测结果一致显示, 未来气候变化会带来全球或 局部降水格局的变化 (Fischer et al, 2013;Knapp et al, 2015)。未来降水将在高纬度和部分热带地区增 加, 而在中低纬度和部分亚热带地区减少 (Harper et al, 2005)。 同时, 极端降水事件的发生频率增加, 降 雨强度和降雨时间分布进一步变化 (Thomey et al, 2011;彭琴等, 2012;IPCC, 2013 (Raich & Sehlesinger, 1992;Hanson et al, 2000;Wang et al, …”