Precipitation temporal repackaging into fewer, larger storms delayed seasonal timing of peak photosynthesis in a semi‐arid grassland

作者：Fangyue Zhang, Joel A. Biederman, Nathan A. Pierce, Daniel L. Potts, Charles John Devine, Yanbin Hao, William K. Smith · 发表于：Functional Ecology · 年份：2021 · DOI：10.1111/1365-2435.13980 · 被引用次数：37 · 研究领域：Plant Water Relations and Carbon Dynamics、Ecology and Vegetation Dynamics Studies、Climate variability and models

Abstract Against a backdrop of rising temperature, large portions of the western United States are experiencing fewer, larger and less frequent precipitation events. How such temporal ‘repackaging’ of precipitation alters the magnitude and timing of seasonal maximum gross primary productivity (GPP max ) remains unknown. Addressing this knowledge gap is critical, since changes to GPP max magnitude and timing can impact a range of ecosystem services and management decisions. Here we used a field‐based precipitation manipulation experiment in a semi‐arid mixed annual/perennial bunchgrass ecosystem with mean annual precipitation ~384 mm to investigate how temporal repackaging of a fixed total seasonal precipitation amount impacts seasonal GPP max and its timing. We found that temporal repackaging of precipitation profoundly influenced the seasonal timing of GPP max . Many/small precipitation events advanced the seasonal timing of GPP max by ~13 days in comparison with climatic normal precipitation. Conversely, few/large events led to deeper soil water infiltration, which delayed the timing of GPP max by up to 16 days in comparison with climatic normal precipitation, and altered end‐of‐season community composition by increasing the diversity of shallow‐rooted annual plants. While GPP max magnitude did not differ across precipitation treatments, it was positively correlated with the abundance and biomass of deeper‐rooted perennial bunchgrasses. The sensitivity of plant growth, biom...