View in EDS

Precipitation amount and event size interact to reduce ecosystem functioning during dry years in a mesic grassland.

Saved in:
Bibliographic Details
Title: Precipitation amount and event size interact to reduce ecosystem functioning during dry years in a mesic grassland.
Authors: Felton, Andrew J.1,2 (AUTHOR) andrew.felton@usu.edu, Slette, Ingrid J.1 (AUTHOR), Smith, Melinda D.1 (AUTHOR), Knapp, Alan K.1 (AUTHOR)
Source: Global Change Biology. Feb2020, Vol. 26 Issue 2, p658-668. 11p.
Abstract: Ongoing intensification of the hydrological cycle is altering rainfall regimes by increasing the frequency of extreme wet and dry years and the size of individual rainfall events. Despite long‐standing recognition of the importance of precipitation amount and variability for most terrestrial ecosystem processes, we lack understanding of their interactive effects on ecosystem functioning. We quantified this interaction in native grassland by experimentally eliminating temporal variability in growing season rainfall over a wide range of precipitation amounts, from extreme wet to dry conditions. We contrasted the rain use efficiency (RUE) of above‐ground net primary productivity (ANPP) under conditions of experimentally reduced versus naturally high rainfall variability using a 32‐year precipitation–ANPP dataset from the same site as our experiment. We found that increased growing season rainfall variability can reduce RUE and thus ecosystem functioning by as much as 42% during dry years, but that such impacts weaken as years become wetter. During low precipitation years, RUE is lowest when rainfall event sizes are relatively large, and when a larger proportion of total rainfall is derived from large events. Thus, a shift towards precipitation regimes dominated by fewer but larger rainfall events, already documented over much of the globe, can be expected to reduce the functioning of mesic ecosystems primarily during drought, when ecosystem processes are already compromised by low water availability.Climate change is expected to increase the variability of precipitation, with uncertain consequences for ecosystem functioning. We experimentally removed variability in growing season rainfall patterns across a large gradient of total precipitation amounts in native grassland. On comparing levels of primary productivity with the removal of rainfall variability to productivity under naturally high rainfall variability using long‐term observational data, we discover that rainfall variability reduces ecosystem functioning primarily during dry conditions, and that the mechanism underpinning this is the presence of large rainfall events. [ABSTRACT FROM AUTHOR]
Copyright of Global Change Biology is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
Database: Engineering Source
Description
Abstract:Ongoing intensification of the hydrological cycle is altering rainfall regimes by increasing the frequency of extreme wet and dry years and the size of individual rainfall events. Despite long‐standing recognition of the importance of precipitation amount and variability for most terrestrial ecosystem processes, we lack understanding of their interactive effects on ecosystem functioning. We quantified this interaction in native grassland by experimentally eliminating temporal variability in growing season rainfall over a wide range of precipitation amounts, from extreme wet to dry conditions. We contrasted the rain use efficiency (RUE) of above‐ground net primary productivity (ANPP) under conditions of experimentally reduced versus naturally high rainfall variability using a 32‐year precipitation–ANPP dataset from the same site as our experiment. We found that increased growing season rainfall variability can reduce RUE and thus ecosystem functioning by as much as 42% during dry years, but that such impacts weaken as years become wetter. During low precipitation years, RUE is lowest when rainfall event sizes are relatively large, and when a larger proportion of total rainfall is derived from large events. Thus, a shift towards precipitation regimes dominated by fewer but larger rainfall events, already documented over much of the globe, can be expected to reduce the functioning of mesic ecosystems primarily during drought, when ecosystem processes are already compromised by low water availability.Climate change is expected to increase the variability of precipitation, with uncertain consequences for ecosystem functioning. We experimentally removed variability in growing season rainfall patterns across a large gradient of total precipitation amounts in native grassland. On comparing levels of primary productivity with the removal of rainfall variability to productivity under naturally high rainfall variability using long‐term observational data, we discover that rainfall variability reduces ecosystem functioning primarily during dry conditions, and that the mechanism underpinning this is the presence of large rainfall events. [ABSTRACT FROM AUTHOR]
ISSN:13541013
DOI:10.1111/gcb.14789