Extreme rainfall events can alter inter-annual biomass responses to water and N enrichment
Water availability has profound effects on plant growth and productivity in temperate and semiarid grasslands. However, it remains unclear how variation of inter-annual precipitation by extreme rainfall events will alter the aboveground and belowground responses of plants, and how these responses ma...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2013-12-01
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| Series: | Biogeosciences |
| Online Access: | http://www.biogeosciences.net/10/8129/2013/bg-10-8129-2013.pdf |
| Summary: | Water availability has profound effects on plant growth
and productivity in temperate and semiarid grasslands. However, it remains
unclear how variation of inter-annual precipitation by extreme rainfall
events will alter the aboveground and belowground responses of plants, and
how these responses may be contingent on N availability. In this
study, we examined the interactive effects of inter-annual precipitation
variation and N addition on aboveground and live fine root biomass of a
semiarid grassland in northern China for two consecutive years (2007 and
2008). Inter-annual variation in precipitation resulting mainly
from the occurrence of extreme rainfall events in 2008 significantly
affected above- and belowground plant biomass responses to water addition.
In addition, variation of inter-annual precipitation by this extreme
rainfall event suppressed plant responses to nitrogen addition and reduced
the interaction effects between water and nitrogen addition. These effects
of inter-annual precipitation fluctuation could be attributed to the
negative influence of the extreme rainfall event on soil N and water
availability, ultimately reducing plant rainfall use efficiency and nitrogen
use efficiency. In conclusion, our results suggest ecosystem
responses to water and N enrichment could be altered by inter-annual
variation of precipitation regime caused by the naturally occurring extreme
rainfall events. |
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| ISSN: | 1726-4170 1726-4189 |