Hourly and daily rainfall intensification causes opposing effects on C and N emissions, storage, and leaching in dry and wet grasslands

TLDR: In this paper, the authors investigate the effects of expected twenty-first century changes in hourly and daily rainfall on soil carbon and nitrogen emissions, soil organic matter (SOM) stocks, and leaching using a coupled mechanistic soil biogeochemical model (BAMS2).

Abstract: Climate change is expected to alter hourly and daily rainfall regimes and, in turn, the dynamics of ecosystem processes controlling greenhouse gas emissions that affect climate. Here, we investigate the effects of expected twenty-first century changes in hourly and daily rainfall on soil carbon and nitrogen emissions, soil organic matter (SOM) stocks, and leaching using a coupled mechanistic carbon and nitrogen soil biogeochemical model (BAMS2). The model represents various abiotic and biotic processes involving 11 SOM pools. These processes include fungal depolymerization, heterotrophic bacterial mineralization, nitrification, denitrification, microbial mortality, necromass decomposition, microbial response to water stress, protection, aqueous advection and diffusion, aqueous complexation, and gaseous dissolution. Multi-decadal modeling with varying rainfall patterns was conducted on nine Australian grasslands in tropical, temperate, and semi-arid regions. Our results show that annual $${\text{CO}}_2$$ emissions in the semi-arid grasslands increase by more than 20% with a 20% increase in annual rainfall (with no changes in the rainfall timing), but the tropical grasslands have opposite trends. A 20% increase in annual rainfall also increases annual $${\text{N}}_2{\text{O}}$$ and NO emissions in the semi-arid grasslands by more than 10% but decreases emissions by at least 25% in the temperate grasslands. When subjected to low frequency and high magnitude daily rainfall events with unchanged annual totals, the semi-arid grasslands are the most sensitive, but changes in annual $${\text{CO}}_2$$ emissions and SOM stocks are less than $$5\%$$ . Intensification of hourly rainfall did not significantly alter $${\text{CO}}_2$$ emissions and SOM stocks but changed annual $${\text{NH}}_3$$ emissions in the tropical grasslands by more than 300%.

Full text

Lawrence Berkeley National Laboratory
Recent Work
Title
Hourly and daily rainfall intensification causes opposing effects on C and N emissions,
storage, and leaching in dry and wet grasslands
Permalink
https://escholarship.org/uc/item/0zs3r5jb
Journal
Biogeochemistry, 144(2)
ISSN
0168-2563
Authors
Tang, FHM
Riley, WJ
Maggi, F
Publication Date
2019-07-30
DOI
10.1007/s10533-019-00580-7
Peer reviewed
eScholarship.org Powered by the California Digital Library
University of California

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
8%-+;-:/
$$&
82-+;A1B-+;5:
8E-+;F:7
&3&
&8C-++A1G
-+;61?-+;6:8G-++61(
-+;F:$82/*=<-+;A1
*-+;,:89
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1
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&$$
C8(9:
7$
9(9
<<$
8(-++6:$8<-+;-:
9
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97
=/9
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$383
HBirch eectI*;4,F1#-+;+1J-+;+:(
$/7&
&&$
$$&9
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8(-+;F:
$$$
8B;4F6:$<$$8&/EK-+;-:
$8-+;5:$
8C-+;-:7&
/L7
$&//$
@$&
(9&
829:$82@:8#-+;F:9
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M7$
$$8**-+++:1
=2@
<$7
3&$
8*-+;-13*;4441

<C-++4:J
$&&
$$8E!-+;+1(
-+;F:&$$(9
<$$<$
$82?3-+;-:3$8##N-+;5:
8-+;6:8**-++,1(3
;44,:8#;44-1
(7;4F,1!-+++:$&
3&/
8-++F1((-++5:<
82?3-+;-:@L
$
$3$$&
97$
8#=;4441#-++5:$
$&&8C
-+;-1*-+;,:=
7&(9
&=/
&$

*%(;&!
8-+;5:&8-++F:$
&(9
O8*%(-1*%$(9
&-:;;(98&
:&$8$
77:3
$=
&=7
*%(-$3/$&
1
-
991$1
3
7
&%
/

*%(-3

&$(9
*%(;$$!8-+;5:
&8-++F:O
38*%(-;:(98
:1&(9
8
:1&8
A
  
9
-
9
-
:1&$
8F
DEP
:$8B
HET
:/7<
$8B
AOB
:/7<$8B
NOB
:$
8B
DEN
:
@*%(- $(98!;O!F
;:%$$$
$&"F,&
8-+;5:@</8!4O
!;;:<$$
& 
$$F
DEP
B
HET
(97<$B
AOB
 
3$(9
*%(;8!-+;5:
$<$$
8(@$(;:
(8!;-O!;A:
8!;5O!;6:8-++F:
$$
$$8($(;:@
*%(-
-
7 8!;4:%!;4
$7
-
7$
7$
-
7$&
$=17$$
$$
8!-+;;:
C3$  8!-+O!-;:$&
8!-FO!-4"A,-++;1
%3;44A:$8!-67"

Frequently asked questions

Q1. What are the contributions in "Hourly and daily rainfall intensification causes opposing effects on c and n emissions, storage, and leaching in dry and wet grasslands" ?

Here, the authors investigate the effects of expected twenty-first century changes in hourly and daily rainfall on soil carbon and nitrogen emissions, soil organic matter ( SOM ) stocks, and leaching using a coupled mechanistic carbon and nitrogen soil biogeochemical model ( BAMS2 ).