Rapid top-down regulation of plant C:N:P stoichiometry by grasshoppers in an Inner Mongolia grassland ecosystem.
Understanding how food web interactions alter the processing of limiting nutrient elements is an important goal of ecosystem ecology. An experiment manipulating densities of the grasshopper Oedaleus asiaticus was performed to assess top-down effects of grasshoppers on C:N:P stoichiometry of plants and soil in a grassland ecosystem in Inner Mongolia (China). With increased grasshopper feeding, plant biomass declined fourfold, litter abundance increased 30%, and the plant community became dominated by non-host plant taxa. Plant stoichiometric response depended on whether or not the plant was a grasshopper host food species: C:N and C:P ratios increased with increasing grasshopper density (GD) for host plants but decreased in non-host plants. These data suggest either a direct transfer of grasshopper-recycled nutrients from host to non-host plants or a release of non-host plants from nutrient competition with heavily grazed host plants. Litterfall C:N and C:P decreased across moderate levels of grasshopper density but no effects on C:N:P stoichiometry in the surface soil were observed, possibly due to the short experimental period. Our observations of divergent C:N:P stoichiometric response among plant species highlight the important role of grasshopper herbivory in regulating plant community structure and nutrient cycling in grassland ecosystems.
State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China.
Guangming
G
Zhang
Xingguo
X
Han
James J
JJ
Elser
D000818:Animals; D002244:Carbon / Q000032:analysis; D057486:Carbon Cycle; D017753:Ecosystem; D005260:Female; D006110:Grasshoppers; D008297:Male; D008986:Mongolia; D009584:Nitrogen / Q000032:analysis; D058458:Nitrogen Cycle; D010758:Phosphorus / Q000032:analysis; D010944:Plants / Q000737:chemistry*; D012987:Soil / Q000737:chemistry*
D012987:Soil; D010758:Phosphorus; D002244:Carbon; D009584:Nitrogen
Science. 1985 May 31;228(4703):1089-91
17737904
Proc Natl Acad Sci U S A. 1994 Jun 7;91(12):5364-7
11607475
New Phytol. 2010 May;186(3):593-608
20298486
Science. 2008 Apr 25;320(5875):492-5
18436780
Oecologia. 2007 Feb;151(1):42-53
17089141
Oecologia. 1997 Oct;112(2):201-208
28307571
Proc Natl Acad Sci U S A. 2008 Feb 12;105(6):1977-82
18238894
J Chem Ecol. 2005 Sep;31(9):2069-90
16132213
Am Nat. 1999 Oct;154(4):449-468
10523491
Oecologia. 2006 Aug;149(1):115-22
16639565
Ecol Lett. 2007 Dec;10(12):1135-42
17922835
Annu Rev Entomol. 2001;46:667-702
11112183
Nature. 2000 Nov 30;408(6812):578-80
11117743
J Theor Biol. 2004 Jul 7;229(1):31-43
15178183
Oecologia. 2010 Mar;162(3):581-90
19916028
Annu Rev Entomol. 2009;54:165-87
18764740
Ecol Lett. 2009 Jun;12(6):516-27
19392711
J Exp Biol. 2003 May;206(Pt 10):1669-81
12682099
Oecologia. 2004 Jan;138(1):91-101
14566555
Oecologia. 1993 Oct;96(1):1-8
28313746
Ecology. 2009 Sep;90(9):2339-45
19769111
Science. 1986 Feb 7;231(4738):605-7
17750971
Science. 1997 Dec 5;278(5344):1798-800
9388182
Oecologia. 1993 Jul;94(4):516-527
28313992
Proc Natl Acad Sci U S A. 2000 Dec 19;97(26):14412-7
11106378
Trends Ecol Evol. 1998 Jul 1;13(7):261-5
21238294