Forage nutritive quality in the serengeti ecosystem: the roles of fire and herbivory

被引:93
作者
Anderson, T. Michael
Ritchie, Mark E.
Mayemba, Emilian
Eby, Stephanie
Grace, James B.
McNaughton, Samuel J.
机构
[1] Univ Groningen, Community & Conservat Ecol Grp, NL-9750 AA Haren, Netherlands
[2] Syracuse Univ, Dept Biol, Syracuse, NY 13244 USA
[3] Serengeti Wildlife Res Ctr, Arusha, Tanzania
[4] US Geol Survey, Natl Wetlands Res Ctr, Lafayette, LA 70506 USA
关键词
fire; herbivory; leaf nutrients; forage element concentration; plant community composition; structural equation modeling;
D O I
10.1086/520120
中图分类号
Q14 [生态学(生物生态学)];
学科分类号
071012 [生物信息与计算生物学]; 0713 [生态学];
摘要
Fire and herbivory are important determinants of nutrient availability in savanna ecosystems. Fire and herbivory effects on the nutritive quality of savanna vegetation can occur directly, independent of changes in the plant community, or indirectly, via effects on the plant community. Indirect effects can be further subdivided into those occurring because of changes in plant species composition or plant abundance (i.e., quality versus quantity). We studied relationships between fire, herbivory, rainfall, soil fertility, and leaf nitrogen (N), phosphorus (P), and sodium (Na) at 30 sites inside and outside of Serengeti National Park. Using structural equation modeling, we asked whether fire and herbivory influences were largely direct or indirect and how their signs and strengths differed within the context of natural savanna processes. Herbivory was associated with enhanced leaf N and P through changes in plant biomass and community composition. Fire was associated with reduced leaf nutrient concentrations through changes in plant community composition. Additionally, fire had direct positive effects on Na and nonlinear direct effects on P that partially mitigated the indirect negative effects. Key mechanisms by which fire reduced plant nutritive quality were through reductions of Na-rich grasses and increased abundance of Themeda triandra, which had below-average leaf nutrients.
引用
收藏
页码:343 / 357
页数:15
相关论文
共 113 条
[1]
Rainfall and soils modify plant community response to grazing in Serengeti National Park [J].
Anderson, T. Michael ;
Ritchie, Mark E. ;
McNaughton, Samuel J. .
ECOLOGY, 2007, 88 (05) :1191-1201
[2]
Nutrient acquisition and physiological responses of dominant Serengeti grasses to variation in soil texture and grazing [J].
Anderson, T. Michael ;
Dong, Yan ;
McNaughton, Samuel J. .
JOURNAL OF ECOLOGY, 2006, 94 (06) :1164-1175
[3]
[Anonymous], 1988, Concepts of Ecosystem Ecology
[4]
Shaping the landscape: Fire-grazer interactions in an African savanna [J].
Archibald, S ;
Bond, WJ ;
Stock, WD ;
Fairbanks, DHK .
ECOLOGICAL APPLICATIONS, 2005, 15 (01) :96-109
[5]
Ungulate effects on the functional species composition of plant communities: Herbivore selectivity and plant tolerance [J].
Augustine, DJ ;
McNaughton, SJ .
JOURNAL OF WILDLIFE MANAGEMENT, 1998, 62 (04) :1165-1183
[6]
GRAZING ECOSYSTEM IN SERENGETI [J].
BELL, RHV .
SCIENTIFIC AMERICAN, 1971, 225 (01) :86-&
[7]
BELSKY JA, 1992, J VEG SCI, V3, P187, DOI 10.2307/3235679
[8]
THE RELATIONSHIPS BETWEEN SOIL FACTORS, GRASS NUTRIENTS AND THE FORAGING BEHAVIOR OF WILDEBEEST AND ZEBRA [J].
BENSHAHAR, R ;
COE, MJ .
OECOLOGIA, 1992, 90 (03) :422-428
[9]
Post-fire seedling recruitment in coastal heathland in relation to regeneration strategy and habitat [J].
Benwell, AS .
AUSTRALIAN JOURNAL OF BOTANY, 1998, 46 (01) :75-101
[10]
Blair JM, 1997, ECOLOGY, V78, P2359, DOI 10.1890/0012-9658(1997)078[2359:FNAAPR]2.0.CO