水保所知识产出(1956---)知识库

Exogenous fertilization could efficiently improve grassland productivity and promote grassland restoration. In-
creasing fertilization may profoundly affect community stability, whereas the underlying compensatory dynam-
ics among functional groups in regulating grassland stability remain unclear. Three different grasslands, annuals
forb (AF) community, perennial grass (PG) community and perennial forb (PF) community, on semiarid Loess
Plateau were selected. We designed a 3-year split-plot experiment (main-plot: 0, 25, 50, and 100 kg N ha −1
yr −1 ; subplot: 0, 20, 40 and 80 kg P 2 O 5 ha −1 yr −1 ) to explore how N and P addition affects community stability
and its relationship with species richness, species asynchrony and functional group stability. Temporal stability
differedlargelybetween functionalgroups underNandPaddition,perennialforbsorgrasses hadhigherstability
than perennial legumes or annuals and biennials. Decreased stability of PG and PF communities was primarily
due to reduced species asynchrony under N addition alone, while it attributed to increased dominance of peren-
nial legumes after P addition alone. 50 and 100 kg N ha −1 yr −1 combined with P addition significantly increased
dominance of annuals and biennials, but decreased stability of annuals and biennials, which caused significant
declines in stability of the three communities. Significant species richness decline induced by N and P addition
onlyoccurredinAFcommunity,whichsuppressedAFcommunitystabilitythroughreducingspeciesasynchrony.
AF community stability was regulated by additively negative effect of diversity decline and decreased annuals
and biennials stability. Whereas, in PG and PF communities, nutrient-induced changes of functional groups sta-
bility were the main driver of community stability rather than diversity. Our study highlights the role of func-
tional group composition and dynamics in regulating the effects of diversity on community stability and
rational N and P combined addition was essential for conserving stability of different grasslands on semiarid
Loess Plateau.