INVESTIGADORES
HIERRO jose luis
artículos
Título:
Resistance to Centaurea solstitialis invasion from annual and perennial grasses in California and Argentina
Autor/es:
JOSÉ L. HIERRO; CHRISTOPHER LORTIE; DIEGO VILLARREAL; MARÍA E. ESTANGA-MOLLICA; RAGAN CALLAWAY
Revista:
BIOLOGICAL INVASIONS
Editorial:
SPRINGER
Referencias:
Año: 2011 p. 2249 - 2259
ISSN:
1387-3547
Resumen:
A common explanation for Centaurea
solstitialis invasion in California is that it occupies an
empty niche created by the replacement of native
perennial grasses by exotic annual grasses and
concomitant increases in soil water availability. This
hypothesis, however, cannot explain C. solstitialis
invasion into perennial-dominated grasslands of central
Argentina. We assessed invasibility of annual
versus perennial grass communities in these regions through parallel field experiments where we created
grass plots and, after one year of establishment,
measured effects on water and light, and added
C. solstitialis seeds in two successive trials. Additionally,
we removed vegetation around naturally
occurring C. solstitialis in both regions, and examined
the performance of Californian and Argentinean
C. solstitialis individuals when growing under common
conditions simulating climate in California and
Argentina. In California, both grass types offered
high resistance to C. solstitialis invasion, water was
generally greater under perennials than annuals, and
light was similarly low beneath both types. In Argentina,
invasibility was generally greater in annual than
perennial plots, water was similar between groups, and
light was much greater beneath annuals. Removal
experiments showed that competition from annual
grasses in California and perennial grasses in Argentina
greatly reduce C. solstitialis performance. Additionally,
Californian and Argentinean individuals did
not exhibit genetic differentiation in studied traits. Our
results suggest that dominant plant functional groups
in both California and Argentina offer substantial
resistance to C. solstitialis invasion. The success of
this species might be tightly linked to a remarkable
ability to take advantage of disturbance in both
regions.