Invasion of the cosmopolitan species Echinochloa colona into herbaceous vegetation of a tropical wetland system
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Date
2004
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
The Ecological Society of Japan 2014
Abstract
The negative effects of alien plant species on
ecosystem structure and functions are increasingly
recognised, and efforts to control these species are vital
to restore degraded ecosystems and preserve biodiver-
sity. However, we lack a full understanding of factors
that determine alien species invasions along spatial
gradients in herbaceous vegetation of tropical systems.
We therefore examined the effects of community prop-
erties, environmental variables and human-related dis-
turbance factors on the invasion of the alien grass
Echinochloa colona (L.) Link at small- and large scales in
the Kilombero Valley wetland, Tanzania. Generalized
additive mixed models showed that E. colona abundance
on a small scale was negatively related to above-ground
biomass and evenness of resident species, whereas E.
colona abundance was positively related to grazing
intensity. On a large scale, biomass (negatively related to
E. colona abundance) and distance to river (positive)
were important in explaining E. colona abundance.
These findings support the assertion that different fac-
tors may contribute to the invasion of alien plant species
at different spatial scales, as also reported in many
temperate systems. Overall, our results show that suc-
cessful invasion of alien species is a function of plant
community properties, human-related disturbance and
favourable environmental conditions. Effective man-
agement strategies should consider mitigations that can
increase the biomass and evenness of native species and
a reduction of grazing pressure to restore the wetland
and conserve biodiversity.
Description
Ecological research,2014; 29: 969-979
Keywords
Biomass, Diversity, Evenness, Alien species, Spatial scales, Human-related disturbance