Invasive Eichhornia crassipes Affects the Capacity of Submerged Macrophytes to Utilize Nutrients

Abstract

Abstract:Invasion by free-floating species, such as Eichhornia crassipes, is one of the most critical threats to the biodiversity and sustainability of wetland ecosystems, where all plants experience spatial heterogeneity in substrate nutrients. However, few studies have focused on the effects of free-floating invaders on the capacity of submerged plants to utilize substrate nutrients. A 10-week greenhouse experiment was conducted to test the effects of free-floating invasive E. crassipes (presence or absence) on the growth of Ceratophyllum demersum and Myriophyllum spicatum, and their capacity to use heterogeneous and homogeneous substrate nutrients. We found that the invasion of E. crassipes could significantly decrease the growth of both submerged C. demersum and M. spicatum and that substrate nutrient heterogeneity increased the growth of C. demersum (approximately 30% in total biomass and 40% in the number of nodes) but not of M. spicatum. The two submerged species have different strategies to address invasion by E. crassipes. These results indicate that E. crassipes can prevent the growth of submerged plants even if the submerged plants can effectively use heterogeneous nutrients. For the effective conservation of submerged macrophytes in wetlands, measures should be taken to restrict the spread of invasive free-floating species.

Negative correlations between native macrophyte diversity and water hyacinth abundance are stronger in its introduced than in its native range

“…The highly competitive ability of E. crassipes (Ruiz Téllez et al, ), for example, may enhance its negative effects on species without an evolutionary history with this invader (Callaway & Aschehoug, ). For example, the nutrient acquisition rates of the species from the introduced range may be slower (Zhou, Pan, Xu, Wang, & Cui, ), whereas the native species at the E. crassipes native range may present similar nutrient acquisition rates of this species as they have competed throughout their evolutionary history. In addition, the release of allelopathic compounds produced by this invasive species may have a negative effect on the species from the introduced range of E. crassipes occurrence (Gul et al, ; Pei et al, ).…”

“…In addition to the biotic interactions in the introduced range, several inherent ecological features of E. crassipes can offer a great invasive potential leading to a lower biotic resistance of native communities and, as a consequence to higher impacts on native communities. The invasion potential enhances, for example, in response to phenotypic plasticity (Center & Spencer, ; Fleming & Dibble, ; Zhang, Zhang, & Barrett, ), high relative growth rates (Cook, ; Ruiz Téllez et al, ), rapid nutrient acquisition, efficient use of resources related to other natives (Fan, Liu, Yu, & Xie, ; Zhou et al, ) and high propagation capacity of propagules (Downing‐Kunz & Stacey, ). All combined, these factors allow E. crassipes to spread rapidly by decreasing the space available to other species (Stiers et al, ).…”

“…and Myriophyllum sp. By being submerged, these species are suppressed due to the shading provided by floating macrophytes (Brendonck et al, ; Khanna, Santos, Hestir, & Ustin, ; Scheffer et al, ; Strange et al, ) due to the use of resources by E. crassipes (Zhou et al, ) or could even not establish in places where the invader had a biomass above 205 g DM m −2 . This elimination of submerged species in plots dominated by E. crassipes is in accordance with the previous conclusion showing negative effect of invasive abundance over species richness.…”

Outbreak of a new alien invasive plant Salvia reflexa in north‐east China

“…Eichhornia crassipes (Mart.) Solms is a major threat to the biodiversity and sustainability of aquatic ecosystems in Dianchi Lake (Zhou et al ., ). Therefore, in addition to existing invasive plants, predicting which exotic plant species exhibit risk of becoming invasive would be cost‐effective and important for preventing new invaders and for managing high‐risk species already present.…”

Defensive functions of volatile organic compounds and essential oils from northern white-cedar in China

“…For example, Eichhornia crassipes (Mart.) Solms, native to South America has been cultivated in China as feed for livestock, but has now become major threat to the biodiversity and sustainability of aquatic ecosystems in Dianchi Lake [ 19 ]. Similarly, Ageratina adenophora (Spreng.)…”