The combined effects of sediment accretion (burial) and nutrient enrichment on the growth and propagation of Phalaris arundinacea

Abstract

Sediment accretion (burial) and nutrient enrichment occur concurrently in lacustrine wetlands, but the role of these two aspects of sedimentation on macrophyte performance has rarely been examined. Here, we investigated the concurrent effects of sediment accretion and nutrient enrichment on the growth and propagation of Phalaris arundinacea L. using a factorial sediment burial by nutrient addition experimental design. Regardless of burial depth, nutrient addition increased biomass accumulation, shoot mass ratio, the number of rhizomes, and the length of ramets and rhizomes. While burial had little effect on plant growth and propagation, it had an interactive effect with nutrient addition on belowground growth and ramet production. These results indicate that P. arundinacea is tolerant to burial, which allows it to grow in habitats with high sedimentation rates. However, the enhanced growth and propagation of P. arundinacea following sedimentation were primarily related to nutrient enrichment. This suggests that nutrient enrichment of sediments, which occurs in many lacustrine wetlands, increases the risk of invasion by P. arundinacea.

Concurrent Effects of Sediment Accretion and Nutrient Availability on the Clonal Growth Strategy of Carex brevicuspis-A Wetland Sedge That Produces Both Spreading and Clumping Ramets

“…In habitats with increasing sedimentation rate, such as many lacustrine wetlands, modification of clonal growth forms might be insufficient to allow C. brevicuspis to overcome severe burial stress. Therefore, in such habitats C. brevicuspis might be less competitive like burial-tolerant species such as Phalaris arundinacea L. ( Chen et al, 2017 ).…”

“…Sediment accretion and nutrient enrichment often occur simultaneously in lacustrine wetlands ( Maun, 1998 ; Frosini et al, 2012 ; Chen et al, 2017 ). Sediments induce hypoxia in the root zone and cause physical overburden to the apical meristems of buried plants ( Chen et al, 2014a ; Pan et al, 2014 ).…”

“…Wetland macrophytes respond to burial by elongating stem, increasing stem biomass, and releasing dormant buds on their shoots and rhizomes ( Maun, 1998 ; Pan et al, 2012 ; Chen et al, 2014a ). Nutrient enrichment might facilitate the acclimation of macrophytes to sedimentation by increasing the shoot length, total biomass, and ramet numbers of wetland macrophytes ( Xie et al, 2013 ; Chen et al, 2017 ). However, the two co-occurring factors might affect plant growth independently or by interacting such that one factor reduces or amplifies the impact of the other factor ( Lenssen et al, 2003 ; Puijalon et al, 2007 ).…”

Potential local adaptation in populations of invasive reed canary grass (Phalaris arundinacea) across an urbanization gradient

“…Second, increasing urbanization often leads to greater wetland sedimentation (Houlahan & Findlay, 2004 ). Reed canary grass is tolerant to burial via sedimentation (Chen et al., 2014 , 2017 ; Pan et al., 2014 ), and, when combined with nutrient addition, reed canary grass decreases its root mass ratio in response (Chen et al., 2017 ) In our study, the intense urban population had lower root mass ratio than the natural population, which suggests that evolved changes in response to sedimentation stress could thus also have contributed to the differences we found between populations at the ends of our land‐use gradient.…”

“…First, increasing anthropogenic land use commonly leads to more nutrient accumulation in wetlands via stormwater runoff (Kaushal et al, 2014). Strong responses to nitrogen enrichment have been documented for reed canary grass (Chen et al, 2017;Kercher & Zedler, 2004;Martina & von Ende, 2012, 2013Maurer & Zedler, 2002), including increased aboveground biomass production (Chen et al, 2017;Kercher & Zedler, 2004) and decreased proportional allocation to root biomass (Chen et al, 2017;Wetzel & van der Valk, 1998). Although these reports are of plastic phenotypic changes only, selection in nutrient-enriched urban wetlands likely also favors highly productive individuals across environmental conditions (Keddy et al, 2000).…”