Vegetative Propagule Pressure and Water Depth Affect Biomass and Evenness of Submerged Macrophyte Communities

Abstract

Vegetative propagule pressure may affect the establishment and structure of aquatic plant communities that are commonly dominated by plants capable of clonal growth. We experimentally constructed aquatic communities consisting of four submerged macrophytes (Hydrilla verticillata, Ceratophyllum demersum, Elodea nuttallii and Myriophyllum spicatum) with three levels of vegetative propagule pressure (4, 8 and 16 shoot fragments for communities in each pot) and two levels of water depth (30 cm and 70 cm). Increasing vegetative propagule pressure and decreasing water level significantly increased the growth of the submerged macrophyte communities, suggesting that propagule pressure and water depth should be considered when utilizing vegetative propagules to re-establish submerged macrophyte communities in degraded aquatic ecosystems. However, increasing vegetative propagule pressure and decreasing water level significantly decreased evenness of the submerged macrophyte communities because they markedly increased the dominance of H. verticillata and E. nuttallii, but had little impact on that of C. demersum and M. spicatum. Thus, effects of vegetative propagule pressure and water depth are species-specific and increasing vegetative propagule pressure under lower water level can facilitate the establishment success of submerged macrophyte communities.

Species identity and diversity effects on invasion resistance of tropical freshwater plant communities

“…Thus, mesocosms with two species contained six individuals of each species, whereas those with three species contained four individuals of each species. Such shoot densities are within the range of the shoot densities of submerged macrophyte communities in natural conditions 65 . The plant fragments were planted 5 cm deep in the sediment.…”

“…Each fragment consisted of a 15 cm long shoot with apical tip, but no lateral branches, to minimize variation in the size of the initial shoot material. This number of fragments is considered to represent medium propagule pressure 65 . We selected fragments with an apical tip, because these have higher regeneration and colonisation abilities, and higher growth rates than fragments without apical tips 66 .…”

Effects of water regime on the growth of the submerged macrophyte Ceratophyllum demersum at different densities

“…The experimental population assembled for this study consisted of the submerged macrophyte C. demersum L. (Ceratophyllaceae), which is a type of perennial, submerged clonal plant and each of its shoot fragments can potentially develop into an independent new plant (Zhang, Xu et al 2014). Furthermore, it is a cosmopolitan species, commonly growing in moderately to highly eutrophic shallow ponds, lakes, and ditches (Keskinkan et al 2004;Li, Wang et al 2015). Considering its ability of the removal of heavy metals such as lead, zinc, and copper, it can be used for lake recovery (Keskinkan et al 2004).…”

Microbial community of nitrogen cycle‐related genes in aquatic plant rhizospheres of Lake Liangzi in winter

“…1). Of the 14 representative OTUs, OTU 1,3,5,6,8,9,and 14 were affiliated with the Nitrosospirathese contained 60 sequences and represented 61.9% of the clone library. OTU 2,…”

“…Aquatic plants can purify water and are important components of lacustrine ecosystems [6,7]. As the main ecological group in shallow lakes, aquatic plants usually occupy most of the space between water and sediment [8]. Aquatic plants play an important role with sediments and provide a space for microorganisms.…”