Structural Traits Driving Water Hyacinth (Eichhornia crassipes) Aggressive Spread and Ecosystem Disruption

Abstract

Water hyacinth is a highly invasive aquatic macrophyte that presents significant ecological and socio-economic challenges, particularly in tropical and subtropical regions. Ten populations of Eichhornia crassipes were collected from ecologically distinct aquatic environments in Punjab to evaluate growth and anatomical traits that contribute to the ecological success of this invasive species under varying water conditions. Structural adaptations related to roots and leaves exhibited phenotypic variation across different habitats. In high-salinity and polluted environments, such as feeder canals, E. crassipes exhibited protective adaptations, including reduced growth, smaller leaves, and minimal modifications in root and leaf tissues. The population from irrigation canals displayed intermediate growth, characterized by enhanced storage and vascular tissues, which facilitated efficient resource allocation. In less stressed environments, such as headworks, the plant showed rapid growth and resource acquisition strategies, developing larger dermal, storage, and vascular tissues, along with increased leaf thickness, chlorenchyma, and cortex. Notably, E. crassipes exhibited pronounced lacunae and larger vascular bundles surrounded by a thicker bundle sheath cell layer, indicative of C4 Kranz anatomy. The plants from highly polluted waters exhibited larger lysigenous cavities, a lignified endodermis in roots, and specialized palisade mesophyll in leaves, aiding buoyancy and survival in degraded aquatic ecosystems. These features collectively contribute to E. crassipes adaptability in diverse aquatic habitats, including headworks, feeder canals, irrigation canals, and polluted water bodies. Effective management strategies should be tailored to local water conditions and incorporate both biological and physical controls.