Realized niche and spatial pattern of native and exotic halophyte hybrids

Area of Science:

• Ecology
• Evolutionary Biology
• Botany

Background:

• Interspecific hybridization is a significant evolutionary process, yet field data on hybrid realized niches and zonation impacts are scarce.
• Understanding how native and exotic hybrids affect native species and ecosystem structure is crucial for conservation and management.

Purpose of the Study:

• To evaluate realized niche dimensions and zonation patterns of native (Sarcocornia) and exotic (Spartina) hybrids compared to their parental species.
• To determine the community structuring role of native hybrids versus the disruptive influence of exotic hybrids in salt marsh ecosystems.

Main Methods:

• Examined sediment characteristics in plots representing realized niches of native and exotic hybrids and parental species across 14 salt marshes.
• Recorded plant taxa presence relative to intertidal plant zonation in a representative marsh to assess community composition and structure.

Main Results:

• Native Sarcocornia hybrids exhibited realized niche dimensions similar to their parents, co-occurring with other species and supporting community diversity.
• Exotic sterile Spartina hybrids displayed narrower realized niches than their parents, forming monocultures and negatively impacting native halophyte zonation and diversity.

Conclusions:

• Native hybrids can play a positive community structuring role, while exotic hybrids pose a disruptive ecological threat, altering native plant communities.
• The ecological niche dimension concept is valuable for assessing species roles and impacts within ecosystems, from individual to community levels.