(Introduction):

Floodplain vegetation plays an important role in providing ecosystem services such as carbon capture and cycle regulation; hence, the need arises to assess its condition.

(Objective):

To analyze the vegetation structure of the “complejo cenagoso de Zapatosa” (CCZ), propose the Floodplain Vegetation Quality Index (FVQI), and evaluate vegetation quality.

(Methodology):

Rectangular plots of 500 m2 in 12 sampling sites were defined; richness, composition, and structure analysis were conducted. The FVQI, a modification of the River Vegetation Quality Index (QBR), is proposed, and CCZ vegetation quality is calculated using the proposed index.

(Results):

48 species were found; most are native, and two are endemic. Of these, 32 are categorized as Least Concern (LC). The proposed FVQI evaluates the naturalness of continental wetland vegetation formations, vertical stratification, longitudinal connectivity, presence of native species, and anthropogenic alterations affecting the ecosystem; 66 % of the evaluated sites showed good vegetation quality, with slight transformation.

(Conclusions):

An assessment of floodplain vegetation in lentic ecosystems was conducted using the FVQI index. This index, along with structural analysis, provided information on the current state of vegetation and the degree of naturalness of vegetation formations. This study offers a more comprehensive view of ecosystem health and quality, crucial for their conservation and proper management.