Flora and plant communities across a complex network of heavily modified water bodies: geographical patterns, land use and hydrochemical drivers in a temperate overexploited plain

The decline of freshwater flora due to alteration, reclamation and trophic perturbation of lowland wetlands is among the most relevant issues in biological conservation. The contribution of heavily modified water bodies (HMWBs) in preserving plant diversity is notable, but the underlying ecological mechanisms are not completely explored. To contribute to this debate and expand the knowledge on the role of HMWBs in maintaining wetland biodiversity in overexploited agroecosystems, a canal network of about 1150 km (SE Po valley, N-Italy) was analysed to study the geographical patterns of riparian flora and plant communities, and their land use and hydrochemical drivers. A systematic sampling procedure was adopted by randomly selecting 96 transects (10 ­m 2 ) along 79 drainage canals. Additionally, 22 transects were sampled for water quality evaluation. Flora was characterised based on species richness and presence of threatened, alien and invasive species. We also studied the contribution of land use and water quality in explaining plant richness and composition. Slope and aspect of canals do not significantly affect plant species composition, whereas the «proximity to protected areas» seems to have a negative influence. Both threatened and alien plants richness decrease approaching protected areas. Among land use types, only agro-zootechnical settlements influence plant species composition, favoring nitrophilous species, as demonstrated by water parameters (the spatial patterns of nitrophilous species mirrored the progressive worsening of canal waters). This work confirms the key role of HMWBs in sustaining plant species diversity in oversimplified landscapes, highlighting complex regulation mechanisms that need further investigations

Phytoplankton community responses to extreme climate events investigated by mesocosm approach

Doctora

Role of irrigation canal morphology in driving riparian flora in over-exploited catchments

Freshwater plants loss is one of the preeminent issues concerning biodiversity conservation, due to the alteration of inland waters by water regulation and agricultural intensification. At the same time, data suggest a relevant contribution of artificial, lowland aquatic ecosystems in supporting plant diversity. However, the underlying ecological mechanisms remain to be fully understood. To add knowledge to this subject, a wide canal network in the Bologna area (~ 1400 km2 , northern Italy) was investigated to analyse the riparian flora in relation to canal morphology. A systematic sampling procedure was adopted by randomly selecting 96 transects (1 m × 10 m) along 79 different canals, classified as small, medium, and large in terms of water depth. Flora was characterised based on the Ellenberg’s humidity and nitrophily indices, life forms, chorotypes, and alien species. The distribution of the number of species and floristic categories between transects and the role of canal depth were explored using linear mixed models and nMDS. 251 plant species were recorded; they were characterised by a broad ecology in terms of soil moisture (71% of the list) and nutrient availability (59%). Wetland and alien species—including invasive ones—were a marginal presence (< 5%, < 6%, respectively)—and canal depth showed a significant effect on com- positional dissimilarity between canals, with larger canals characterised by lower diversity rates. This work reinforces the pivotal contribution of heavily modified water bodies in supporting plant richness in oversimplified landscapes, confirming the role of canal depth in driving local flora

Proceedings Of The 23Rd Paediatric Rheumatology European Society Congress: Part Two

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