The vegetation of the Po Plain has long been modified by natural and human factors. The present plant landscape is almost entirely anthropogenic. Many hydro-hygrophilous species, quite common until a few decades ago, are now very rare and in danger of extinction, so conservation programmes are necessary for their protection and maintenance. It is known that the former vegetation can be reconstructed thanks to palynological data, but assessing the real presence of a given species is not always possible. This work aims to understand whether palynology can give information about the presence and identification of hydro-hygrophilous species, supporting the classical flora analyses commonly conducted on herbarium data. In some cases, these species are well characterized from a morphopalynological and phytogeographical viewpoint: the plant occurrence may be suggested even by pollen findings in surface-samples. Discovering the presence of some of these species by pollen morphotypes offers a real opportunity to gear the reintroduction/reinforcing programmes, but ecological analysis will obviously be essential to ascertain the real suitability of the chosen sites, according to the ecological requirements of the species. Our analysis refers to wetlands of the southern Po plain within the Modena Province, where detailed palynological data about present and historical local flora were available.

Can palynology contribute to plant diversity conservation activities? the wetland plants in southern po plain as a case study.

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 compositional 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.

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

Historical Floras are biodiversity-oriented textual sources, which refer to times when scientific methods were far different compared to the present. They are also geographical documents, as the entire work is referred to a focal region explored by certain collectors and following certain principles, since the taxa recorded are usually accompanied by a description of the locality of the observation. Retrospective georeferencing, as well as taxonomic revision, of the records in Historical Floras are, however, very challenging processes, which are usually not taken into account. As a result, very few global overviews of Historical Floras exist to date. In this article we present the analysis of the 7767 floristic records of the late XIX century Flora of the province of Bologna (N-Italy) compiled by Girolamo Cocconi. We processed these records by georeferencing them, whenever possible, to 659 pairs of coordinates and coupling them with the analysis of the collectors involved besides the author, as to provide the spatial and temporal dimension that permits us to further understand the taxonomic information given by the species listed. This allowed us to detect a bias in the exploration of the territory, which depended on accessibility and/or attractivity of the areas for fieldwork and shifted through time as function of the available collaborators who influenced the definition of the floristic pattern of the territory. Finally, we provided a diachronic analysis with the present flora to document the most significant land use changes based on selected floristic target groups. 

Historical Floras: addressing their genesis in order to be viewed from a modern-day perspective. A case study from Northern Italy

L’Erbario della Bonifica. Un progetto per la conoscenza del territorio e della biodiversità vegetale nei canali della Bonifica Burana

“L’Erbario della Bonifica”. Un progetto per la conoscenza del territorio e della biodiversità vegetale nei canali della Bonifica Burana (Emilia orientale).

Annalisa Managlia

Papers

L’Erbario della Bonifica. Un progetto per la conoscenza del territorio e della biodiversità vegetale nei canali della Bonifica Burana

“L’Erbario della Bonifica”. Un progetto per la conoscenza del territorio e della biodiversità vegetale nei canali della Bonifica Burana (Emilia orientale).