Coexistence of rice production and threatened plant species: testing Marsilea quadrifolia L. in N-Italy

Abstract

In the past, the aquatic pteridophyte Marsilea quadrifolia L. was considered as a weed in paddy fields of southern Europe. The systematic use of herbicides as a crucial component of intensive agronomic approach has led to a dramatic decline in M. quadrifolia populations in European countries, mostly in the Mediterranean area. However, the introduction in recent years of sustainable rice cultivation practices has allowed partial recovery. We present here the results of a research aimed at analyzing the effects of farming typologies in respect to M. quadrifolia growth in the Po Valley area. After having transplanted M. quadrifolia swards in rice fields belonging to different farming systems, we monitored its growth and diffusion. Our results showed that M. quadrifolia has higher vegetative performance in organic farms, even though it can survive in conventional fields with reduced herbicide supply. Differences in water chemistry have limited effects on M. quadrifolia performance, because of its wide ecological amplitude. The shady conditions provided by rice canopy create micro-habitats suitable for M. quadrifolia growth. Cultivating M. quadrifolia in organic rice farms represents an important opportunity for preserving this endangered species in areas of intensive agriculture. This can, meanwhile, represent a valid opportunity to combine nature conservation and productivity offering a new possible income for farmers.

The Alien Plant Species Impact in Rice Crops in Northwestern Italy

“…This could help in identifying targeted precautions for addressing biodiversity issues in Po Plain rice lands. Rice fields, if properly managed, are wet habitats that can act as biodiversity source areas and plant diversity conservation sites, where productive and conservation functions can positively coexist [42,46,47]. Rice fields are also pivotal habitats for faunal conservation: indeed, rice lands often host high conservation interest areas, such as "Natura 2000" European Network sites [98,99].…”

“…These shifts in agronomic and water management techniques, together with the prolonged chemical weed control, led to changes in rice weed flora and fostered alien species invasion [31,32,37,38,42]. Rice paddy environments often constitute refuge areas for rare species, substituting the role of wetlands and protected habitats, which are currently severely threatened by climate change, changes in agricultural management practices as well as by alien species invasion [42][43][44][45][46][47].…”

“…s.l. = Mediterranean.Most of current detected species are of wide distribution and trivial, with the exception of Marsilea quadrifolia L., which is classified as an endangered species by the IUCN[47,93]. Many species observed in the 1950s and are now missing, are classified by the IUCN as critically endangered species (Isoëtes malinverniana Ces.…”

On farm plant reintroduction: A decision framework for plant conservation translocation in EU agro-ecosystems

“…Bioindicators can often provide more reliable information than soil, water or crop chemical analyses that might not detect occasional use of banned products. Three farmers consented to the experimental cultivation of M. quadrifolia on their farms to demonstrate that their cultivation methods were compatible with the presence of this plant (Corli et al 2021b). Interestingly, the group of organic farmers also proposed to use M. quadrifolia as a marketing strategy.…”

Application of Organic and Inorganic Fertilizers Affects the Growth and Biomass Semanggi (Marsilea crenata Presl.)

“…Semanggi (Marsilea sp. ), Is one of the ferns that usually grows in muddy environments, moist soils, watery places or wet habitats such as rice fields [1], ditches and shallow puddles [2], [3], lakes under full sun and shady conditions have a cosmopolitan distribution, but are rarely distributed in subtropical areas.…”