EFFECT OF CONSERVATION PRACTICES ON FUNCTIONAL DIVERSITY AND ASSEMBLY OF WEED COMMUNITIES: A DATABASE OF FUNCTIONAL TRAITS

The incorporation of conservation agriculture techniques (e.g. reduced tillage and green manures) in organic farming systems brings many benefits to the environment and reduces energy use (Holland, 2004). One of the main drawbacks of the use of reduced tillage is the potential increase in weed infestation and shifts in the weed community composition, sometimes to the benefit of more difficult-to-control species (Bàrberi, 2002; Peigné et al., 2007; Sans et al., 2011). However, weeds have an important role in maintaining farmland functional biodiversity (Bàrberi et al, 2010; Caballero et al., 2010), and this should be balanced with their potential negative impact on crop yield and quality. Within the frame of the European project “Reduced tillage and green manures for sustainable cropping systems” (TILMAN-ORG), in 2012 we started a study with the aim of evaluating the effects of conservation agricultural methods on functional attributes of weed communities, taking into account both the potential detrimental effects of weeds on crop growth and yield and the potential ecological services or dis-services. Knowledge on the outcome of positive and negative effects will be useful in the context of evaluating soil conservation practices in organic farming. In this paper we highlight the approach used to build the weed functional traits database, the first step in this study

Contrasting effects of cover crops on 'hot spot' arbuscular mycorrhizal fungal communities in organic tomato

Arbuscular mycorrhizal fungal (AMF) communities are fundamental in organic cropping systems where they provide essential agro-ecosystem services, improving soil fertility and sustaining crop production. They are affected by agronomic practices, but still, scanty information is available about the role of specific crops, crop rotations and the use of winter cover crops on the AMF community compositions at the field sites. A field experiment was conducted to elucidate the role of diversified cover crops and AMF inoculation on AMF diversity in organic tomato. Tomato, pre-inoculated at nursery with two AMF isolates, was grown following four cover crop treatments: Indian mustard, hairy vetch, a mixture of seven species and a fallow. Tomato root colonization at flowering was more affected by AMF pre-transplant inoculation than by the cover crop treatments. An enormous species richness was found by morphological spore identification: 58 AMF species belonging to 14 genera, with 46 and 53 species retrieved at the end of cover crop cycle and at tomato harvest, respectively. At both sampling times, AMF spore abundance was highest in hairy vetch, but after tomato harvest, AMF species richness and diversity were lower in hairy vetch than in the cover crop mixture and in the mustard treatments. A higher AMF diversity was found at tomato harvest, compared with the end of the cover crop cycle, independent of the cover crop and pre-transplant AMF inoculation. Our findings suggest that seasonal and environmental factors play a major role on AMF abundance and diversity than short-term agronomic practices, including AMF inoculation. The huge AMF diversity is explained by the field history and the Mediterranean environment, where species characteristic of temperate and sub-tropical climates co-occur

A pan-European model of landscape potential to support natural pest control services

Pest control by natural enemies (natural pest control) is an important regulating ecosystem service with significant implications for the sustainability of agro-ecosystems. The presence of semi-natural habitats and landscape heterogeneity are key determinants of the delivery of this service. However, to date, synthetic and consistent indicators at large scales are lacking. We developed a pan-European, spatially-explicit model to map and assess the landscape potential to sustain natural pest control. The model considers landscape composition in terms of semi-natural habitats types, abundance, spatial configuration and distance from the focal field. It combines recent high-resolution geospatial layers with empirical results from extensive field surveys measuring the specific contribution of different semi-natural habitats to support insects flying enemies providing natural pest control. The resulting maps facilitate a comparison of the relative biological control potential of different areas and show that currently a large proportion of high-productive agricultural areas in Europe has low potential. The obtained indicator can inform the formulation of policies and planning strategies aimed at increasing biodiversity and ecosystem services and can be used to assess trade-offs between different services. Potential fields of application include the Common Agricultural Policy and the EU Biodiversity Strategy, in particular the implementation of Green Infrastructure

Un caso di studio: la Tenuta di Coltano

Con questo lavoro si sono volute analizzare alcune delle funzioni ecosistemiche che alcuni elementi paesistici degli agroecosistemi possono avere, focalizzando l'analisi sulla componente vegetale dell'ecosistema. Nell'ambito dell'area d'esame scelta (la Tenuta di Coltano, situata in provincia di Pisa) si sono volute analizzare le seguenti ipotesi: Ï i boschi costituiscono delle aree source per le specie vegetali Ï i canali fungono da corridoi di connessione per le stesse (si è cercato di capire quali parametri potessero inluenzare il numero di specie vegetali presenti lungo questi elementi) Ï esistono delle relazioni tra cenosi vegetali presenti lungo i canali e tipologie di aziende agricole presenti (biologico e convenzionale) Ï diverse tipologie di conduzione agricola portano a livelli di biodiversità vegetale diversi nelle aree adiacenti Dal lavoro svolto risulta che, almeno nell'area d'esame, i boschi non possono essere considerati aree source e i canali non fungono da corridoi di dispersione per le specie vegetali. I canali, però, indipendentemente dalle loro dimensioni, fungono da stazioni rifugio per le specie igrofile. La composizione delle cenosi vegetali risulta poi influenzata sopratutto da parametri di tipo ambientale, mentre i fattori legati all'attività agricola rivestono un ruolo secondario. Per quel che concerne i parametri di biodiversità, abbiamo osservato che nelle aree con agricoltura di tipo convenzionale si osserva un maggior numero di specie, ma i pattern di biodiversità (abbondanza relativa delle specie e profili di Rènyi) risultano analoghi

Augmenting flower trait diversity in wildflower strips to optimise the conservation of arthropod functional groups for multiple agroecosystem services

Sown wildflower strips are increasingly being established in Europe for enhancing arthropod conservation and the provision of ecosystem services, including biotic pollination and natural pest control. Here we use floral traits to identify different plant functional effect groups. Floral resources were provided in four experimental levels characterised by a cumulatively increasing flower trait diversity and vegetation stand complexity. The first level consisted of a bare control strip, whilst in each subsequent level three wildflower species with different functional traits were added (Level 0: control; Level 1: three Apiaceae species; Level 2: three Apiaceae and three Fabaceae species; Level 3: three Apiaceae, three Fabaceae species, and Centaurea jacea (Asteraceae), Fagopyrum esculentum (Polygonaceae), Sinapis alba (Brassicaceae)). Plots with sown wildflower strip mixtures were located adjacent to experimental plots of organically-managed tomato crop, which is attacked by multiple pests and partially relies on bees for fruit production, and hence dependent on the provision of pollination and pest control services. Results obtained here show that the inclusion of functionally diverse wildflower species was associated with an augmented availability of floral resources across time, and this increased the abundance of bees and anthocorids throughout the crop season. Several natural enemy groups, such as parasitoids, coccinelids and ground-dwelling predators, were not significantly enhanced by the inclusion of additional flower traits within the strips but the presence of flower resources was important to enhance their conservation in an arable cropping system

Landscape complexity and field margin vegetation diversity enhance natural enemies and reduce herbivory by Lepidoptera pests on tomato crop.

Agricultural intensification may lead to higher pest pressure through the loss of natural plant assemblages, and associated reduction in natural enemy diversity, while providing increased crop area. We investigate the influence of field margin vegetation and landscape complexity on natural enemy diversity and crop damage caused by two Lepidoptera tomato pests (Tuta absoluta and Noctuidae). At the local scale, fields were bordered with herbaceous field margins of varying vegetation diversity. At the landscape scale, these fields were set in landscapes with increasing landscape complexity. Margin vegetation diversity was higher in landscapes with lower arable land cover, and was associated with increased floral resources and enemy diversity, with the latter being negatively related to T. absoluta-caused fruit injury. Total crop damage increased with arable land cover. These results imply that the suitability of farming practices for the conservation of natural enemies and pest control services is influenced by the landscape context. © 2015 International Organization for Biological Control (IOBC

Utilisation of plant functional diversity in wildflower strips for the delivery of multiple agroecosystem services

Increased plant diversity in cropping systems can play an important role in agriculture by enhancing arthropod-mediated ecosystem services, including biological control and pollination. However, there is limited research investigating the concurrent influence of plant functional diversity within cultivated systems on different arthropod functional groups, the provision of multiple ecosystem services, and crop yield. During a field experiment, repeated over 2 years, we measured the effect of increasing plant functional diversity on community structure of arthropod visitors, the abundance of multiple pests and induced crop damage, and fruit production in two varieties of tomato. Plant resources (floral and extra-floral nectar and pollen) were included within experimental plots in four levels, with each level increasing the plant functional group richness, based on floral morphology and availability of resources, in a replacement series. The presence of sown flower mixtures in experimental plots was associated with increased abundance and diversity of natural enemy functional groups and an enhanced abundance of bees (Hymenoptera: Apiformes). However, we only detected relatively small variability in arthropod visitors among types of mixtures, and increased abundance of natural enemies did not translate into stronger pest suppression or reduced crop damage. Lepidoptera pest damage was significantly higher in plots adjacent to wildflower strips, an ecosystem disservice, but a significantly higher crop productivity was recorded from these plots. Our results provide evidence that inclusion of non-crop plant resources in agroecosystems can improve the conservation of beneficial arthropods and may lead to increased crop productivity. Entomologia Experimentalis et Applicat

Il paesaggio vegetale delle ANPIL del Fiume Magra

Nell'ambito di studi sul paesaggio vegetale di aree pedemontane della Toscana Nord occidentale, sono state censite, interpretate e cartografate le fitocenosi igrofilo-riparie di due aree proteete del fiume Magra in Lunigiana ed è stata censita la flora dell'are