1,721,062 research outputs found
La conservazione della biodiversità nelle coltivazioni permanenti e negli ambienti prativi
No full textLa biodiversità degli ambienti agricoli è soggetta a forti pressioni di origine antropica, in particolare l’intensificazione delle pratiche agricole e l’abbandono dei sistemi agricoli tradizionali e marginali.
In questa tesi è presentata una raccolta di studi sugli effetti delle pratiche colturali, dei cambiamenti di uso del suolo e della struttura del paesaggio sugli uccelli a vari livelli di scala condotti in quattro tipologie di agroecosistemi permanenti.
Lo scopo ultimo di questa tesi è di individuare possibili pratiche gestionali che favoriscano la conservazione degli uccelli (che sono specie indicatrici e ombrello) in questi ecosistemi artificiali. Queste misure potrebbero essere inserite in adeguate regolamentazioni volte a ridurre gli impatti dell’agricoltura sulla biodiversità e favorire infine la sostenibilità complessiva dell’agroecosistema.
I risultati mostrano come, nelle coltivazioni permanenti, la diversità ornitica e l’abbondanza di alcune specie dipendono da una moltitudine di elementi relativi al contesto paesaggistico, gestionale e topografico-climatico. Considerando l’intera comunità, il livello paesaggistico è quello che maggiormente influenza la diversità, tuttavia anche alcuni elementi relativi alla gestione agricola hanno un effetto su di essa. Diversamente, l’abbondanza di alcune specie non è solo influenzata dalle caratteristiche del paesaggio, ma anche significativamente, o primariamente, da effetti di caratteristiche climatico-topografiche e, soprattutto, dalle pratiche colturali.
L’uso del suolo predominante a scala di paesaggio è risultato avere effetti negativi a livello di comunità e generalmente anche sulle specie più comuni.
I risultati presentati evidenziano anche un ampio effetto positivo della copertura di habitat diversi da quello dominante (es. habitat marginali) e degli elementi tradizionali (es. siepi e filari, alberi ed edifici isolati) sugli uccelli, che permettono la presenza di specie non adattate all’habitat dominante che caratterizza la matrice, verosimilmente perché queste specie non riescono a nidificare o nutrirsi nella coltivazione.
Nel corso del progetto si è investigato inoltre l’effetto dell’agricoltura biologica sugli uccelli, considerando vari indicatori e scale spaziali, senza tuttavia dimostrare alcun effetto positivo di questo tipo di gestione rispetto a quella convenzionale. Le principali cause di questo risultato riguardano il fatto che l’agricoltura biologica, a conferma di precedenti studi, ha di norma maggiori effetti in sistemi agricoli annuali e in contesti paesaggistici molto semplificati, quindi in agroecosistemi molto diversi da quelli indagati e che nell’area di studio le due forme di gestione non differiscono di molto in termini di utilizzo di pesticidi e altre pratiche colturali. In generale, per rendere l’agricoltura biologica più favorevole alla biodiversità sono necessari maggiori sforzi a scala di paesaggio.
In un contesto gestionale o conservazionistico, è necessario identificare il target di una specifica azione (es. l’intera comunità o una specifica specie) perché se i bisogni principali della maggior parte delle specie che costituiscono la comunità possono essere soddisfatti in prima battuta a una scala di paesaggio, al contrario, alcune specifiche necessità di determinate specie di interesse conservazionistico possono riguardare principalmente, o esclusivamente, particolari elementi determinati dalla gestione agricola. Di conseguenza, questi elementi dovrebbero essere conservati o ricreati, per favorire queste particolari specie.Permanent crops and anthropogenic grasslands used to be the most important low-intensity semi-natural farmlands of the continent and were both negatively impacted by agricultural intensification and land abandonment.
I present a collection of studies on the effects of agricultural practices, land use change, and landscape structure on birds conducted in four agricultural typologies: vineyards, olive groves, fruit orchards, and hay meadows. The studies were conducted at different levels of scale, from landscape to foraging sites.
I focused on farmland birds, because they are reliable indicators of biodiversity and could be regarded as “umbrella species.”
The ultimate scope of this thesis is to inform possible best-management practices to favour bird conservation in man-made ecosystems.
My findings show that, in permanent crops, bird diversity and the abundance of individual species are driven by a multitude of elements related to the landscape, management, and topographic-climatic contexts. Considering the whole community, the landscape level emerged as the most important driver of biodiversity patterns, but some agricultural management traits also affect biodiversity; conversely, the abundance of individual species could be influenced not only by the landscape characteristics, but also by the significant, or even predominant, effects of climatic-topographic attributes and, especially, of management practices.
At the community level, the predominant land use throughout the landscape had negative effects on the community itself; this is also generally true for the reproductive outcome of the most common species dwelling in those crops.
A relevant exception to this pattern was represented by three insectivores of conservation concern (i.e. common redstart, spotted flycatcher and wryneck), which are favoured by vineyard cover at the landscape scale likely because vineyards are structurally similar to their “ancestral” habitat. However, investigating the wryneck habitat selection at a finer spatial scale (i.e. territory), I showed that it is more affected by specific vineyard characteristics, which determined nesting site availability, than by general land cover traits.
Importantly, my results also point out a broadly positive effect on birds with the cover of habitats different from their dominant ones (e.g. marginal habitats) and with traditional elements (e.g. hedge and tree rows, isolated trees, and buildings), which allowed for the persistence of species that are not adapted to the main habitat that characterise the matrix, since those species are unable to nest or forage in the crops.
I also investigated the effect of organic viticulture on birds by considering several indicators and spatial scales without finding any positive effect of this kind of management. Main causes for this are that organic farming was previously shown to exert much more positive effects in annual crop systems and in simplified landscapes, thus in agroecosystems quite different from vineyards. Additionally in the study area, organic and conventional management forms do not differ very much in terms of pesticide use or other agricultural practices. Based on these findings, I suggest that much effort should be allocated at a wider landscape scale in making organic viticulture more biodiversity-friendly.
In a conservation or planning framework, it is fundamental to identify the target (i.e. the whole community or a singular species) of a defined action. Indeed, if the primary needs of the majority of the species which constitute the community could be satisfied by acting at a landscape level, then some needs of individual species could rely mainly, or exclusively, on particular elements determined by agricultural management. As a consequence, to favour these particular species, these elements should be conserved or restored
Is the Spectacled Warbler Sylvia conspicillata expanding northward because of climate warming?
No full textComing back home: recolonisation of abandoned dens by crested porcupines Hystrix cristata and European badgers Meles meles after wood-cutting and riparian vegetation mowing events
Full text linkSemifossorial species excavate dens and are considered as landscape engineers, often responsible for soil oxygenation, shuffling, landslides and floods. The crested porcupine and the European badger are semifossorial mammals sharing dens in central Italy. Both species localise their setts mainly in densely vegetated areas, providing them with cover and protection from local predators and poachers. This is particularly evident for the porcupine, widely poached in central and southern Italy, whereas badgers may locally exploit burrows also in open and periurban areas. Wood-cutting and mowing of riparian vegetation surrounding den setts force both porcupines and badgers to leave their burrows. We evaluated the probability of den re-occupancy in the years following the vegetation removal, through intensive camera-trapping at 14 den setts monitored for 9 years. We performed GLMMs to test the annual probability of sett occupancy by the two species after vegetation disturbance events. The probability of re-occupying the burrow by porcupines increased with increasing time from the disturbance cessation. A similar pattern was also observed for the badger, which probability of den occupancy was also negatively correlated with the porcupine presence at the same den, confirming the aggressive behavior of this rodent. We also tested whether, since the first year after vegetation removal, the proportion of years of occupation by porcupines on the total of years has been affected by the disturbance repetition. This effect was found to be significant only for the badger. The crested porcupine, protected by international and national laws, is more sensitive than the badger, protected according to the Italian national law, to vegetation removal. A single disturbance event is sufficient to force it to abandon the den sett, followed by a slow recolonisation with growing vegetation. Conversely, the badger is sensitive to continuous vegetation removal whereas it can colonise porcupine dens abandoned after single disturbances
Nest density, nest-site selection and breeding success of birds in vineyards: management implication for conservation in a highly intensive farming system
No full textBiodiversity in limestone quarries: a review and future perspectives
Full text linkThe demand for cement and other building materials is increasing due to the growth of the human population and will continue to grow. Consequently, there will be an increase in the areas dedicated to the extraction of limestone and other materials needed to produce cement. Mining through quarrying has significant impacts on the environment (SOUZA and SANCHEZ 2018). In addition to large-scale habitat destruction, dust, noise and vibration emissions further exacerbate the environmental impact (KUMARASINGHE et al., 2013) Limestone quarries mostly occur in calcareous and karst environments, which has an outstanding biodiversity value and are in rapid, as a result of mining activity (CLEMENTS et al., 2006). These environments host a huge variety of endemic species, both vertebrates (GRISMER et al., 2013) and invertebrates (OSIELE et al., 2022). However, the knowledge about biodiversity and the impact from quarrying is still scarce and targeted to few taxa. Here, we report the results of a systematic bibliographic review addressed to highlight the state of knowledge in this field. Through a keyword search in WOS we extracted 795 articles related to biodiversity. Only 135 of these have been assessed for eligibility and included in the review. The 46% of the studies were focused on “Quarry rehabilitation”, considering especially habitat restoration at abandoned mining sites, but most of them concerned vegetation and only nine studies focused on fauna. Only 12 papers focused on analysing quarrying impacts, with a particular attention to the effects of dust pollution on lichens. About Quarry rehabilitation studies, the 69% of them analysed the management and dynamics during the process of recovery in the quarry through the plant community. Only 14% of these studies used animals, all invertebrates, as bioindicators to assess the success and trajectory of the revegetation process during extraction site recovery. Six of them (66%) used terrestrial arthropods, mostly at community level. Regarding spatial distribution, the outcome shows that Europe dominates 69% of studies, with the Czech Republic (22 papers) having the highest number of scientific works followed by Spain (17 papers). Our results show the presence of a wide knowledge gap, at the expense of active sites and their impacts on biodiversity, and a generalized lack of data regarding animal biodiversity for those sites where vegetation successional stages have been monitored during restoration activities
Biodiversity and its restoration in limestone quarries: a review
Full text linkINTRODUCTION: Limestone quarries impact natural areas, and they are spreading in relation to human population growth. Little is known about the impact of limestone quarries and their restoration on biodiversity.
OBJECTIVES: This review aims to provide an overview of how biodiversity is assessed in limestone quarries, how it impacts biodiversity, and the restoration practices applied after mining.
METHODS: We reviewed the published literature, including a total of 140 studies.
RESULTS: Very few studies were designed to include more than one quarry or different control areas. Few studies examined the role of quarries as open habitats during mining operations, while the majority focused on habitat restoration after excavation. Restoration can occur through active or natural processes. Although active restoration, such as soil amendments and planting, was preferred, natural processes may better support communities that resemble those inhabiting natural calcareous grasslands. Even natural recovery often requires active management. Most studies focused on plants and arthropods, with very few addressing vertebrates. The impact of dust emission was mainly analyzed on plants and lichens.
CONCLUSION: There is a significant knowledge gap regarding biodiversity in active quarries and limited data on animal communities. Restoration efforts should integrate both active and passive strategies, with improved monitoring programs and broader taxonomic coverage.
IMPLICATIONS FOR PRACTICE: Limestone quarries can host significant biodiversity, including several threatened species, such as those inhabiting calcicolous ecosystems. These can be enhanced through targeted restoration, which should involve native and xerophilous plant species, allowing natural processes to begin the recovery process. However, successful regeneration requires mitigation of harsh environmental conditions and alien species colonization. It is crucial to investigate a broader range of quarries and include more natural control areas. Monitoring and conservation actions must also target vertebrates, soil fauna, and microbial communities, especially threatened and early successional habitat species, which often find refuge in these novel ecosystems. This could be achieved by creating targeted microhabitats and improving landscape connectivity to facilitate colonization. Incorporating a traits-based approach would further enhance understanding of the conservation value and ecological dynamics of these environments
Three new species for the odonatofauna of Piedmont (NW Italy)
Full text linkBetween 2020 and 2023, three new species of Odonates were recorded in Piedmont (NW Italy). Lestes barbarus was observed at an artificial wetland in the Turin Plain in 2021. Even though at least one individual was fresh, we cannot conclude that the species developed at the site. Subsequent visits did not permit to confirm the species. Coenagrion hastulatum was discovered at a peat bog in the NW Alps (Lac Falin, Valle di Viù) in 2023 and here reproduction was confirmed. This population is the fifth to be recorded for the central and western Italian Alps. Trithemis annulata was first recorded in Piedmont in July 2020, and subsequently, the observations of the species in the region rapidly increased, with a total of 66 records relative to 29 sites up to the end of 2023. These are distributed in most of the low-altitude areas of the region. The species was reported mostly in late summer, with only one site where the early spring records suggest successful overwintering. However, this needs further confirmation. The odonate list of Piedmont now accounts for 70 species, representing 73.6% of the taxa reported for Italy, and this makes Piedmont, along with Lombardy, the most odonate-rich region of Italy
The value of abandoned olive groves for blackcaps (Sylvia atricapilla) in a Mediterranean agroecosystem: a year-round telemetry study
No full textThe European Common Agricultural Policy has promoted the intensification of productive olive orchards and the abandonment of the unproductive ones. This strategy has resulted in a significant loss of biodiversity and ecosystem functionality of this type of agroecosystem. Here, we studied the blackcap Sylvia atricapilla, a common frugivorous bird species, in an olive-dominated agroecosystem of southern Spain to assess the effects of the abandonment of olive groves and undergrowth structure on habitat selection in this species. By means of radiotelemetry, we determined habitat selection of blackcaps during both the breeding (N = 30) and the non-breeding (N = 27) seasons of 2011 and 2012. We found that outside the breeding season, olive groves were widely used by blackcaps, which invariably preferred abandoned olive groves over intensively managed ones. Additionally, deciduous woods and poplar plantation were positively selected, whereas open habitats and Pinus forests were avoided. Generally, woody habitats without undergrowth or with herbaceous undergrowth were avoided. During the breeding season, the species selected mainly riverine habitats and poplar plantations, favoring habitats with well-developed undergrowth. Our results suggest that the blackcap could benefit from maintaining patches of abandoned olive groves freely left to natural succession within intensive olive groves. In such a landscape, ecological services (i.e., seed dispersal provided by frugivorous birds) and functioning could also improve as a consequence of these measures
Land-use and bird occurrence at the urban margins in the Italian Alps: implications for planning and conservation
Full text linkNegative effects of urban sprawl on biodiversity are widely recognised, but information on how to counteract such effects are still scarce, especially for urban ecosystems in mountain regions.
We evaluated the effect of land-use and topography on the occurrence of eight passerine species in five urbanized study areas in the Italian Alps, which have undergone recent urban sprawl. Our aim was to identify the best planning and management practices to favour these indicator species in mountain periurban areas.
We surveyed the species' presence/absence at 142 point counts during the 2013 breeding season and evaluated the effects of environmental variables on occurrence using binomial multivariate adaptive regression splines (MARS). Species occurrence was mostly affected by meadows (positively) and woodland (negative effect, except in contexts with high meadow cover or high habitat diversity).
In Alpine valleys affected by recent sprawl, the conservation or restoration of grassland patches and the maintenance of heterogeneous landscapes can contribute to the conservation of some species of conservation concern found in suburban habitats. Afforestation, a common mitigation practice in and around urban centres, could be counter-indicated when urbanization occurs at the expense of open and semi-open habitats.
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