Detecting patterns of species co-occurrence is among the main tasks of plant community ecology. Arable plant communities are important elements of agroecosystems, because they support plant and ...animal biodiversity and provide ecosystem services. These plant communities are shaped by both agricultural and environmental drivers. The pressure of intensive agriculture worldwide has caused the decline of many characteristic arable species and communities. Italy is the European country where arable plant biodiversity is the best preserved. In this study, we assessed the patterns of co-occurrence of rare and threatened arable plants in 106 plots of winter arable vegetation located from Piedmont to Calabria, in the mainland part of the country. For this purpose, we based our investigation on the analysis of a recently acquired dataset and on the European list of rare and threatened arable plants. We highlight how different species of conservation interest tend to occur in the same community. On the other hand, generalist and more competitive taxa show similar patterns of co-occurrence. We suggest that single species of conservation value could be suitable indicators of a well-preserved community. On the other hand, to be effective, conservation strategies should target the whole community, rather than single species.
To improve the phytogeographic characterization of peninsular Italy, we analysed and compared the spatial distribution of woody flora at both the species and genus level along an approximate 160 km ...west–east transect within the central peninsula. Sampling sites were selected using a subjective stratified sampling design. A total of 1710 occurrence records, 138 species, and 74 genera from 153 floristic relevés was used. The congruence in species and genera patterns, supported by Mantel and Procrustes tests, confirmed the validity of the higher‐taxon approach to analyse woody flora patterns. Non‐metric multi‐dimensional scaling and Pearson's chi square analysis pointed out that elevation and related bioclimatic factors were the most important drivers of woody species composition. Three well‐defined woody flora types (coastal low‐elevation, inland middle‐elevation, and inland high‐elevation) were identified using partition around medoids clustering. The species‐rich inland middle‐elevation type supports the recently described Transition unit between the Mediterranean and Euro‐Siberian Regions. Contrary to previous assumptions, floristic and chorological differences between the Tyrrhenian and the Adriatic subtypes were detected only in the inland high‐elevation type and not in the coastal low‐elevation type. The adopted methodological approach, based on higher‐taxon approach and on clustering and ordination of floristic relevés, proved to be valuable to detect woody flora distribution patterns and to delineate the phytogeographic characters of a very heterogeneous and biodiverse area.
The segetal flora of winter crops includes mostly native or archaeophyte annual species that are often strong specialists of their habitats. Threatened by the intensification of agriculture, segetal ...flora is particularly valuable from a perspective of biodiversity conservation and evolution. Moreover, it contributes to maintain biodiversity in agroecosystems and provides several ecosystem services. The dataset here described was set up to provide the first inventory of the segetal flora of Italian winter cereal crops and allied crop types, the latter including flax and autumn-sown legumes. It includes 24,676 georeferenced occurrence data deriving from 1,240 floristic and phytosociological relevés. The data were collected from the greater part of Italian territory, in a temporal range spanning from 1946 to 2018.
The weed vegetation of the bean “Fagiolo Cannellino di Atina” (
Phaseolus vulgaris
L.) and the red pepper “Peperone di Pontecorvo” (
Capsicum annuum
L.) PDO (Protected Designation of Origin) crops ...was surveyed by means of 16 relevés, sampled in four farms of southern Latium during July 2019. The relevés were subjected to multivariate analysis, which revealed that the two crops are weeded by vegetation types referable to two different subassociations of
Panico
-
Polygonetum persicariae
(
Spergulo
-
Erodion
,
Eragrostietalia
,
Digitario
-
Eragrostietea)
. Namely, communities colonizing bean fields, which are more mesophilous and richer in Eurasian taxa, are ascribable to the subassociation
sorghetosum halepensis
. Communities colonizing red pepper fields, which are more thermophilous and richer in Mediterranean taxa, are ascribable to the subassociation
cyperetosum rotundi
. Floristic, structural, and chorological features of the communities are discussed in relation to environmental factors and agricultural management.
The interest in knowledge of the weed communities of arable land is growing worldwide. Italy is one of the countries in Europe that is the most biodiverse, geographically and environmentally ...heterogeneous, and rich in arable weed species. Thus, in this study, the geo-environmental factors influencing the floristic composition, the species richness, and the Shannon diversity of weed communities of Italian winter arable crops were investigated along a gradient across mainland Italy. Original data were collected in the spring of 2018 in 106 winter cereal and legume arable fields from one fixed area plot per field. Environmental and geographic data were retrieved for each plot, including latitude, longitude, elevation, soil texture, soil pH, continentality, temperature, and precipitation. The effect of crop type was also tested. Latitude was the main driver of floristic differentiation between the studied plant communities, followed by precipitation, temperature, continentality, elevation, and longitude. Soil features and crop type had no significant effects. Higher values of species richness and Shannon diversity were found in southern areas and at higher elevations. Significant explanatory variables accounted for 11.55% of the total variation in species composition of the surveyed communities. The results are discussed and compared with those of similar studies in other Eurasian countries.
Changes in agricultural practices represent one of the main causes of shift in species composition of arable plant communities. In particular, the intensification of agriculture going on worldwide ...since several decades led to heavy transformations of arable plant diversity. Basing on a study conducted in 1964 in Latium (central Italy), we re-surveyed the arable plant communities of 21 maize fields in order to assess the shifts that occurred over 50 years. The results showed a relevant decrease in the number of species (both in the total number and in the mean number per relevé), accompanied by a major species turnover. An increase in neophyte, wide-distribution, geophyte, C4 photosynthetic pathway, and monocot species was observed, while the incidence of insect-pollinated taxa decreased. The calculation of the mean Ellenberg indicator values per relevé showed an increase, in particular, of nutrients and moisture levels.
We present a phytogeographic regionalization based on native woody flora, identifying the most useful taxonomic level, geographic variables, and orographic pattern, selecting Italy as a case study. ...We generated seven distance matrices among the 20 administrative regions, and using Pearson’s correlation coefficients and PCA, we verified whether distances between regions were invariant across the different sampling strategies. Once this invariance was established, we focused on genera representation. We defined two orographic indices and performed Kruskal–Wish multidimensional scaling and K-means clustering to assess Italy’s phytogeographic regionalization. A major north–south and a minor east–west gradient described the relationships between regions. Floristic diversity was strongly correlated with the region’s orography, with hills being the most important orographic feature that increased plant diversity; the effect of the orographic patterns was independent from the geographic clines observed. Despite the coarse scale, our phytogeographic regionalization comprising six clusters (variables = 133 woody genera) was consistent with previous ones based on the endemic flora (variables = 1371 units) or on bioclimatic approaches. In particular, the phytogeographic uniqueness of Northern and peninsular Italy, and of Sardinia Island, was confirmed. The next step will be to test our method at a finer scale.
We present a statistically derived phytogeographic regionalization based on the spatial distribution of native woody flora, investigating environmental correlates and assessing congruence between the ...spatial patterns of species, genera, and families. A sector of central peninsular Italy (Lazio and Abruzzo regions) was selected as a case study. A rich georeferenced floristic database was compiled, including information from different sources. A total of 43,968 occurrence data, 290 10 × 10 km cells, 224 species, 103 genera, and 80 families was used; Ward's clustering was performed to identify phytogeographic units. Three well-defined and relatively spatially coherent units were identified at the species, genus, and family levels: a Mediterranean unit, a Transition unit, and a Eurosiberian one. Congruence between taxonomic levels was well supported. Further divisions in subunits were detected using species data. The main environmental descriptors of the clusters were distance from the sea, elevation, temperature, and lithology.
•Benefits provided by GIs in Mediterranean cities are impaired by stressful conditions.•Plant ecophysiology provides key functional parameters for ESs quantification.•Urban and periurban Forests ...contribute differently to regulating services.•Urban green management could substantially increase benefits from GIs.
Green infrastructures (GI), such as urban forests, deliver ecosystem services (ESs) and benefits. Among ESs the amelioration of urban air quality through the removal of air pollutants deserves large attention owing to the positive impact on human well-being. Experimental data, as detailed descriptions of functional parameters, are needed for reliable quantification of ESs. The present study was carried out in the metropolitan area of Rome, considering an urban and a periurban forest. Both forests are dominated by Quercus ilex L., which has been chosen as target species for its wide natural distribution in the Mediterranean Basin, as well as for its widespread use in urban contexts. The two studied sites were characterized by different environmental stressor and forest management practices, resulting in different trends of leaf gas exchanges, photosystems functionality and plant water status. During spring, gas exchanges were lower in the urban than in the periurban forest, due to higher air temperature and vapor pressure deficit in the latter site. During summer, instead, in the periurban area the functionality of Q. ilex was affected by drought, which did not occur in the urban forest due to higher summer rainfalls as well as periodic irrigations. The water use efficiency was basically lower in the urban park, as well as the photosystems functionality. Differences in the intensity of the main phenological phases were also highlighted. Our results point out that the two GIs fulfill a complementary role in the ESs provision in the metropolitan area of Rome, in relation to the ozone removal and the resulting air quality improvement and climate regulation.
Lemna valdiviana Phil. and L. minuta Kunth are native species of the Americas. At present L. minuta colonizes in Europa and Asia, where it is often considered an invasive alien species. Recent ...floristic surveys in the Agro Pontino area (Lazio region, central Italy) allowed to find a population referring to L. valdiviana, supported by the recent gathering in Sardegna region. With the aim to identify correctly the two species, we carried out a morphometric study based on measurements of both qualitative and quantitative characters, made on herbarium and living specimens collected from America and Europe. The univariate and multivariate analyses clearly support the attribution of the population from Lazio to L. valdiviana. This gathering is the first record of this species for the Italian peninsula. Moreover, the checking of Herbaria allowed us to find the older specimen of L. minuta collected in Europe (around 1877). At present L. valdiviana is to be considered as a casual alien species in Agro Pontino, but the rapid colonization of the aquatic environments by Lemna species by means of vegetative reproduction allows us to recognize it as a potential invasive species.
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