Summer roadside vegetation dominated by Sorghum halepense in peninsular Italy: survey and classification

Sorghum halepense is a synanthropic tall grass distributed worldwide from tropical to temperate zones, and it is often considered an invasive alien. It is a perennial, rhizomatous plant that tends to form dense stands derived from vegetative and sexual propagation. Despite roadside plant communities dominated by Sorghum halepense are very common in southern Europe, their phytosociological aspects are scarcely studied. In this work, we present the results of a vegetation survey in peninsular Italy, carried out by means of the phytosociological method. In total, we carried out 73 releves in Liguria, Tuscany, Latium, Campania, Basilicata, and Apulia. We statistically compared our releves to those from the Balkans classified in the Cynodonto-Sorghetum halepensis, an association of agricultural annual weed vegetation of the class Stellarietea mediae s.l. used in the past as a reference for Italian S. halepense-dominated communities. Our results show that the Italian communities are different from the Cynodonto-Sorghetum halepensis communities, since the latter are rich in annual species, while the former are rich in perennial species. From the syntaxonomic point of view, the Italian communities are better classified in the class Artemisietea vulgaris. We describe the new (sub-)ruderal association Potentillo reptantis-Sorghetum halepensis, including a meso-hygrophilous variant with Urtica dioica and an agricultural variant with Elymus repens. We have evidence that the Potentillo-Sorghetum occurs in Italy, Kosovo and Slovenia, but its distribution is possibly wider due to conspicuous presence of cosmopolitan species characterizing the association. Our work provides a baseline for the knowledge of an alien-dominated plant community that can invade habitats with high conservation value

Fifteen emerging challenges and opportunities for vegetation science: A horizon scan by early career researchers

With the aim to identify future challenges and opportunities in vegetation science, we brought together a group of 22 early career vegetation scientists from diverse backgrounds to perform a horizon scan. In this contribution, we present a selection of 15 topics that were ranked by participants as the most emergent and impactful for vegetation science in the face of global change. We highlight methodological tools that we expect will play a critical role in resolving emerging issues by providing ways to unveil new aspects of plant community dynamics and structure. These tools include next generation sequencing, plant spectral imaging, process-based species distribution models, resurveying studies and permanent plots. Further, we stress the need to integrate long-term monitoring, the study of novel ecosystems, below-ground traits, pollination interactions and global networks of near-surface microclimate data at fine spatio-temporal resolutions to fully understand and predict the impacts of climate change on vegetation dynamics. We also emphasize the need to integrate traditional forms of knowledge and a diversity of stakeholders into research, teaching, management and policy-making to advance the field of vegetation science. The conclusions reached by this horizon scan naturally reflect the background, expertise and interests of a representative pool of early career vegetation scientists, which should serve as basis for future developments in the field

Effectiveness of different metrics of floristic quality assessment: The simpler, the better?

Vascular plants are good environmental indicators. Thus, floristic inventories have a high potential in environmental management since they reflect the current and past status of the environment. In this study, we used the flora of a suburban riverscape in central Italy to test the performance of the Floristic Quality Assessment (FQA) approach, an expert-based evaluation technique. Ten expert botanists assigned coefficients of conservatism (CC) to 382 plant species. We found statistically significant differences between the values assigned to the inventoried flora by botanical experts. In spite of this, the analysis of pseudo multivariate dissimilarity-based standard errors of CC values assigned by the different experts revealed that, in our case, an assessment by a minimum of five botanists allows characterizing the flora with a stable level of precision. We used the distance from agricultural and urban surfaces as a proxy of anthropogenic disturbance to divide the area around the river in four belts of increasing disturbance. The disturbance gradient was mirrored by median CC values and by the Adjusted Floristic Quality Assessment Index (Adjusted FQAI). Conversely, the Floristic Quality Assessment Index (FQAI), which is based on CC values and on the number of native species, showed increasing values with increasing disturbance. Comparing the performance of median CC values to Ellenberg Indicator Values (EIVs), life forms, and chorotypes, we revealed that the last three indicators may be ineffective in highlighting the conservation status of the environment. We suggest that the use of the median CC values may be a simpler and effective alternative to the calculation of indices in FQA, when the adequacy of the number of experts in minimizing the variability of CC values is a posteriori verified

The leaf economic and plant size spectra of European forest understory vegetation

Forest understories play a vital role in ecosystem functioning and the provision of ecosystem services. However, the extent to which environmental conditions drive dominant ecological strategies in forest understories at the continental scale remains understudied. Here, we used ~29 500 forest vegetation plots sampled across Europe and classified into 25 forest types to explore the relative role of macroclimate, soil pH and tree canopy cover in driving abundance-weighted patterns in the leaf economic spectrum (LES) and plant size spectrum (PSS) of forest understories (shrub and herb layers). We calculated LES using specific leaf area (SLA) and leaf dry matter content (LDMC) and PSS using plant height and seed mass of vascular plant species found in the understories. We found that forest understories had more conservative leaf economics in areas with more extreme mean annual temperatures (mainly Fennoscandia and the Mediterranean Basin), more extreme soil pH and under more open canopies. Warm and summer-dry regions around the Mediterranean Basin and areas of Atlantic Europe also had taller understories with heavier seeds than continental temperate or boreal areas. Understories of broadleaved deciduous forests, such as Fagus forests on non-acid soils, or ravine forests, more commonly hosted species with acquisitive leaf economics. In contrast, some coniferous forests, such as Pinus, Larix and Picea mire forests, or Pinus sylvestris light taiga and sclerophyllous forests, more commonly hosted species with conservative leaf economics. Our findings highlight the importance of macroclimate and soil factors in driving trait variation of understory communities at the continental scale and the mediator effect of canopy cover on these relationships. We also provide the first maps and analyses of LES and PSS of forest understories across Europe and give evidence that the understories of European forest types are differently positioned along major axes of trait variation

Traditional soil fertility management ameliorates climate change impacts on traditional Andean crops within smallholder farming systems

Global changes, particularly rising temperatures, threaten food security in smallholder mountain communities by impacting the suitability of cultivation areas for many crops. Land-use intensification, associated with agrochemical use and tillage threaten soil health and overall agroecosystem resilience. In the Andean region, farmers often cultivate crops at multiple elevations. Warming climates have led to a shift in cultivation upslope, but this is not feasible in many areas. Traditional soil fertility management practices together with a focus on traditional (orphan) crops offers promise to cope with rapid climate warming in the region. To understand the impacts of warming and changing nutrient management, we established two side-by-side experiments using the traditional Andean crops Oxalis tuberosa (Oca) and Lupinus mutabilis (Tarwi) at three elevations, each with two fertility treatments (organic and synthetic). Soil and climate data (i.e., temperature and precipitation) were collected throughout the growing season, and crop performance was evaluated through impacts on yield and other growth metrics (e.g., biomass, pest incidence). We used two-way ANOVA to assess the influence of site (elevation) and management type (organic vs. synthetic) on crop performance. Results indicated that warmer climates (i.e., lowest elevation) negatively impact the production and performance of O. tuberosa, but that organic fertilization (sheep manure) can help maintain crop yield and biomass production in warmer conditions relatively to synthetic nutrient inputs. In contrast, L. mutabilis showed accelerated growth in warmer conditions, but grain yield and biomass production were not significantly affected by site and showed no interaction with nutrient management. Our findings highlight that climate warming represents a serious threat to small-scale crop production in the Peruvian Andes and could cause severe declines in the production of locally important crops. Additionally, the continued reliance traditional crops with organic inputs, instead of synthetic fertilizers, may help support agricultural productivity and resilience under climate change

Habitats Directive in northern Italy: a series of proposals for habitat definition improvement

Habitats Directive (92/43/EEC) is the cornerstone of nature conservation in Europe and is at the core of the EU Biodiversity Strategy for 2030. There is room, however, for its improvement, at least for northern Italy, where ambiguities in the definition of habitat types of Annex I of the Habitats Directive are not novel and interpretation difficulties have been highlighted. Sharpening the characterization of habitat types represents an opportunity for lowering classification uncertainties and improving conservation success. With the aim to refine the definitions of habitat types and associated typical species of the Habitats Directive, a group of vegetation scientists of the Italian Society of Vegetation Science based in northern Italy made the exercise of finding viable proposals for those habitat types having a problematic interpretation in the Alpine biogeographical region of Italy. Such proposals arise from group discussions among scientists, and professionals, thus offering a shared view. We prepared 9 habitat proposals important for this geographic area. They include new habitat types at the European level, new subtypes within pre-existing habitat types, including some adjustments of the recently proposed subtypes with respect to northern Italy, and recognition of priority criteria for a pre-existing habitat type. With a vision of tailored conservation, our proposals represent a starting point in view of a future update of Annex I. Furthermore, the list of typical species could be useful for preparing expert systems for automatic classification. Irrespective of legally binding solutions in place, we caution these proposals represent relevant baseline conservation indications that local and regional administrations of the Alpine Arch should consider

Probabilistic and preferential sampling approaches offer integrated perspectives of Italian forest diversity

Aim: Assessing the performances of different sampling approaches for documenting community diversity may help to identify optimal sampling efforts and strategies, and to enhance conservation and monitoring planning. Here, we used two data sets based on probabilistic and preferential sampling schemes of Italian forest vegetation to analyze the multifaceted performances of the two approaches across three major forest types at a large scale. Location: Italy. Methods: We pooled 804 probabilistic and 16,259 preferential forest plots as samples of vascular plant diversity across the country. We balanced the two data sets in terms of sizes, plot size, geographical position, and vegetation types. For each of the two data sets, 1000 subsets of 201 random plots were compared by calculating the shared and exclusive indicator species, their overlap in the multivariate space, and the areas encompassed by spatially-constrained rarefaction curves. We then calculated an index of performance using the ratio between the additional and total information collected by each sampling approach. The performances were tested and evaluated across the three major forest types. Results: The probabilistic approach performed better in estimating species richness and diversity of species assemblages, but did not detect other components of the regional diversity, such as azonal forests. The preferential approach outperformed the probabilistic approach in detecting forest-specialist species and plant diversity hotspots. Conclusions: Using a novel workflow based on vegetation-plot exclusivities and commonalities, our study suggests probabilistic and preferential sampling approaches are to be used in combination for better conservation and monitor planning purposes to detect multiple aspects of plant community diversity. Our findings can assist the implementation of national conservation planning and large-scale monitoring of biodiversit

Classification of the Mediterranean lowland to submontane pine forest vegetation

Vegetation SurveyAim: Vegetation types of Mediterranean thermophilous pine forests dominated by Pinus brutia, Pinus halepensis, Pinus pinaster and Pinus pinea were studied in various areas. However, a comprehensive formal vegetation classification of these forests based on a detailed data analysis has never been developed. Our aim is to provide the first broad-scale classification of these pine forests based on a large data set of vegetation plots. Location: Southern Europe, North Africa, Levant, Anatolia, Crimea and the Caucasus. Methods: We prepared a data set of European and Mediterranean pine forest vegetation plots. We selected 7,277 plots dominated by the cold-sensitive Mediterranean pine species Pinus brutia, Pinus halepensis, Pinus pinaster and Pinus pinea. We classified these plots using TWINSPAN, interpreted the ecologically and biogeographically homogeneous TWINSPAN clusters as alliances, and developed an expert system for automatic vegetation classification at the class, order and alliance levels. Results: We described Pinetea halepensis as a new class for the Mediterranean lowland to submontane pine forests, included in the existing Pinetalia halepensis order, and distinguished 12 alliances of native thermophilous pine forests, including four newly described and three informal groups merging supposedly native stands and old-established plantations. The main gradients in species composition reflect elevational vegetation belts and the west–east, and partly north–south, biogeographical differences. Both temperature and precipitation seasonality co-vary with these gradients. Conclusions: We provide the first formal classification at the order and alliance levels for all the Mediterranean thermophilous pine forests based on vegetation-plot data. This classification includes traditional syntaxa, which have been critically revised, and a new class and four new alliances. We also outline a methodological workflow that might be useful for other vegetation classification syntheses. The expert system, which is jointly based on pine dominance and species composition, is a tool for applying this classification in research and nature conservation survey, monitoring and managementinfo:eu-repo/semantics/publishedVersio