Key message
Xylem hydraulic traits of native Quercus robur are more sensitive to previous-summer drought than those of alien Robinia pseudoacacia. The latter modulates vessel traits and ring porosity ...to cope with inter-annual climate variability, and is less affected by extreme events. This suggests that R. pseudoacacia might be more competitive under future drier conditions
.
Context
Forest management strategies require knowledge on how co-occurring native and alien species respond to unprecedented climate conditions, which can severely affect xylem conductivity and tree performance.
Aims
We aimed at quantitatively comparing xylem anatomical traits of co-occurring native
Quercus robur
and alien
Robinia pseudoacacia
and assessing similarities and differences in their response to climate variability.
Methods
We analyzed tree-ring anatomy and built chronologies of several parameters related to vessel number, size, and theoretical conductivity. Mean chronologies for each parameter were correlated to monthly temperature and precipitation data for the period 1954–2005 and within 30-year moving windows. We also assessed responses to extreme conditions in 2003.
Results
Quercus robur
showed typical ring-porous vessel distribution, while
R. pseudoacacia
modulated vessel size and number year by year, frequently showing semi-ring porous appearance. Previous rainy summers increased size of large vessels in
Q. robur
, and number of large vessels in
R. pseudoacacia
. In winter,
R. pseudoacacia
was sensitive to water excess. High temperature in March increased vessel size in
Q. robur
, but reduced it in
R. pseudoacacia
. The 2003 summer heatwave strongly reduced vessel size and number in the following year in
Q. robur
, but had much less effect on
R. pseudoacacia
.
Conclusion
Quercus robur
xylem traits are more influenced by both inter-annual climate variability and extreme events than those of
R. pseudoacacia
. Lower performance under dry conditions might reduce competitiveness of
Q. robur
in the future, slowing down the natural replacement of the invasive pioneer
R. pseudoacacia
by later-stage
Q. robur
.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
In dry habitats of European lowlands terricolous lichens and bryophytes are almost neglected in conservation practises, even if they may strongly contribute to biodiversity. This study aims at (a) ...testing the role of heathlands, acidic and calcareous dry grasslands for lichen and bryophyte diversity and conservation in lowland areas of northern Italy characterized by high human impact and habitat fragmentation; (b) detecting the effect of environmental drivers and vegetation dynamics on species richness and composition. Lichens, bryophytes, vascular plants, and environmental variables were recorded in 287 circular plots for 75 sites. Our results indicate that heathlands, acidic and calcareous dry grasslands host peculiar terricolous lichen and bryophyte communities that include several species of conservation concern. Thus, each habitat provides a complementary contribution to lichen and bryophyte diversity in continental lowland landscapes. Furthermore, in each habitat different factors drive species richness and composition with contrasting patterns between lichens and bryophytes. In terms of conservation, our results indicate that management of lowland dry habitats should act at both local and landscape scales. At local scale, vegetation dynamics should be controlled in order to avoid biodiversity loss due to vegetation dynamics and wood encroachment. At the landscape scale, patches of all the three habitats should be maintained to maximize regional diversity.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
During the years, many usnic acid (UA) conjugates have been synthesized to obtain potent endowed with biological properties. Since (
)-UA is less abundant in nature than (
)-enantiomer, it is ...difficult to source, thus precluding a deeper investigation. Among the lichens producing UA,
is a valuable (S)-UA source. In the present work, we report on a rapid HPLC-UV/PAD-CD protocol suitable for the analysis and the identification of the main secondary metabolites present in
extract. Best results were achieved using XBridge Phenyl column and acetonitrile and water, which were both added with formic acid as mobile phase in gradient elution. By combining analytical, spectroscopical, and chiroptical analysis, the most abundant analyte was unambiguously identified as (
)-UA. Accordingly, a versatile microwave-assisted extractive (MAE) protocol, assisted by a design of experiment (DoE), to quantitatively recover (
)-UA was set up. The best result in terms of UA extraction yield was obtained using ethanol and heating at 80 °C under microwave irradiation for 5 min. Starting from 100 g of dried
, 420 mg of (
)-UA were achieved. Thus, our extraction method resulted in a suitable protocol to produce (
)-UA from
for biological and pharmaceutical investigation or commercial purposes.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Coastal dunes are among habitats with the worst conservation status on a global, European and national scale. Monitoring and reporting are of strategic importance to determine the effectiveness of ...the implementation of Habitats Directive and to preserve the unique biodiversity heritage of the Italian dunes. In this study we show main results of the 4th National Report with specific reference to the macro-habitat “Coastal Sand Dunes and Inland Dunes”, highlighting its updated current conservation status at the national and Biogeographical level. A comprehensive Working Group of territorial experts collected, updated, validated and integrated the data available for 11 Annex I Habitats, distributed in the Alpine, Continental and Mediterranean Biogeographical Regions. The conservation status was evaluated through the following criteria: geographic range, surface area, structure, functions, pressures, threats, conservation measures and prospects. Results highlighted the dramatically bad conservation status of Italian dune Habitats: the overall assessment reported 88% of habitats in bad conservation status and the remaining 12% is in inadequate conditions. Results showed a generalised threat and a worrying conservation status both on herbaceous and wooded communities, in particular in some relevant habitats, such as the shifting dunes. Main pressures and threats were linked to residential, commercial and industrial activities, as well as alien species. Although some of the changes in distribution and trends are probably deriving from more accurate and updated data, the alarming conservation status of Italian sand dunes requires a better knowledge of pressures and threats for further management actions and monitoring plans, inside and outside protected areas.
Epiphytic lichens were surveyed in the “Bosco Siro Negri” Integral Nature State Reserve (province of Pavia, Lombardy, NW Italy), which hosts a well-preserved fragment of oak-elm floodplain forest ...(Natura 2000 Habitat 91F0). The core woodland fragment hosted only four species on the tree boles, i.e. Lepraria finkii plus the forest specialists Coenogonium pineti, Diarthonis spadicea, and Opegrapha vermicellifera. An additional eight nitro- and photophytic species were recorded on the highest twigs of the canopy. The whole Reserve, including the neighbouring degraded woodlands and poplar plantations, hosted 27 epiphytic lichen taxa. The lower Ticino River valley between Vigevano and Pavia, in which the Reserve is located, was surveyed for epiphytic lichens in an additional 45 sites, including 15 wellpreserved oak-elm/hornbeam woodlands (Habitat 91F0), 15 degraded broadleaved woodlands with high occurrence of black locust and 15 poplar plantations. Overall, 32 species were recorded. Well-preserved woodlands had a lower species richness, but they hosted forest specialists not occurring in the other two habitats. Graphis pulverulenta and Lecania cyrtellina are new to Lombardy. Anisomeridium polypori, Diarthonis spadicea, Lecanora expallens and Pseudoschismatomma rufescens are reported from Lombardy for the second time.
Due to habitat loss and fragmentation, numerous forest species are subject to severe population decline. Investigating variation in genetic diversity, phenotypic plasticity and local adaptation ...should be a prerequisite for implementing conservation actions. This study aimed to explore these aspects in ten fragmented populations of
in view of translocation measures across its Italian range.
For each population we collected environmental data on landscape (habitat size, quality and fragmentation) and local conditions (slope, presence of alien species, incidence of the herbivorous insect
and soil parameters). We measured vegetative and reproductive traits in the field and analysed the genetic population structure using ISSR markers (STRUCTURE and AMOVA). We then estimated the neutral (F
) and quantitative (P
) genetic differentiation of populations.
The populations exhibited moderate phenotypic variation. Population size (range: 16-655 individuals), number of flowering adults (range: 3-420 individuals) and inflorescence size (range: 5.0-8.4 cm) were positively related to Mg soil content. Populations' gene diversity was moderate (Nei-H = 0.071-0.1316); STRUCTURE analysis identified five different clusters and three main geographic groups: upper, lower, and Apennine/Western Po plain. Fragmentation did not have an influence on the local adaptation of populations, which for all measured traits showed P
< F
, indicating convergent selection.
The variation of phenotypic traits across sites was attributed to plastic response rather than local adaptation. Plant translocation from suitable source populations to endangered ones should particularly take into account provenance according to identified genetic clusters and specific soil factors.
Terricolous lichen communities in lowlands occur especially in open dry habitats. Such communities are often dominated by species of the genus
, which are very variable in morphology, reproduction ...strategies, and secondary metabolites. In this work, we investigated traits-environment relationships considering vegetation dynamics, substrate pH, disturbance, and climate. A total of 122 plots were surveyed in 41 acidic dry grasslands in the western Po Plain (Northern Italy). Relationships between
traits and environmental variables were investigated by means of a model-based Fourth Corner Analysis. Thallus morphology and metabolites responded to vegetation dynamics, substrate pH, disturbance, and climate, whereas reproduction strategies responded only to vegetation dynamics. Traits' correlations with vegetation dynamics elucidate their colonization patterns in open dry habitats or suggest biotic interactions with bryophytes and vascular plants. In addition, correlations between metabolites and environmental factors support interpretations of their ecological roles. Our results also stress the importance of studying traits' relationships with climatic factors as an alert towards lichen reactions to climate change.
In this contribution, new data concerning the distribution of native vascular flora in Italy are presented. It includes new records, confirmations, and exclusions to the Italian administrative ...regions. Nomenclatural and distribution updates, published elsewhere, and corrigenda are provided as supplementary material.
Full text
Available for:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The majority of the world’s plants rely on animal pollinators for reproduction, making pollination a key ecosystem service for the maintenance of natural and cultivated plant communities. Mutual ...interactions between plants and pollinators, also called “plant-pollinator networks”, are becoming increasingly vulnerable due to the intensification of anthropogenic land use and climate change. Thus, due to the rapid decline of semi-natural grasslands in the Northern Apennines (Italy), we aimed at understanding how the fragmentation of these habitats, the spatial distribution, and the amount of semi- and natural areas surrounding them, could affect species diversity and plant-pollinator networks. Specifically, in the Northern Apennines, we monitored semi-natural grasslands belonging to the EU habitat type 6510 to evaluate the effect of fragmentation on plant and pollinator richness and on the plant-pollinator network. We carried out generalized linear models considering three taxonomical and six network descriptors as response variables and the combinations of grasslands size and isolation, as well as 10 other factors describing landscape composition as explanatory variables. We found a well-structured plant-pollinator network, characterized by a high diversity of both plants and pollinators, with mutual relations marginally specialized, highly affected by habitat fragmentation and the land use of surrounding grasslands. Moreover, large and neighboring patches increased pollinator richness and improved the overall network structure while the occurrence of meadows and shrubs around fragmented patches was important to ensure the continuity of floristic resources. Finally, extensive croplands and agricultural settlements significantly reduced plant and pollinator diversity, favoring generalist (probably invasive) species, which however increased the strength and stability of the network.
In this contribution, new data concerning bryophytes, fungi and lichens of the Italian flora are presented. It includes new records, confirmations or exclusions for the bryophyte genera
Acaulon
,
...Campylopus
,
Entosthodon
,
Homomallium
,
Pseudohygrohypnum
, and
Thuidium
, the fungal genera
Entoloma
,
Cortinarius
,
Mycenella
,
Oxyporus
, and
Psathyrella
and the lichen genera
Anaptychia
,
Athallia
,
Baeomyces
,
Bagliettoa
,
Calicium
,
Nephroma
,
Pectenia
,
Phaeophyscia
,
Polyblastia
,
Protoparmeliopsis
,
Pyrenula
,
Ramalina
, and
Sanguineodiscus
.
Full text
Available for:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
PDF
