Mast seeding is a crucial population process in many tree species, but its spatio-temporal patterns and drivers at the continental scale remain unknown.
Using a large dataset (8000 masting ...observations across Europe for years 1950–2014) we analysed the spatial pattern of masting across the entire geographical range of European beech, how it is influenced by precipitation, temperature and drought, and the temporal and spatial stability of masting–weather correlations.
Beech masting exhibited a general distance-dependent synchronicity and a pattern structured in three broad geographical groups consistent with continental climate regimes. Spearman’s correlations and logistic regression revealed a general pattern of beech masting correlating negatively with temperature in the summer 2 yr before masting, and positively with summer temperature 1 yr before masting (i.e. 2T model). The temperature difference between the two previous summers (DeltaT model) was also a good predictor. Moving correlation analysis applied to the longest eight chronologies (74–114 yr) revealed stable correlations between temperature and masting, confirming consistency in weather cues across space and time.
These results confirm widespread dependency of masting on temperature and lend robustness to the attempts to reconstruct and predict mast years using temperature data.
•Engineering resilience of Scots pine 4years after forest fire has been quantified.•Spatial distribution of root reinforcement (RR) has been modeled.•RR decay by a factor of 3.6, 4years after a stand ...replacing forest fire.•Natural regeneration has almost no root reinforcement 4years after fire.•Decay of root mechanical properties determine most of RR loss.
Natural disturbances may cause a temporary reduction or elimination of the protective effect of forests. The management of protection forests aims to influence forest dynamics to ensure an optimal and continuous protective effect. To achieve this goal quantitative and detailed information about the post-disturbance stand dynamics is needed. In the case of hillslopes prone to shallow landslides in particular, there is a lack of knowledge about the effect of fire on the dynamic of root reinforcement and on the related increment in landslide risk. Such quantitative information is of paramount importance when dealing with forest system engineering resilience after disturbances.
The objective of this work is to quantify the temporal and spatial dynamics of root reinforcement in a burnt Scots pine (Pinus silvestris) forest 4years after a stand replacing fire in Switzerland. To this purpose, we compare the contribution of root reinforcement to soil strength of a burnt forest patch with a nearby-located, similar mature and healthy, stand. Root distribution measurements and field pullout tests on roots were used to calculate the spatial distribution of root reinforcement in both types of stand.
The results show a reduction by a factor of 3.6 in root reinforcement 4years after the forest fire due to the degradation of the root mechanical properties. Moreover, we demonstrate that at this post-fire stage the natural regeneration is not able to counterbalance the protective function loss in term of root reinforcement.
Climate teleconnections drive highly variable and synchronous seed production (masting) over large scales. Disentangling the effect of high-frequency (inter-annual variation) from low-frequency ...(decadal trends) components of climate oscillations will improve our understanding of masting as an ecosystem process. Using century-long observations on masting (the MASTREE database) and data on the Northern Atlantic Oscillation (NAO), we show that in the last 60 years both high-frequency summer and spring NAO, and low-frequency winter NAO components are highly correlated to continent-wide masting in European beech and Norway spruce. Relationships are weaker (non-stationary) in the early twentieth century. This finding improves our understanding on how climate variation affects large-scale synchronization of tree masting. Moreover, it supports the connection between proximate and ultimate causes of masting: indeed, large-scale features of atmospheric circulation coherently drive cues and resources for masting, as well as its evolutionary drivers, such as pollination efficiency, abundance of seed dispersers, and natural disturbance regimes.
Effects of land use changes on chemical soil properties were studied in a southern alpine valley of Ticino, Switzerland by analysing three different land cover-topography units: (i) natural forested ...slopes (NFS); (ii) deforested, cultivated terraces (DCT), and (iii) reforested, abandoned terraces (RAT). Whereas NFS represents the natural reference state with negligible anthropogenic influence, DCT corresponds to intense agricultural utilization, and RAT refers to a post-cultural natural evolution after terrace cultivation. Land use-induced changes in vegetation cover and topography (i.e., terracing) had a clear influence on chemical soil properties. The presence or absence of the European chestnut (Castanea sativa Mill.), one of the main soil acidifying agents in the study area, clearly affected soil acidity, soil organic matter (SOM), and nutrient status. Compared to the vegetation change, terracing has a less obvious effect on soil chemistry. A greater effective rooting depth and a flat microtopography on terraces lead to a rapidly increased SOM accumulation due to better growing conditions for trees. Thus, the reforested, abandoned terraces develop peculiar soil chemistry conditions after 36 to 46 years of abandonment only.
Fire regimes are strongly related to weather conditions that directly and indirectly influence fire ignition and propagation. Identifying the most important meteorological fire drivers is thus ...fundamental for daily fire risk forecasting. In this context, several fire weather indices have been developed focussing mainly on fire-related local weather conditions and fuel characteristics. The specificity of the conditions for which fire danger indices are developed makes its direct transfer and applicability problematic in different areas or with other fuel types. In this paper we used the low-to-intermediate fire-prone region of Canton Ticino as a case study to develop a new daily fire danger index by implementing a niche modelling approach (Maxent). In order to identify the most suitable weather conditions for fires, different combinations of input variables were tested (meteorological variables, existing fire danger indices or a combination of both). Our findings demonstrate that such combinations of input variables increase the predictive power of the resulting index and surprisingly even using meteorological variables only allows similar or better performances than using the complex Canadian Fire Weather Index (FWI). Furthermore, the niche modelling approach based on Maxent resulted in slightly improved model performance and in a reduced number of selected variables with respect to the classical logistic approach. Factors influencing final model robustness were the number of fire events considered and the specificity of the meteorological conditions leading to fire ignition.
The Mediterranean Basin is the region of Europe most vulnerable to negative climate-change impacts, including forest decline, increased wildfire, and biodiversity loss. Because humans have affected ...Mediterranean ecosystems for millennia, it is unclear whether the region's native ecosystems were more resilient to climate change than current ecosystems, and whether they would provide sustainable management options if restored. We simulated vegetation with the L
and
C
lim
model, using present-day climate as well as future climate-change scenarios, in three representative areas that encompass a broad range of Mediterranean conditions and vegetation types. Sedimentary pollen records that document now-extinct forests help to validate the simulations. Forests modeled under present climate closely resemble the extinct forests when human disturbance is limited; under future scenarios, characterized by increased temperatures and decreased precipitation, extinct forests are projected to re-emerge. When combined with modeling, paleoecological evidence reveals the potential of native vegetation to re-establish under current and future climate conditions, and provides a template for novel management strategies to maintain forest productivity and biodiversity in a warmer and drier future.
‘
Candidatus
Phytoplasma ulmi’ (
Ca.
P. ulmi) belongs to the ribosomal subgroup 16SrV-A and is associated with dieback, shoot proliferation and yellows disease on various
Ulmus
spp. Other plant ...species, such as
Carpinus betulus
and
Prunus
spp. have also been reported infected by the same pathogen. In 2021, in the frame of research activities focused on grapevine’s Flavescence dorée (FD), one specimen of
Orientus ishidae
- an East Palearctic leafhopper that was identified as an alternative vector of FD phytoplasmas - was found harboring
Ca.
P. ulmi in southern Switzerland. No phytoplasmas were detected in plant samples taken in the same location.
Orientus ishidae
has already been reported to be able to acquire diverse phytoplasmas associated with other plant diseases, such as Peach X-disease. This is the first report of
Ca.
P. ulmi in Switzerland, as well as in
O. ishidae
.
Ca.
P. ulmi may potentially be present in the wild compartment of the Swiss Pre-alpine and Alpine range, but no dedicated survey has so far been conducted. In the case of
O. ishidae
, this finding highlights the broad affinity of such a species for the acquisition of several phytoplasmas. This calls for a further investigation regarding its potential role as a vector on various pathosystems of agronomic importance.
Tree masting is one of the most intensively studied ecological processes. It affects nutrient fluxes of trees, regeneration dynamics in forests, animal population densities, and ultimately influences ...ecosystem services. Despite a large volume of research focused on masting, its evolutionary ecology, spatial and temporal variability, and environmental drivers are still matter of debate. Understanding the proximate and ultimate causes of masting at broad spatial and temporal scales will enable us to predict tree reproductive strategies and their response to changing environment. Here we provide broad spatial (distribution range-wide) and temporal (century) masting data for the two main masting tree species in Europe, European beech (Fagus sylvatica L.) and Norway spruce (Picea abies (L.) H. Karst.). We collected masting data from a total of 359 sources through an extensive literature review and from unpublished surveys. The data set has a total of 1,747 series and 18,348 yearly observations from 28 countries and covering a time span of years 1677–2016 and 1791–2016 for beech and spruce, respectively. For each record, the following information is available: identification code; species; year of observation; proxy of masting (flower, pollen, fruit, seed, dendrochronological reconstructions); statistical data type (ordinal, continuous); data value; unit of measurement (only in case of continuous data); geographical location (country, Nomenclature of Units for Territorial Statistics NUTS-1 level, municipality, coordinates); first and last record year and related length; type of data source (field survey, peer reviewed scientific literature, gray literature, personal observation); source identification code; date when data were added to the database; comments. To provide a ready-to-use masting index we harmonized ordinal data into five classes. Furthermore, we computed an additional field where continuous series with length >4 yr where converted into a five classes ordinal index. To our knowledge, this is the most comprehensive published database on species-specific masting behavior. It is useful to study spatial and temporal patterns of masting and its proximate and ultimate causes, to refine studies based on tree-ring chronologies, to understand dynamics of animal species and pests vectored by these animals affecting human health, and it may serve as calibration–validation data for dynamic forest models.
The first record of
Erasmoneura vulnerata
Fitch, 1851 in Switzerland is reported. Specimens were collected in 2019 using yellow sticky traps during a
Scaphoideus titanus
monitoring campaign in ...vineyards in Ticino (Southern Switzerland).
E. vulnerata
is a grapevine pest that has recently been introduced to Europe, whose phytophagy causes detrimental damage to grapevine leaves. Its occurrence in this area has likely been favored by the ongoing suspension of insecticide treatments for the control of the
S. titanus
population, the vector agent of the “Flavescence dorée” phytoplasma in grapevines.
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