Giorgio Vacchiano

University of Milan | UNIMI · Department of Agricultural and Environmental Sciences - Production, Landscape, Agroenergy

Our understanding of the mechanisms that maintain forest diversity under changing climate can benefit from knowledge about traits that are closely linked to fitness. We tested whether the link between traits and seed number and seed size is consistent with two hypotheses, termed the leaf economics spectrum and the plant size syndrome, or whether re...

Spatio-ecological heterogeneity is strongly linked to many ecological processes and functions such as plant species diversity patterns and change, metapopulation dynamics, and gene flow. Remote sensing is particularly useful for measuring spatial heterogeneity of ecosystems over wide regions with repeated measurements in space and time. Besides, de...

In the context of global change, the integration of non-native tree (NNT) species into European forestry is increasingly being discussed. The ecological consequences of increasing use or spread of NNTs in European forests are highly uncertain, as the scientific evidence is either constraint to results from case studies with limited spatial extent,...

Abstract Poplar cultivation in Italy is a sector of excellence for the production of wood for industrial and energy use. This contribution intends to analyze the state of the poplar production chain in Italy, illustrating the main prospects for increased productivity and sustainability of the sector, in line with a perspective of sustainable intens...

European beech (Fagus sylvatica L.) can regenerate successfully from seeds after mixed-severity fires with mid-to-long fire return intervals (>60 years). However, if fire return interval is lower than the age of sexual maturity, post-fire seeding will be limited, leaving vegetative resprouting as the only viable option for recovery. This means that...

Lack of tree fecundity data across climatic gradients precludes the analysis of how seed supply contributes to global variation in forest regeneration and biotic interactions responsible for biodiversity. A global synthesis of raw seedproduction data shows a 250‐fold increase in seed abundance from cold‐dry to warm‐wet climates, driven primarily by...

The relationships that control seed production in trees are fundamental to understanding the evolution of forest species and their capacity to recover from increasing losses to drought, fire, and harvest. A synthesis of fecundity data from 714 species worldwide allowed us to examine hypotheses that are central to quantifying reproduction, a foundat...

Climate change is expected to increase both the frequency and the intensity of climate extremes, consequently increasing the risk of forest role transition from carbon sequestration to carbon emission. These changes are occurring more rapidly in the Alps, with important consequences for tree species adapted to strong climate seasonality and short g...

Significant gaps remain in understanding the response of plant reproduction to environmental change. This is partly because measuring reproduction in long-lived plants requires direct observation over many years and such datasets have rarely been made publicly available. Here we introduce MASTREE+, a dataset that collates reproductive time-series d...

The timing of seed production and release is highly relevant for successful plant reproduction. Ecological disturbances, if synchronized with reproductive effort, can increase the chances of seeds and seedlings to germinate and establish. This can be especially true under variable and synchronous seed production (masting). Several observational stu...

Forest fire is a common concern in Mediterranean watersheds. Fire-induced canopy mortality may cause the degradation of chemical–physical properties in the soil and influence hydrological processes within and across watersheds. However, the prediction of the pedological and hydrological effect of forest fires with heterogenous severities across ent...

Determining the spatiotemporal variability in the annual streamflow volume plays a relevant role in hydrology with regard to improving and implementing sustainable and resilient policies and practices of water resource management. This study investigates annual streamflow volume trends in a newly assembled, consolidated, and validated data set of d...

Populations of many long-lived plants exhibit spatially synchronized seed production that varies extensively over time, so that seed production in some years is much higher than on average, while in others, it is much lower or absent. This phenomenon termed masting or mast seeding has important consequences for plant reproductive success, ecosystem...

Despite its importance for forest regeneration, food webs, and human economies, changes in tree fecundity with tree size and age remain largely unknown. The allometric increase with tree diameter assumed in ecological models would substantially overestimate seed contributions from large trees if fecundity eventually declines with size. Current esti...

The quantification of post-disturbance root reinforcement (RR) recovery dynamics is of paramount importance for the optimisation of forest ecosystem services and natural hazards risk management in mountain regions. In this work we analyse the long-term root reinforcement dynamic of spruce forests combining data of the Swiss National Forest Inventor...

Forest harvesting in Europe: a healthy scientific debate Is forest harvesting increasing in Europe? There is scientific debate about methodological approach and data regarding clearcut increment in Europe but, besides the discussion, there is a general agreement about the need to collect reliable scientifically robust remote sensing data for sound...

Forest restoration is currently a primary objective in environmental management policies at a global scale, to the extent that impressive initiatives and commitments have been launched to plant billions of trees. However, resources are limited and the success of any restoration effort should be maximized. Thus, restoration programs should seek to g...

There is evidence that variable and synchronous reproduction in seed plants (masting) correlates to modes of climate variability, e.g. El Niño Southern Oscillation and North Atlantic Oscillation. In this perspective, we explore the breadth of knowledge on how climate modes control reproduction in major masting species throughout Earth's biomes. We...

Drought will increasingly threaten forest ecosystems worldwide. Understanding how competition influences tree growth response to drought is essential for forest management aiming at climate change adaptation. However, published results from individual case studies are heterogeneous and sometimes contradictory. We reviewed 166 cases from the peer-re...

1. Understanding the processes that shape forest functioning, structure, and diversity remains challenging, although data on forest systems are being collected at a rapid pace and across scales. Forest models have a long history in bridging data with ecological knowledge and can simulate forest dynamics over spatio-temporal scales unreachable by mo...

Partendo dall’esperienza nordamericana, si propongono modelli selvicolturali per aumentare l’eterogeneità strutturale di boschi di conifere per la prevenzione degli incendi boschivi, quali interessanti spunti di riflessione anche per le realtà mediterranee e alpine.

The monitoring of environmental policies in Europe has taken place since the 1980s and still remains a challenge for decision- and policy-making. For forests, it is concretized through the publication of a State Of Europe's Forests every five years, the last report just been released. However, the process lacks a clear analytical framework and appe...

Root reinforcement is a mechanism through which forests contribute to the prevention and mitigation of shallow instabilities in soils, one of the main hazards in mountain areas. This study aims to assess how spatial tree distribution and whether thinning operations affect root reinforcement in the most common forest types of the European Southern A...

Vaia storm facing the unbearable lightness of forest reporting Recently published data on Italian forest removals from FAO and EUROSTAT are still ridden with inaccuracies and underestimation. In this work we show how and why the Italian forestry data collection system is in itself unreliable. This represents a major obstacle for designing sector po...

Surface biomass characterization plays a key role in wildfire management. It allows classifying vegetation fuels flammability for fire risk analysis, to define silvicultural prescriptions for fire hazard reduction, to plan prescribed burning , or to model fire behavior and its effects, such as greenhouse gas and pollutant emissions. To facilitate f...

According to the European Landscape Convention (ELC), a landscape means "an area, as perceived by people, whose character is the result of the action and interaction of natural and/or human factors". Therefore, both human actions and natural processes play a role in shaping the landscape, which is, by this definition, ever changing. "Protecting" th...

Beliefs, expectations and values are often assumed to drive decisions about climate change adaptation. We tested hypotheses based on this assumption using survey responses from 508 European forest professionals in 10 countries. We used the survey results to identify communication needs and the decision strategies at play, and to develop guidelines...

I cambiamenti climatici, l’omogeneità dei boschi, il progressivo abbandono di aree agricole e pascolive, la mancanza di gestione del territorio e un approccio che si concentra principalmente sulla gestione dell’emergenza incendi piuttosto che sul loro governo e prevenzione, sono le principali cause all’origine dei Grandi Incendi Forestali e di ince...

Projections of landscape dynamics are uncertain, partly due to uncertainties in model formulations. However, quantitative comparative analyses of forest landscape models are lacking. We conducted a systematic comparison of all forest landscape models currently applied in temperate European forests (LandClim, TreeMig, LANDIS-II, iLand). We examined...

In his recent communication on our original paper 1,2 , D. Kelly, claiming that nutrient scarcity cannot select for masting behaviour in plants, initiated a fruitful discussion on traditionally settled hypotheses about the evolution of reproductive behaviour in plants. In his commentary, Kelly raises support for a contrasting hypothesis explaining...

In questa pubblicazione si presenta una sintesi dei contributi al workshop “Deforestation made in Italy” tenutosi a Padova nel dicembre 2019. Dopo aver inquadrato il tema della deforestazione e del degrado delle foreste, analizzandone i principali driver e impatti, nel testo sono presentati approcci metodologici e risultati preliminari relativi all...

Forest ecosystems are threatened by different natural disturbances. Among them, the irruption of large herbivores represents one of the most alarming issues. Several local-scale studies have been carried out to clarify the mechanisms governing ungulate–forest interactions, to understand the effect of wild ungulates overabundance, and to apply conse...

In these days, the role that fine particles in urban areas could play in facilitating the pandemic spread of the COVID-19 virus is becoming increasingly important. It is also well known that exposure to air pollution and in particular to fine dust favors diseases involving the respiratory system. In this context of strong concern, we argue that urb...

The role of values in climate-related decision-making is a prominent theme of climate communication research. The present study examines whether forest professionals are more driven by values than scientists are, and if this results in value polarization. A questionnaire was designed to elicit and assess the values assigned to expected effects of c...

In the last years, intensity of wildfires and burned areas have increased around the world due to the anthropogenic climate change. Recent forest fire events proved quite well that forest fires are also an urgent issue in the Alpine region which can lead to the destruction of protection forests, increasing vulnerability to natural hazards and resul...

Highly variable and synchronised production of seeds by plant populations, known as masting, is implicated in many important ecological processes, but how it arises remains poorly understood. The lack of experimental studies prevents underlying mechanisms from being explicitly tested, and thereby precludes meaningful predictions on the consequences...

Abstract. Determining the spatio-temporal variability of annual streamflow volume plays a relevant role in hydrology for improving and implementing sustainable and resilient policies and practices of water resource management. This study investigates annual streamflow volume trends in a newly-assembled, consolidated and validated dataset of daily m...

A petition entitled “Italian forests: an invaluable environmental heritage under attack” was recently published on the web. The petition is a perfect example of how environmental communication and public awareness can be manipulated. And, even more seriously, how people claiming to be environmental experts, use the “environment” label to spread the...

Climate change is expected to cause major changes in forest ecosystems during the 21 st century and beyond. To assess forest impacts from climate change, the existing empirical information must be structured, harmonised and assimilated into a form suitable to develop and test state-of-the-art forest and ecosystem models. The combination of empirica...

Carbon allocation plays a key role in ecosystem dynamics and plant adaptation to changing environmental conditions. Hence, proper description of this process in vegetation models is crucial for the simulations of the impact of climate change on carbon cycling in forests. Here we review how carbon allocation modelling is currently implemented in 31...

Mast seeding is one of the most intriguing reproductive traits in nature. Despite its potential drawbacks in terms of fitness, the widespread existence of this phenomenon suggests that it should have evolutionary advantages under certain circumstances. Using a global dataset of seed production time series for 219 plant species from all of the conti...

Background. Uncertainty about climate change impacts on forests can hinder mitigation and adaptation actions. Scientific enquiry typically involves assessments of uncertainties, yet different uncertainty components emerge in different studies. Consequently, inconsistent understanding of uncertainty among different climate impact studies (from the i...

Uncertainty about climate change impacts on forests can hinder mitigation and adaptation actions. Scientific enquiry typically involves assessments of uncertainties, yet different uncertainty components emerge in different studies. Consequently, inconsistent understanding of uncertainty among different climate impact studies (from the impact analys...

Planting trees in Italy for the health of the planet. Where, how and why The Laudato Si' communities have put forward the proposal to plant 60 million trees in Italy to fight the climate crisis. The role of forests in mitigating climate change is scientifically unequivocal. However, a sound reforestation strategy must be consistent with the country...

Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) is an important exotic tree species that was planted across a large part of Europe during the last century. In both experimental trials and conventional forest plantations, the trees grow at a high rate and produce high-quality timber. The present study investigated climate-growth relationships of...

1.Synchronous pulses of seed masting and natural disturbance have positive feedbacks on the reproduction of masting species in disturbance‐prone ecosystems. We test the hypotheses that disturbances and proximate causes of masting are correlated, and that their large‐scale synchrony is driven by similar climate teleconnection patterns at both inter‐...

Fire disturbance is an intrinsic component of the Mediterranean biome playing an important role in ecosystem dynamics and processes. However, frequent and severe anthropogenic wildfires can be detrimental to natural ecosystems, particularly in small natural protected areas, where they may hamper the flow of ecosystem services (ES). While post-fire...

Negli ultimi decenni le attività umane ed i cambiamenti climatici da un lato, l'evoluzione della normativa e lo sviluppo di una efficace prevenzione dall'altro, hanno mutato notevolmente la frequenza e l'estensione degli incendi nel contesto europeo. Il 2017 ha rappresentato un anno particolarmente significativo per la quantità di ettari bruciati i...

El alerce europeo (Larix decidua) domina el paisaje forestal en los valles internos de los Alpes occidentales. A pesar de su importancia, su respuesta a los incendios forestales apenas ha sido estudiada. En este trabajo se examina la hipótesis de que el alerce europeo es una especie resiliente al fuego. Para ello se establecieron 200 parcelas en nu...

Tree growth and reproduction are subject to trade-offs in resource allocation. At the same time, they are both influenced by climate. In this study, we combined long records of reproductive effort at the individual- (29 years), population- (41 years) and regional (up to 53 years) scale, and tree ring chronologies, to investigate the effects of clim...

Models are pivotal for assessing future forest dynamics under the impacts of changing climate and management practices, incorporating representations of tree growth, mortality, and regeneration. Quantitative studies on the importance of mortality submodels are scarce. We evaluated 15 dynamic vegetation models (DVMs) regarding their sensitivity to d...

On October 29th, 2018, storm Vaia hit forests in north-eastern Italy, causing the loss of 8 million cubic meters of standing trees and, more importantly, the sudden reduction of forest-related ecosystem services. Such event is not unprecedented: a similar storm had occurred in the same regions in 1966. Every year, an average of two extratropical st...