Papers by Alessio Collalti
Data in brief, Jun 1, 2024
bioRxiv (Cold Spring Harbor Laboratory), Jan 26, 2024
Carbon storage in harvested wood products (HWPs) and the associated substitution effects resultin... more Carbon storage in harvested wood products (HWPs) and the associated substitution effects resulting from their utilization over fossil fuels and energy-intensive materials are pivotal strategies in climate change mitigation. Recognition of this nature-based solution as integral to climate change mitigation targets is notably solidified in many Nationally Determined .
bioRxiv (Cold Spring Harbor Laboratory), May 25, 2024
Carbon assimilation and wood production are influenced by environmental conditions and endogenous... more Carbon assimilation and wood production are influenced by environmental conditions and endogenous factors, such as species auto-ecology, age, and hierarchical position within the forest structure. Disentangling the intricate relationships between those factors is more pressing than ever before due to the pressure of climate change. Yet, our understanding of how future climate will interact with forests of different ages is particularly limited, and only a few studies have explored this relationship under changing climate conditions. We employed a validated process-based forest model for simulating undisturbed forests of different ages under five climate change scenarios coming from five Earth System Models. In this context, carbon stocks and increment were simulated via total carbon woody stocks (MgC ha-1) and the mean annual increment (m 3 ha-1 year-1), which depend mainly on age and long-term processes, such as climate trends. We find greater differences among different age cohorts under the same scenario than in different climate scenarios under the same age class. We found different C-accumulation patterns under climate change between coniferous stands and broadleaves. Increasing temperature and changes in precipitation patterns led to a decline in above-ground biomass in spruce stands, especially in the older age classes. On the contrary, the results show that beech forests at DK-Sor will maintain and even increase C-storage rates under most RCP scenarios. Scots pine forests show an intermediate behavior with a stable stock capacity over time and in different scenarios but with decreasing mean volume annual increment. These results confirm current observations worldwide that indicate a stronger climate-related decline in conifers forests than in broadleaves. We, therefore, advocate for a better understanding of the interaction between forests and climate to better inform forest management strategies, ultimately dampening the impacts of climate change on forest ecosystems.
The prediction of atmospheric CO 2 concentrations is limited by the high interannual variability ... more The prediction of atmospheric CO 2 concentrations is limited by the high interannual variability (IAV) of terrestrial gross primary productivity (GPP). However, there are large uncertainties in the drivers of GPP IAV among Earth system models (ESMs). Here, we evaluate the impact of these uncertainties on the predictability of atmospheric CO 2 in six ESMs. We use regression analysis to determine the role of environmental drivers on (i) the patterns of GPP IAV, and (ii) the predictability of GPP. There are large uncertainties in the spatial distribution of GPP IAV. Although all ESMs agree on the high IAV in the tropics, several ESMs have unique hotspots of GPP IAV. The main driver of GPP IAV is temperature in the ESMs using the Community Land Model, and soil moisture in IPSL-CM6A-LR and MPI-ESM-LR, revealing underlying differences in the source of GPP IAV among ESMs. Between 13% and 24% of the GPP IAV is predictable one year ahead, with four out of six ESMs between 19% and 24%. Up to 32% of the GPP IAV induced by soil moisture is predictable, while only 7% to 13% of the GPP IAV induced by radiation. The results show that while ESMs are fairly similar in their ability to predict themselves, their predicted contribution to the atmospheric CO 2 variability originates from different regions and is caused by different drivers. A higher coherence in atmospheric CO 2 predictability could be achieved by reducing uncertainties of GPP sensitivity to soil moisture, and by accurate observational products for GPP IAV.
Agricultural and Forest Meteorology, Dec 1, 2022
This page was generated automatically upon download from the ETH Zurich Research Collection. For ... more This page was generated automatically upon download from the ETH Zurich Research Collection. For more information, please consult the Terms of use.
EGU General Assembly Conference Abstracts, Apr 1, 2018
bioRxiv (Cold Spring Harbor Laboratory), Jun 14, 2023
Points 1. We apply a process-based forest model on a regular grid at 1 km spatial resolution in a... more Points 1. We apply a process-based forest model on a regular grid at 1 km spatial resolution in a Mediterranean region. 2. Initial forest state is estimated using spatially explicit input data derived from national forest inventory data and remote sensing. 3. The model shows satisfactory performances in simulating the gross primary productivity fluxes, when compared to three independent multi-sources satellite-based observations.
Global Change Biology, Apr 6, 2023
Microclimate research gained renewed interest over the last decade and its importance for many ec... more Microclimate research gained renewed interest over the last decade and its importance for many ecological processes is increasingly being recognized. Consequently, the call for high‐resolution microclimatic temperature grids across broad spatial extents is becoming more pressing to improve ecological models. Here, we provide a new set of open‐access bioclimatic variables for microclimate temperatures of European forests at 25 × 25 m2 resolution.
Science of The Total Environment, 2023
Environmental Pollution, Feb 1, 2022
Surface ozone (O3) is a threat to forests by decreasing photosynthesis and, consequently, influen... more Surface ozone (O3) is a threat to forests by decreasing photosynthesis and, consequently, influencing the strength of land carbon sink. However, due to the lack of continuous surface O3 measurements, observational-based assessments of O3 impacts on forests are largely missing at hemispheric to global scales. Currently, some metrics are used for regulatory purposes by governments or national agencies to protect forests against the negative impacts of ozone: in particular, both Europe and United States (US) makes use of two different exposure-based metrics, i.e. AOT40 and W126, respectively. However, because of some limitations in these metrics, a new standard is under consideration by the European Union (EU) to replace the current exposure metric. We analyse here the different air quality standards set or proposed for use in Europe and in the US to protect forests from O3 and to evaluate their spatial and temporal consistency while assessing their effectiveness in protecting northern-hemisphere forests. Then, we compare their results with the information obtained from a complex land surface model (ORCHIDEE). We find that present O3 uptake decreases gross primary production (GPP) in 37.7% of the NH forested area of northern hemisphere with a mean loss of 2.4% year-1. We show how the proposed US (W126) and the currently used European (AOT40) air quality standards substantially overestimate the extension of potential vulnerable regions, predicting that 46% and 61% of the Northern Hemisphere (NH) forested area are at risk of O3 pollution. Conversely, the new proposed European standard (POD1) identifies lower extension of vulnerability regions (39.6%).
Forest@, Mar 26, 2008
In passato molti Autori hanno utilizzato ed elabo rato indici bioclimatici per interpretare le co... more In passato molti Autori hanno utilizzato ed elabo rato indici bioclimatici per interpretare le correlazio ni tra variabili climatiche e distribuzione delle spe cie. Sulla base di tali indici si è arrivati ad alcune classificazioni bioclimatiche con la suddivisione del pianeta per macro-aree (Köppen 1936, Bagnouls & Gaussen 1957, Rivas-Martinez 1996). Generalmente il dato climatico di partenza di cui si dispone è un dato di tipo puntuale, proveniente dal la rete di stazioni termo-pluviometriche distribuite sul territorio. Per ottenere una carta che descriva l'andamento delle variabili su una superficie è neces sario interpolare tale dato con tutti gli altri dati pun tuali che si hanno a disposizione generando cosi su perfici climatiche statistiche. I metodi di interpolazione vengono utilizzati per stimare andamenti di temperatura e precipitazioni tenendo conto della distanza reciproca tra il punto geografico effettivamente misurato e quello da sti mare (distance weighting
Forests, Feb 16, 2023
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Forest age is the result of population dynamics, disturbance regimes, silviculture and plays an i... more Forest age is the result of population dynamics, disturbance regimes, silviculture and plays an important role in the global Carbon (C) cycle. To examine the shaping effects of forest age on Carbon budget under current and future climate conditions, we used a biogeochemical-based model in three managed forest stands and then modeled their development as undisturbed systems. The model was forced with climate outputs under four representative climate scenarios over a matrix of 11 age classes for each stand. We find that the Net Primary Production (NPP) peak was reached in the middle-aged class (42- to-70-year-old) regardless of the climate scenario, while total C-woody stocks (tCWS) increased with age with different trajectories in the three sites, but not linearly as expected. Under climate change scenarios, the beech forest shows as expected increasing NPP with increasing atmospheric CO2and temperature as much for younger age classes as for older ones. Conversely, in the spruce and ...
Global Change Biology
Forest models are instrumental for understanding and projecting the impact of climate change on f... more Forest models are instrumental for understanding and projecting the impact of climate change on forests. A considerable number of forest models have been developed in the last decades. However, few systematic and comprehensive model comparisons have been performed in Europe that combine an evaluation of modelled carbon and water fluxes and forest structure. We evaluate 13 widely used, state‐of‐the‐art, stand‐scale forest models against field measurements of forest structure and eddy‐covariance data of carbon and water fluxes over multiple decades across an environmental gradient at nine typical European forest stands. We test the models' performance in three dimensions: accuracy of local predictions (agreement of modelled and observed annual data), realism of environmental responses (agreement of modelled and observed responses of daily gross primary productivity to temperature, radiation and vapour pressure deficit) and general applicability (proportion of European tree species...
AGU Fall Meeting Abstracts, Dec 1, 2018
Forest management practices might act as nature-based methods to remove CO2 from the atmosphere a... more Forest management practices might act as nature-based methods to remove CO2 from the atmosphere and slow anthropogenic climate change and thus support an EU forest-based climate change mitigation strategy. However, the extent to which diversified management actions could lead to quantitatively important changes in carbon sequestration and stocking capacity at the tree level remains to be thoroughly assessed. To that end, we used a state-of-the-science bio-geochemically based forest growth model to simulate effects of multiple forest management scenarios on net primary productivity (NPP) and potential carbon woody stocks (pCWS) under twenty scenarios of climate change in a suite of observed and virtual forest stands in temperate and boreal European forests. Previous modelling experiments indicated that the capacity of forests to assimilate and store atmospheric CO2 in woody biomass is already being attained under business-as-usual forest management practices across a range of climate...
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Papers by Alessio Collalti