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Correction to: Branca, g., et al. forest protection unifies, silviculture divides: A sociological analysis of local stakeholders’ voices after coppicing in the marganai forest (sardinia, italy). forests 2020, 11, 708
No full textWe have recently been made aware by the Forests Editorial Offices of some errors and omissions in the Introduction Section 1.1.2 of our recent paper [1]. The authors wish to make the following corrections: 1. The fifth paragraph of said Introduction Section 1.1.2 currently reads as follows: In the same period, the professionals involved in the renewal of the plan for the Margani SCI expressed very strong concerns about the activation of coppice practices in the Marganai area. During the third participatory meeting, held in Iglesias in 2014, the professionals involved in this SCI’s planned renewal denounced the high risk of erosive phenomena triggered by such a silvicultural operation [21]. However, [22] questioned their results, showing that their data did not support their interpretation of the facts. To clarify this from a scientific standpoint, we would like to make the following corrections: In the same period, the professionals involved in the renewal of the plan for the Margani SCI expressed very strong concerns about the activation of coppice practices in the Marganai area [21]. During the participatory meeting, held in the Iglesias area in 2014, the professionals denounced the high risk of erosive phenomena triggered by such silvicultural operations [22]. However, Giadrossich et al. questioned the hypothesis of such risks in the Marganai forest [23]. 2. The References [21–23] currently read as follows: 21. Vacca, A.; Aru, F.; Ollesch, G. Short-term impact of coppice management on soil in a quercus ilex l. Stand of Sardinia. Land Degrad. Develop. 2017, 28, 553–565, doi:10.1002/ldr.2551. 22. Giadrossich, F.; Guastini, E. A critical analysis of Vacca, A., Aru, F., Ollesch, G. (2017). Short term impact of coppice management on soil in a Quercus ilex L. Stand in Sardinia. Land Degrad. Develop. 2019, 30, 1765–1885, doi:10.1002/ldr.3246. 23. Gruppo D’intervento Giuridico Onlus. La Foresta del Marganai e la Sua Poco Accorta Gestione. 2018. Available online: https://gruppodinterventogiuridicoweb.com/2018/10/21/la-foresta-del-marganai-e-la-sua-poco-accorta-gestione/ (accessed on 18 May 2020). The corrected references are provided below: 21. A.T.P “C.C.W.R” Progettazioni e Soluzioni Ambientali, Sviluppo Equo ed Ecosostenibile. Richiesta Incontro Tecnico: Discussione su Problematiche Riscontrate su Habitat Forestali in Area SIC MONTE LINAS-MARGANAI ITB041111 e limitrofe, 2015. Letter Addressed to the “Sardegna Regional Forest Service”, Dated 11 November 2014. Available online: https://gruppodinterventogiuridicoweb. files.wordpress.com/2015/01/richiesta-incontro-tecnico-ente-for.pdf (accessed on 28 September 2020). 22. Gruppo d’Intervento Giuridico odv. Foreste Demaniali Sarde e Direttiva Habitat, un Contributo del Dott. Francesco Aru. Available online: https://gruppodinterventogiuridicoweb. com/2014/06/20/foreste-demaniali-sarde-e-direttiva-habitat-un-contributo-del-dott-francesco-aru/ (accessed on 18 May 2020). 23. Giadrossich, F.; Guastini, E. A critical analysis of Vacca, A., Aru, F., Ollesch, G. (2017). Short term impact of coppice management on soil in a Quercus ilex L. Stand in Sardinia. Land Degrad. Develop. 2019, 30, 1765–1885, doi:10.1002/ldr.3246. The authors would like to apologize for any inconvenience caused to the readers by these changes while stating that the scientific conclusions are unaffected. The published version will be updated on the article webpage, with a reference to this correction notice
Minimum representative root distribution sampling for calculating slope stability in pinus radiata d.Don plantations in New Zealand
No full textBackground: Rainfall-triggered shallow landslides on steep slopes cause significant soil loss and can be hazards for property and people in many parts of the world. In New Zealand’s hill country, they are the dominant erosion process and are responsible for soil loss and subsequent impacts on regional water quality. Use of wide-spaced trees and afforestation with fast growing conifers are the primary land management tools in New Zealand to help control erosion and improve water quality. To decide where to implement erosion controls in the landscape requires determining the most susceptible places to these processes and models that incorporate how trees reinforce soils to understand if, and when, such treatments become effective. Methods: This paper characterises the mechanical properties of Pinus radiata D.Don roots (the common tree species used for afforestation in New Zealand) by means of field pullout tests and by measuring the root distribution at 360 degrees around trees. The Root Bundle Model (RBM) was used to calculate the root reinforcement. Statistical analysis was carried out to assess the statistical reduction coefficients of root reinforcement that depend on the number of measurements, used in geotechnical analysis to reduce the mean value of a parameter to a so-called characteristic value. Results: We show that to reach an effective level of root reinforcement, trees of 0.5 m DBH require a density of about 300 trees per hectare. Trees of this size are about 30 years of age across many sites and have generally reached the recommended conditions for clear-fell harvesting. The analysis of variance shows that 4 trees are the minimum number to be excavated to obtain sufficient root information to obtain less than 5% of error with a 95% of probability on the estimation of a design value of root reinforcement in accord with geotechnical standards. Conclusions: We found that the variability of lateral and basal root reinforcement does not limit the implementation of vegetation in slope stability models for Pinus radiata. We adopt for the first time the concept of a minimum sampling requirement and characteristic value, similarly to what is assumed for the value of effective soil cohesion in geotechnical guidelines for slope stability calculations
Analisi della dinamica del rinforzo radicale
No full textL’obiettivo del presente studio è verificare e validare uno dei più recenti modelli per il calcolo del rinforzo radicale, il Root Bundle Model (Schwarz et al. 2011), nella sua versione estesa alla distribuzione di Weibull per la tensione massima a rottura di radici di uno stesso diametro denominato RBMw (Schwarz et al. 2012). A questo scopo sono stati utilizzati i dati sperimentali di rinforzo radicale in Giadrossich et al. (2010) e i dati sperimentali delle caratteristiche meccaniche delle radici in Giadrossich et al. (2009). La particolarità di questo modello sta nel nuovo approccio di considerare l’azione meccanica delle radici nella dinamica dell’innesco di una frana su suolo vegetato, passando dalla schematizzazione per incrementi di forza a quella basata su incrementi di spostamento della radice sottoposta a trazione e all’allungamento della stessa. I dati sperimentali di riferimento per il rinforzo radicale sono stati ottenuti da prove di taglio diretto su provini radicati, mentre i dati sperimentali di resistenza e di elasticità in funzione del diametro sono stati ottenuti da prove di trazione, sempre utilizzando radici di Robinia pseudoacacia L.. I risultati hanno dimostrato che i valori di coesione apparente dovuta alle radici ottenuti dal modello RBMw sono coerenti con i dati sperimentali
Large-scale lateral saturated soil hydraulic conductivity as a metric for the connectivity of subsurface flow paths at hillslope scale
Full text linkLateral saturated soil hydraulic conductivity, Ks,l, is the soil property governing subsurface water transfer in hillslopes, and the key parameter in many numerical models simulating hydrological processes at the hillslope and catchment scales. Likewise, the hydrological connectivity of the lateral flow paths plays a significant role in determining the rate of the subsurface flow at various spatial scales. This study investigates the relationship between Ks,l and hydrological connectivity at the hillslope spatial scale. Ks,l was determined by the subsurface flow rates intercepted by drains and water table depths observed in a well network. The hydrological connectivity was evaluated by the synchronicity among water table peaks, and between these and the peaks of the drained flow. Rainfall and soil moisture were used to investigate the influence of the transient hydrological soil condition on connectivity and Ks,l. As the synchronicity of the water table response between wells increased, the lag times between the peaks of water levels and those of the drained subsurface flow decreased. Moreover, the most synchronic water table rises determined the highest drainage rates. The relationships between Ks,l and water table depths were highly non-linear, with a sharp increase in the values for water table levels close to the soil surface. Estimated Ks,l values for the full saturated soil were in the order of thousands of mm h−1, suggesting the activation of macropores in the root zone. The Ks,l values determined at the peak of the drainage events were correlated with the indicators of synchronicity. The sum of cumulative rainfall and antecedent soil moisture was correlated with the connectivity indicators and Ks,l. We suggest that, for simulating realistic processes at the hillslope scale, the hydrological connectivity could be implicitly considered in hydrological modelling through an evaluation of Ks,l at the same spatial scale
Occurrence of the potential ichthyotoxic Prymnesium cf parvum (Prymnesiophyceae) in the Baratz Lake (north western Sardinia): impacts and perspectives
No full textShallow landslide disposition in burnt European beech (Fagus sylvatica L.) forests
Full text linkTree roots contribute significantly to soil strength on hillslopes. In the case of wildfires, this effect may abruptly vanish and be lacking for a considerable period of time depending on the resistance and resilience of the forest. Despite its importance, quantitative data on the impact and dynamics of wildfires on slope stabilization is still lacking. We use the study case of the Fagus sylvatica L. to quantify the medium-term evolution of root reinforcement and its effect on slope stability in fire-injured forests. In the study, we upscale root reinforcement using field data for the calibration of the Root Bundle Model and detailed information on forest structure in 244 plots, and calculate the spatio-temporal dynamics of forest protective capacity using a three-dimensional probabilistic slope stability model (slideforNET) for different site types. In unburnt and low-burn forests, the protective capacity was found to remain constant over time. Forests hit by moderate burns continue to provide adequate protection for shallow (depth < 0.5 m) and cohesive soils only, whereas in the case of high severity fires, the protective capacity vanishes for 15 years and an increased shallow landslide probability remains for at least 40 years. These conditions call for appropriate sylvicultural post-fire measures
GlmGUI v1.0: An R-based graphical user interface and toolbox for GLM (General Lake Model) simulations
No full textNumerical modeling provides an opportunity to quantify the reaction of lakes to alterations in their environment, such as changes in climate or hydrological conditions. The one-dimensional hydrodynamic General Lake Model (GLM) is an open-source software and widely used within the limnological research community. Nevertheless, no interface to process the input data and run the model and no tools for an automatic parameter calibration yet exist. Hence, we developed glmGUI, a graphical user interface (GUI) including a toolbox for an autocalibration, parameter sensitivity analysis, and several plot options. The tool is provided as a package for the freely available scientific code language R. The model parameters can be analyzed and calibrated for the simulation output variables water temperature and lake level. The glmGUI package is tested for two sites (lake Ammersee, Germany, and lake Baratz, Italy), distinguishing size, mixing regime, hydrology of the catchment area (i.e., the number of inflows and their runoff seasonality), and climatic conditions. A robust simulation of water temperature for both lakes (Ammersee: RMSE D 1:17 °C; Baratz: RMSE D 1:30 °C) is achieved by a quick automatic calibration. The quality of a water temperature simulation can be assessed immediately by means of a difference plot provided by glmGUI, which displays the distribution of the spatial (vertical) and temporal deviations. The calibration of the lake-level simulations of lake Ammersee for multiple hydrological inputs including also unknown inflows yielded a satisfactory model fit (RMSE D 0:20 m). This shows that GLM can also be used to estimate the water balance of lakes correctly. The tools provided by glmGUI enable a less time-consuming and simplified parameter optimization within the calibration process. Due to this, i.e., the free availability and the implementation in a GUI, the presented R package expands the application of GLM to a broader field of lake modeling research and even beyond limnological experts
Effects of Land Cover Changes on Shallow Landslide Susceptibility Using SlideforMAP Software (Mt. Nerone, Italy)
No full textLand cover changes in mountainous areas due to silvo-pastoral abandonment can affect soil stability, especially on steep slopes. In addition, the increase in rainfall intensity in recent decades requires re-assessing landslide susceptibility and vegetation management for soil protection. This study was carried out using the software SlideforMAP in the Mt. Nerone massif (central Italy) to assess (i) the effects of land cover changes on slope stability over the past 70 years (1954–2021) and (ii) the role of actual vegetation cover during intense rainfall events. The study area has undergone a significant change in vegetation cover over the years, with a reduction in mainly pastures (−80%) and croplands (−22%) land cover classes in favor of broadleaf forests (+64%). We simulated twelve scenarios, combining land cover conditions and rainfall intensities, and analyzed the landslide failure probability results. Vegetation cover significantly increased the slope stability, up to three to four times compared to the unvegetated areas (29%, 68%, and 89%, respectively, in the no cover, 1954, and 2021 scenarios). The current land cover provided protection against landslide susceptibility, even during extreme rainfall events, for different return periods. The 30-year return period was a critical condition for a significant stability reduction. In addition, forest species provide different mitigation effects due to their root system features. The results showed that species with deep root systems, such as oaks, provide more effective slope stability than other species, such as pines. This study helps to quantify the mitigation effects of vegetation cover and suggests that physically based probabilistic models can be used at the regional scale to detect the areas prone to failure and the triggering of rainfall-induced shallow landslides. This approach can be important in land planning and management to mitigate risks in mountainous regions
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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