scholarly journals Demographic variability in spruce-fir-beech forest stands in Europe

2017 ◽  
Author(s):  
Guillaume Lagarrigues ◽  
Franck Jabot ◽  
Andreas Zingg ◽  
Jean-Claude Gégout ◽  
Matija Klopčič ◽  
...  
Keyword(s):  
Forest Dynamics ◽  
Abies Alba ◽  
Beech Forest ◽  
Distribution Area ◽  
Distribution Models ◽  
Regional Variability ◽  
Mixed Stands ◽  
Data Set ◽  
Demographic Processes

1AbstractMany studies have predicted large changes in forest dynamics during the next century because of global warming. Although empirical approaches and studies based on species distribution models provide valuable information about future changes, they do not take into account biotic interactions and stand-level demographic variations. The objective of this study was to quantify the local and regional variability of the growth and regeneration of three important forest species growing often in mixed stands in Europe (Picea abies (L.) Karst., Abies alba Mill., Fagus sylvatica), and to assess the climatic drivers of this variability. For that purpose, we collected a large forestry data set compiling the long-term (up to 100 years) evolution of species and size distributions for 163 stands across Europe, in the mesic distribution area of these forests. We used an inverse modeling approach, Approximate Bayesian Computation, to calibrate an individual-based model of forest dynamics on these data. Our study revealed that the variability of the demographic processes was of the same order of magnitude between stands of a same forest as between different forests. Out of the three species and two demographic processes studied, only the fir growth strongly varied with temperature. Water availability did not explain any demographic variation over stands. For these forests experiencing mesic conditions, local unmeasured factors seem therefore to have an influence at least as important as macro-environmental factors on demographic variations. Efforts to include these important factors in projection scenarios should therefore be prioritized. Besides, our study demonstrates that inverse modelling methods make possible the analysis of long-term forestry data. Such data should therefore be more widely compiled and used for ecological and global change research.

scholarly journals Wood quality and value production in mixed fir-spruce-beech stands: long-term research in the Western Carpathians

2016 ◽  
Vol 62 (2) ◽  
pp. 98-104 ◽  
Author(s):  
Rudolf Petráš ◽  
Julián Mecko ◽  
Michal Bošeľa ◽  
Vladimír Šebeň
Keyword(s):  
Wood Quality ◽  
Abies Alba ◽  
Repeated Measurements ◽  
Mixed Stands ◽  
Average Value ◽  
Mean Diameter ◽  
Stem Quality ◽  
The Mean ◽  
Value Production

Abstract Stem quality and damage was evaluated in mixed spruce-fir-beech stands. Moreover, an assortments structure was determined with their financial value. Results were compared with pure spruce (Picea abies [L.] Karst.), fir (Abies alba Mill.) and beech (Fagus sylvatica L.) stands. Repeated measurements on 31 long-term research plots, stand assortment models, assortment yield models and value yield models were used. Stem quality of fir and spruce was only slightly lower in mixed stands compared to pure stands but beech stem quality was considerably worse in mixed stands. Fir and spruce had slightly lower proportions of better IIIA quality logs and higher proportions of IIIB quality in mixed stands. Beech had worse assortment structure than spruce and fir, in general. Pure beech stands had higher proportions of better I–IIIA quality assortments than mixed stands by 1–7%. Fir and spruce average value production (€ m−3) culminated at about 56 and 62 cm mean diameters. Almost the same value production was found in pure stands. In these stands it culminated at the mean diameter of 58 and 60 cm. Beech produced substantially less value on the same sites. In mixed stands, its value production culminated at the mean diameter of 40 cm. In pure stands, it culminated at the mean diameter of 36 cm. Although the production was found to be similar in both mixed and pure forests, higher damage intensity and less stem quality in mixed forests suggest that the pure forests can be more profitable.

scholarly journals Photovoltaic power potential in West Africa using long-term satellite data

2020 ◽  
Vol 20 (21) ◽  
pp. 12871-12888
Author(s):  
Ina Neher ◽  
Susanne Crewell ◽  
Stefanie Meilinger ◽  
Uwe Pfeifroth ◽  
Jörg Trentmann
Keyword(s):  
West Africa ◽  
Temporal Variability ◽  
Solar Irradiance ◽  
Negative Trend ◽  
Positive Trend ◽  
Wet Season ◽  
Regional Variability ◽  
Surface Solar Radiation ◽  
Data Set

Abstract. This paper addresses long-term historical changes in solar irradiance in West Africa (3 to 20∘ N and 20∘ W to 16∘ E) and the implications for photovoltaic systems. Here, we use satellite irradiance (Surface Solar Radiation Data Set – Heliosat, Edition 2.1 – SARAH-2.1) and temperature data from a reanalysis (ERA5) to derive photovoltaic yields. Based on 35 years of data (1983–2017), the temporal and regional variability as well as long-term trends in global and direct horizontal irradiance are analyzed. Furthermore, a detailed time series analysis is undertaken at four locations. According to the high spatial resolution SARAH-2.1 data record (0.05∘×0.05∘), solar irradiance is largest (up to a 300 W m−2 daily average) in the Sahara and the Sahel zone with a positive trend (up to 5 W m−2 per decade) and a lower temporal variability (<75 W m−2 between 1983 and 2017 for daily averages). In contrast, the solar irradiance is lower in southern West Africa (between 200 W m−2 and 250 W m−2) with a negative trend (up to −5 W m−2 per decade) and a higher temporal variability (up to 150 W m−2). The positive trend in the north is mostly connected to the dry season, whereas the negative trend in the south occurs during the wet season. Both trends show 95 % significance. Photovoltaic (PV) yields show a strong meridional gradient with the lowest values of around 4 kWh  kWp−1 in southern West Africa and values of more than 5.5 kWh  kWp−1 in the Sahara and Sahel zone.

scholarly journals Deadwood Density and Moisture Variation in a Natural Temperate Spruce-Fir-Beech Forest

2017 ◽  
Author(s):  
Tomáš Přívětivý ◽  
Petr Baldrian ◽  
Pavel Šamonil ◽  
Tomáš Vrška
Keyword(s):  
Mass Loss ◽  
Abies Alba ◽  
Beech Forest ◽  
Environmental Data ◽  
Time Since Death ◽  
Moisture Variation ◽  
Decomposition Time ◽  
Fagus Sylvatica L

Deadwood represents a source of nutrients, carbon and water for metabolism within forest ecosystem. Nutrients are mobilized due to the decomposition of wood, which is a long-term process that can be best studied by analysing environmental data on a temporary scale. Our study provides physico-temporal data on the downed logs of three major tree species in European temperate forests: Abies alba Mill., Fagus sylvatica L. and Picea abies (L.) Karst. Time since death was obtained using tree censuses (repeated for 40 years) and dendrochronology for each single downed log, the oldest being 75 years old. Standard laboratory methods were used for the determination of wood density and moisture changes. F. sylvatica was decomposed rapidly in the initial phase &ndash; mass loss was 50% during the 5 years after death, while A. alba and P. abies lost 13% and 16%, respectively. Downed logs of F. sylvatica contained 391 kg of water per m3, while these of P. abies 279 kg. A log-transformed linear model was created that shows the dependence of time since death on mass loss. According to the model, F. sylvatica had the shortest total decomposition time (39 years), followed by A. alba (58 years) and P. abies (86 years).

scholarly journals A PROBABILISTIC MODEL OF REGIONAL-SCALE RESPONSE TO EXTREME STORM EVENTS

2018 ◽  
pp. 46
Author(s):  
Tomas Beuzen ◽  
Kristen D. Splinter ◽  
Ian L. Turner ◽  
Mitchell D. Harley ◽  
Lucy A. Marshall ◽  
...  
Keyword(s):  
Regional Scale ◽  
Airborne Lidar ◽  
Beach Erosion ◽  
Storm Events ◽  
Regional Variability ◽  
Data Set ◽  
High Resolution Data ◽  
Extreme Storm ◽  
Lidar Measurements

Predicting beach erosion caused by extreme storms remains a key focus of the coastal engineering community, having important implications for both emergency and long-term coastal management and planning. In June 2016, an extra-tropical cyclone impacted the east coast of Australia, resulting in the largest erosion event recorded in this region for several decades. High-resolution data collected during this event included immediate pre and post-storm airborne LIDAR measurements of the subaerial beach along 400 km of coastline, as well as detailed modeling of inshore wave conditions. This unprecedented data set presents a unique opportunity to explore key drivers of the observed local and regional variability in the response of beaches to extreme storm events.

scholarly journals Global variation in the long-term seasonal changes observed in ionospheric F region data

2015 ◽  
Vol 33 (4) ◽  
pp. 449-455 ◽  
Author(s):  
C. J. Scott ◽  
R. Stamper
Keyword(s):  
Regional Variation ◽  
Critical Frequency ◽  
Relative Magnitude ◽  
Striking Similarity ◽  
Regional Variability ◽  
Data Set ◽  
Annual Variations ◽  
F Region ◽  
Region Data

Abstract. Long-term variability has previously been observed in the relative magnitude of annual and semi-annual variations in the critical frequency (related to the peak electron concentration) of the ionospheric F2 layer (foF2). In this paper we investigate the global patterns in such variability by calculating the time varying power ratio of semi-annual to annual components seen in ionospheric foF2 data sequences from 77 ionospheric monitoring stations around the world. The temporal variation in power ratios observed at each station was then correlated with the same parameter calculated from similar epochs for the Slough/Chilton data set (for which there exists the longest continuous sequence of ionospheric data). This technique reveals strong regional variation in the data, which bears a striking similarity to the regional variation observed in long-term changes to the height of the ionospheric F2 layer. We argue that since both the height and peak density of the ionospheric F2 region are influenced by changes to thermospheric circulation and composition, the observed long-term and regional variability can be explained by such changes. In the absence of long-term measurements of thermospheric composition, detailed modelling work is required to investigate these processes.

scholarly journals Long-term variability of solar irradiance and its implications for photovoltaic power in West Africa

2020 ◽  
Author(s):  
Ina Neher ◽  
Susanne Crewell ◽  
Stefanie Meilinger ◽  
Uwe Pfeifroth ◽  
Jörg Trentmann
Keyword(s):  
West Africa ◽  
Power Systems ◽  
Solar Irradiance ◽  
Positive Trend ◽  
Wet Season ◽  
Regional Variability ◽  
Surface Solar Radiation ◽  
Data Set ◽  
Photovoltaic Power

Abstract. This paper addresses long-term changes in solar irradiance for West Africa (3° N to 20° N and 20° W to 16° E) and its implications for photovoltaic power systems. Here we use satellite irradiance (Surface Solar Radiation Data Set-Heliosat, Edition 2.1, SARAH-2.1) to derive photovoltaic yields. Based on 35 years of data (1983–2017) the temporal and regional variability as well as long-term trends of global and direct horizontal irradiance are analyzed. Furthermore, at four locations a detailed time series analysis is undertaken. The dry and the wet season are considered separately. According to the high resolved SARAH-2.1 data record (0.05° x 0.05°), solar irradiance is largest (with up to 300 W/m² daily average) in the Sahara and the Sahel zone with a positive trend (up to 5 W/m²/decade) and a lower variability (

Configurations to Superior Environmental Innovation Strategy: A Both–And Approach

2021 ◽  
pp. 108602662110316
Author(s):  
Tiziana Russo-Spena ◽  
Nadia Di Paola ◽  
Aidan O’Driscoll
Keyword(s):  
Climate Change ◽  
Value Chain ◽  
Critical Role ◽  
Well Being ◽  
Point Of View ◽  
Future Generations ◽  
Innovation Strategy ◽  
Environmental Innovation ◽  
Data Set

An effective climate change action involves the critical role that companies must play in assuring the long-term human and social well-being of future generations. In our study, we offer a more holistic, inclusive, both–and approach to the challenge of environmental innovation (EI) that uses a novel methodology to identify relevant configurations for firms engaging in a superior EI strategy. A conceptual framework is proposed that identifies six sets of driving characteristics of EI and two sets of beneficial outcomes, all inherently tensional. Our analysis utilizes a complementary rather than an oppositional point of view. A data set of 65 companies in the ICT value chain is analyzed via fuzzy-set comparative analysis (fsQCA) and a post-QCA procedure. The results reveal that achieving a superior EI strategy is possible in several scenarios. Specifically, after close examination, two main configuration groups emerge, referred to as technological environmental innovators and organizational environmental innovators.

EXPRESS: How Does Bonus Payment Affect the Demand for Auto Loans and Their Delinquency?

2021 ◽  
pp. 002224372110092
Author(s):  
Zhenling Jiang ◽  
Dennis J. Zhang ◽  
Tat Chan
Keyword(s):  
Consumer Products ◽  
Data Set ◽  
Financial Decisions ◽  
Consumer Panel ◽  
Loan Demand ◽  
Bonus Payments ◽  
Base Salary ◽  
Long Term Impact ◽  
Shed Light

This paper studies how receiving a bonus changes the consumers’ demand for auto loans and the risk of future delinquency. Unlike traditional consumer products, auto loans have a long-term impact on consumers’ financial state because of the monthly payment obligation. Using a large consumer panel data set of credit and employment information, the authors find that receiving a bonus increases auto loan demand by 21 percent. These loans, however, are associated with higher risk, as the delinquency rate increases by 18.5 −31.4 percent depending on different measures. In contrast, an increase in consumers’ base salary will increase the demand for auto loans but not the delinquency. By comparing consumers with bonuses with those without bonuses, the authors find that bonus payments lead to both demand expansion and demand shifting on auto loans. The empirical findings help shed light on how consumers make financial decisions and have important implications for financial institutions on when demand for auto loans and the associated risk arise.

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