Longer Growing Seasons Cause Hydrological Regime Shifts in Central European Forests

In this study, we present evidence for a hydrological regime shift in upland central European forests. Using a combination of long-term data, detailed field measurements and modelling, we show that there is a prolonged and persistent decline in annual runoff:precipitation ratios that is most likely linked to longer growing seasons. We performed a long term (1950-2018) water balance simulation for a Czech upland forest headwater catchment calibrated against measured streamflow and transpiration from deciduous and coniferous stands. Simulations were corroborated by long-term (1965-2018) borehole measurements and historical drought reports. A regime shift from positive to negative catchment water balances likely occurred in the early part of this century. Since 2007, annual runoff:precipitation ratios have been below the long-term average. Annual average temperatures have increased, but there have been no notable long term trends in precipitation. Since 1980, there has been a pronounced April warming, likely leading to earlier leaf out and higher annual transpiration, making water unavailable for runoff generation and/or soil moisture recharge. Our results suggest a regime shift due to second order effects of climate change where increased transpiration associated with a longer growing season leads to a shift from light to water limitation in central European forests. This will require new approaches to managing forests where water limitation has previously not been a problem

Urban Parks Hydrological Regime in the Context of Climate Change-A Case Study of Štěpánka Forest Park (Mladá Boleslav, Czech Republic)

The paper presents the results of a case study that was prepared as a basis for decision-making processes in the context of the impacts of global climate change. The article is focused on a very important part of the urban environment, namely urban forests. When taking planning measures in periurban forests, two realities must always be addressed, i.e., adaptation measures to mitigate the effects of climate change on the forest complex in question and its use to mitigate the effects of climate change in its surroundings must both be considered. It is a well-known fact that forest communities (of any kind) are on the one hand affected by the impacts of climate change, but on the other hand are able to mitigate its effects on their surroundings. The case study was of land near the town of Mladá Boleslav. The aim was to analyse the hydrological regime of the Štěpánka Forest Park, nicknamed "the lungs of Mladá Boleslav". Modelling of the runoff coefficient was made for the whole park area, as well as for the part on the left bank of the Klenice River (forested part). The runoff conditions of the site and their subparameters are addressed in the study by comparing the current state with the modelled state after deforestation of the site, e.g., due to drought. As far as the spatial layout of the forest is concerned, it is absolutely essential to maintain an integrated stand on the site with a lower stem cover (fewer individuals per plot) and a lower regeneration period. These aspects of a growing matrix forest stand will ensure its sustainability, in particular the sustainable water management of the trees in the context of lower water reserves in the rhizosphere and the greater ability of younger individuals to adapt to changes in site conditions (replacement of stress-resistant types by resilient types).O

JOINIG OF MG ALLOY AZ31B BY SELECTED TECHNOLOGIES

This contribution presents metallurgical joining of Mg alloy AZ 31B by several technologies - Friction Stir Welding - FSW, Laser Beam Welding - LBW, soldering and their mutual comparison. The difficulty of joining Mg alloys is connected with the strong MgO layer, low ductility of the weld metal (WM), a presence of intermetallic phases connected with the hardness increase. To successfully join Mg alloys, a precise setting of welding parameters is needed. The welds are susceptible to low mechanical properties as all samples fractured at WM. From the tested methods, laser beam welding proved the best results, because laser welding is the fastest and weld strength reached the highest values, i.e. 87% of BM (base metal) strength

Willingness to Pay for Forest Existence Value and Sustainability

Uganda is richly endowed with flora and fauna. Until the early 2000s, most of the types of vegetation have remained natural/virgin forests and shrubs until recent years, when human activities have damaged them. Understanding the different ways that people value such endangered forest resources is very important. The main hypothesis in our study is that willingness to pay (WTP) for forest existence value and sustainability depends on the preference for the same values. In addition, we examined socioeconomic characteristics, such as sex, education, and household incomes, which could influence the WTP for forest existence value and sustainability. We carried out field questionnaire interviews with the aim of ascertaining Willingness to Pay (WTP) for forest existence. The WTP values were in a range between 1 and 200 USD based on the contingent valuation method (CVM). A sample with a size of 203 was interviewed in selected towns and villages in Uganda, and the data collected were subjected to statistical analysis. The cross-tabulation of the expressed preferences illustrates that 81.9% of the representative sample are willing to pay for forest existence value and sustainability. We concluded that the willingness to pay for forest existence significantly depends on the preference for forest existence values and sustainability. Our results equally express that the mean WTP in this region is 15 USD per year and that over 60% are willing to pay this amount. The socioeconomic determinants' results demonstrate heterogeneity and that over 90% of the respondents are willing to pay for forest existence, conservation, and sustainability.O

Ecohydrological consequences of tree removal in an urban park evaluated using open data, free software and a minimalist measuring campaign

With ongoing global climate change and an increasingly urbanized population, the importance of city parks and other forms of urban vegetation increases. Trees in urban parks can play an important role in mitigating runoff and delivering other ecosystem services. Park managers, E-NGOs, citizen scientists and others are increasingly called upon to evaluate the possible consequences of changes in park management such as, e.g., tree removal. Here, we present an unorthodox approach to hydrological modelling and its potential use in local policy making regarding urban greenery. The approach consists of a minimalist field campaign to characterize vegetation and soil moisture status combined with a novel model calibration using freely available data and software. During modelling, we were able to obtain coefficients of determination (R2) of 0.66 and 0.73 for probe-measured and simulated soil moisture under tree stand and park lawn land covers respectively. The results demonstrated that tree cover had a significant positive effect on the hydrological regime of the locality through interception, transpiration and effects on soil moisture. Simulations suggested that tree cover was twice as effective at mitigating runoff than park lawn and almost seven times better than impervious surfaces. In the case of a potential replacement of tree vegetation in favour of park lawn or impervious surfaces an increase in runoff of 14% and 81% respectively could be expected. The main conclusion drawn from our study was that such an approach can be a very useful tool for supporting local decision-making processes as it offers a freely available, cheap and relatively easy-to-use way to describe the hydrological consequences of landcover change (e.g., tree removal) with sufficient accuracy.OA-hybri

Ecohydrological consequences of tree removal in an urban park evaluated using open data, free software and a minimalist measuring campaign

With ongoing global climate change and an increasingly urbanized population, the importance of city parks and other forms of urban vegetation increases. Trees in urban parks can play an important role in mitigating runoff and delivering other ecosystem services. Park managers, E-NGOs, citizen scientists and others are increasingly called upon to evaluate the possible consequences of changes in park management such as, e.g., tree removal. Here, we present an unorthodox approach to hydrological modelling and its potential use in local policy making regarding urban greenery. The approach consists of a minimalist field campaign to characterize vegetation and soil moisture status combined with a novel model calibration using freely available data and software. During modelling, we were able to obtain coefficients of determination (R-2) of 0.66 and 0.73 for probe-measured and simulated soil moisture under tree stand and park lawn land covers respectively. The results demonstrated that tree cover had a significant positive effect on the hydrological regime of the locality through interception, transpiration and effects on soil moisture. Simulations suggested that tree cover was twice as effective at mitigating runoff than park lawn and almost seven times better than impervious surfaces. In the case of a potential replacement of tree vegetation in favour of park lawn or impervious surfaces an increase in runoff of 14% and 81% respectively could be expected. The main conclusion drawn from our study was that such an approach can be a very useful tool for supporting local decision-making processes as it offers a freely available, cheap and relatively easy-to-use way to describe the hydrological consequences of landcover change (e.g., tree removal) with sufficient accuracy. (C) 2018 The Authors. Published by Elsevier B.V

Analýza potenciálů celospolečenských funkcí lesů LZ Židlochovice

Angl. resum

Will the removal of the recreational symbol of Jeseniky Mountain summit parts, the dwarf pine forests, affect the ecosystem functions of the hills?

The study evaluates how the removal of the dwarf pine from the forest stands of the summit parts of the Jeseníky Mountains will affect the performance of their ecosystem functions. The primary interest of the study is the assessment of the effect of the removal of the dwarf pine on the runoff conditions of the investigated locations, however, their recreational function is also considered. It is obvious that the dwarf pine has historically become one of the symbols of the local landscape in the summit parts of the Jeseníky Mountains. The results achieved by the author's team indicate that the removal of the dwarf pine will not significantly affect the functions of the forests in the monitored area compared to their current functionality. However, the social perception of this intervention will probably be very significant, both in the professional sphere (foresters) and in the sphere of the public (recreationists). It turns out that currently, the social significance of interventions implemented in socially exposed localities is as serious as its ecological and technical significance.Published Versio

Planting a Linear Vegetation Element in Landscape Using a Forestry and Landscaping Method—Can We Tell Which Deliver Greater Success?

Since the end of the 20th century, the Czech Republic has been developing an ecological network. Areas of ligneous greenery are being established throughout the landscape. The projects use different sizes of planting material: forestry seedlings and landscaping seedlings. In the South Moravian Region, in the vicinity of the village of Šardice, a series of measurements was carried out in 2016–2019 to compare the vitality of the greenery elements established by each of the methods. The height of the seedlings and trunk diameter were measured for the young trees while the shrubs were monitored for the seedling height only. Mortality was recorded successively for all the seedlings. The forestry method demonstrated greater growing vigour as indicated by the ratio of the trunk diameter increment to height while the landscaping method had lower mortality. In the forestry plantations, high mortality was found especially in poplars, oaks and hornbeams while in the landscaping plantations the poplars and oaks had the highest mortality. Elm, sycamore and poplar trees had the highest increments in the forestry plantations (but the latter was planted at different size). In the landscaping plantations, poplar trees (planted at a different size) delivered the best results, followed by maple, elm and lime trees. Shrub mortality was similar in both types of plantings. Hazel had a very high mortality while ivy, privet and honeysuckle had low mortality. Shrub height gain was higher in fenced forestry plantations. In unfenced landscaping plantations, damage by game was evident

Longer Growing Seasons Cause Hydrological Regime Shifts in Central European Forests

In this study, we present evidence for a hydrological regime shift in upland central European forests. Using a combination of long-term data, detailed field measurements and modelling, we show that there is a prolonged and persistent decline in annual runoff:precipitation ratios that is most likely linked to longer growing seasons. We performed a long term (1950–2018) water balance simulation for a Czech upland forest headwater catchment calibrated against measured streamflow and transpiration from deciduous and coniferous stands. Simulations were corroborated by long-term (1965–2018) borehole measurements and historical drought reports. A regime shift from positive to negative catchment water balances likely occurred in the early part of this century. Since 2007, annual runoff:precipitation ratios have been below the long-term average. Annual average temperatures have increased, but there have been no notable long term trends in precipitation. Since 1980, there has been a pronounced April warming, likely leading to earlier leaf out and higher annual transpiration, making water unavailable for runoff generation and/or soil moisture recharge. Our results suggest a regime shift due to second order effects of climate change where increased transpiration associated with a longer growing season leads to a shift from light to water limitation in central European forests. This will require new approaches to managing forests where water limitation has previously not been a problem