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Die Bayerische Leseholzordnung in der heutigen Zeit - Eine Analyse zu Hintergründen und Auswirkungen
(2023)
Im Herbst 2022 steigen die Energie – und Gaspreise in Deutschland. Dadurch wird zum Thema, was
lange keine Beachtung mehr fand: Die bayerische Leseholzordnung. Diese Bekanntmachung, deren
neuste Fassung aus dem Jahr 1986 stammt, kann, wenn von vielen Personen angewendet, verschiedene Auswirkungen auf den Wald haben, wodurch sich ein Konfliktfeld zwischen den verschiedenen
Zielen in Bezug auf dieses Ökosystem ergeben kann. Diese Arbeit nimmt sich daher zum Ziel, jene
Auswirkungen der Leseholzordnung zu untersuchen. Dafür werden mithilfe einer Literaturrecherche
Hintergründe und die ökologische Bedeutung von Leseholz analysiert und eine computerbasierte Umfrage unter Revierförstern der Bayerischen Staatsforsten liefert Informationen zur heutigen Situation
der Leseholznutzung. Mehrere Experteninterviews ergänzen die Ergebnisse. Hierbei konnte festgestellt werden, dass Leseholz als Bodentotholz viele essenzielle Funktionen im Wald erfüllt und daher
eine höhere Wertschätzung erhalten sollte. Dies erstreckt sich über die Nährstoffzirkulation, den Wasserhaushalt, Erosion – und Verjüngungsschutz bis hin zur Lebensraumschaffung für zahlreiche Tier-,
Pflanzen- und Pilzarten. Als Energiequelle hingegen weist es meist mindere Qualität auf und kann in
dieser Aufgabe sinnvoll durch konventionell bereitgestelltes Brennholz ersetzt werden. Um aber dennoch einen Ausgleich zwischen den ökologischen und sozioökonomischen Interessen dieser Ressource zu ermöglichen, wäre eine stärkere Kontrolle der Leseholznutzung vonnöten, welche sich allerdings als sehr aufwendig erweist und bei nachweislich trotz Energiekrise geringem Interesse der
Bevölkerung nicht sonderlich sinnvoll erscheint. Die heutige Nutzung beschränkt sich weitestgehend
auf ländliche Räume, wo an Wegrändern meist nicht mehr als ein Festmeter (Fm) pro Hektar und Jahr
gesammelt wird und dies ungleichmäßig über das Jahr verteilt. In jedem Fall ist eine Überarbeitung
der Leseholzordnung überfällig, da sie in ihrem aktuellen Wortlaut nicht mit den heutigen Gegebenheiten abgestimmt ist und dadurch zu Unklarheiten führen kann. Um den besten Weg zu finden, wie
weiter mit ihr verfahren werden soll, müssen weitere Untersuchungen durchgeführt und eine Zusammenarbeit mit der Bevölkerung angestrebt werden.
The prevalence of the microsporidium Nosema maddoxi in populations of brown marmorated stink bug (Halyomorpha halys) from three sites in Guria and eight sites in Samegrelo, Georgia is described. Investigations were conducted on adults collected in fall and spring from fall 2020 to spring 2022. The prevalence of infection differed by both region and season. Total prevalence of N. maddoxi in adults from the Guria region was significantly higher than the Samegrelo region. Infection levels in fall were higher than in the spring in the Guria region, but inconsistent over seasons in the Samegrelo region. Infection levels did not differ by sex. We hypothesize that higher population densities and more adult aggregation in Guria compared with Samegrelo helps to explain the higher infection levels in Guria.
Multi-scenario dynamic prediction of ecological risk assessment in an arid area of northwest China
(2023)
Ecological security is essential for the development of environmental health and human society. However, the driving mechanisms and spatial non-stationarity of ecological risks are still unknown, particularly in arid areas. Thus, this study constructed an ecological risk index (ERI) research framework in arid areas based on land use and socio-economic data from 1980 to 2020 to investigate the spatiotemporal evolution trend, driving mechanisms, and spatial non-stationarity of ecological risk and predict the ecological risk under business-as-usual, economic development, and ecological protection scenarios using a patch-generating land use simulation (PLUS) model. The results show that: (1) cropland and build-up land were expanding, whereas forestland and grassland water bodies were shrinking. Compared with the two development stages from 1980 to 2000 and from 2000 to 2020, cropland increased by 4.73% and 51.52%, respectively, whereas build-up land increased by 12.64% and 106.52%, respectively, indicating rapid development and drastic changes in the past 20 years. (2) With the change in landscape diversity, the regional ecological risks showed an increasing trend, whereas the future ecological risks showed an increasing trend because of the cumulative effect of landscape pattern changes caused by human activities. (3) Moreover, dramatic changes in ecological risk, particularly in areas of intense human activity in build-up land, agricultural land, artificial oases, and mountainous areas. Corresponding to the analysis of driving mechanisms, population, GDP, distance to government, water, and primary roads; have a significant effect on ecological risk, whereas DEM has direct and indirect effect paths. Ultimately, the proposed analysis framework can present the spatiotemporal changes of ecological risks and their influencing mechanisms, which can help develop sustainable development policies.
The measurement of roadside wood stacks in the forest still plays an important role in many forestry operations. Traditional manual measuring methods can be laborious, inaccurate and error-prone. Therefore, the issue is whether 2.5D or 3D optical remote sensing measuring methods provide more precise or detailed results and advantages in further data processing. This study examined and partly developed nine different manual, photo-optical, iPad®-LiDAR and handheld laser scanner-LiDAR-based wood stack measurement methods. Forty-seven wood stacks, ranging from 8.9 to 209.3 m3 (totalling approximately 2700 m3), were measured and compared using these nine methods. All the methods give volume estimations, and none can be seen to give the real or true wood stack gross volume. Surprisingly, the results varied significantly within and between the individual methods, with up to a 9% mean relative deviation. The relative deviation is strongly dependent on the size of the wood stack. The 3D measurement methods using iPad® RGB and LiDAR recorded lower timber volumes than the other methods, in contrast to the method based on samples taken with handheld laser scanner-LiDAR, which overestimated the volume. Generally, optical- and laser-based surveying techniques could be more widely applied in measuring wood stacks in the future. However, such automatic wood stack gross volume determination approaches still face some challenges, regarding accuracy in the case of the 2.5D methods and the lack of automatisation in the case of 3D methods. Consequently, further research is required in the near future.
Perspektiven von Schlüsselakteuren auf das Potenzial der Agroforstwirtschaft in Nordostdeutschland
(2023)
Entwicklung ertragskundlicher und ökologischer Paramter in einem Brandenburger Alley Cropping System
(2023)
Tajikistan's agricultural sector, primarily dominated by cotton cultivation, has experienced significant changes since the Soviet era. Although farmers introduced food crops into agricultural production to ensure food security after the collapse of the Soviet Union in 1991, the government still mandates that cotton cultivation occupy a considerable portion of Tajikistan's limited irrigated land. However, following the recent Covid-19 pandemic crisis, farmers have encountered the need to reassess their agricultural practices, given constrained governmental assistance and a range of socioeconomic considerations. This research adopts resilience as a conceptual framework to examine the coping strategies of smallholder farmers in the Khatlon region of Tajikistan, with a specific emphasis on the period spanning from 2019 to 2022. At the outset, our research employed the snowballing technique to increase respondent participation, later transitioning to a representative sample size that facilitated the collection of qualitative data from around 100 semi-structured interviews, 10 focus groups, and personal visits to agricultural fields over the course of four years. The paper not only demonstrates the overall creativity of Tajikistani farmers in growing and selecting non-cotton crops in this most recent period of crisis, but also points to wealthier farmers’ generally greater willingness to adopt technological innovations and gain new knowledge to apply to them. Although these strategies have been taken in order to address farmers’ immediate needs in troubled times against the backdrop of the existing state cotton policy, their sustainability remains uncertain. While the qualitative focus of this study bears certain inherent limitations, the data collected nevertheless show that this period of crisis has been generative for many farmers as they seek out new methods of subsistence.
Das im Februar gestartete Forschungsvorhaben "Adapt-Wald-Holz" unter der Leitung der Hochschule für nachhaltige Entwicklung Eberswalde (HNEE) steht im Zeichen von Branchenvernetzung, regionaler Wertschöpfung und Nachwuchsförderung. Ziel ist es, ein adaptives, d.h. anpassungsfähiges, Wald-Holz-Managementsystem für die Region Brandenburg-Berlin am Beispiel der Waldkiefer zu entwickeln.
Crop sensing technology is in continuous development. Proximal and remote sensors measuring different physical properties of plant tissue, as surrogates for nutritional and health status are being developed in response to the ever-increasing need of quick and reliable crop monitoring for precision agriculture. A recently developed fluorescent-based device, Multiplex, is of particular interest for high spatial resolution modeling and managing systems, given its capacity of measuring fluorescence properties of chlorophyll and other pigments at both leaf and canopy levels, and both in discrete (“one-shot”) and continuous (“on-the-go”) measuring modes.
The goal of this research was to assess the ability of Multiplex to measure nitrogen (N) content of different crops and compare it with the performance of other well-established sensors.
Several fields with spring and winter barley and corn at three locations in Brandenburg representing different levels of N fertilization were chosen for the measurements. Leaf N content (% weight) from plant samples was compared to measurements of: Fluorescence (Multiplex Research sensor), light transmittance (SPAD sensor), and reflectance (ASD Field Spectrometer). Additionally, direct canopy fluorescence (Multiplex Research sensor) was compared to canopy reflectance (ASD Field Spectrometer), light transmittance of leaf composites (SPAD sensor) and remote reflectance from multispectral sensors on remotely piloted aircrafts (RPA) or drones.
Out of the 25 variables Multiplex produces at each reading, the Chlorophyll Index, the Flavonoid Index and the Nitrogen Balance Index showed the closest relationships to N. All these variables contain infrared and red fluorescence components suggesting that these have a key role in chlorophyll and N determination. In general, however, SPAD showed higher accuracy than fluorescence as a predictor of N content in leaves. Despite of this, Multiplex seems particularly convenient for fast on-field assessment of crop canopy status.
At the canopy level, drone-based sensors can be as accurate as Multiplex to assess the N status of the crops under study. In the case of Multiplex, however, since the device reads are taken below the canopy and parallel to the ground, measurements are not affected by canopy density and soil background, which can be an inconvenience for vertical reflectance measurements as provided by drones and spectrometers.