Niels Thevs - Academia.edu (original) (raw)
Papers by Niels Thevs
Central Asian Journal of Water Research
Purpose: This study investigated the water consumption (crop evapotranspiration) of industrial he... more Purpose: This study investigated the water consumption (crop evapotranspiration) of industrial hemp on a newly established hemp field in Aqmola Region of Northern Kazakhstan. Methodology: The water consumption of hemp was investigated through direct measurements of the sapflow movement during the second half of the growing season 2021. These sapflow data yielded data on the water consumption. The water consumption of the first part of the growing season was assessed through the Penman-Monteith approach by FAO. Findings: The water consumption of hemp was 353 mm over the growing season at a stem yield of 10 t/ha. Under the water supply conditions of the study site, hemp offers higher yields than grasslands or grains. Originality/value: This is the first study that revealed data on water consumption of hemp for the region Central Asia as a potential raw material plant for bioeconomy.
Forests
Background: Agroforestry systems have the potential to provide timber and wood as a domestic raw ... more Background: Agroforestry systems have the potential to provide timber and wood as a domestic raw material, as well as an additional source of income for rural populations. In Central Asia, tree windbreaks from mainly poplar trees have a long tradition, but were largely cut down as source for fuel wood after the disintegration of the Soviet Union. As Central Asia is a forest-poor region, restoration of tree windbreaks has the potential to provide timber and wood resources to that region. This study aimed to assess the potential of tree windbreaks to contribute to domestic timber and wood production. Methods: This study rests on a GIS-based analysis, in which tree lines (simulated by line shape files) were intersected with cropland area. The tree data to calculate timber and wood volumes stem from a dataset with 728 single trees from a relevant range of climatic conditions. Results: The potential annually available timber volumes from tree windbreaks with 500 m spacing are 2.9 million...
The floodplain ecosystems along the Naryn River in Kyrgyzstan still show largely natural dynamics... more The floodplain ecosystems along the Naryn River in Kyrgyzstan still show largely natural dynamics and represent a regional hotspot of biodiversity. For the local population, they provide important ecosystem services, such as the provision of firewood and pasture land, areas for recreation and protection against erosion. However, the intensive use of the forests endangers their persistence. In addition, several hydropower plants are a threat to the natural dynamics of the river system and its biodiversity. There is thus a conflict between energy supply for the local population, the development of the country through the expansion of hydropower, and the preservation of natural ecosystems and their biodiversity. Preserving the riparian forests along the Naryn River and creating sustainable alternatives for energy supply is the aim of the ÖkoFlussPlan project, which is funded by the Federal Ministry of Education and Research. This article summarizes the current situation in the Naryn re...
Evidence of climate change at geological time scales are long known, and are attributed to natura... more Evidence of climate change at geological time scales are long known, and are attributed to natural causes. However, climatic change since the mid-19th century is mostly attributed to anthropogenic causes, and specifically, to the increasing emissions of greenhouse gases. Climatic change has become particularly evident since the 1970s, with global temperatures increasing at faster rates and precipitations decreasing over extensive parts of the world (Masson-Delmotte et al., 2019). Over recent decades, record-breaking high temperatures and severe droughts on the one hand, with extremely powerful rainstorms and devastating floods on the other hand, have become the new “normal” weather regime (Bowen, 2015). While these new climatic patterns affect vast parts of the world, they are most prominent in dryland regions. Over the last decades, the world’s drylands have faced both aridity aggravation and territorial expansion into previously moister areas (Huang et al., 2016), consequently low...
Agroforestry Systems, 2022
Journal of Current Chinese Affairs, 2011
The Tarim River is the major water source for all kinds of human activities and for the natural e... more The Tarim River is the major water source for all kinds of human activities and for the natural ecosystems in the Tarim Basin, Xinjiang, China. The major water consumer is irrigation agriculture, mainly cotton. As the area under irrigation has been increasing ever since the 1950s, the lower and middle reaches of the Tarim are suffering from a water shortage. Within the framework of the Water Law and two World Bank projects, the Tarim River Basin Water Resource Commission was founded in 1997 in order to foster integrated water resource management along the Tarim River. Water quotas were fixed for the water utilization along the upstream and downstream river stretches. Furthermore, along each river stretch, quotas were set for water withdrawal by agriculture and industry and the amount of water to remain for the natural ecosystems (environmental flow). Furthermore, huge investments were undertaken in order to increase irrigation effectiveness and restore the lower reaches of the Tarim...
Earth System Dynamics Discussions, 2014
The Tarim River Basin, located in Xinjiang, NW China, is the largest endorheic river basin of Chi... more The Tarim River Basin, located in Xinjiang, NW China, is the largest endorheic river basin of China and one of the largest in whole Central Asia. Due to the extremely arid climate with an annual precipitation of less than 100 mm, the water supply along the Aksu and Tarim River solely depends on river water. This applies for anthropogenic activities (e.g. agriculture) as well as for the natural ecosystems so that both compete for water. The on-going increase of water consumption by agriculture and other human activities in this region has been enhancing the competition for water between human needs and nature. Against this background, 11 German and 6 Chinese universities and research institutes formed the consortium SuMaRiO (<a href="www.sumario.de"target="_blank">www.sumario.de</a>), which aims at gaining a holistic picture of the availability of water resources in the Tarim River Basin and the impacts on anthropogenic activities and natural ecosystem...
Earth System Dynamics Discussions, 2014
Naturally, the floodplains of Central Asian rivers harbour riparian, so-called ‘Tugai’ forests, r... more Naturally, the floodplains of Central Asian rivers harbour riparian, so-called ‘Tugai’ forests, reeds with Phragmites australis, and shrub communities which form a mosaic depending on the variety of available ground water. In recent decades, these natural ecosystems have been strongly altered anthropogenically or even completely destroyed. In order to restore those ecosystems, knowledge on vegetation, ecosystem dynamics, and natural regeneration processes is essential. In our study, we present results of ecological investigations at the Tarim River. We gathered comprehensive data on soil, vegetation, forest stand age, tree vitality, river course dynamics, and land use and brought it to the landscape level. Thus, recommendations are derived for the maintenance of these floodplain ecosystems, in particular with regard to their biological diversity.
Environmental Earth Sciences, 2016
Trees, Forests and People
Forests
Research Highlights: Despite a long tradition of using poplars as wood source across Central Asia... more Research Highlights: Despite a long tradition of using poplars as wood source across Central Asia, recent international breeding developments have not penetrated that region yet. This study therefore explored growth performance of 30 local and international poplar cultivars. Background and Objectives: The Central Asian countries are forest poor countries, which need to cover the domestic wood demand through costly imports. Therefore, fast growing trees, such as poplars, are gaining increasing attention as option to grow wood domestically. The most common cultivars date back to Soviet Union times. As recent breeding developments have not reached the region, this study aims at investigate the growth performance of a number of newly developed poplar cultivars. Materials and Methods: The investigated cultivars were planted as cuttings across nine sites in Kyrgyzstan, Kazakhstan, and Tajikistan between 2018 and 2020. Results: Under warm climate conditions, i.e., low elevations, P. deltoi...
Frontiers in Environmental Science
Soil salinization and sodification are common processes that particularly characterize drylands. ... more Soil salinization and sodification are common processes that particularly characterize drylands. These processes can be attributed either to natural conditions or anthropogenic activities. While natural causes include factors such as climate, lithology, topography, and pedology, human causes are mostly related to agricultural land-use, and specifically, to irrigated agriculture. The objective of this study was to thoroughly review this topic, while highlighting the major challenges and related opportunities. Over time, the extent of saline, sodic, and saline-sodic croplands has increased, resulting in accelerated land degradation and desertification, decreased agricultural productivity, and consequently jeopardizing environmental and food security. Mapping and monitoring saline soils is an important management tool, aimed at determining the extent and severity of salinization processes. Recent developments in advanced remote sensing methods have improved the efficacy of mapping and ...
Central Asian Journal of Water Research
Purpose: This study investigated the water consumption (crop evapotranspiration) of industrial he... more Purpose: This study investigated the water consumption (crop evapotranspiration) of industrial hemp on a newly established hemp field in Aqmola Region of Northern Kazakhstan. Methodology: The water consumption of hemp was investigated through direct measurements of the sapflow movement during the second half of the growing season 2021. These sapflow data yielded data on the water consumption. The water consumption of the first part of the growing season was assessed through the Penman-Monteith approach by FAO. Findings: The water consumption of hemp was 353 mm over the growing season at a stem yield of 10 t/ha. Under the water supply conditions of the study site, hemp offers higher yields than grasslands or grains. Originality/value: This is the first study that revealed data on water consumption of hemp for the region Central Asia as a potential raw material plant for bioeconomy.
Forests
Background: Agroforestry systems have the potential to provide timber and wood as a domestic raw ... more Background: Agroforestry systems have the potential to provide timber and wood as a domestic raw material, as well as an additional source of income for rural populations. In Central Asia, tree windbreaks from mainly poplar trees have a long tradition, but were largely cut down as source for fuel wood after the disintegration of the Soviet Union. As Central Asia is a forest-poor region, restoration of tree windbreaks has the potential to provide timber and wood resources to that region. This study aimed to assess the potential of tree windbreaks to contribute to domestic timber and wood production. Methods: This study rests on a GIS-based analysis, in which tree lines (simulated by line shape files) were intersected with cropland area. The tree data to calculate timber and wood volumes stem from a dataset with 728 single trees from a relevant range of climatic conditions. Results: The potential annually available timber volumes from tree windbreaks with 500 m spacing are 2.9 million...
The floodplain ecosystems along the Naryn River in Kyrgyzstan still show largely natural dynamics... more The floodplain ecosystems along the Naryn River in Kyrgyzstan still show largely natural dynamics and represent a regional hotspot of biodiversity. For the local population, they provide important ecosystem services, such as the provision of firewood and pasture land, areas for recreation and protection against erosion. However, the intensive use of the forests endangers their persistence. In addition, several hydropower plants are a threat to the natural dynamics of the river system and its biodiversity. There is thus a conflict between energy supply for the local population, the development of the country through the expansion of hydropower, and the preservation of natural ecosystems and their biodiversity. Preserving the riparian forests along the Naryn River and creating sustainable alternatives for energy supply is the aim of the ÖkoFlussPlan project, which is funded by the Federal Ministry of Education and Research. This article summarizes the current situation in the Naryn re...
Evidence of climate change at geological time scales are long known, and are attributed to natura... more Evidence of climate change at geological time scales are long known, and are attributed to natural causes. However, climatic change since the mid-19th century is mostly attributed to anthropogenic causes, and specifically, to the increasing emissions of greenhouse gases. Climatic change has become particularly evident since the 1970s, with global temperatures increasing at faster rates and precipitations decreasing over extensive parts of the world (Masson-Delmotte et al., 2019). Over recent decades, record-breaking high temperatures and severe droughts on the one hand, with extremely powerful rainstorms and devastating floods on the other hand, have become the new “normal” weather regime (Bowen, 2015). While these new climatic patterns affect vast parts of the world, they are most prominent in dryland regions. Over the last decades, the world’s drylands have faced both aridity aggravation and territorial expansion into previously moister areas (Huang et al., 2016), consequently low...
Agroforestry Systems, 2022
Journal of Current Chinese Affairs, 2011
The Tarim River is the major water source for all kinds of human activities and for the natural e... more The Tarim River is the major water source for all kinds of human activities and for the natural ecosystems in the Tarim Basin, Xinjiang, China. The major water consumer is irrigation agriculture, mainly cotton. As the area under irrigation has been increasing ever since the 1950s, the lower and middle reaches of the Tarim are suffering from a water shortage. Within the framework of the Water Law and two World Bank projects, the Tarim River Basin Water Resource Commission was founded in 1997 in order to foster integrated water resource management along the Tarim River. Water quotas were fixed for the water utilization along the upstream and downstream river stretches. Furthermore, along each river stretch, quotas were set for water withdrawal by agriculture and industry and the amount of water to remain for the natural ecosystems (environmental flow). Furthermore, huge investments were undertaken in order to increase irrigation effectiveness and restore the lower reaches of the Tarim...
Earth System Dynamics Discussions, 2014
The Tarim River Basin, located in Xinjiang, NW China, is the largest endorheic river basin of Chi... more The Tarim River Basin, located in Xinjiang, NW China, is the largest endorheic river basin of China and one of the largest in whole Central Asia. Due to the extremely arid climate with an annual precipitation of less than 100 mm, the water supply along the Aksu and Tarim River solely depends on river water. This applies for anthropogenic activities (e.g. agriculture) as well as for the natural ecosystems so that both compete for water. The on-going increase of water consumption by agriculture and other human activities in this region has been enhancing the competition for water between human needs and nature. Against this background, 11 German and 6 Chinese universities and research institutes formed the consortium SuMaRiO (<a href="www.sumario.de"target="_blank">www.sumario.de</a>), which aims at gaining a holistic picture of the availability of water resources in the Tarim River Basin and the impacts on anthropogenic activities and natural ecosystem...
Earth System Dynamics Discussions, 2014
Naturally, the floodplains of Central Asian rivers harbour riparian, so-called ‘Tugai’ forests, r... more Naturally, the floodplains of Central Asian rivers harbour riparian, so-called ‘Tugai’ forests, reeds with Phragmites australis, and shrub communities which form a mosaic depending on the variety of available ground water. In recent decades, these natural ecosystems have been strongly altered anthropogenically or even completely destroyed. In order to restore those ecosystems, knowledge on vegetation, ecosystem dynamics, and natural regeneration processes is essential. In our study, we present results of ecological investigations at the Tarim River. We gathered comprehensive data on soil, vegetation, forest stand age, tree vitality, river course dynamics, and land use and brought it to the landscape level. Thus, recommendations are derived for the maintenance of these floodplain ecosystems, in particular with regard to their biological diversity.
Environmental Earth Sciences, 2016
Trees, Forests and People
Forests
Research Highlights: Despite a long tradition of using poplars as wood source across Central Asia... more Research Highlights: Despite a long tradition of using poplars as wood source across Central Asia, recent international breeding developments have not penetrated that region yet. This study therefore explored growth performance of 30 local and international poplar cultivars. Background and Objectives: The Central Asian countries are forest poor countries, which need to cover the domestic wood demand through costly imports. Therefore, fast growing trees, such as poplars, are gaining increasing attention as option to grow wood domestically. The most common cultivars date back to Soviet Union times. As recent breeding developments have not reached the region, this study aims at investigate the growth performance of a number of newly developed poplar cultivars. Materials and Methods: The investigated cultivars were planted as cuttings across nine sites in Kyrgyzstan, Kazakhstan, and Tajikistan between 2018 and 2020. Results: Under warm climate conditions, i.e., low elevations, P. deltoi...
Frontiers in Environmental Science
Soil salinization and sodification are common processes that particularly characterize drylands. ... more Soil salinization and sodification are common processes that particularly characterize drylands. These processes can be attributed either to natural conditions or anthropogenic activities. While natural causes include factors such as climate, lithology, topography, and pedology, human causes are mostly related to agricultural land-use, and specifically, to irrigated agriculture. The objective of this study was to thoroughly review this topic, while highlighting the major challenges and related opportunities. Over time, the extent of saline, sodic, and saline-sodic croplands has increased, resulting in accelerated land degradation and desertification, decreased agricultural productivity, and consequently jeopardizing environmental and food security. Mapping and monitoring saline soils is an important management tool, aimed at determining the extent and severity of salinization processes. Recent developments in advanced remote sensing methods have improved the efficacy of mapping and ...