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tom 12
147-153
EN
First elaborations on desertification come from the Renaissance, but the term was used for the first time by Aubreville in 1949. In later years, many significantly varying in meaning definitions were elaborated. In later periods, researchers' attention concentrated on different areas. At the turn of the XIXth century, interest was mainly focused on Asia, later on the peripheries of the Sahara, in recent years on desertification in post-soviet Central Asia, China and Mongolia.
EN
The research sought to evaluate the normalized difference vegetation index (NDVI) of the study area located in the province of Tayacaja, which includes the districts of Acraquia, Ahuaycha, Pampas and Daniel Hernández, which is part of the central Andes of Peru. The data were collected in low water seasons with a longitudinal cut of 30 years with one sample per year, starting in 1993 until 2022; these samples corresponded to the month of August of each year. The images were extracted from maps from Landsat satellite databases, which were filtered for low cloud cover to avoid interference with the images. Maps from 1993 to 2012 were obtained from Landsat 5 satellite, while from 2013 to 2022 data were obtained from Landsat 8 satellite. The normalized difference vegetation index was determined using Quantum GIS based on the red and near infrared maps; being the minimum NDVI value obtained -0.18, which corresponds to the aquatic body of the Upamayu River that crosses from west to east the study area; while the highest NDVI obtained was 0.79 indicating a greater vegetation cover constituted by mainly eucalyptus plants. The mean NDVI of the 30 years is close to 0.21; this is an indicator that the vegetation is scarce and that it is decreasing mainly due to population growth.
EN
The subject of the article is an analysis of changes in the environment and economy of oases in southern Morocco, on the basis of a case study of Mhamid. The conclusions are that water investments carried out in the Draa Valley intensified the desertification process. This is exemplified by a stronger aeolian deflation, worsening living conditions of the population, limiting of arable areas and finally, migration. Paradoxically, because of desertification, the region has a chance to develop economically because the newly created sand dunes fields stimulate development of tourism.
EN
The Xilin Gol area is located in central Inner Mongolia, China. It had been a fertile prairie in northern China, but desertification and sand storms have increased in past decades. This study shows the spatial and temporal distribution of sand storms in the Xilin Gol area. The results of the analysis show: (i) Factors such as strong winds (usually beyond seven levels), rain and temperature have an impact on sand storms. The correlation coefficient between sand storm days and strong wind days is 0.89. (ii) There are more sand storm days in the west than in the east. (iii) In the last 30 years, the frequency of sand storms have been consistently decreasing.
PL
Istotnym problemem współczesnego azerbejdżańskiego rolnictwa w warunkach gospodarki rynkowej jest przygotowanie bazy paszowej odpowiedniej do rozwoju chowu zwierząt, z wykorzystaniem całorocznego wypasu pastwiskowego, który zapewnia odpowiednią ilość pasz objętościowych. Postępujące globalne ocieplenie uznawane jest za jedną z przyczyn postępujących procesów erozji i pustynnienia rozległych terenów wypasowych. Wyniki doświadczeń zaprezentowanych w pracy sugerują sposób polepszania walorów wypasowych zimowych pastwisk, a także tworzenia warunków, zapobiegających erozji i poprawiających żyzność gleb. Dzięki zastosowaniu zabiegów uprawowych, polegających na wysiewie motylkowato-trawiastych mieszanek i nawożeniu mineralnym N30P30K30, polepszono warunki wilgotnościowe gleb i ich zasobność w składniki pokarmowe, a szczególnie w azot. Doświadczenia umożliwiły również rozpoznanie dynamiki powstawania w glebie amonowych i azotanowych form azotu w okresie wiosenno-letnio-jesiennym.
EN
An important issue of current Azerbaijan agriculture under market economy is to prepare food base for animal breeding using year-long pasture grazing which provides sufficient amount of bulk fodder. Proceeding global warming is considered one of the reasons for erosion and desertification of vast pasturelands. Results of experiments presented in this paper suggest a way of improving the grazing value of winter pastures, preventing erosion and increasing soil fertility. Soil moisture and nutrient abundance (particularly nitrogen) were improved after sowing legume-grass mixtures and mineral fertilisation with N30P30K30. The experiments allowed also for understanding the dynamics of ammonium ions and nitrates in soil from spring to autumn.
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tom 60
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nr 2
EN
In arid and semi-arid areas, heavy grazing combined with climate change cause land degradation (e.g., desertification). Grazing management is essential for ecosystem recovery and desertification control in these areas, including Northern China’s Horqin Sandy Land. However, the recovery of soil faunal community during grazing exclusion is unknown. We examined plant and soil macro-invertebrate community structure together with soil properties in three treatments in a representative degraded Horqin sandy grassland: exclosure for 15 and 10 years (15EX and 10EX) and long-term continuous grazing (CG). The vegetation cover and height increased significantly and soil bulk density decreased significantly along the gradient from CG to 15EX, but there were no significant differences in soil pH, electrical conductivity, organic carbon and total nitrogen. Soil macro-invertebrate abundance, group richness and diversity increased along the gradient from CG to 15EX, with significant differences in invertebrate abundance and group richness between CG and 15EX; there was no significant differences between CG and 10EX. There were no significant differences in soil macro- invertebrate diversity and evenness between these three treatments. These results suggested that grazing exclusion for at least 15 years might be necessary for the recovery of these fauna. The vegetation height and the soil electrical conductivity, organic carbon, and total nitrogen determined the distribution and community structure of soil macro-invertebrates. Some faunal groups lived in specific habitats due to strong adaptation to different management practices. For example, the Thomisidae, Philodromidae, Salticidae, and Rhopalidae tended to live in habitats with tall vegetation. The Lygaeidae, Miridae, Teneberionidae, and Linyphiidae adapted to live in soil with low soil organic carbon and nitrogen (ungrazed grassland).
EN
Desertification, which affects more than two-thirds of the world's arid and semi-arid regions, is a significant global ecological and environmental problem. There is a strong link between desertification of the drylands and emission of CO₂ from soil and vegetation to the atmosphere. The Horqin Sandy Land is a severely desertified area in China's agro-pastoral ecotone due to its fragile ecology, combined with unsustainable land management. We estimated changes of organic carbon content in the bulk soil (0–5 cm), in the light-fraction of soil organic matter (based on density fractionation), and in the various particle-size fractions in areas with mobile sand dunes after implementing grazing exclusion (12 and 27 years) and tree and shrub planting (22 and 24 years). Carbon stocks in the bulk soil and all soil density and particle-size fractions increased significantly in the exclosure and plantation plots. The average rates of carbon accumulation in the bulk soil in the exclosure and plantation plots were 16.0 and 17.8 g m⁻² y⁻¹, respectively, versus corresponding values of 2.3 and 7.1 g m⁻² y⁻¹ for the light fraction, 4.3 and 8.0 g m⁻² y⁻¹ for the coarse fraction, 5.0 and 3.4 g m⁻² y⁻¹ for the fine sand, 4.5 and 4.2 g m⁻² y⁻¹ for the very fine sand, and 1.8 and 1.8 g m⁻² y⁻¹ for the silt clay fraction. The older the exclosure and plantation, the more carbon accumulated in the bulk soil and in each fraction. The carbon pool exceeded the level in non-desertified grasslands after 27 years of grazing exclosure and 24 years of the shrub plantation. Our results suggest that both grazing exclusion and planting trees and shrubs can restore desertified grassland, creating a high potential for sequestering soil carbon, but that the plantations appeared to accumulate soil carbon faster than the exclosures.
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2020
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nr 5
185-195
EN
The article presents trends that will determine contemporary challenges and threats to state security. With the development of descriptive works and explanations of non-military security, ecology is becoming a more and more frequently described issue. As regards the limitation of ecological safety, climate change is indicated as one of the key security megatrends in the 21st century. In the article the term determining ecological safety presents the challenges that must be acknowledged and faced in order to effectively create safety.
PL
W niniejszym artykule przedstawiono zagrożenia dla bezpieczeństwa ekologicznego. Cel postawiony przez autora realizowany jest poprzez analizę historyczną dokumentów i raportów zogniskowanych wokół problematyki ekologii. Ważnym zjawiskiem jest rozwój prac opisujących i objaśniających bezpieczeństwo pozamilitarne. W powyższych publikacjach ekologia staje się coraz częściej opisywanym zagadnieniem i wpływa na właściwą – szerszą – optykę na sprawy bezpieczeństwa. O wpływie bezpieczeństwa ekologicznego świadczy fakt, iż zmiany klimatyczne są wskazywane jako jeden z kluczowych megatrendów bezpieczeństwa w XXI wieku. W artykule opisano determinanty bezpieczeństwa ekologicznego, ukazano wyzwania, które należy dostrzec i którym trzeba sprostać, aby skutecznie kreować bezpieczeństwo na wielu poziomach.
EN
Desertification, which affects more than two-thirds of the world’s arid and semi-arid regions, is a significant global ecological and environmental problem. There is a strong link between desertification of the drylands and emission of CO2 from soil and vegetation to the atmosphere. The Horqin Sandy Land is a severely desertified area in China’s agro-pastoral ecotone due to its fragile ecology, combined with unsustainable land management. We estimated changes of organic carbon content in the bulk soil (0–5 cm), in the light-fraction of soil organic matter (based on density fractionation), and in the various particle-size fractions in areas with mobile sand dunes after implementing grazing exclusion (12 and 27 years) and tree and shrub planting (22 and 24 years). Carbon stocks in the bulk soil and all soil density and particle-size fractions increased significantly in the exclosure and plantation plots. The average rates of carbon accumulation in the bulk soil in the exclosure and plantation plots were 16.0 and 17.8 g m-2 y-1, respectively, versus corresponding values of 2.3 and 7.1 g m-2 y-1 for the light fraction, 4.3 and 8.0 g m-2 y-1 for the coarse fraction, 5.0 and 3.4 g m-2 y-1 for the fine sand, 4.5 and 4.2 g m-2 y-1 for the very fine sand, and 1.8 and 1.8 g m-2 y-1 for the silt+clay fraction. The older the exclosure and plantation, the more carbon accumulated in the bulk soil and in each fraction. The carbon pool exceeded the level in non-desertified grasslands after 27 years of grazing exclosure and 24 years of the shrub plantation. Our results suggest that both grazing exclusion and planting trees and shrubs can restore desertified grassland, creating a high potential for sequestering soil carbon, but that the plantations appeared to accumulate soil carbon faster than the exclosures.
EN
We constructed an aeolian soil database across arid, semi-arid, and dry sub-humid regions, China. Soil particle size distribution was measured with a laser diffraction technique, and fractal dimensions were calculated. The results showed that: (i) the predominant soil particle size distributed in fine and medium sand classifications, and fractal dimensions covered a wide range from 2.0810 to 2.6351; (ii) through logarithmic transformations, fractal dimensions were significantly positive correlated with clay and silt contents (R2 = 0.81 and 0.59, P < 0.01), and significantly negative correlated with sand content (R2 = 0.50, P < 0.01); (3) hierarchical cluster analysis divided the plots into three types which were similar to sand dune types indicating desertification degree. In a large spatial scale, fractal dimensions are still sensitive to wind-induced desertification. Therefore, we highly recommend that fractal dimension be used as a reliable and quantitative parameter to monitor soil environment changes in desertified regions. This improved information provides a firm basis for better understanding of desertification processes.
EN
This paper aims at assessing the challenges for sustainable forest management in China. The Communist government is going to improve the essential ecosystem by restoring severely degraded forests. It wants to enhance the biodiversity of natural systems as well as prevent, control and reverse desertification. It defines actions that could be taken to prevent deforestation and land degradation. The forest policy focuses on environmental protection and emphasizes the ecological and socio-economic functions of forests resources. It mainly underlines their protective and regulatory functions to sequester carbon by capturing carbon dioxide from the atmosphere. Currently, China has to primarily improve the implementation and enforcement of existing laws and regulations at the local level as well as raise environmental awareness of Chinese community.
PL
Głównym celem opracowania jest zdefiniowanie wyzwań dla zrównoważonej gospodarki leśnej w Chinach. Komunistyczny rząd dąży do przywracania podstawowych funkcji ekosystemu poprzez sadzenie drzew. Dąży do zwiększenia różnorodności biologicznej i odwrócenia procesu pustynnienia. Określa działania, które mogą być podjęte w celu zapobiegania wylesianiu i degradacji gruntów. Polityka leśna skupia się na ochronie środowiska jak również podkreśleniu ekologiczno-przyrodniczych, społecznych i gospodarczych funkcji leśnych ekostemów. Drzewa spełniają funkcję ochronne pochłaniając i neutralizując substancje toksyczne, tj. dwutlenek węgla w procesie fotosyntezy. Obecnie przed Chinami stoi konieczność poprawy skuteczności w zakresie wdrażania i egzekwowania prawa ochrony środowiska na szczeblu lokalnym, jak i kwestia systematycznego podnoszenia świadomości ekologicznej wśród obywateli Państwa Środka.
EN
We compared soil properties beneath naturally-occurring patches of Lycium ruthenicum Murray (fam. Solanaceae) to evaluate the shrub’s potential to improve the fertility of saline soils. Soil pH, total nitrogen and carbon and extractable potassium, magnesium and phosphorus were respectively significantly higher in the A and B horizons of Lycium shrub patches compared to adjacent unvegetated soils. The influence of Lycium on these soil properties increased with shrub density. Total soil N and extractable Mg and K concentrations were 1.8, 2.6- and 6.6-fold higher under dense Lycium shrub patches compared to unvegetated, bare areas and soil pH was 0.5 units higher. In contrast, the presence of shrubs and shrub density had no clear affect on the EC, Na or CEC of the A horizon soils. The shrub effect extended to the gypsum-rich By horizon (20–50 cm depth) and underlying B horizon (30–80 cm depth) for several soil properties. Total soil C and N were 1.8- and 1.6-fold higher beneath dense Lycium patches than bare soil areas. Soil pH remained 0.4 units higher under dense Lycium than bare soil patches. In the B horizon total soil C was twice as high beneath dense Lycium patches compared to the other patch types. Lycium ruthenicum not only tolerates the saline and drought conditions, it also produces sufficient biomass to increase the nutrient and organic matter content of surface mineral soils in this arid ecosystem and may have potential to improve soil conditions, facilitate ecosystem development and slow desertification.
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2017
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tom 65
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nr 2
EN
The present paper attempts to evolve a new model by considering various indicators of different types of land degradation or desertification, namely, water erosion, soil salinity, vegetation degradation, and lowering of ground water table for finding areas with higher rate of degradation. The Runiz basin, located in the southern Iran, has been selected as a study area to assess the hazard of desertification. The thresholds for the severity classes of indicators were established and then the hazard map for each indicator of types of desertification has been prepared in a GIS. The risk classes of different risk maps were calculated on the basis of classification of risk scores derived by cumulative effect of all the attributes of indicators after overlying them in the GIS. It was possible to distinguish the areas under ‘actual risk’ from areas under ‘potential risk’ of desertification types. Also areas under potential risk were classified to subclasses with different probability level to show a statistical picture of risk in future. The final map of risk of desertification was produced by overlaying all four maps of degradation types. Results show that potential risk areas and areas under actual risk are almost equal, indicating further threat of desertification in future in the half of the region. Also severe condition in the half of region shows environmentally bad situation in the study area. It is hoped that this attempt using GIS will be found applicable for other regions of the world.
EN
Drought poses one of the most important environmental constraints to plant survival and productivity and by implication-food insecurity in the tropics. Pigeon pea (Cajanus cajan) has the potential of fertilizing the soil thereby improving agricultural production and ensure green environmental and ecosystem stability. Despite the ability of the plant to improve soil fertility and promote greening environment, it has not attracted adequate awareness as a soil improvement plant. This paper highlights the information on the plant in order to intensify awareness for its widespread adoption to achieve the much desired sustainable resource use for greening our economy and environmental management. The successful widespread adoption of the plant will translate to effective drought, desertification and sustainable climate change mitigation approach in Nigeria.
EN
The present paper attempts to evolve a new model by considering various indicators of different types of land degradation or desertification, namely, water erosion, soil salinity, vegetation degradation, and lowering of ground water table for finding areas with higher rate of degradation. The Runiz basin, located in the southern Iran, has been selected as a study area to assess the hazard of desertification. The thresholds for the severity classes of indicators were established and then the hazard map for each indicator of types of desertification has been prepared in a GIS. The risk classes of different risk maps were calculated on the basis of classification of risk scores derived by cumulative effect of all the attributes of indicators after overlying them in the GIS. It was possible to distinguish the areas under ‘actual risk’ from areas under ‘potential risk’ of desertification types. Also areas under potential risk were classified to subclasses with different probability level to show a statistical picture of risk in future. The final map of risk of desertification was produced by overlaying all four maps of degradation types. Results show that potential risk areas and areas under actual risk are almost equal, indicating further threat of desertification in future in the half of the region. Also severe condition in the half of region shows environmentally bad situation in the study area. It is hoped that this attempt using GIS will be found applicable for other regions of the world.
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