Opportunities for an African greenhouse gas observation system

Global population projections foresee the biggest increase to occur in Africa with most of the available uncultivated land to ensure food security remaining on the continent. Simultaneously, greenhouse gas emissions are expected to rise due to ongoing land use change, industrialisation, and transport amongst other reasons with Africa becoming a major emitter of greenhouse gases globally. However, distinct knowledge on greenhouse gas emissions sources and sinks as well as their variability remains largely unknown caused by its vast size and diversity and an according lack of observations across the continent. Thus, an environmental research infrastructure—as being setup in other regions—is more needed than ever. Here, we present the results of a design study that developed a blueprint for establishing such an environmental research infrastructure in Africa. The blueprint comprises an inventory of already existing observations, the spatial disaggregation of locations that will enable to reduce the uncertainty in climate forcing’s in Africa and globally as well as an overall estimated cost for such an endeavour of about 550 M€ over the next 30 years. We further highlight the importance of the development of an e-infrastructure, the necessity for capacity development and the inclusion of all stakeholders to ensure African ownership.

Influence of Slope Gradient and Aspect on Soil Organic Carbon Content in the Region of Niš, Serbia

Topography-induced microclimate differences determine the local spatial variation of soil characteristics as topographic factors may play the most essential role in changing the climatic pattern. The aim of this study was to investigate the spatial distribution of soil organic carbon (SOC) with respect to the slope gradient and aspect, and to quantify their influence on SOC within different land use/cover classes. The study area is the Region of Niš in Serbia, which is characterized by complex topography with large variability in the spatial distribution of SOC. Soil samples at 0–30 cm and 30–60 cm were collected from different slope gradients and aspects in each of the three land use/cover classes. The results showed that the slope aspect significantly influenced the spatial distribution of SOC in the forest and vineyard soils, where N- and NW-facing soils had the highest level of organic carbon in the topsoil. There were no similar patterns in the uncultivated land. No significant differences were found in the subsoil. Organic carbon content was higher in the topsoil, regardless of the slope of the terrain. The mean SOC content in forest land decreased with increasing slope, but the difference was not statistically significant. In vineyards and uncultivated land, the SOC content was not predominantly determined by the slope gradient. No significant variations across slope gradients were found for all observed soil properties, except for available phosphorus and potassium. A positive correlation was observed between SOC and total nitrogen, clay, silt, and available phosphorus and potassium, while a negative correlation with coarse sand was detected. The slope aspect in relation to different land use/cover classes could provide an important reference for land management strategies in light of sustainable development.

Insecticide Residues in Cotton, Sorghum and Fallow Soil from the Nuba Mountains Cotton Corporation of South Kordofan State, Sudan

Background. Soil is the final depot of most environmental contaminants, including pesticides. Soil may be contaminated by pesticides as a result of direct application or drift during spray activities. Soil contamination with pesticide residues may affect the quality of food crops, animal products, and soil micro-organisms which may in turn negatively affect human health and the environment. Objectives. The main objective of the current study was to determine the soil residues of commonly used pesticides in rain-fed crops grown by the Nuba Mountains Cotton Corporation (NMCC) in South Kordofan state of Western Sudan. Methods. Four locations (representing the four directions around the state capital Kadugli) were chosen for sample collection: Alefain (East Kadugli), Elmashaish (West Kadugli), Ed Dalling uncultivated area (North Kadugli) and Lagawa (Southwest Kadugli). Nine soil samples were randomly taken from each location representing areas under cotton, sorghum, and uncultivated land covered with natural vegetation. Soil samples were analyzed by gas chromatography (GC) equipped with electron capture detector (ECD) and GC-mass spectrometry (MS). Results. The results generally indicated that organophosphate levels were greater than organochlorine and pyrethroids with heptachlor, malathion, and dimethoate present in all samples analyzed, while the level of p,p-dichlorodiphenyltrichloroethane (DDT) was below the detection limit. Endosulfan α and β isomers were detected in some samples. Dimethoate had the highest level (22.02 mg/kg), while β endosulfan was found at the lowest level (0.015 mg/kg). Generally, samples collected from cotton soils showed higher residue levels compared to sorghum soil with average concentrations of 307.25 mg/kg versus 58.63 mg/kg, respectively. Almashaish showed the highest residues levels followed by Alefain, Lagawa, and Ed Dalling with total residues of 57.56 mg/kg, 26.34 mg/kg, 22.63 mg/kg, and 17.07 mg/kg, respectively. Conclusions. The current study sheds light on the residue levels of some of the commonly used pesticides in the cotton rain-fed scheme in South Kordofan State, western Sudan. The study calls for regular residue monitoring in various environmental components in the area and suggests possible management measures. Competing Interests. The authors declare no competing financial interests.

Tree-Ring Analysis of Intermediate Hawthorn (Crataegus media Bechst.) in NW Poland

Intermediate hawthorn (Crataegus × media Bechst.) is broadly distributed in Europe but very rarely examined by dendrochronologists. In NW Poland, it is one of three naturally occurring hawthorn species, growing mainly at forest margins, along roads, in mid-field woodlots, and on uncultivated land. Biocenotically, it is a very valuable species. This study aimed to determine the age of trees, tree-ring dynamics, and growth–climate relationship for intermediate hawthorn. Signature years were also determined. Samples for analysis were collected from 22 trees growing in a typical agricultural landscape in a monospecific mid-field woodlot comprised of several hundred specimens of various ages and forms (shrubs and trees). Using classic methods of dendrochronological dating, a 40-year long chronology spanning 1981–2020 was constructed. The radial growth rate of intermediate hawthorn is comparable to other tree species forming stands in NW Poland and equals 2.41 mm/year. Considerable intersubject variability is noted, from 1.48 to 4.44 mm/year. The chronology was also used for dendroclimatological analyses, including correlation and response function and signature years. Of the meteorological parameters analyzed, annual incremental growth in hawthorn is the most strongly shaped by precipitation totals from May to August of the current vegetation year: high rainfall favors the formation of wide tree-rings. Statistically significant growth–climate relationships were also obtained for winter months (December of the preceding vegetation year, January and February), for which period negative correlation and regression values are noted for air temperature and insolation. Furthermore, high precipitation, low-temperature and low insolation late in the preceding vegetation year (especially in August) make a positive influence on the condition of trees in the upcoming growing season. Signature year analysis clearly pointed to precipitation as the dominant factor in shaping tree-rings in the studied hawthorn population. As there are no dendrochronological papers concerning indigenous hawthorn species, future studies should be expanded to include diverse geographic locations and habitat conditions and should include all three species of hawthorn occurring in Poland.

Weedness of uncultivated land in the Polessye zone of Ukraine

Goal. Clarification of the species of vegetation on uncultivated lands of Polessye, Zhytomyr region, which have been withdrawn from agricultural use for a long time. Methods. Field research, expedition — route observations, statistical analysis. Monitoring of vegetation of lands that came out of agricultural use and the study of species of plant groups was carried out during 2011—2015 in the southern Yemilchyn and Novohrad-Volynskyi and northern — Ovruch and Narodytsky districts of Zhytomyr region. Results. The vegetation cover of uncultivated lands of Polessye part of Zhytomyr region has been studied. During the years of non-use of land in agricultural circulation, separate micro-groups of plants have been formed, the area of which is gradually increasing. Six microgroups belonging to two associations were identified and studied. The first association of Poo-Festucetum pratensis was on a close-knit medium-high mane, which included three microgroups with a predominance of meadow oatgrass, meadow clover, and common viper. The second association, Poopalustris-Alopecuretum pratensis, was found on lowland plains and included microgroups with a predominance of meadow foxtail, mouse pea, and northern butterbur. It was determined that both plant groups of the surveyed areas were dominated (according to Raunkier) by hemicryptophytes — plants whose buds are at ground level or submerged up to 5 cm — 87.1 % in the southern and 91.3 % in the northern regions of Zhytomyr region. A smaller number of 3.2 and 8.7 % are hamephytes — plants whose buds are 20—30 cm above ground level. Conclusions. It has been established that uncultivated lands of the Polessye part of Zhytomyr region, under the influence of natural factors, are intensively transformed into unsuitable lands and reserves of malignant weeds, which cause a steady risk of constant threat of their spread to arable lands. Vegetation of lands withdrawn from agricultural use includes in the southern regions of Zhytomyr region. — Yemilchynsky and Novograd-Volynsky groups of weeds of 23 species from 21 genera, 13 families, in the northern districts — Ovruch and Narodytsky — 31 species from 26 genera, 11 families.

Margaret Atwood: A Sound Ecologist

This paper is an attempt to explore the ecological issues in Margaret Atwood’s novels. She happens to raise her voices against the demolition of the forests, advocating very strongly to pay attention to ecological principles for the preservation of the environment for the future generation. She tends to express her deep sense of anxiety over the ecological issues as depicted in The Handmaid’s Tale (1985) and again in the stories and fables of Wilderness Tips (1991) and Good Bones (1992). Her novel – Surfacing (1972) begins and ends with the forest starting like a detective story. Her most significant search-operation begins when she happens to dive into the lake, looking for the Indian rock paintings recorded in her father’s drawings in chapter 17 of the novel. Environment or wilderness strongly figures out in her fabric of Canadian identity. It has multiple functions : as a marker of geological location, as a spatial metaphor and as a popular cultural myth of Canada. Geographically, it is defined as ‘wild uncultivated land’. She rediscovers the White English – Canadian construction of identity, charting a distinctive New World positioning in relation to history, geography and culture suggestive of continuity between immigration narratives and a contemporary awareness of psychic location. Environment holds a very significant place in her portrayal of Canadian identity. She personally holds a bitter experience of Colonialism and its outcome on Canada and Canadians in the post-colonial era. Her fiction comprises of several post-colonial themes such as survival, hybridization, isolation, hegemony, displacement, loss of identity, banishment, multiculturalism, homelessness, colonization of the mind and of the natural world. Thus this paper seeks to analyze the different shades of ecology and ecocriticism exploring the organic unity between the man and the environment. This theory has gained a great importance since last few years. The ecological balance between the human and environment is shattered. People have deviated from their moral duties towards nature. Thus as a sound observer of ecology, she finds out the misuse and colonization of the natural world.

Defining Targets for Reversing Declines of Soil Carbon in High-Intensity Arable Cropping

Soil organic carbon (SOC) is declining globally due to intensification of agriculture. Reversing declines should reduce soil erosion, maintain yields, raise the soil’s atmospheric carbon sink, and improve habitat for biodiversity. Commercial fields were sampled in a diverse European Atlantic zone cropland to relate SOC status to cropping intensity and to define a realistic target for restoration. SOC (%C by mass) decreased from 4% to 2% as the proportion of high-intensity crops increased from zero to 55% (linear regression, F pr. < 0.001). In further sampling in and around high-intensity fields, mean SOC increased from 2.4% in cultivated soil to 3.3% in field margins and 4.8% in nearby uncultivated land (F pr. < 0.001). Three broad zones of SOC in close spatial proximity were then defined: 1) high-intensity arable from 1% to 3%, 2) mid-intensity arable and arable-grass from 3% to 5% and 3) uncultivated and semi-natural land from 5% upwards. C:N ratio was constrained around 12, unaffected by cropping intensity, but slightly lower in fields than in margins and uncultivated land (F pr. < 0.001). A feasible target SOC of just above 3% was defined for high-intensity sites. There should be no biophysical obstacle to raising SOC above 3% in the high-input sector. Results argue against treating cropland of this type as uniform: assessment and restoration should be implemented field by field.

PLANTS COVERING INFLUENCE TO THE RADIOISOTOPES EXISTENCE OF Cs-137 AND Pb-210 IN THE SOIL

PLANTS COVERING INFLUENCE TO THE RADIOISOTOPES EXISTENCE OF 137Cs and 210Pbex IN THE SOIL. Cs-137 and Pbex-210 of environmental radioisotope content in the soil can be useful to estimate the rate of erosion/deposition in an area, by comparing the inventory value of Cs-137 or Pbex-210 in observed site with those in a stable reference site. Cs-137 and Pbex-210 stick very strongly at the surface of the soil (clay), so it can use as a tracer for the movement of soil. Plants very influence the existence of Cs-137 and Pbex-210 environmental radioisotopes as a cover. If without a plant cover, then this environmental radioisotope at the soil would be gone by rain off. This experiment aims to observe the effect of plant cover on the existence of Cs-137 and Pbex-210 at the soil in uncultivated land. Sampling had been done in two uncultivated lands when the land still covering by plants (2016) and after becoming vacant land (2018), using coring (10 cm) for the surface layer and coring (7 cm) for the depth of 20 cm. The result showed that the activity of 137Cs and 210Pbex environmental radioisotopes at the surface layer decreased very significantly, and total inventory values until the depth of 20 cm decreased quite significantly at a vacant land condition. The corrosion rate for the vacant land is higher than the planted land. The value of erosion rate using the 137Cs method is 44.1 t/ha.y (CBG); -4.3t/ha.y (BMC) and 4 t/ha.y (CBG); -27.1 t/ha.y (BMC) for planted land and vacant land, respectively. Meanwhile, using the 210 Pb ex method is -8 t/ha.y (CBG); -36.9 t/ha.y (BMC) for planted land and -58 t/ha.yrs (CBG), -79.9 t/ha.yrs (BMC) for vacant land.

INVESTIGATING OF FOREST CHANGE IN GOLESTAN PROVINCE USING LANDSAT IMAGE

In recent years, forests in the north of the country have been attacked due to human interference. Increasing population and development of residential and agricultural areas have led to deforestation. Change detection is one of the most common methods for evaluating natural resources. The aim of this study is to monitor changes in forests of Golestan province in two period times from 1990 to 2019, using Landsat images. Accordingly, by incorporating those data sets land use maps are produced. Also, the SVM algorithm is used with six different classes including forest (F), urban area (U), agriculture (A), uncultivated land (UL), water (w) and bare soil (BS). The achieved overall accuracies are 85.48% and 89.86%. Then the map and matrix changes were obtained by post-classification comparison method. The results showed that the Golestan province's forests were reduced and converted to agricultural and urban land uses.