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Background and purpose The fertility of anthropogenic soils developed from dumpsites used for arable fields is not well-studied. The study aimed to evaluate the fertility of anthropogenic soils from an abandoned dumpsite in Awotan, Nigeria, by measurable indicators and the bioaccessibility of elements of selected plant species. Methods The study adopted multi-analytical approaches to determine the signatures of the soils and further parameterized the bioaccessibility of elements to plants. Results The comparatively high content of Ca and Na in the anthropogenic soil contributed to the slightly alkaline soil reaction against the slightly acidic control. The high amount of organic matter is well-indicated by the enrichment of organic C and N in the anthropogenic soil. Waste deposition significantly contributed to the high accumulation of macronutrients (P, Ca, K, S) and micronutrients (Mn, Na, Fe) sufficient for maximum plant growth and yields, with an adequate C/N ratio supporting effective mineralization. The high cation exchange capacity of the anthropogenic soil contributed to cations binding. Indiscriminate waste deposition resulted in a high accumulation of potentially toxic elements (PTEs; Cu, Zn, As, Cd, Pb) above permissible limits in agricultural soils following WHO limits. Potential effects on lives are evident in the high PTEs accumulation in roots and leaves of Chromolaenaodorata, Saccopetalumtectonum, Passiflorafoetida, and Sennasiamea. These plant species exhibited various PTEs accumulation, especially for Cd and Pb. Conclusion Although anthropogenic soils remained fertile, the bioaccessibility of PTEs by plants indicates potential threats to consumers of crops and herbs produced from such sites.

The fertilizer values of ashes from commonly used woody species in the tropics are not well-known. To determine whether ashes of Theobroma cacao, Persea americana, Cola nitida, Mangifera indica, Citrus sinensis, Prunus dulcis, and Senna siamea are suitable fertilizers, we studied the contents of total and plant-available elements. Ashes of dry wood samples burnt at 500 °C were digested in Aqua-regia and Mehlich-3 extractants to determine the contents of total and plant-available elements, respectively, with inductively coupled plasma-mass spectrometry. Ash yields ranged from 3.1 to 7.1% with pH (H2O) of 7.8–12.9. The ashes contained high P, Ca, K, Mg, S, Fe, Na, Mn, Cu, and Zn contents, with significant effects among the species. Total element content ranged from (g kg−1) 2–49 P, 19–218 Ca, 64–325 K, 48–95 Mg, 0.4–16 Fe, 3.6–29 Na, (mg kg−1) 143–798 Mn, 52–81 Cu, and 188–312 Zn. Available plant elements ranged from (mg kg−1) 22–512 P, 37,491–88,303 K, 2948–19,713 Ca, 13,719–29,001 Mg, 75–168 Mn, 40–74 Cu, 44–91 Zn, 1.5–383 Fe, and 836–6937 Na. The releasability (proportion of plant-available elements from the total) ranged from 0.08 to 92.8%. The relatively high releasability (25.4–80.4%) of Ca, K, Mg, Mn, Cu, and Zn in the ashes of the over-all species can supplement low nutrient availability for plants. The low releasability of P (1.1%) of the overall species explains its persistence in soils applied with ashes. The high yield of the ashes and pH support their ideal use, especially for very acidic soils. Ashes of the studied species are suitable fertilizers for soils according to the availability and releasability of macro(P, Ca, K, Mg S) and microelements (Mn, Cu, Zn, Fe, Na). Total and plant-available Ni, Pb, As, and Cd contents in the ashes were below permissible limits in soils. Thus, the studied ashes are especially suitable for soils with high acidity and low fertility.

Law enforcement in protected areas is critical for ensuring long-term conservation and achieving conservation objectives. In 2004, patrol-based monitoring of law enforcement was implemented in protected areas in Ghana. Here, we evaluate long-term trends and changes in patrol staff performance, and illegal activities, in the Kogyae Strict Nature Reserve. The assessment was based on ranger patrol-based monitoring data collected during January 2006–August 2017. Along the patrol routes, patrol officers recorded all encounters with illegal activities associated with hunting and capturing or harming of animals. Across all years, staff performance was lowest in 2006 as staff learned the system but increased in 2007 and peaked in 2010, the latter as a result of motivation of the patrol staff. After 2011, staff performance decreased, mainly because of the retirement of some patrol staff and insufficient logistical support for successful patrolling. Snares were the most commonly recorded indicators of illegal activity. Because their use is silent, poachers using snares are less likely to be detected than poachers using other forms of hunting. Long-term assessment of patrol-based monitoring data provides reliable information on illegal activities related to wildlife, to enable stakeholders to design effective measures for biodiversity conservation. Our assessment indicates that patrol staff performance in Kogyae is, at least partly, dependent on governmental or external support and incentives, in particular the provision of equipment and transport facilities.

The analysis of minor/microelements in anthropogenic soils resulting from past settlement activities in different environmental conditions and geographical regions is not well-known. The study aimed to determine whether minor/microelements are suitable proxy indicators of past human activities of Archaeological Dark Earth (ADE) soils from two past hilltop settlements- Ziavi-Galenkuito in Ghana and Dřevic hillfort, Czech Republic. Total and plant-available (Mehlich 3) contents of minor/microelements were determined using portable X-Ray Fluorescence spectrometry and Inductively coupled plasma mass spectrometry, respectively. The black color of the soils from Ziavi-Galenkuito and Dřevic hillfort contrasted the brownish Ferric Acrisol and greyish Luvic Cambisol control, respectively. The contents of total and plant-available Cu, Zn, Mn, Sr, and total Rb was substantially higher in both sites compared to their control of the same geological substrates. The highest total and plant-available Mn content in Ziavi-Galenkuito may indicate specific intensive settlement activities in a comparatively shorter duration. The highest total Cu, Zn, Sr, and Rb content in the soil from Dřevic hillfort compared to Ziavi-Galenkuito related to longevity and intensity of the past human activities. Total Cu, Zn, Mn, and Sr can well reflect past human activities from different geographical regions according to their significant correlations from both studied sites. Except for Mn and Sr, total and plant-available content of Cu and Zn were not well correlated. Except for Mn and Sr, total and plant-available content of Cu and Zn were not well correlated. In the calculation of enrichment factors in ADE soils for geoarchaeological purposes, total Mn, Cu, Zn, and Sr are more suitable. Enrichment by minor/microelements can be reliable enough in predicting past human activities in ADE soils of different geology and climatic conditions, even after hundreds of years.

Archaeological Dark Earth soil is a category of archaeological anthrosols that has gained much attention because it exhibits higher nutrient content and organic matter stocks and a characteristic dark colour, and enables higher crop yields in comparison to neighbouring soil. However, much is unknown about the chemical properties of Archaeological Dark Earth soils in Central Europe. Therefore, we studied a European Dark Earth (EDE) soil, a type of Archaeological Dark Earth soil, in the territory of the early medieval Dřevic hillfort, Czech Republic, aiming to compare the chemical properties of EDE with a control soil unaffected by settlement activities. The black colour of EDE soil contrasted highly with the light grey Cambisol of the control. Soil reaction and total element contents (N, P, Ca, Mn, Fe, Al, Cu, Zn, Sr and Rb) were substantially larger in the EDE soil compared with the control and vice versa in the case of the C/N ratio. Also, the content of plant‐available (Mehlich III) P, Ca, K and Mg was larger in the EDE soil than the control. In contrast to Ca, plant‐available and total P and K were not well correlated. Total element contents are highly suitable for geoarchaeological purposes as enrichment factors can be easily calculated. The increased contents of these elements, together with pieces of charcoal visible in the EDE soil, indicate the deposition of organic waste and biomass ash during the existence of the hillfort. Thus, medieval hillforts can represent extraordinary nutrient‐rich islands in the cultural landscape of Central Europe. The chemical signatures generated by past settlement activities are so intense that they cannot easily be masked by short‐term intensive application of mineral fertilizers. HIGHLIGHTS: Settlement activities increased soil pH and the content of anthropogenic elements. Enrichment by P, Ca, Mn, Fe, Al, Zn, Cu, Sr and Rb may indicate settlement activities. Analysis of total element contents is suitable for geoarchaeological purposes. Application of mineral fertilizers cannot easily mask signatures of medieval settlement activities.

The study used scattered literature to summarize the effects of excess Cd, As, and Pb from contaminated soils on plant secondary metabolites/bioactive compounds (non-nutrient organic substances). Hence, we provided a systematic overview involving the sources and forms of Cd, As, and Pb in soils, plant uptake, mechanisms governing the interaction of these risk elements during the formation of secondary metabolites, and subsequent effects. The biogeochemical characteristics of soils are directly responsible for the mobility and bioavailability of risk elements, which include pH, redox potential, dissolved organic carbon, clay content, Fe/Mn/Al oxides, and microbial transformations. The radial risk element flow in plant systems is restricted by the apoplastic barrier (e.g., Casparian strip) and chelation (phytochelatins and vacuole sequestration) in roots. However, bioaccumulation is primarily a function of risk element concentration and plant genotype. The translocation of risk elements to the shoot via the xylem and phloem is well-mediated by transporter proteins. Besides the dysfunction of growth, photosynthesis, and respiration, excess Cd, As, and Pb in plants trigger the production of secondary metabolites with antioxidant properties to counteract the toxic effects. Eventually, this affects the quantity and quality of secondary metabolites (including phenolics, flavonoids, and terpenes) and adversely influences their antioxidant, antiinflammatory, antidiabetic, anticoagulant, and lipid-lowering properties. The mechanisms governing the translocation of Cd, As, and Pb are vital for regulating risk element accumulation in plants and subsequent effects on secondary metabolites.

Background and aimsRumex alpinus is a native plant in the mountains of Europe, whose distribution is affected by its utilization as a vegetable and medicinal herb. The distribution of micro and risk elements in its organs and the possibility for phytoremediation are not well-known. We aimed to examine the safety of consuming R. alpinus from the Krkonoše Mountains, Czech Republic, and Alps (Austria and Italy).MethodsWe determined the total and plant-available concentration of Fe, Zn, Cu, Mn, Al, As, Cr, Ni, Pb, and Cd in the soil and total concentration in the organs of R. alpinus using inductively coupled plasma-optical emission spectrometry.ResultsThe uptake and distribution of elements by plants were characterized by bioaccumulation and translocation (TF) factors. The intensity of elements accumulation by R. alpinus is considerably different, depending on locality. R. alpinus has considerable tolerance to Zn, Cu, As, Cr, Ni, with easy accumulation strategy. High Al and Cd concentration in belowground biomass (rhizome) indicates a defensive mechanism for them. Although the aboveground biomass (emerging, senescent, mature leaves, petiole) has some degree of accumulation of risk elements, R. alpinus is potentially suitable for phytoremediation of moderately contaminated soils. The results revealed that R. alpinus excludes Al, with high TF for Mn, Zn, Cu, As, Ni, and Pb. Given the accumulation of As and Cr, we recommend caution in its usage.ConclusionDetailed elemental analysis of R. alpinus organs is recommended before its application as medicinal herb or food, especially in contaminated soils.

The socio-economic needs of ancient societies before the onset of the industrial revolution thrived the exploitation of metals, with resultant adverse effects on the chemical signatures of soils. So far, there are no studies that summarize the contamination of soils by metals due to mining and metallurgy before the industrial revolution (c. 1800 century AD). The article presents an overview of soil contamination by metals due to ancient (prehistory up to the end of medieval period) mining and metallurgy, the global distribution of metal exploitations, the effects on soils and lives, as well as their speciation and bioavailability. The study established that the concentrations of Cu, Ag, Pb, Hg, and Zn were substantially higher in the soils affected by ancient mining and metallurgy in comparison to background values, eventually causing harm to ecosystems after centuries without mining and metallurgy. The concentrations of the metals subsequently are bioaccumulated in recent fields. Understanding the persistence, distribution, and bioavailability of the metals is pertinent in selecting suitable remediation techniques for contaminated soils from ancient mining and metallurgy sites. Even after centuries without mining and metallurgy in ancient sites, the long-term fate of metal contaminations in soils is detectable. The still-unsolved question is the level of metals available and releasable from the total content to plants, especially on arable fields of previous mining and metallurgy sites and their surroundings. Contemporary effects of past mining and metallurgy on contamination of soils provide relevant information on the current and future implications of recent metalliferous activities.

The initial cyanide (CN-) concentration and amount of co-contaminants in GCTs can inhibit bacterial growth and reduce the CN--degrading ability of bacteria. Several microorganisms can biotransform a wide range of organic and inorganic industrial contaminants into nontoxic compounds. However, active enzymatic CN- metabolism processes are mostly constrained by the physical and chemical characteristics of GCTs. High concentrations of toxic metal co-contaminants, such as, Pb, and Cr, and factors, such as pH, temperature, and oxygen concentration create oxidative stress and limit the CN--degrading potential of cyanotrophic strains. The effects of such external and internal factors on the CN--degrading ability of bacteria hinder the selection of suitable microorganisms for CN- biodegradation. Therefore, understanding the effects of the physicochemical properties of GCTs on cyanobacteria strains can help identify suitable microbes and favorable environmental conditions to promote microbial growth and can also help design efficient CN- biodegradation processes. In this review, we present a detailed analysis of the physicochemical properties of GCTs and their effects on microbial CN- degradation.

How long decomposed buried human bodies affect soil elemental composition is so far not well-known. Using portable X-ray fluorescence spectrometry, we determined the elemental composition of sandy necrosols from a Corded Ware Culture (ca 2800–2500 BCE) graveyard, Chudeřin, Czech Republic. The elemental compositions of soils in the grave infills were studied and compared with arable and subsoil layers. After removal of the arable layer, infills of graves were identified by the black color in contrast with their reddish surroundings. The burials affected the content of elements even after more than 4500 years. Increased C contents compared with arable and subsoil layers were recorded only close to bones. The lowest P content was in grave infill, where soft tissues decomposed, because of P leaching. Therefore, increased P content in the infill of the prehistoric graves mentioned by previous authors is not a reliable indicator of soft tissue decomposition. In the acidic environment, P and Ca released from bones partly fixed in the grave infill ≤ 5 cm to bones. The high contents of P and Ca in bones and soils close to bones were a source of these elements for plants, indicated by a high density of fine roots. The highest contents of trace elements (Mn, Cu, As, and Pb) were in the arable layer because of recent disposition. The most reliable soft tissue decomposition indicator was an increased Zn content in the grave infill. The multi-elemental analyses of prehistoric necrosols were neglected so far and require further detailed research as the chemical signatures are well-preserved for millennia.

Archaeological Dark Earth (ADE) is a layer of anthrosol (syn. anthroposol) visually characterized by dark color mainly due to homogenous charcoal inclusion, and substantial enrichment by nutrients in comparison to surrounding soils. ADE is distributed from the tropics (Amazonian Terra preta, African ADE), moderate climatic zones (European ADE) up to the Arctic (kitchen middens). Although ADE soils have been studied also in other regions of the world, they have no special regional names. All types of ADE developed as a result of deliberate and/or unintentional deposition of domestic/occupational wastes, charred residues, bones, shells, and biomass ashes from prehistoric up to recent times. ADEs have optimum C : N ratio for effective mineralization, stable organic matter content, reduced acidity, higher CEC and C, N, P, Ca, Mn, Cu, Zn, Mn, Mg, Fe, Sr, and Ba content in comparison to surrounding soils. The unclear remains the level of ADEs enrichment by these elements as enrichment factors for different elements are based on different analytical approaches from plants-available up to total contents in the soil. Although generally highly productive, comparison of herbage production and crop yields between ADEs and natural soils are still rare. The distribution and persistence of anthropogenic activities leading to the formation of ADEs indicate that they are subject to the continual formation.

The scarcity of environmental data means that other sources of information are needed to complement empirical evidence for conservation decisions. We, therefore, aimed to explore Local Ecological Knowledge (LEK) on mammal abundance and qualitative population trends through interviews from 331 local people in and around Kogyae Strict Nature Reserve, Ghana. The results show that 62% of the respondents perceived that mammal abundances had decreased, 31% perceived stability, and 8% perceived that mammals had increased between 2006 and 2017. The respondents attributed the decline to habitat degradation and illegal hunting. The knowledge of local people about mammal population trends is consistent with reported mammal encounters by law enforcement rangers. However, the length of residence, location of communities, and cardinal direction of communities influenced local peoples’ knowledge of mammal abundance and population trends. Our results highlight the ability of LEK to provide reliable ecological information on animal abundance and qualitative population trends. Integrating LEK into monitoring and management is appealing because it can be cost-effective, enhance community participation, and provide novel insights into sustainable resource use.

Local communities in rural areas are dependent on hunting for their livelihoods and rely on their knowledge to understand wildlife ecology. Their knowledge and perceptions may be vital for forming effective and sustainable management plans related to wildlife conservation. We aimed to examine perceptions of local people living inside (n = 153 households) and outside (n = 178 households) the Kogyae Strict Nature Reserve (KSNR, Ghana) regarding bushmeat prevalence and long-term trends in illegal hunting, and to explore people’s knowledge about hunting tools, species, and reasons to hunt illegally. Perceptions of bushmeat sightings and illegal hunting trends were influenced by living inside or outside the protected area, gender, and residence time. Residents living inside the reserve perceived bushmeat and hunting as frequently present in their environment mainly due to frequent sightings of bushmeat and other wildlife products, while people living adjacent to the KSNR were more knowledgeable about the decrease in illegal hunting trends, probably because of awareness about penalties and biodiversity conservation. Furthermore, the perceptions of most residents about the decrease in hunting over time were validated by long-term KSNR law enforcement data. The perception in local communities that snares were the commonest form of hunting equipment used was also consistent with the ranger-based monitoring data. The need for money, bushmeat, unemployment, and retaliatory killings were the main drivers for illegal hunting. Our findings indicated that local people’s knowledge can have a valid relevance in protected area management and may assist in developing effective conservation strategies and in overall improvement of local socio-ecological systems.

Past settlement sites are associated with the accumulation and depletion of many elements. The effects of past settlement activities on recent arable land-use are not well known. The study aimed to determine the effect of past human activities on contemporary arable soil according to the physical and chemical properties and magnetic susceptibility. We studied anthroposols developed on metamorphic maritime sediment of Proterozoic age in an Early Medieval to 1945 settlement, Běla nad Radbuzou, Czech Republic. The study compared the anthroposols with surrounding control of the same geological substrate unaffected by past settlement activities. The originally brown Luvic Cambisol in control turned black in the settlement site mainly due to the decomposition of organic wastes and partly from charcoal inclusion, with a high proportion of clay. The anthroposols additionally were characterized by reduced acidity and higher accumulation of total (P, K, Ca, Mg, Mn, Fe, Cu, Zn, Sr, and Rb) and plant-available (mehlich-3 P, K, Ca, Fe, Cu, and Zn) elements compared to the control. Furthermore, anthropogenic stress was well recorded by the magnetic susceptibility of soil from the anthroposols, with a significant correlation to the Ca, Mn, Cu, Zn, and Pb. Magnetic susceptibility can, therefore, be a suitable proxy indicator for past settlement activities. The comparatively lower releasability (proportion of elements available for plants from the total content) of P, Ca, Cu, and Zn in the settlement site explains why their signatures in archaeological localities are very stable and long-lasting. Total P correlated well with total K, Ca, Mn, Fe, Cu, Zn, and Rb, rendering them suitable indicators of past human settlement activities. Past settlement activities on contemporary arable soils can be reflected by high elemental composition and magnetic susceptibility, even after many years.

Can less than a hundred years of past settlement activities in former European settlements substantially increase the concentration of elements and result in the formation of African Dark Earth soil is a question not addressed. We performed multi–element analysis of Africa Dark Earth soil from a late 19th to mid–20th century CE former German–Togoland settlement, Ziavi–Galenkuito in the Volta Region, Ghana. Relatively neutral reaction and black color of soil mainly from charcoal inclusion in the settlement site contrasted highly with moderately acidic brown Ferric Acrisol in the control located on the same metasedimentary/Voltaian bedrock. Organic C and total N, P, K, Ca, Mn, Fe, Cu, Zn, Sr and Rb concentrations were substantially increased and vice–versa for the C/N ratio in the 0–40 cm layer of the settlement soil compared to the control without settlement activities. The concentrations of plant–available P, K, Ca, S, Fe, Cu and Zn were higher in the settlement soil in comparison to the control. The increased concentrations of the elements mentioned above resulted in the disposition of organic waste and biomass ash. Significantly higher concentrations of total and plant–available elements in 0–10, 10–20 and 20–40 cm layers of settlement site compared to their respective control suggested that chemical signatures from past settlement activities can be determined even in the upper soil layer. Positive correlations between the concentration of P and K, Mn, Sr, Fe, Ca, Zn, Rb, Cu implied that these elements were indicators of past settlement activities. The concentrations of total and plant–available P, K, Ca, Fe, Cu and Zn were well correlated; however, total elements concentrations are much suitable for geoarchaeological purposes as it is easy to calculate enrichment factors. We concluded that intensive human settlement activities in even