Anthropogenic Causes Research Articles

Hydro-chemical characterization of groundwater using multivariate statistics in Hawassa City, Southern Ethiopia

ABSTRACT This study characterized the hydro-chemical characteristics of groundwater for assessing the possibility of managed aquifer recharge in Hawassa City. A total of 48 water samples were taken from hand-dug wells and boreholes and examined to determine the water type, critical metrics, and key determinants of water quality. Multivariate statistical techniques such as hierarchical cluster, principal component, and linear discriminant analysis were used. The samples were divided into four variable groups and four case cluster groups. The results depicted the water hardness group (C1), soil salinity group (C2), weak and strong acids forming group (C3), and pollution indicator group (C4). Four water types were identified, Na–HCO3 and Ca–Na–HCO3 (87.5%), Ca–HCO3, and Na–Cl. Na–HCO3 was the dominant in hand-dug wells than in deep boreholes, which may account for evaporation or contaminations. Seven principal components with a cumulative variance of 78.58% were also formed. The first two, hardness and salinity, contributed 25.4 and 11.4% variance, respectively. In linear discriminate analysis, three discriminate functions with eight variables were generated, namely pH, K+, Na+, Ca2+, HCO3−, Cl−, BOD5, and COD. Thus, it is revealed that the decline in water quality attributed to natural and anthropogenic causes that require regulation enforcement and higher recharge to reverse the situation.

Selection and Effect of Plant Growth-Promoting Bacteria on Pine Seedlings (Pinus montezumae and Pinus patula).

Forest cover is deteriorating rapidly due to anthropogenic causes, making its restoration urgent. Plant growth-promoting bacteria (PGPB) could offer a viable solution to ensure successful reforestation efforts. This study aimed to select bacterial strains with mechanisms that promote plant growth and enhance seedling development. The bacterial strains used in this study were isolated from the rhizosphere and endophyte regions of Pinus montezumae Lamb. and Pinus patula Schl. et Cham., two Mexican conifer species commonly used for reforestation purposes. Sixteen bacterial strains were selected for their ability to produce auxins, chitinase, and siderophores, perform nitrogen fixation, and solubilize inorganic phosphates; they also harbored genes encoding antimicrobial production and ACC deaminase. The adhesion to seeds, germination rate, and seedling response of P. montezumae and P. patula were performed following inoculation with 10 bacterial strains exhibiting high plant growth-promoting potential. Some strains demonstrated the capacity to enhance seedling growth. The selected strains were taxonomically characterized and belonged to the genus Serratia, Buttiauxella, and Bacillus. These strains exhibited at least two mechanisms of action, including the production of indole-3-acetic acid, biological nitrogen fixation, and phosphate solubilization, and could serve as potential alternatives for the reforestation of affected areas.

Assessment of groundwater quality for irrigation purpose in aquifers of the Upper Brahmaputra floodplains of Assam, India.

Groundwater is an essential natural resource for mankind. Due to various geogenic and anthropogenic causes, groundwater quality has raised serious concern over the years. In this study, groundwater quality was evaluated for its suitability for irrigation in the Jorhat and Golaghat Districts of Assam, India. A total of 100 groundwater samples were collected from shallow aquifers (< 35m) from different locations during the pre-monsoon season (March-April 2022). Groundwater in the study area is slightly alkaline in nature (mean pH value of 7.44). The average cations and anions chemistry are in the order of Na+ > Ca2+ > Mg2+ > K+ and HCO3- > Cl- > SO42- > CO32-, respectively. Ca-Mg-HCO3 followed by Na-Ca-HCO3-Cl are the primary water types in the study area. Pearson's correlation matrix showed a positive correlation between TDS and EC (r = 0.78) and sodium showed a positive correlation with TDS and bicarbonate (r = 0.62 and r = 0.65), respectively. Gibbs plot indicated that rock-water interaction is the dominant factor that controls the chemistry of the groundwater of the area. Irrigation parameters like Sodium Absorption Ratio (SAR), Permeability Index (PI), Magnesium Absorption Ratio (MAR), Kelly's Ratio (KR), and Irrigation Water Quality Index (IWQI) indicated that groundwater is overall suitable for irrigation. USSL diagram illustrated that most of the samples fell into the C2 (medium salinity) and S1 (low sodium hazard) categories. Wilcox plot showed the samples fell in excellent to good categories indicating fitness of groundwater for irrigation in the area.

Medicinal plants diversity among the oromo community in heban-arsi district of Ethiopia used to manage human and livestock ailments.

Medicinal plants are commonly employed mainly due their accessibility, affordability and potency. However, medicinal plants and the associated knowledge are disappearing at an alarming rate due to natural and anthropogenic causes and thus a need for their proper documentation conservation. This study was performed to document traditional knowledge related to use of medicinal plants in Heban-Arsi district, West-Arsi Zone, Oromia Regional State, Ethiopia. Interviews were conducted with 185 informants to identify medicinal plants used in traditional therapies in the study area. Informant consensus factor (ICF), rank order priority (ROP) values were computed, and preference ranking exercises were performed to assess the relative importance of medicinal plants. Descriptive and inferential statistics were used to measure and compare medicinal plants knowledge between social groups. A total of 120 medicinal plants were identified for being used to treat different human and animal illnesses in the study area. Most of the medicinal plants (76.4%) were uncultivated ones obtained from different habitats. Leaf was the most frequently used plant part constituting 62.6% of preparations. Oral was the most commonly used route of remedy administration (46%) in treating diseases. Gastrointestinal ailments category had the highest ICF value (0.83). In the study area, the highest rank order priority (ROP) values were recorded for Dombeya torrida (J.F. Gmel.), Artemisia absinthium L., Balanites aegyptiaca (L.) Del., Combretum pisoniiflorum Klotzsch) Engl., Celtis africana Burm. f, Ocimum gratissimum L. and Lagenaria sp. for their uses against snake poison, tuberculosis, liver disorder, stomachache, tuberculosis, febrile illness and liver disorder, respectively, each scoring a value of 100. Significant differences in medicinal plant use knowledge were recorded between male and female informants of different educational level, age and experience. Anthropogenic factors were the primary threats to medicinal plants in the area. The study area was found to be rich in medicinal plants that are useful in treating a wide range of human and animal illnesses. In future pharmacological and phytochemical investigations, priority needs to be given to medicinal plants of the highest ROP values and those that were reported against ailment categories scoring the highest ICF values.

Efficacy of non‐lead ammunition distribution programs to offset fatalities of golden eagles in southeast Wyoming

AbstractGolden eagles (Aquila chrysaetos) face many anthropogenic risks including illegal shooting, electrocution, collision with wind turbines and vehicles, and lead poisoning. Minimizing or offsetting eagle deaths resulting from human‐caused sources is often viewed as an important management objective. Despite understanding the leading anthropogenic sources of eagle fatalities, existing scientific research supports few practical solutions to mitigate these causes of death. We implemented a non‐lead ammunition distribution program in southeast Wyoming, USA, and evaluated its effectiveness as a compensatory mitigation action to offset incidental take (i.e., fatalities) of golden eagles at wind energy facilities. In 2020 and 2022, we distributed non‐lead ammunition to 699 hunters with big‐game tags specific to our &gt;400,000‐ha study area. These hunters harvested 296 pronghorn (Antilocapra americana), 14 deer (Odocoileus spp.), and 33 elk (Cervus canadensis) in the study area, which accounted for 6.9% and 6.5% of the harvest in these hunt units in 2020 and 2022, respectively. We used road surveys in 2020 to estimate a density of 0.036 (95% CI = 0.018–0.058) golden eagles/km2 during the big game hunting season in our study area. Model output suggests that our non‐lead ammunition distribution program offset the fatality of 3.84 (95% CI = 1.06–23.72) eagles over the course of these 2 hunting seasons. Our work illustrates the potential usefulness of non‐lead ammunition distribution programs as an action to mitigate eagle fatalities caused by wind facilities or other anthropogenic causes of death.

Combining Historical and Molecular Data to Study Nearly Extinct Native Italian Grey Partridge (Perdix perdix) at the Turn of the Twentieth Century.

The grey partridge (Perdix perdix Linnaeus, 1758), is a polytypic species with seven recognized subspecies, including P. p. italica (Hartert, 1917), which is endemic to Italy. Until World War II, the species was widespread across Europe but severely declined due to anthropogenic causes, jeopardizing the Italian subspecies gene pool. Genetic characterization and haplotype identification were performed by analyzing the 5'-end of the mitochondrial control region (CR). A total of 15 haplotypes were detected, seven of which were present in the population before 1915. Among them, three haplotypes were never detected again in the individuals collected after 1915. Interestingly, eight of the 15 haplotypes detected in Italian museum samples belonged exclusively to individuals collected after 1915. The obtained data highlight a high presence of specimens originating from other European populations and, despite all the conservation efforts, suggest an uncertain situation of the subspecies in Italy. This research was strongly backed up by extensive bibliographic research on historical documents, allowing the identification of hundreds of restocking events all over Italy. This is an integral part of this research and has laid the foundations for identifying and circumscribing historical periods in which introductions from the rest of Europe had different pressures, aiming to define a baseline.

Development of a subsurface monitoring system for land subsidence hazard in the Bandung basin: a laboratory prototype

Abstract Land subsidence is a global environmental hazard posed by urban area worldwide, causing degradation in environmental quality and leads to further disasters such as increased flood risk, contamination risk, and infrastructure damages. Anthropogenic causes, such as groundwater extraction and building weight, cause high land subsidence rates. The behaviour of the subsurface under the influence of anthropogenic causes must be well understood to mitigate this problem. Conventional subsurface monitoring is robust and costly. In this case, we aim to first develop a versatile and low-cost subsurface monitoring prototype for land subsidence at a laboratory scale using a model box. Methods employed were constructing an experiment model box, developing the monitoring system, and trial experiments in the laboratory. The sensors are linear vertical displacement transducer, potentiometer, water level and pressure sensors. The monitoring system uses Arduino microcontroller to convert sensors inputs to desirable outputs and a logger to record the real-time data and transmit it to personal computer in the laboratory. Land subsidence in the Gedebage area in Bandung basin was taken as a model case. The model box was filled with soil from Gedebage, Bandung. A scenario of exploitation of confined groundwater and weight of building was applied for the model case. The results show that the laboratory prototype can monitor the subsurface changes due to the applied anthropogenic forces. In the case of Bandung soil, groundwater exploitation did not immediately cause subsidence instantaneously. There is a time delay between the drawdown of groundwater level and the subsequent vertical deformation. The rate of subsidence varies spatially inside the tank, the largest is close to the pump well and surface loads. A maximum of 2.88 mm subsidence over 663 days was recorded following 1 m groundwater drawdown. This information asserts the importance of long-time monitoring in subsidence areas.

Moderate evidence for the sex‐dependent effect of poisoning on adult survival in a long‐lived raptor species

AbstractSurvival rate is usually the greatest contributor to population growth in long‐lived species, and its accurate estimation along with the evaluation of the factors influencing it is therefore essential for effective conservation. Here, we studied the survival of breeding eastern imperial eagles Aquila heliaca in Hungary between 2011 and 2022 and investigated the effect of poisoning, the leading known anthropogenic cause of mortality. We used the Cormack‐Jolly‐Seber mark‐recapture model to estimate annual apparent survival and encounter probabilities based on the capture histories of 208 males and 411 females. We obtained encounter data from the DNA profiles of shed feathers collected at the nest sites, which we also supplemented with presences inferred from parentage analysis. The most supported model estimated a constant 91.6% annual survival over the study period, but models including the effect of sex and poisoning rate on survival had similar support. Sex difference in survival was less than 1% on average, but the survival of males decreased more with poisoning rate than the survival of females. However, due to smaller encounter probabilities, the estimates for males were less precise compared to females. Males may be more at risk from poisoning than females not only due to their more active foraging behaviour during incubation and chick‐rearing but also due to their smaller body size. Apart from providing direct practical information for the conservation management of imperial eagles, our results also highlight the importance of long‐term studies for estimating population parameters of birds of prey.

Geomorphological characteristics of Gandak river between Sahibganj and confluence with Ganga river during 1989–2022

The Gandak River originates in Nepal and merges with the Ganga River in India. The Gandak River is experiencing significant geomorphological alterations due to climate change and anthropogenic causes. In this study, an attempt has done to examine river bank erosion & accretion, shifting of the river bank, sinuosity, and braiding index of the Gandak River between Sahibganj and the confluence with the Ganga River, covering a length of 92.4 km from 1989 to 2022 (33 years) using remote sensing and geospatial technologies. The delineation of the river bank line for different periods, along with the quantification of erosion and accretion of the river’s right and left banks, were analysed using GIS, including the sinuosity and braiding patterns. The overall sinuosity value ranged from 1.16 to 1.01 and did not follow any specific pattern in significant reaches. The sinuosity value was almost constant over the most d/s reach of 30.74 km. The braiding index of the River was found to be the maximum between Ismailpur and Baijalpur and the minimum value between Munja and Chakia in 2015 and 1995 respectively. This study revealed that the river is shifting to the right, and bank protection measures were needed. Finally, the proposed investigation revealed the braiding phenomenon, river shifting in the transverse direction, and shifting of the meander bend was primarily responsible for the erosion and accretion of the river banks. This study will benefit local government agencies, concerned authorities, and people residing along the banks of the Gandak River by providing insights into the river’s migration patterns. Further, this knowledge aids in better planning of riverbank protection measures and developing a navigation system.

Measuring climate change perception in China using mental images: A nationwide open-ended survey.

Current knowledge about public climate change perception mainly covers belief, concern, and attitudes. However, how this discourse is interpreted using individuals' own frame of reference remains largely unknown, particularly in many large emitters from non-Annex I countries such as China. This study, for the first time, performs a nationwide open-ended survey covering 4,037 respondents and collected 12,100 textual answers. Using a semiautomated coding method, we find seven mental images that exclusively represent the Chinese interpretation of the climate change issue, including global warming, distant icons, natural disasters, environmental degradation, cause, solution, and weather. Analysis of influencing factors shows that females, those with lower education levels, lower income, and older individuals tend to connect climate change with natural weather phenomena. Younger and well-educated residents in developed cities are more aware of various consequences and anthropogenic causes of climate change. People with stronger climate change beliefs, policy support, and personal experience of extreme weather are more likely to mention disastrous impacts, carbon emission as causes, and potential solutions. Employing the multilevel regression and post-stratification technique, we map the prevalence of mental images in China at the prefecture-city level. The results reveal significant geographical heterogeneity, with estimated national means ranging from a high of 55% (weather) to a low of 11% (solution). Our findings reveal diverse perspectives and a widespread misconception of climate change in China, suggesting the need for tailored clarification strategies to gain public consent.

Genetic structure of populations of Salvia ceratophylloides endemic to southern Calabria (southern Italy)

Assessing the degree of genetic diversity and differentiation of rare or endangered endemic species is essential to evaluate the conservation status of populations and successively implement appropriate conservation strategies. We investigated the population structure of Salvia ceratophylloides Ard., a scapose hemicryptophyte endemic to Calabria (southern Italy), both to answer questions about its genetic structure and to determine whether the actual population size has undergone significant demographic changes in the near past. The data obtained from the census showed that the populations are characterised by a greater number of adult individuals than juveniles and are on declining. The genetic analysis carried out on 99 individuals from four populations of the species under study, shows a mean expected heterozygosity value of 0.50 and an overall differentiation value of 0.083. The population structure shows that the four studied populations are distinct genetic units, genetically linked to four different ancestral gene pools. Bayesian analysis based on ABC models indicates that the present populations underwent a significant reduction in size in the past. This corresponds to the demographic decline at the end of the 19th century, which according to the literature, was due to the strong anthropic pressure (agriculture, grazing, fire and plantations) of Reggio Calabria suburbs. We can therefore conclude that populations are not affected by inbreeding and low genetic diversity and that there is no immediate danger of genetic erosion, and that the problems associated with population decline, past and present, are exclusively due to anthropogenic causes.

Embracing uncertainty: porous and actionable responses to climate change at the borders of Indigenous and scientific expertise(s) in Siberia

AbstractThis article explores uncertainty as an onto‐epistemological concept that reveals integrative capacities of Indigenous and scientific knowledge. Looking at official scientific approaches to climate change in Russia, it traces how Indigenous peoples in Siberia navigate their lives as they continue to witness anthropogenic causes of climatic degradation intertwined with forceful denial of Indigenous needs and sociopolitical turbulence. By focusing on two ethnographic accounts involving Indigenous Eveny and Nanai, the article explores how uncertainty, and in particular environmental uncertainty, can be dealt with, acted upon, and deployed productively while broadening our understandings of vulnerability, agency, and resilience. Drawing on discrete Indigenous strategies of hariok among Nanai and nyamnin among Eveny, the analysis reveals a pathway to think about adaptive potentialities of uncertainty as a mode of responding to rapidly shifting environmental and sociopolitical conditions.

Causes of admissions and mortality in patients of a wildlife rehabilitation centre in Bulgaria.

Wildlife rescue centres are specialised units with ecological, conservational and veterinary medical activities, which include treatment, rehabilitation, breeding and releasing rare and endangered wild animals into their natural habitat, as well as environmental education. These centres provide an opportunity to monitor ongoing ecological changes in wildlife, environmental pollution and emerging diseases. With the present study, we aimed to analyse the causes and conservation status of the largest wildlife rehabilitation centre in Bulgaria. A total of 18,720 patients, from 26 orders with various conservation statuses and different etiology, have been admitted to the rehabilitation centre for over 25 years. The summarised results showed that 40% of the patients were admitted with an unknown etiology and the proportion of anthropogenic causes was 18%. Natural factors related to incidents with wild animals were 32%, while a share of 10% of the wildlife which resided at the WRBC referred to a part of re-introduction programmes. This type of analysis of wildlife rehabilitation centres could provide useful information about the status of populations and ecosystems, as well as support conservation practices.

An Analysis of K–12 Climate Change Science Standards in the United States

Abstract To produce a climate-literate society willing to take action, students must be educated on the causes, changes, impacts, and solutions of climate change. One way to ensure students are educated on climate change is to have robust science standards. However, little is known about the collective climate change standards in the United States. Therefore, the purpose of this study is to conduct an analysis of the U.S. K–12 science standards to uncover where the climate change standards are located in different grade levels and the extent to which the collective U.S. curriculum covers topics of climate change. This study was a qualitative content analysis of the U.S. K–12 climate change standards. The results show that most U.S. climate change standards are found within the high school grade levels and Earth and space science domains. All U.S. states address topics of climate change within their standards; however, general mentions of climate change were cited most often. Finally, the majority of states address both natural and anthropogenic causes of climate change. Implications for policymakers and educators are included.

Watershed-Based Participatory Sustainable Land Management using Integrated physical SWC Measure in Ilasa Watershed of Goba District, Bale Highland South-Eastern Ethiopia

Soil erosion is among the most challenging and continuous environmental problems in the highlands of Bale particularly in Ilasa Watershed of Goba District. Soil erosion which emanates from both anthropogenic and natural causes currently results decline in agricultural productivity, crop production on the other hand increases downstream flooding and reservoir sedimentation, and loss of valuable plant nutrients. Soil and water conservation (SWC) practices have been carried out to solve land degradation and erosion severity problems in the Ilasa Watershed through participatory approaches the objective of this study was to implement integrated physical SWC practices through participatory approach in the Ilasa watersheds; to rehabilitate degraded watershed using different physical SWC measures and to minimize the risk of soil erosion and increasing soil depth by trapping sediment loss from Ilasa watershed. Hence, different participatory integrated watershed management practices were introduced in the Ilasa watershed for five consecutive years to avert the problem of soil erosion. Community participatory in integrated watershed management particularly soil and water conservation measures interventions for degraded rehabilitation and gulley treatment were capacitated through training, practical field works, and researchable materials support. Awareness creation, increasing knowledge and skill of farmers, providing technical and resource supports, and implementing slope based appropriate SWC structure could help sustainable land management that ensures environmental quality and food security in the study area as well as in the other areas having related biophysical and socioeconomic settings. Among the major types of physical SWC structures and gulley rehabilitation structures constructed in the study watershed were soil bund; stone bund; stone-faced soil bund and cut-off drains, gully reshaping and filling, brushwood check dam, loose stone check dame, sandbag check dam ...

Spatial and temporal trends of Tamanend’s bottlenose dolphin (Tursiops erebennus) strandings in South Carolina, USA, 2006–2020

Marine mammal strandings data contribute towards overall assessments of cetacean populations, including seasonal, annual and life‐history trends which result from both natural and anthropogenic causes. We conducted spatial and temporal analyses of Tamanend’s bottlenose dolphin (Tursiops erebennus) strandings in the waters of South Carolina, USA, over a 15‐year period from 2006 to 2020, with the following objectives: (1) to determine spatial and temporal trends; (2) to analyse seasonal reproductive trends; (3) to determine life‐history parameters, such as sex ratio and age class; (4) to determine the extent to which human interaction contributed to strandings; and (5) to compare stranding patterns with historical data from 1992–2005. A total of 837 strandings occurred over the study period, with a mean of 55.8 strandings per annum. The season with most strandings was Spring (April–June), while March and April had the highest number of strandings. A relatively equal number of male and females dolphins stranded, and mortality was highest in neonates, first‐year calves and adults. Neonatal strandings comprised 22.1% of all strandings and were predominant in May. Ninety‐five human‐interaction (HI) cases were observed, representing 22.9% of strandings where HI or non‐HI could be determined. Confirmed crab‐pot buoy‐line entanglements were the predominant HI category (n = 31). Density maps and hot spot analysis showed most strandings, including live and neonatal strandings and HI cases, occurred in defined areas of Charleston and Beaufort Counties. While many trends were similar to historical data, some new trends emerged, particularly an increase of strandings in March and April. Neonatal strandings decreased in November and the historical spike during this month has essentially disappeared. The results of this analysis serve as a tool to predict stranding rates and inform conservation and management decisions to better protect bottlenose dolphins.

Mercury Levels in the Crab Grapsus grapsus across the Galápagos Archipelago

The levels of mercury (Hg) were examined in the leg muscle of the crab Grapsus grapsus from five sites on four islands within the Galápagos archipelago. Mercury values obtained using a Milestone DMA 80 evo direct mercury analyzer varied both within and among sites. Total mercury concentrations (mg kg−1 dry weight) ranged from the lowest at a protected location at Isabela Island (0.06 ± 0.02) to the highest at the San Cristóbal urban location (2.04 ± 0.069). Crabs from South Plaza Island also had surprisingly high levels of mercury with a mean of 1.2 ± 0.6. Values from urban sites at Isabela Island and Academy Bay, Santa Cruz, had intermediate values. When converted to wet weight, crabs from both San Cristóbal and South Plaza were within or above the levels (0.3–0.5 mg kg−1 wet weight set by various government agencies) considered potentially harmful to human health if ingested. A lesser number of both oysters and barnacles were also analyzed for mercury at South Plaza and Academy Bay, and while the values were lower compared to the crabs, they followed the same pattern of elevated levels at South Plaza compared to Academy Bay. It is unclear as to whether the mercury comes from natural sources, such as volcanism, or anthropogenic causes.

Providing predictive models for quality parameters of groundwater resources in arid areas of central Iran: A case study of kashan plain

Groundwater pollution can occur due to both anthropogenic and natural causes, leading to a decline in water quality and posing a threat to human health and the environment. The pollution of ground water resources with chemical pollutants is often considered. To manage water resources sustainably, ensuring their quality and quantity is crucial. Yet, testing groundwater can be expensive and time-consuming. So, using modeling to predict the chemical parameters of groundwater resources is considered to be an efficient and economical method. In this study, we examined three models to predict groundwater quality in dry regions by using R programming language. The random forest (RF) outperformed the other models in developing predictive models for water quality. Also, the multiple linear regression (MLR) model demonstrated strong performance, particularly in predicting total hardness (TH) in Aran Va Bidgol groundwater resources. The decision tree (DT) model did well but had lower performance than the RF model in predicting quality parameters. This approach can be efficacious in the field of effective management and protection of groundwater resources and enables the assessment of risks related to water resources.

The contribution of natural and anthropogenic causes to soil acidification rates under different fertilization practices and site conditions in southern China

Excessive application of mineral fertilizers has accelerated soil acidification in China, affecting crop production when the pH drops below a critical value. However, the contributions of natural soil acidification, induced by leaching of bicarbonate, and anthropogenic causes of soil acidification, induced by nitrogen (N) transformations and removal of base cations over acid anions, are not well quantified. In this study, we quantified soil acidification rates, in equivalents (eq) of acidity, by assessing the inputs and outputs of all major cations and anions, including calcium, magnesium, potassium, sodium, ammonium, nitrate, bicarbonate, sulphate, phosphate and chloride, for 13 long-term experimental sites in southern China. The acidification rates strongly varied among fertilizer treatments and with the addition of animal manure. Bicarbonate leaching was the dominant acid production process in calcareous soils (23 keq ha−1 yr−1) and in non-calcareous paddy soils (9.6 keq ha−1 yr−1), accounting for 80 % and 68 % of the total acid production rate, respectively. The calcareous soils were strongly buffered, and acidification led no or a limited decline in pH. In contrast, N transformations were the most important driver for soil acidification at one site with upland crops on a non-calcareous soil, accounting for 72 % of total acid production rate of 8.4 keq ha−1 yr−1. In this soil, the soil pH considerably decreased being accompanied by a substantial decline in exchangeable base cation. Reducing the N surplus decreased the acidification rate with 10 to 54 eq per kg N surplus with the lowest value occurring in paddy soils and the highest in the upland soil. The use of manure, containing base cations, partly mitigated the acidifying impact of N fertilizer inputs and crop removal, but enhanced phosphorus (P) accumulation. Combining mineral fertilizer, manure and lime in integrative management strategies can mitigate soil acidification and minimize N and P losses.

Wetland Changes and Ecosystem Services Valuation of Kapla Beel in Assam

Background: Wetlands are productive ecosystem with immense potentiality of providing various goods and services. But they are fast depleting due to various natural and anthropogenic causes. Kapla beel is a freshwater wetland located in Barpeta district in the lower Brahmaputra valley of Assam. Area of the Kapla beel has been decreasing over the years. This study shall make an attempt to analyse the causes of land use and land cover changes of Kapla beel of Assam and assess its ecosystem services value changes during the period 1990 to 2022. Methods: To assess the changes, two Landsat images for the year 1990 and 2022 of Kapla beel were taken from the United State Geological Survey (USGS) Earth Explorer. Land-use change analysis was assessed by comparing the areas occupied by each land use in each period using the ArcGIS software. The dynamicity index is used to calculate the rate of change in land cover. In order to assess the changes in the wetland ecosystem service value due to wetland changes, Benefit Transfer Method is used which involves transferring monetary values of ecosystem services from previous studies. Result: The valuation of ecosystem services underlines the fact that wetlands are highly productive and economically viable ecosystems. Accounting of ecosystem services provides information about the need for optimal decision -making towards judicious use of wetland resources for their sustenance.