A Century of Human-Induced Environmental Changes and the Combined Roles of Nutrients and Land-Use in Lake Victoria Catchment on Eutrophication

2022 ◽  
Author(s):  
Moses Odhiambo ◽  
Dennis Njagi ◽  
Joyanto Routh ◽  
Gayatri Basapuram ◽  
Chen Luo ◽  
...  
Oecologia ◽  
2021 ◽  
Author(s):  
Jörg Bendix ◽  
Nicolay Aguire ◽  
Erwin Beck ◽  
Achim Bräuning ◽  
Roland Brandl ◽  
...  

AbstractTropical mountain ecosystems are threatened by climate and land-use changes. Their diversity and complexity make projections how they respond to environmental changes challenging. A suitable way are trait-based approaches, by distinguishing between response traits that determine the resistance of species to environmental changes and effect traits that are relevant for species' interactions, biotic processes, and ecosystem functions. The combination of those approaches with land surface models (LSM) linking the functional community composition to ecosystem functions provides new ways to project the response of ecosystems to environmental changes. With the interdisciplinary project RESPECT, we propose a research framework that uses a trait-based response-effect-framework (REF) to quantify relationships between abiotic conditions, the diversity of functional traits in communities, and associated biotic processes, informing a biodiversity-LSM. We apply the framework to a megadiverse tropical mountain forest. We use a plot design along an elevation and a land-use gradient to collect data on abiotic drivers, functional traits, and biotic processes. We integrate these data to build the biodiversity-LSM and illustrate how to test the model. REF results show that aboveground biomass production is not directly related to changing climatic conditions, but indirectly through associated changes in functional traits. Herbivory is directly related to changing abiotic conditions. The biodiversity-LSM informed by local functional trait and soil data improved the simulation of biomass production substantially. We conclude that local data, also derived from previous projects (platform Ecuador), are key elements of the research framework. We specify essential datasets to apply this framework to other mountain ecosystems.


Insects ◽  
2018 ◽  
Vol 9 (4) ◽  
pp. 152 ◽  
Author(s):  
Da-Yeong Lee ◽  
Dae-Seong Lee ◽  
Mi-Jung Bae ◽  
Soon-Jin Hwang ◽  
Seong-Yu Noh ◽  
...  

Odonata species are sensitive to environmental changes, particularly those caused by humans, and provide valuable ecosystem services as intermediate predators in food webs. We aimed: (i) to investigate the distribution patterns of Odonata in streams on a nationwide scale across South Korea; (ii) to evaluate the relationships between the distribution patterns of odonates and their environmental conditions; and (iii) to identify indicator species and the most significant environmental factors affecting their distributions. Samples were collected from 965 sampling sites in streams across South Korea. We also measured 34 environmental variables grouped into six categories: geography, meteorology, land use, substrate composition, hydrology, and physicochemistry. A total of 83 taxa belonging to 10 families of Odonata were recorded in the dataset. Among them, eight species displayed high abundances and incidences. Self-organizing map (SOM) classified sampling sites into seven clusters (A–G) which could be divided into two distinct groups (A–C and D–G) according to the similarities of their odonate assemblages. Clusters A–C were characterized by members of the suborder Anisoptera, whereas clusters D–G were characterized by the suborder Zygoptera. Non-metric multidimensional scaling (NMDS) identified forest (%), altitude, and cobble (%) in substrata as the most influential environmental factors determining odonate assemblage compositions. Our results emphasize the importance of habitat heterogeneity by demonstrating its effect on odonate assemblages.


2021 ◽  
Vol 21 (3) ◽  
Author(s):  
Leonardo Antunes Pessoa ◽  
Matheus Tenório Baumgartner ◽  
Marcelo Percilio Santana Junior ◽  
João Paulo Alves Pagotto ◽  
Luiz Gustavo Antunes Pessoa ◽  
...  

Abstract The use and occupation of land by human population substantially influence environmental variables and fish assemblage in streams. However, there is little knowledge on how these changes affect the ecomorphological structure of fish assemblage in mesohabitats. Therefore, we aim to assess whether the land-use types affect the ecomorphological structure of fish assemblage in distinct mesohabitats. Environmental and ichthyofaunistic data were collected in three mesohabitats (rifles, runs, and pools) of five rural and five urban streams. Twenty-one ecomorphological indices were obtained from the mean of linear morphological measurements and areas of the fishes. Subsequently, the Euclidean distance was calculated, based on the ecomorphological indices, between each pair of species, to measure the ecomorphological distances for the mesohabitats of the rural and urban streams. The results show that the urban environment is more harmful to streams than the rural one, due to changes in the environmental variables and decrease in species richness. The main environmental changes found in urban streams were the decrease in canopy cover by riparian vegetation and dissolved oxygen, and the increase in electrical conductivity and bed silting. Also, there was a significant decrease in the morphological similarity between fish species in the mesohabitats of urban streams compared to rural ones. Therefore, we can conclude that the urban environment leads to the loss of morphologically similar fish species in the mesohabitats, with only a few functionally distinct species remaining.


2021 ◽  
Author(s):  
Sadaf Pourghorbani

This thesis is a supporting paper for a photographic exhibition that explores contemporary social and political issues in the country of Iran, through the depiction of a changing landscape. The work consists of photographs of the northern province of Gilan, Iran. As a critical body of work, the installation engages audiences to experience the changing environment and asks viewers to question the causes of the environmental changes in agricultural areas. A brief history of land use change in Iran during the White revolution is presented followed by a description of the current situation of farmlands in contemporary Iran. Goals for the project, methodology and issues of subjectivity are discussed. The shooting strategies, selection of the images, and presentation of the project is outlined. Finally, the essay discusses the project’s documentary relevance.


2021 ◽  
pp. 57-61
Author(s):  
Arunima Dasgupta

Given that urbanization is considered as one of the most signicant anthropogenic alteration of the overall environment, the present study attempts to understand spatial-temporal characteristics of urban population growth and its implications on land-use as well as understanding their relationship with environmental degradation with special focus on the Kolkata, the capital city of West Bengal. Urbanization is one of the major driving forces behind the development of today's land-use and land cover system. A large number of contemporary urbanization has been characterized as urban sprawl namely in an extensive form of land-use for urban uses that have environmentally detrimental effects. There are indications of Urban sprawl and city expansion in our Study Area of Kolkata indicating expansion of settlements and built-up area and thus causing environmental degradation in the city area. The process of urbanization always had signicant implications that can affect cumulative changes in demographic characteristics and/or transformation of the physical environment; unplanned, unsystematic and rapid urbanization can cause intense impacts on various environmental aspects, specically on land and air and water. A thorough understanding of the dynamic relationship between urbanization and its generated land-cover changes thus becomes completely essential for managing environmental changes and enabling sustainability of the environment and its resources.


Author(s):  
Antonio Tomao ◽  
Barbara Ermini ◽  
Marcela Prokopov ◽  
Adriano Conte

Negative environmental changes generally addressed as ‘syndromes’ are evaluated in the context of Soil Degradation (SD) and interpreted by using a ‘Land-Use/Land Cover Changes’ (LULCCs) framework in order to disentangle ‘past trajectories’, ‘present patterns’, and ‘future changes’. This approach allows to discuss the potential impact on SD processes and it represents an informed basis for identifying measurable outcomes of SD. This study focuses on the case of Emilia Romagna, a region located in the North of Italy with high-value added agricultural productions. A multi-temporal analysis of land-use changes between 1954 and 2008 has been proposed, discussing the evolution of associated SD syndromes in Emilia Romagna. The contributing information have been used as a baseline for Sustainable Land Management (SLM) strategies. This framework of analysis provides useful tools to investigate and to monitor the effects of SD in the Mediterranean basin where several regions underwent common development patterns yelding global pathological symptoms of environmental degradation.


Author(s):  
Nkemdilim Maureen Ekpeni ◽  
Amidu Owolabi Ayeni

This chapter examines both concept of global hazard and disaster and its management in the lights of its vulnerability. It categorized the different types of hazards and disasters and their components. From the research findings, it is observed that hazards and disaster are two sides of a coin. They occur at the interface between human systems and natural events in our physical environments. This chapter highlights that the major environmental changes driving hazards and vulnerability to disasters are climate change, land-use changes, and degradation of natural resources. After presenting a typology of disasters and their magnitude globally, management of disaster has transited from just being a “response and relief”-centric approach to a mitigation and preparedness approach.


Author(s):  
Kristin Armstrong Oma

In archaeology, changes in human–animal relationships are rarely considered beyond the moment of domestication. This is influenced by Ingold’s idea that domestication led to a shift in the human engagement with animals (Ingold 2000: 61–76; see Armstrong Oma 2007: 62–4, 2010 for critique). I do not question the validity of such a claim; however, I argue that changes in terms of engagement also happened beyond domestication, and that various configurations of human–animal relationships have existed throughout history. Further, I argue that such changes also have consequences for the environment, by choice of land use strategies and husbandry regimes. A twofold purpose is pursued: first, to investigate how changes in social systems, in my case changes in terms of engagement between humans and animals, affect land use in such a way as to impinge upon natural systems and ecosystems. Second, I wish to grasp the political underpinnings of the models that are employed by archaeologists and, by doing so, to deconstruct the political use of the past (see also Stump, Chapter 10 this volume). Alternative models regarding economic strategies are sought, and the implications of these are discussed. Human–environment studies frequently deal with the impact of human intrusive land use strategies on ecosystems. Awareness has been created around these processes regarding land use techniques and practices (for example Denham and White 2007; Mazoyer and Roudart 2006). However, in European archaeology the impact of husbandry practices upon ecosystems has received considerably less, if any, attention. People in past societies from the Neolithic onwards made the conscious decision to live with animals as herders or as farmers, blending together social and economic choices that had repercussions for landscape developments and ecosystems. Investigations into the relationship between environmental changes caused by husbandry practices and the social systems that instigated those changes are an important contribution to research on past environmental development. These changes are identifiable in the archaeological record.


2019 ◽  
Vol 11 (17) ◽  
pp. 4663
Author(s):  
Habibullah Rajpar ◽  
Anlu Zhang ◽  
Amar Razzaq ◽  
Khalid Mehmood ◽  
Maula Bux Pirzado ◽  
...  

Agriculture is the mainstay of Pakistan’s economy. However, it has been noticed that farmers are increasingly giving up agriculture in favor of non-agricultural activities. This study was conducted in the Khairpur district of Sindh province, which is part of the Indus Plains in Pakistan. The main purpose of the study was to investigate the current and future land use change (LUC) trends and to study farmers’ perceptions of the causes and consequences of LUC and agricultural land abandonment (ALA) in the study area. The study used field survey data and secondary data obtained from the government sources. The results show that agricultural land in the region has decreased by about 9% in the past two decades. Survey data analysis confirms this because more than 80% of farmers believe that agricultural land in the area has declined over time. In addition, farmers believe that socioeconomic and environmental changes are the main reasons for LUC and ALA. We used a logistic regression model to determine the factors that influence farmers’ decisions to sell agricultural land for other uses. The results show that the age, income, land ownership, farm inheritance by successors, social networks and lack of basic facilities in the study area are the main determinants of farmers’ decisions to sell agricultural lands. In particular, farmers’ integration into the social network and their belief that the farm will be inherited by heirs reduces the possibility of selling land. As for the consequences of LUC and ALA, the results indicate that farmland prices, weeds infestation, urban diffusion, and pressure on existing infrastructure have increased in the study area. In addition, the results show that the prospects of farming in the area remain grim as most farmers indicated that they were willing to abandon agricultural lands in favor of other revenue generation activities. The study suggests that policymakers should pay close attention to controlling rapid LUC and ALA to keep lands green.


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