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These general purpose regions are critical for structuring and implementing ecosystem management strategies across federal agencies, state agencies, and non-government organizations that are responsible for different types of resources within the same geographical areas Omernik and others, The approach used to compile this map is based on the premise that ecological regions can be identified through the analysis of the spatial patterns and the composition of biotic and abiotic phenomena that affect or reflect differences in ecosystem quality and integrity Wiken, ; Omernik, , These phenomena include geology, physiography, vegetation, climate, soils, land use, wildlife, and hydrology.

The relative importance of each characteristic varies from one ecological region to another regardless of the hierarchical level. Department of Interior - U. This project is associated with an interagency effort to develop a common framework of ecological regions.

Reaching that objective requires recognition of the differences in the conceptual approaches and mapping methodologies that have been used to develop the most common ecoregion-type frameworks, including those developed by the U.

Regional collaborative projects such as this one in the Mississippi Alluvial Plain, where agreement can be reached among multiple resource management agencies, are a step toward attaining consensus and consistency in ecoregion frameworks for the entire nation. Department of Agriculture - Forest Service, scale ,, Chapman Dynamac Corporation , Barbara A.

Griffith Dynamac Corporation , Daniel J. These general purpose regions are critical for structuring and implementing ecosystem management strategies across federal agencies, state agencies, and nongovernment organizations that are responsible for different types of resources within the same geographical areas Omernik and others, The approach used to compile the ecoregion map of Louisiana is based on the premise that ecological regions can be identified through the analysis of the spatial patterns and the composition of biotic and abiotic characteristics that affect or reflect differences in ecosystem quality and integrity Wiken, ; Omernik, , These characteristics include geology, physiography, vegetation, climate, soils, land use, wildlife, and hydrology.

Louisiana contains barrier islands and coastal lowlands, large river floodplains, rolling and hilly coastal plains with evergreen and deciduous forests, and a variety of aquatic habitats.

There are 6 level III ecoregions and 28 level IV ecoregions, and most of these continue into ecologically similar parts of adjacent states Chapman and others, ; Griffith and others, ; Woods and others, Reaching that objective requires recognition of the differences in the conceptual approaches and mapping methodologies applied to develop the most common ecoregion-type frameworks, including those developed by the USFS Bailey and others, , the USEPA Omernik , , and the U.

Each collaborative ecoregion project, such as this one in Louisiana, is a step toward attaining consensus and consistency in ecoregion frameworks for the entire nation.

Woods, A. Griffith Dynamac Corporation , James M. Chapman Dynamac Corporation. New Mexico contains semiarid shrub- and grass-covered plains, forested mountains, glaciated peaks, woodland- and shrubland-covered hills, lava fields and volcanic plateaus, river floodplains, and arid deserts. Ecological diversity is enormous.

There are 8 level III ecoregions and 55 level IV ecoregions in New Mexico and many continue into ecologically similar parts of adjacent states Griffith and others, ; Woods and others, ; Chapman and others, The project is associated with an interagency effort to develop a common framework of ecological regions McMahon and others, Department of Agriculture—Soil Conservation Service, Collaborative ecoregion projects, such as this one in New Mexico, are a step toward attaining consensus and consistency in ecoregion frameworks for the entire nation.

Jacobi Jacobi and Associates , Christopher M. Moran Indus Corporation. Environmental Protection Agency, Methods used by the U. The Oklahoma ecoregion map was compiled at a scale of ,; it revises and subdivides an earlier level III ecoregion map that was originally compiled at a smaller scale Omernik, ; U.

The approach used to compile the Oklahoma ecoregion map is based on the premise that ecoregions can be identified through the analysis of the spatial patterns and the composition of biotic and abiotic characteristics that affect or reflect differences in ecosystem quality and integrity Wiken, ; Omernik, , The relative importance of each characteristic varies from one ecoregion to another regardless of ecoregion hierarchical level.

Research conducted in the eThekwini Municipality has shown that households tend to abandon the urine-diversion units once they are full Austin et al. Lack of community participation has been frequently blamed for this scenario and therefore the aim of this study is to investigate the level and extent to which community participation was used in the implementation of the Danga Ecological Sanitation Project. Overall objective of the study The overall objective of this study is to determine the level and extent of community participation in the Danga Ecological Sanitation project, which was carried out by the Mvuramanzi Trust in Zimbabwe, and to provide recommendations for current and future developmental initiatives.

Research Design A research design is important because it provides a structure or framework for collecting and analysing information for the research. Kothari and Babbie and Mouton stipulated that a research design should be a plan or structured framework of how one intends conducting the research process in order to solve the research problem.

As indicated in the main objective, the aim of the study is to determine the level and extent of community participation in the Danga Ecological Sanitation Project carried out by the Mvuramanzi Trust in Zimbabwe and to provide recommendations for current and future developmental initiatives.

Methodology Primary and secondary data were used in this study, as well as both qualitative and quantitative methods in gathering information. This methodology provided a wider approach towards data gathering and analysis. The different methods will be discussed in the section below. A total of 40 structured questionnaires were distributed to households through a simple random sampling method. The structured questionnaire first gathered demographic and socio- economic information from respondents.

Second, it elicited information relating to the nature and extent of household participation in the ecological sanitation project. Qualitative data gathering methods included observation, focus group discussions and semi-structured interviews. Schools, clinics and households where the ecological sanitation units were built were visited to find out how they were constructed and the extent of usage.

Ward committee meetings as well as village development committee meetings were also attended. Attending the aforementioned meetings enabled a determination of the level and extent of community participation, and more specifically, assessment of the number of households who generally attend such meetings. Observation was also used to determine different dynamics in the community.

Furthermore, the ability of stakeholders to articulate and voice their concerns in the community was monitored and special attention was paid to the behaviour of dominant groups and the impact on the process. For the purposes of this study, a total of five focus group discussions FGDs were conducted. The purpose of the focus groups was to determine the nature and extent of community participation in the ecological sanitation project, as well as to identify participatory structures in the community.

Each focus group was comprised of 5 to 8 people, representing varying interests. The researcher ensured that a cross section of interest groups in the community was represented. Two focus groups were identified during attendance at ward committee meetings as well as at the village development committee meetings.

Questions for these three focus groups were formulated around understanding ecological sanitation, the use of human waste in agriculture, participation levels, and recommendations on improving community participation in ecological sanitation projects. Semi-structured interviews involve the use of open-ended questions as an interview guide, and this method is crucial to the study in order to gather more in-depth information relating to the research problem. In all, 10 semi-structured interviews were conducted.

Four interviews were conducted with Chief Masunda, Headman Danga and two village heads from Chemhere and Mutare villages. These interviews were conducted to try to determine the exact role they played in the implementation process of EcoSan Project, as well as to determine the role of beneficiaries.

The traditional perceptions of human waste in the view these headmen were also investigated. Furthermore, one official from the Runde Rural District Council, working in the sanitation section, was interviewed with the intention of determining the success of local projects initiated by different organisations.

Interviews were held with the Project Officer for the Danga Ecological Sanitation Project in order to determine the implementation process, two headmasters from Danga Primary and Wasima Secondary school, as well as two ward councillors from the Shavahuru and Mapirimira wards to determine the role each played from the inception to the implementation of the project.

Data Processing, Analysis and Presentation Collection of primary data is followed by arrangement of data before analysing or interpreting their implications. Before carrying out processing and analysis, the raw data were coded and arranged according to their respective themes. Babbie noted that coding is a process whereby raw data are transformed into a standardised form suitable for machine processing and analysis. As pointed out earlier in the previous section, two sets of data were collected, namely qualitative and quantitative data.

The data from both individual and group questionnaires were coded, processed and analysed using the Statistical Package for Social Scientists SPSS and presented in the form of frequencies, tables, graphs and charts. The data are presented in the form of written textual quotes, frequencies, graphs, pie charts, tables and labelled categories. Research Procedure In order to gather both qualitative and quantitative data, the following procedure was applied: After the proposal was approved by the University of the Western Cape, the researcher organised a meeting with Runde Rural District Council officials.

The meeting was aimed at gaining permission to carry out the research as well sharing the aims of the study. Emails were also sent to the organisation which carried out the Danga Ecological Sanitation project.

A further meeting was planned with the traditional leaders, as well as the respective councillors for permission to conduct the study in their area. This meeting was further used for selecting the sample groups and individual members to be interviewed, both during the pre-testing phase of the study and during the actual data collection phase.

A research assistant was recruited to assist in data collection and facilitation of focus group discussions as well as individual interviews. The research assistant was trained in data collection, more specifically, in going through the questionnaire and interpreting the questions in the Shona language.

The actual field data collection was undertaken between September and February Limitations of the Study There were some limitations in the process of executing this study and they included the following: First, a severe challenge was experienced in tracking the Mvuramanzi Trust officials implementing organisation.

In addition, as non-governmental organisations are sometimes perceived to be sympathetic to opposition parties, the organisations themselves try to protect their officials. The researcher was rigorously questioned on who had sponsored the study and why the study had to be done in the community.

Second, the community members initially thought that they would be paid for participating in the study, but after the purpose of the study and the importance of the validity of the results had been explained, the community members were willing to co-operate.

Third, initially, the questionnaire was in English but after testing had been done on a few randomly selected respondents and difficulties with English became apparent, a copy in Shona was made available to community members.

Finally, challenges were experienced in bringing together focus group members. Since it was the farming season, the majority of community members were busy in their fields. Meetings had to be restricted to Sundays and Thursdays when people are not allowed to be in the fields.

Despite these limitations, the researcher is confident enough that lessons drawn from the study serve as a point of departure for other related research on the topic. The findings of the research are still reliable and will provide insight not only on ecological sanitation but also on future projects to be carried out in the community.

Research Agenda Chapter 1 introduces the research problem that led into the formulation of the research questions, aims of the study, research design and methodology to be used. This thesis has been divided into five chapters. Below is an outline of how the subsequent chapters proceed: Chapter 2 provides the literature review and a theoretical background of the study and lays a solid conceptual foundation for the research.

Chapter 3 is focused on physical, social and economic aspects of the case study area of the Danga community in the Zvishavane district and places the study topic in perspective. Chapter 4 provides a detailed account of the empirical field work undertaken in the different case study sites and presents the research findings on the research questions that were raised for investigation on the role of community participation in development initiatives, with special focus on the Danga Ecological Sanitation Project.

Chapter 5 presents general conclusions and recommendations on how best community participation can be structured to improve community empowerment and decision making in developmental projects. This increased interest arose after discovering that the previous approaches to understanding development modernisation and dependency had failed, and resulted in the propagation of the people-centred approach.

The classical development theories lay the foundation upon which the people-centred approach in development will be discussed. The limitations associated with the classical theories will be demonstrated in this chapter and an in-depth analysis of the people-centred approach provided, outlining its merits.

The concept of development is discussed in the first section, providing a foundation for discussing the traditional theories of development. The people-centred approach is discussed before embarking on the ecological sanitation section. In the last section of the chapter, the legislation framework of participation in sanitation projects in Zimbabwe is also discussed.

Conceptualisation of Development The term development has been at the centre of serious contestation in recent decades. Development is multi-dimensional, with scholars and practitioners disagreeing, however, on relative emphasis, priority, and timing.

This definition is broad and attempts to take into cognisance all that can be referred to as development. However there are always dangers of being too broad, which result in losing focus of the main tenets of development.

Recent writings by post-modernists even claim that there is no development, while others, like Gustavo Esteva, have argued that the term itself, underdevelopment, was only coined by President Truman during his inauguration speech Sachs, Schuurman, Chambers viewed development as shifting from ill-being to well-being. This is illustrated in Figure 1 below. In the context of this research the term development is thus viewed as a process of progressive change in a community, which results in the betterment of the lives of ordinary people.

This is achieved through communities themselves indentifying their own challenges and charting the way forward. In the context of this research the term development is viewed as a process of progressive change in a community, which results in the betterment of the lives of ordinary people.

This is achieved communities themselves indentifying their own challenges and charting the way forward. Classical Theories of Development 2. Modernisation theory Modernisation theory such as the evolutionist theory of Darwin is based on the broad belief that societies move from traditional to modern, through a series of stages.

According to Davids et al. Graaff 16 summarised the main principles of evolutionism: It occurs gradually over time; all societies go through the same number of stages, irreversible and progressive, and at the end, all societies end up looking the same. Societies eventually reach a mature stage, characterised by neo-liberalism, a system where the economy is determined by markets, with little or no intervention from the state.

The training and technology required to reach this stage, according to modernists, is provided by the West. For example, interventions in developing countries in terms of aid have been structured along the lines of the modernisation theory. This results in several projects failing to achieve the desired goals. The modernisation theory has also failed to explain growing inequalities within societies, where both very rich and extremely poor people are found.

Other observers have pointed out that this is the case in the majority of countries in Africa. Among the criticisms laid against modernisation theory is that the theory assumes there is a single way to advancement, which is not the case.

Furthermore, the current world economic crisis poses a huge challenge for modernisation theory. This criticism against the modernisation theory laid the foundation for a more radical dependency theory. According to Frank, contemporary underdevelopment is, in large, part of the historical product of past and continuing economic relations between the satellite underdeveloped and the now metropolitan countries cited in Ayres, This relationship can be explained by three distinct factors: lack of investment by multinational companies, unequal balance of trade, and surplus extraction.

The economies of the developing countries are geared towards the export of raw materials. Such attempts have been disastrous Zimbabwe, Cuba and Venezuela and have failed to address underdevelopment. In addition, globalisation has led to crucial interdependence between nations. Dependency theorists have also laid all the blame on Western nations but ignore poor governance and corruption in developing nations.

Alternative Approach to Development 2. People-centred development The two classical development theories of modernisation and dependency failed to explain the continued underdevelopment of the third world nations, epitomised by increasing poverty and inequalities.

This led to the emergence of the people-centred approach, which will be discussed in the section below. This paradigm shift to a more people-centred approach focused on micro-level as opposed to macro-level theorising.

Theron argued that in the people-centred approach, four fundamental questions are asked about the development process and include the following: From what? By whom? From whom? In what way? Participation in development projects 2. Participation Participation describes active involvement by people in civic and developmental organisations, political parties and local government, with the purpose of influencing decisions that affect their lives Roodt, Mikkelsen argued that participation is the sensitisation of people to increase their receptivity and ability to respond to development projects.

In the context of this research, the term participation is regarded as the ability of the community to identify their challenges and needs and then take charge of their scenario. Change agents are only there as catalysts, and the community members are at the centre of development. Types of participation in community development Traditionally, participation was viewed as active, passive or interactive Mikkelsen, Active participation is open and community members take part actively in all stages of the project.

On the other hand, during passive participation, the community maintains a distance and never intervenes in the activities; they are told what is going to happen or what has happened already. Interactive participation is when people take part in joint analysis as well as the planning process and the members of the target community improve their existing structures as well taking charge of their development process Roodt, Recent work by researchers like Mikkelsen identifies more types of participation, which will be discussed below.

The first, passive participation, describes a situation where people are told what is going to happen or has already happened, with no ability to change it Mikkelsen, It typifies the top-down approach; the people are only informed, probably as a way to legitimise the project.

There is no true ownership of the project because people are not involved from the inception of the project. The second type, according to Mikkelsen , is participation in information giving, where people participate by answering questions posed by extractive researchers and developers.

The people do have the opportunity to influence the proceedings, and the findings are not checked for accuracy. Not entirely different is the third type of participation, that is, by consultation, where people participate by consultation and decision regarding the nature of problems, and possible ways to solve them depend entirely upon the researchers. The people do not take part in the decision-making process. This appears to be the case in most communities in South Africa currently. The onus for decision making lies with the local government authorities, not the affected communities.

People also participate for material incentives, such as providing labour and land in return for food, cash or other material incentives Mikkelsen, In this case, people do not have the will to proceed once the incentives are finished. Functional participation is when people participate by forming groups or committees which are externally initiated Mikkelsen, These groups are seen as the means to achieve predetermined goals.

On the other hand, interactive participation is seen as being involved in analysis and development of action plans Mikkelsen, In this regard, participation is considered as a right and not just a mechanical function. Groups are formed, together with partnerships, and there is use of systematic and structured learning processes.

Groups therefore take control of the local decisions, so people have a stake in maintaining structures or practices Mikkelsen, This type of participation empowers the community and is hence ideal for community development. It leads to sustainability and ownership of the projects. Optimum participation, according to Mikkelsen , indicates the need to focus closer attention on the different contexts and purposes in order to determine what form of participation makes sense.

The extreme form of analysis of participation is when it is seen as manipulation. In this sense, for Rahnema cited in Mikkelsen. Khwaja, raised a concern that, in light of the importance of community driven development and decentralisation of public services, there may currently be too great a reliance on participation as a cure for all.

Participation in this sense is regarded as a scapegoat to blame the failure of certain projects on the community. Mikkelsen supported this view by stating that people participate by taking initiatives to change systems, independent of external institutions, although the latter can help with an enabling framework. People retain control of resources used, and in addition, such self- initiated mobilisation may change the distribution of resources.

Though Rahman called for complete self-reliance, he noted the fact that human dignity plays an important role in participation and eventually development.

For Jeppe , cited in Roodt , community development is the conscious process wherein small, geographical contiguous communities are assisted by more developed communities to achieve improved standards of social and economic life. As pointed out earlier, these interventions have the sole purpose of improving the lives of the community. An understanding of the concept of community development is essential to this study, particularly in terms of the ecological sanitation process.

In the context of this research, the concept community development denotes a conscious process, in which a group of individuals with a common interest come together with or without the help of outsiders to make positive change in their lives. First, community organising involves mobilising the target community and identifying problems. Through mobilising and raising awareness, interventions sustainable development is identified. Thereafter, community visioning and planning takes place, which is a process through which the community identifies its future vision.

The visioning process establishes a desired end state for the community and a vision for the future towards which they strive Green, The purpose of monitoring is to provide indications of whether corrections need to be made in the action plan Green, Unlike monitoring, evaluation is collection and analysis of information about the work of the organisation at a single point in time. Empowerment Development is not about the delivery of goods to a passive citizenry.

It is about active participation and growing empowerment Callaghan, The aim of this study is to raise awareness so that the community may be elevated to a platform where decision making lies in their hands. It is hoped that through this study the Danga Community as well as other rural communities will realise the need for collective effort towards improving their lives.

Capacity building Capacity building refers to enabling institutions to be more effective and efficient in the process of identifying, implementing, monitoring and evaluating of developmental projects Davids et al.

It is the overall ability of the individual or group to perform their responsibilities Frank, According to Swanepoel , by continuously fulfilling their needs, people learn to realise their objectives more easily. It is a mechanism to enable local people to determine their own values and priorities and act on their own decisions. Just as in the concept of consientisation, the full potential of individuals is realised after they have been made aware; then, depending on their capabilities, they act in order to achieve their goals and objectives Freire, The study is intended to show to what extent participation can be used as a vehicle to enable capacity building in rural communities with regards to sanitation provision.

Training of community members also encompasses capacity building. Self-reliance For Kotze and Kellerman , people-centred development shifts the emphasis in development action to people, rather than to objects and production, and to the enhancement of their capacity to participate in the development process.

Heavily relying on outside resources, such as funding, has resulted in most interventions being unsustainable. A people- centred approach enhances self-reliance in communities. Resources to start an intervention maybe needed, but continued support in terms of resources may result in the collapse of certain projects when funding is no longer available. In this research, the term self-reliance can be viewed as the ability for individuals or communities to generate resources for their own initiatives without over reliance from donor help.

If the community members start appreciating their strengths and explore the use of cheap and locally available resources, there is a greater chance for sustainability of projects. In order to achieve acceptance, a sense of ownership must be engendered. Furthermore, ownership can only be achieved through active participation of the target community.

He goes on to say that successful development is dependent not only on the quantity or quality of the product but also on the process of introduction. Once the community is empowered, members of the community take ownership as the development project belongs to them.

Sustainability of any project is crucial since the development process is continuous. Failure of a community to take ownership has resulted in, for instance, vandalism, corruption and sometimes premature termination of projects which are supposed to benefit the community.

Ecological Sanitation 2. Explanation of terms This section will outline the three major terms used in this study. These are sanitation and waste, ecological sanitation, and ecological sustainability. This usually includes disposing of or hygienic management of human and animal excreta, refuse, and wastewater, the control of disease vectors and the provision of washing facilities for personal and domestic hygiene. Sanitation involves both behaviors and facilities which work together to form a hygienic environment.

However, sanitation is an extremely complex issue since there is no single solution or a universal approach to tackling it, especially in developing countries Austin et al. The concept waste has never been subject to a single straight-forward definition. Although this definition encompasses several categories of waste, this study will be focusing on human waste.

This includes urine and solid faecal waste from people. Special attention is given to this type of waste because if untreated, it can be a hazardous breeding source for pathogens and other infectious diseases. Careful management of human waste leads to better sanitation and eventually a healthier population. Ecological sanitation Ecological sanitation is an approach in which human waste is recycled for purposes of agriculture. Duncker et al.

According to Morgan , ecological sanitation is a system that makes use of human excreta and turns it into something useful, where the available nutrients can be recycled in agriculture to enhance food production, with minimal risk of pollution of the environment and with minimal threat to human health. Faecal matter is generally responsible for most diseases spread by human excreta. Therefore, ecological sanitation seeks prevention of pollution and disease caused by human excreta, treatment of human excreta as a resource rather than waste and recovery and recycling of the nutrients Esrey et al.

According to EcoSanRes , ecological sanitation can be viewed as a three-step process: containment, sanitisation and recycling of human excreta. Austin et al. Even though the technologies developed for ecological sanitation across the world vary, yet the concept of ecological sanitation remains at the core.

The diagram below represents a simplified concept of closing the loop Esrey et al. The current challenges in countries across the globe indicate that a change towards sustainable waste management is a prerogative. Some of the advantages outlined in favour of ecological sanitation, according to Werner et al. According to the World Commission on Environment and Development, sustainable development is not a fixed state of harmony, but rather a process of change in which the exploitation of resources, the direction of investments, the orientation of technological development, and institutional change are made consistent with the future as present needs Irwin, One of the most important goals to be achieved by ecological sanitation is sustainability.

In the opinion of Warburton , humanity has the ability to make development sustainable, which means to ensure that it meets the needs of the present without compromising the ability of future generations to meet their own needs.

Limitations of Current Conventional Sanitation Systems According to Unesco , current conventional sanitation systems are based on water- borne sewerage. In addition, they require huge investment to establish as well as to operate.

Even pit latrines found in most rural areas in developing countries are causing ground water pollution. Research has shown that the bulk of the sewage in fast growing cities in developing countries is dumped, untreated, into fresh water sources. Water usage in these systems is often unprecedented, already stressing depleted fresh water sources in the world. Obviously, there is a need for alternative sanitation systems which are cheap, accessible and have little or no impact on the environment.

Health Risks Associated with Ecological Sanitation Despite the plausible benefits, as well as sound environmental gains, associated with ecological sanitation, concerns have been raised in terms of its health risks.

However, human excreta contain pathogens which cause diseases. Feachem et al. Special conditions under which urine is stored can result in the reduction of pathogens, rendering it safe for agricultural purposes. The most effective way to reduce transmission of pathogens from one stage to the next is to form barriers between faecal matter and flies as well as the human environment.

Successful ecological sanitation systems should follow necessary environmental strategies to kill pathogens so that the excreta can be safe for handling. Research has shown that if these strategies are followed properly, pathogens can be effectively destroyed. These results suggest that models of lake metabolism based on temperate 52 ecosystems can be expanded to include dryland river waterholes, which group with 53 eutrophic lakes due to their high inorganic nutrients, low allochthonous inputs, and 54 autotrophic metabolic balance.

GPP exceeds R in autotrophic 67 ecosystems, resulting in excess organic carbon that is exported or stored. In contrast, 68 R exceeds GPP in heterotrophic ecosystems, resulting in net consumption of organic 69 carbon and a requirement for allochthonous organic carbon inputs to maintain R. However, 72 autotrophy has been reported for some desert streams Minshall ; Fisher et al.

Bacteria use both allochthonous and 78 autochthonous sources of organic carbon for R and production incorporation into 79 biomass , with the availability of the two sources in the ecosystem expected to 80 influence their relative importance to bacteria Kritzberg et al.

The dominant source of organic carbon used by bacteria should therefore 82 indirectly relate to the metabolic balance of the system, with autochthonous carbon 83 being important in autotrophic systems and allochthonous carbon in heterotrophic 84 systems.

Relationships between chlorophyll a and bacterial production have been 85 found in cross-system comparisons of pelagic zones Cole et al. However, in other 89 heterotrophic systems, no relationship is found between bacterial and algal 90 production, consistent with bacterial production from a non-algal source of carbon 91 Findlay et al.

To date, studies of bacterial carbon use 92 have focused predominately on pelagic environments del Giorgio et al. In some cases, multiple aspects have been 97 measured, though usually a single process in both benthic and pelagic zones e. Chrzanowski and Hubbard ; Cole et al. Rarely have both zones and both types of production been measured in a single system but see Edwards and Meyer ; Edwards et al.

The benthic zone has been the main focus of studies of small streams because its metabolism typically greatly exceeds that of the water column Keithan and Lowe ; Davies In contrast, lake studies have predominately focused on the pelagic zone, given the generally greater water depths. Similar to many dryland rivers worldwide, large inland rivers in Australia exhibit extremely variable flow Puckridge et al. Episodic floods inundate the extensive floodplains and networks of channels that characterise these river systems.

Extended periods of no or low flow are typical between floods, therefore surface water is often limited to a series of disconnected channels and waterholes. Even under lentic conditions, mineral turbidity is high in these river systems due to fine clays in suspension Bailey ; Sheldon et al. The combination of a large terrestrial-aquatic interface created by long, narrow channels and low light availability associated with high turbidity would be expected to create conditions in which allochthonous carbon from riparian vegetation would be more important than autochthonous production in waterholes.

Because of the high turbidity, there are no aquatic macrophytes, and benthic algal production is restricted to shallow littoral margins where light levels are sufficient. Despite this limited spatial extent, stable isotope analysis suggested that benthic algae were the major source of energy supporting waterhole food webs during a period of no flow Bunn et al.

It is likely that the general patterns observed in temperate, clear-water systems may not hold when applied to the high mineral turbidity and associated low light availability of dryland systems in Australia and elsewhere. While some studies have reported on components of primary production Pieterse and Roos ; Bunn et al.

The purpose of this study was to quantify pelagic and benthic primary production, respiration and heterotrophic bacterial production to obtain an understanding of whole-ecosystem carbon cycling in a turbid, dryland waterhole. Specific aims were to: 1 assess rates of waterhole metabolism during no flow conditions and 2 determine the relative importance of autochthonous and allochthonous sources of carbon for fuelling bacterial metabolism.

We used methods measuring changes in dissolved oxygen as well as those employing radioisotope tracers to provide information on different aspects of carbon cycling, including variation in GPP within the narrow photic zone, and to provide independent constraints on components of the waterhole carbon budget. The Cooper Creek catchment is in a relatively undisturbed state with no intensive agriculture, low cattle stocking densities 1.

Cooper Creek has an extremely low gradient and is characterised by multiple, anastomosing channels, particularly in the Channel Country near Windorah See Figure 1 in Bunn et al. Maximum daily air temperatures at Windorah range from Stream flow is generated by seasonal monsoons as well as periodic local rainfall, resulting in high inter-annual variability in flow Puckridge et al.

Analysis of the flow data at the Currareeva gauge near Windorah showed an average of 3 dry spells no surface flow per year during the period — , with more than half lasting longer than 25 days and a quarter lasting greater than days Bunn et al.

Further description of waterholes in the region can be found in Arthington et al. There were no other flow events between then and when the study was conducted. Dimensions of the waterhole were estimated using a combination of field surveys of waterhole cross sections and a long section and remotely sensed imagery Davis et al. Glen Murken is small to moderate in size compared to other waterholes in the Windorah area Bunn et al.

At the time of sampling, the dimensions of Glen Murken were as follows: surface area 13, m2, perimeter 1, m, width The small chambers were deployed in pairs and run for 2 h around mid-day — , with one of each pair covered with metal foil to create dark conditions total of 6 chambers.

Each probe was attached to a data-logger TPS , which recorded DO and temperature at min intervals. The thick clay substrate provided a reliable seal at these depths of insertion.

For large chambers, the mean rate of change for 6 to 8 h after dark was taken as the rate of R, and daily respiration was calculated by assuming the rate was constant over 24 h. GPP was calculated as the sum of the DO produced during daylight hours plus the DO consumed by respiration during that period of time based on the night-time respiration rate.

Hourly average rates of GPP were also calculated for comparison with the small chambers and the 14C incubations, which lasted for 2 h. Changes in DO concentrations over time mg O2 L-1 h-1 were multiplied by chamber volume and divided by substrate surface area to obtain values in units of mg O2 m-2 h These rates were converted to units of carbon assuming that one mole of carbon is equivalent of one mole of O2 for both respiration and photosynthesis i.

Calculations of R and GPP for the small chambers were similar to those for the large chambers, except the dark chamber in each pair was used to obtain the rate of respiration. A weighted mean for the whole photic zone was obtained using the proportion of the photic zone represented by each section and either the mean of two rates at the ends of the section or single rates for the shallowest and deepest sections.

The rates obtained from the large chambers were applied over the entire photic zone and are presented as the mean of 4 replicates. Water was collected from two depths: 0. At the end of the incubations, the bottles were put on ice in the dark, and two mL sub-samples were filtered from each bottle onto 0. The chambers were transparent screw-cap vials modified to have an open bottom and fitted with a rubber septum in the cap.

The chambers were deployed at five depths ranging from 0. At the end of the 2 h incubation, the chambers were retrieved by carefully digging below the chamber and inserting a rubber stopper at the base of the chamber.

The top 3 mm of benthic sediment was collected by extruding the core contained within the chamber and slicing the sediment into a vial. Benthic samples were also left for 19 h and then sonicated for 10 sec at 15W Branson Sonifier to homogenise the samples. The benthic sample values reported are the mean values of the replicate sub-samples.

Rates from different light intensities water column and different depths benthic were used to scale rates to the entire photic zone using a weighted mean as described above for small DO chambers.

For water column rates, a representative depth was calculated for each light intensity using the measured extinction coefficient. To measure bacterioplankton production, several litres of water from the photic zone 0. A time course was conducted from 0 — 30 min in 5 min intervals to assess the linearity of incorporation total of 7 samples. The filters were radioassayed using a liquid scintillation counter within 1 week of collection.

Each 15 ml sample yielded 3 sub-samples that were filtered and counted separately, and their resulting values averaged to represent the time point. The rate of thymidine incorporation reported is the mean of the six rates determined from time points 5 — 30 min.

Rates of thymidine incorporation were converted to rates of bacterial production in units of carbon as described by Pollard and Greenfield A value of carbon content per cell is required for this conversion, and values vary substantially across environments Nagata Two values were considered to provide high and low bounds to the rates of bacterial carbon production.

Burford and A. In the laboratory, three sub-samples were taken from each sample, diluted to a ratio of with distilled water, sonicated, and filtered onto black polycarbonate 0. A minimum of 65 cells were counted per subsample. Cell densities of the three sub-samples were averaged to represent each sample, and the value of water column bacterial abundance reported is the mean of the three samples.

A composite sample of benthic sediment was collected with a flat trowel by scraping the top 3 mm of sediment from a delineated area in the photic zone 0. The filters were then processed and rates of bacterial production calculated as described above for the bacterioplankton. The procedure followed was similar to that for the bacterioplankton counts, with greater dilution and fewer subsamples.

Two sub-samples were taken from each sample, and serial dilutions with sonification and vortexing were carried out. Cell densities of the two sub-samples were averaged to represent each sample, and the value of benthic bacterial abundance reported is the mean of the three samples. For consistency of comparison between GPP and R, values were taken from 24 h large chamber incubations, from which both measurements were obtained. Because of the shallow bathymetry, the waterhole benthic zone was assumed to have the same surface area as that of the waterhole.

The benthic photic zone area was calculated as the width of the zone parallel to the bank slope, multiplied by the perimeter. The mean rate of benthic GPP was applied to the photic zone area. The portion of the benthic zone not in the photic zone was assumed to make no contribution to primary production see Bunn et al.

The rest of the benthic zone was assumed to have a rate of R of 0. The remainder of the waterhole volume was calculated as the average waterhole depth minus the photic zone depth times the surface area. Three of the large chambers used for benthic measurements were fitted with lids water volume 9 L and were suspended in the water column in the photic zone 0 — 0. Measurements were made over 24 h, and calculations were made as described for the large benthic chamber incubations.

Conditions were comparable with those at the time of sampling Glen Murken, including greater than 6 months since flow, the same photic depth of 0. I would highly recommend their services to anyone. Acquisition Experts arranged the transition of my current medical practice from the previous owner. Their contribution to the smooth transition was tremendous; helping me understand the dynamics and the elements to look at when buying a medical practice.

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