Ecosystem Services and River Basin Ecohydrology

Ecohydrology is a new challenging approach to aquatic ecosystems management that considers dual regulation between biota and hydrology, at the entire river basin scale, as the key to restoration and long term sustainability of aquatic ecosystems health. Managing human-environmental systems, such as river basins, is strongly accompanied by several decisions about the intensity of human actions, which potentially affect natural or nature-near ecological systems. At river basin, upstream uses of water impact on the ecohydrologic functioning of downstream ecosystem, and on the tradeoffs between provision of upstream and downstream ecosystem services. This chapter introduces the the importance of integrating the concept of ecosystem goods and services with the ecohydrology approach, for the management of water resources from riverine do estuarine and coastal ecosystems.

In this chapter we discuss the different definitions, advantages and limitations of the concept of ecosystem services. Ecosystem services are sets of environmental properties derived from ecosystem structures and processes which are arranged from an anthropocentric point of view. They are the benefits people obtain from ecosystems, and thus they can be used to represent the environmental interrelations between the three sectors of sustainability. The managing human-environmental systems, such as river basins, is strongly accompanied by several decisions about the intensity of human actions, which potentially affect natural or nature-near ecological systems. At river basins, upstream uses of water impact on the ecohydrologic functioning of downstream ecosystems, and thus provoke tradeoffs between the provision of upstream and downstream ecosystem services. Ecosystem services can be classified in many ways depending on the objectives of the observer but in all recent classifications, three groups of services are distinguished: regulating, provisioning and cultural services. The Identification of ecosystem services can be used to quantify the impacts on ecological systems, to contribute to the identification of gaps and to provide policy-relevant information on a sustainable use of these services to maintain their capacities for future generations. The ecosystem service concept has been developed very fast during the last years and a methodological framework has been created that can be applied in environmental management. Incorporating this concept into assessment frameworks, such as the DPSIR approach, makes it more broadly applicable. Despite some limitations, ecosystem services have the advantage to demonstrate the enormous human dependence from nature by focusing on the critical roles of ecosystem functions and structures for sustaining human life and well-being.

Many people seek and interact with aquatic ecosystems such as seas, rivers and wetlands to obtain non-material benefits provided by cultural ecosystem services. These services influence the way people live and feel in the world and contribute to the satisfaction of fundamental human needs. However, cultural ecosystem services are often undervalued, underprotected, and neglected from ecosystem services studies. This arises from difficulties in their operation such as uncertainties on their generation and on people’s demand for cultural ecosystem services.

This chapter provides an overview of cultural services generated by aquatic ecosystems. It gives insights into their biophysical generation and it explores the relationships between human needs and ecosystem service demand. Furthermore, it illustrates the values of cultural ecosystem services with a case study, and it proposes a driver-pressure-state-impact-response (DPSIR) framework as a management tool for decision-makers.

These topics are fundamental to apply better strategies that can effectively protect and conserve aquatic ecosystems and their cultural service provision.

The influence of hyporheic exchange on the transport and transformation of solutes occurs in the environments where hydrologic and biogeochemical processes are dynamic and highly heterogeneous. We present three examples to specify the importance of hyporheic zone processes on different spatial scales ranging from small reach scale to whole river sections. We investigate the (i) impact of physical and biological clogging on the functional significance of the hyporheic zone, use (ii) small scale numerical studies analysing factors controlling advective exchange and solute transport and transformation and reveal (iii) spatial variation of nitrogen removal in river networks. Using a river in a pristine environment in central Mongolia we demonstrate that biological clogging shows seasonal effects on the hydrologic connectivity whereas biogeochemical regulation and habitat seemed to be affected less. Physical clogging revealed to have long-term impacts on the hydrologic connectivity, biogeochemical regulation and habitat. The simulation study of a lower mountain range river in central Germany shows that the location of highest hydraulic gradient is the location of the highest water exchange and nitrogen transformation. In spite of uncertainties involved in the process-based models valuable conclusions can be made towards focused theoretical and experimental studies for new process understating. The large scale denitrification study indicates a decreasing denitrification rate with increasing river length, but river morphology may modulate this general trend considerably. Furthermore nitrate concentration affects the nitrogen removal significantly. The associated longitudinal pattern of nitrogen removal can be assumed to be typical in highly eutrophic low order rives of central Europe.

Despite the important role of ecosystem services, their study and associated monetary value is limited mostly to terrestrial, estuarine and coastal systems, with few studies undertaken in open marine waters and deep water systems. In addition, human activities are degrading marine ecosystems and the services they provide. To reverse this situation, various legislations have been implemented worldwide. Within this context, conservation activities (i.e. protection, prevention and restoration) are strongly encouraged. Hence, this Chapter: (i) reviews the marine goods and services provided by marine ecosystems; (ii) reviews conservation activities (as a means to maintain and improve goods and services), paying special attention to the effects of restoration on ecosystem services; and (iii) determines the gaps to be covered and the ways to move forward, in relation to conservation of marine goods and services.

The concept of ecosystem services is a promising approach to assess ecosystems also in river basins, particularly in view of their multifunctional use and sustainable development. The chapter mainly focuses on terrestrial ecosystems. Starting from the definition and classification of these ecosystems, relevant provisioning, regulating and socio-cultural services are listed, together with short descriptions, examples, their relations to water, and with suitable indicators. The EPPS assessment framework (Ecosystem Properties, Potentials and Services) is presented and then illustrated on the example of two very frequently occurring terrestrial ecosystems or land use types: (1) semi-natural grassland, and (2) farmland (with the specification “energy cropping”).

Quantifying, modelling and mapping ecosystem services is an important step to the application of ecosystem services in practice and decision making. Watersheds are functional entities that provide an appropriate spatial scale for water flow analysis and integrate all the processes that occur within their boundaries. Multiple ecosystem functions occur within watersheds, providing water-related ecosystem services such as freshwater provision, groundwater recharge, water purification and flood regulation. A matrix approach was applied, linking different land cover types within watersheds to different ecosystem functions and services. Supply capacities of different land cover types and respective changes over time were assessed. By applying the watershed-based hydrologic model KINEROS and the GIS based AGWA tool, water retention functions of different land cover classes in the Bulgarian case study areas Malki Iskar, Vidima and Yantra were assessed. Based on the modelling results, flood regulating ecosystem service supply capacities were quantified and mapped in the three watersheds. A digital elevation model, land cover information and accessibility data were used to compile maps of demands for flood regulating ecosystem services. Supply-demand budgets were calculated and mapped for the study areas using the flood regulation supply and demand maps. The results quantify and illustrate complex ecosystem function–service–benefit relations in watersheds. Comparable procedures and calculation algorithms can be applied for other ecosystem functions and services relevant on the watershed scale. The approach is transferable to other regions and can provide important information for integrated watershed management.

Watershed processes – physical, chemical, and biological – are the foundation for many benefits that ecosystems provide for human societies. A crucial step toward accurately representing those benefits, so they can ultimately inform decisions about land and water management, is the development of a coherent methodology that can translate available data into the ecosystem services (ES) produced by watersheds. Ecosystem services (ES) provide an instinctive way to understand the tradeoffs associated with natural resource management. We provide a synthesis of common terminology and explain a rationale and framework for distinguishing among the components of ecosystem service delivery, including: an ecosystem’s capacity to produce a service; societal demand for the service; ecological pressures on this service; and flow of the service to people. We discuss how interpretation and measurement of these components can differ among provisioning, regulating, and cultural services and describe selected methods for quantifying ES components as well as constraints on data availability. We also present several case studies to illustrate our methods, including mapping capacity of several water purification services and demand for two forms of wildlife-based recreation, and discuss future directions for ecosystem service assessments. Our flexible framework treats service capacity, demand, ecological pressure, and flow as separate but interactive entities to better evaluate the sustainability of service provision across space and time and to help guide management decisions.

In this chapter, requirements for and lessons learnt from assessing the impact of land use and land cover change (LULCC) on the provision of hydrological ecosystem functions (ESF) and services (ESS) are demonstrated based on selected case studies. First, potentials, limits and transferability of a detailed land classification scheme developed for Germany are explored. Second, an approach how to make use of landscape metrics to correct the assessment of ESF and ESS provision in LULCC impact assessment is presented to better account for land-use pattern heterogeneity. Third, the potential of Hydrological Response Units (HRU) to bridge scale-related discrepancies between modeling, assessment and decision units is discused. Finally, a conceptual framework approach is suggested that builds on the HRU concept and merges the latter with a cellular automaton based LULCC impact assessment framework.

Using the example of the catchment area of the Jahna River in the loess region of Saxony (Germany) status and deficit analyses were accomplished with regard to environmental objectives of the EU Water Framework Directive. Currently, there is no body of water in the study area in good ecological condition. In this intensively used agricultural area, the nutrients nitrogen and phosphorus as well as the acceptance and costs of measures against soil erosion and water pollution were determined as target variables. Significant water pollution through nutrient leaching was identified, and spatially differentiated risk and reduction potentials were demonstrated. The multi-criteria analysis in form of the utility value analysis was applied to support the objective decision process in the selection and prioritization of measures to reduce erosion and nutrient inputs to water. By equal weighting of the target variables the conservation tillage on the critical source areas and the cultivation of catch crops are representing the measures with the highest benefit in the catchment area of the Jahna River. A benefit-cost-ratio of 2 to 1 was estimated.

For planning and obtaining a sustainable environmental management of river basins, stakeholder information and participation is an important procedure for the decision-making process. Stakeholders need suitable information on spatio-temporal variations in ecosystem services which can be derived by different quantification methods such as modelling. This study shows an approach to combine ecohydrological modelling results with valuation methods for assessing ecosystem services. The rural lowland Kielstau river basin in Northern Germany serves as the study area. Based on the results of the ecohydrological model SWAT, simulated variables were used as indicators for regulating services and were directly translated into a 0–5 valuation scale for each different land use/land cover classes. One detailed example is given by providing and analysing the SWAT variable ‘sediment yield’ as an indicator for the regulating ecosystem service ‘erosion regulation’. The SWAT model results reveal the temporal changes in erosion regulation due to crop rotation and different precipitation patterns over the years, which includes important information in the assessment of ecosystem services and the formulation of management actions.

Diverse aquatic ecosystems in Tanzania provide economically important ecosystem services. The rich supply of these services is under threat. Projections show critical water scarcity in the country by the year 2050. Demography, excessive withdrawals, land use changes, exotic species invasions and climate change that result in loss of perennial flows, eutrophication, sedimentation, and algal blooms are among the major drivers of aquatic ecosystem changes in Tanzania. Water resources uses and their management in Tanzania are mainly determined by the national macroeconomics and policies. In this review, Great Ruaha River (GRR) and Lake Victoria Basin (LVB) are used as case examples for demonstrating status, trends and drivers of ecosystem changes, and their management options in Tanzania through government and donor efforts. As a way forward, in the new Tanzania National Water Policy (NAWAPO) of 2002, Integrated Water Resource Management (IWRM) approaches as tools to ensure ecosystem protection and stakeholder’s participation have been adopted. Water for environment is given a second priority in water allocation after basic human needs. The Integrated Water Resources management and Development (IWRMD) plans currently being developed will form legal basis in management of water in an environmentally and ecosystem responsible manner. Through the IWRMD approved plans, drastic actions can be legally taken to protect and/or restore important ecosystem services in hotspot areas like the GRR.

Demands for ecosystem services such as food and clean water are growing with concurrent human actions diminishing the capability of many ecosystems to meet these demands. In West Africa, coastal watershed ecosystems are subject to many pressures (e.g., land-use change, resource demands, and population changes); their extent and pattern of distribution is changing, and landscapes are becoming more fragmented. In this context, we review the current state and analyze the drivers of change in coastal watershed ecosystem goods and services in West Africa (Ghana and Nigeria). Based on identified critical drivers of change- “climate change” and “socio-economic”, we present possible scenario for effective management of coastal watershed ecosystem services. Whilst there is an urgent need to safeguard ecosystem services, policy goals leading to sustainable management of coastal watershed ecosystems for delivery of ecosystem services need to be established and implemented at both international and national levels.

Coral reef and seagrass ecosystems of the Great Barrier Reef (GBR) are in severe decline. Water quality associated with pollutant discharge from the rivers discharging into the GBR is a major issue for these GBR ecosystems and associated species such as dugongs, turtles and fish. The main source of river pollution is agriculture with sugarcane cultivation, beef grazing, grain cropping and horticulture the principal industries. Discharge to the GBR is of poor quality in many rivers, contaminants are present in the GBR lagoon at concentrations likely to cause environmental harm and the causal relationship between poor water quality and declining GBR ecosystem health is well understood. Action to improve management practices to reduce sediment, fertiliser and pesticide losses from farms is being taken and the pollutant loading of river discharge reduced. Improved practices are funded through the combined efforts of Australian Governments (Federal, State and local) and farmers. Whether these improved practices and the pollution reductions achieved are sufficient to improve GBR ecosystem health is not certain in the face of other threats to the GBR such as climate change and large scale coastal development associated with urban and port expansion.

Aquatic ecosystems of Bangladesh have crucial importance as majority of the people of Bangladesh are dependent on this sector. Recently this ecosystem is under constant threat due to increase of population, intensive agriculture, overexploitation, pollution, poorly planned infrastructures, climate change, water diversion by India, lack of proper policy and directives. These threats results degradation of this aquatic ecosystem which have deleterious impact on human livelihood and agro-environmental practice. Taking this into consideration, this review article describes the importance of aquatic ecosystem; causes and effects of degradation of aquatic ecosystem as well as the existing management practices are highlighted and based on this discussion probable solution are proposed for aquatic ecosystem management by focusing ecohydrological approach.

Estuaries can be considered strategic locations for human settlement, supporting many anthropogenic activities. These pressures are then added to the naturally occurring ones, resulting in many cases in eutrophication processes and water pollution. The integrity of ecosystems functioning, especially concerning the benefits that attain human well-being, can come easily under pressure if not properly managed. Assuming that human well-being relies on the services provided by well-functioning ecosystems, changes in the ecological functioning of a system can have direct and indirect effects on human welfare. However, many of the interrelations between ecosystem functioning and the provision of services still require quantification in estuarine ecosystems. Therefore, it becomes fundamental to understand the complex and intricate relations in estuarine ecosystems, among ecological, social and economic factors, which are fundamental in designing and implementing management policies. Hence, this chapter tries to explore the interrelations between ecosystem functioning and services provision in estuaries, highlighting that linear relationships between biodiversity and services provision are unlikely to occur. A general overview of several pressures influencing biodiversity, functioning and integrity of estuarine systems, as well as their associated services, is also provided. Furthermore, an illustrative example is provided based on the evaluation of the trade-offs among the services provided by the Mondego Estuary (Portugal). Limitations of the methodologies used to assess estuarine services are discussed. The use of this knowledge on natural resources governance is assumed to be the key to attain the sustainable use of these systems.