Climate Change and Ecosystem Services

In this post, we will delve into the inevitable relationships between provision/delivery of ecosystem services and future environmental change.  

Climate Change in Southern Africa

The most direct impact of future climate change in the continent would be changes to the water balance of lakes, wetlands and rivers. More intense, less frequent extreme precipitation events and more frequent dry episodes would fundamentally alter the regime of rivers and generally reduce annual discharge. Climate change will also impact storage capacity of dams and encourages greater evaporative losses (Magadza 1994). Loss of perennial drainage sustaining surface water due to the non-linear response of drainage to changes in rainfall would also mean loss of perennial surface water and increased water scarcity (Wit and Stankiewicz 2006). This will be much more prevalent for rural areas where technology are not readily available . Ironically, these rural areas are,  the most dependent on ecosystem services provided by freshwater systems.

Climate Change and freshwater resources in Africa

Changes in the presence, timing and distribution of surface water would no doubt have significant impacts on productivity and thus the ecosystem's capacity to provide and deliver ecosystem services. Modelled increases in dry season flow and increased hydrological variability in Africa will also mean increased importance of irrigation to sustain food production which no doubt will involve dams and river regulations that will have substantial impacts to ecosystem services themselves (Hollis and Thompson 1995). On a cultural and supporting services, the timing and presence of water would dictate recreational activities, navigational routes and eco-tourism. On regulating and provisioning services, knock-on effects to food supply, water supply and aquatic productivity will have immense societal impacts. 

In Lake Tanganyika in East Africa, it was found that regional warming and increased surface water temperature reduced water column mixing, nutrient upwelling and entrainment, resulting in decreased aquatic productivity. The lake historically produced up to 40% of animal protein food supply for surrounding countries, but fisheries yield declined by up to 30% since the beginning of the 20th century (O'Reilly et.al. 2003).

Having said that, climate change is by no means the single threatening element to freshwater ES. Lake Chad is probably the most famous case study in the coupling between anthropogenic actions and climate change in driving the collapse of ecosystem services (Salman and Martinez 2015). Rice and cotton irrigation, river diversion/substantial irrigation schemes and declining water quantity/quality from increased use of agro-chemicals all contributed to a dramatic decline in surface area and lake levels alongside climatic changes to inter-annual hydrological variability (Coe and Foley 2001). Food/export production were therefore boosted at the expense of dramatic decline in an entire suite of other ecosystem services:

Ecosystem services at risk after coupled impacts from agricultural development and climate change at Lake Chad

Wetlands and Lakes IIII - Impact Assessments

In this post, I will address the use hydrological modelling to better carry out scenario planning and safeguard the sustainable delivery and integrity of the entire suite of freshwater 'umbrella' services.

Impact assessments

Modelling potential impacts  have been an important part of contemporary hydrological research. Studies may use models built for climate scenarios to simulate changes in river/flood regimes. Other studies may model potential changes by different irrigation development. I will assess both through modelling studies at the Inner Niger Delta and the Pongola basin.

Inner Niger Delta

Ecosystem Services

The largest floodplain wetland in West Africa, the Inner Niger Delta is located downstream of the Upper Niger river basin which covers an area of >100,000 km2. The Inner Niger Delta is one of the most productive region in West Africa, supporting over 1 million people across the Sahel in 'river-dependent economies'. Ecosystem services include:

1. Agriculture (dams, irrigation schemes) - mainly for rice cultivation
2. Fisheries
3. Grazing (sheep, cow and goats)
4. Hydroelectric power
5. Wetlands regulating services (one of the world's largest RAMSAR site)

Future climate change is most likely to inflict substantial changes to the duration, timing, quantity and quality of river flow which will impact the integrity of these ES. 

Modelled changes to inflow
discharge into Inner Delta

Hydrological Modelling

Using a semi-distributed conceptual model , river discharge were projected to decrease by 0.8% to >50% and flood extent can reduce by up to 50% by 2100 under a 2 degrees rise in temperature according to different GCM output (Thompson et.al. 2016). Projected changes to the river/flood regime through modelling therefore sheds light on the potential detrimental effects to ecosystem services within the basin. Reductions to peak flow would lead to a significant decline in available agricultural areas and may impact food security alongside increasing population pressures (Liersch et.al. 2013). Environmental flows analyses on ecosystem integrity using results from hydrological modelling would further provide information on the impacts climate change exert on ecosystem integrity and capability to provide and supply ES.

Pongola Floodplain

Ecosystem Services

The Pongola River basin occupies an area of >7000 km2 in South Africa. Controlled releases of the Pongolapoort dam regulates inflow into floodplains, significantly impacting downstream provision and access to ecosystem services which were dependent on the natural peak/low flow regimes. Ecosystem services include: grazing, building, fuel wood, food production, biodiversity, flood attenuation, water quality control and cultural activities.

Hydrological Modelling

In order to adequately plan for future development scenarios to safeguard both ecosystem services and economic livelihoods, Lankford et.al. 2011 undertook hydrological modelling of 3 different flow releases scenarios to examine possible socioeconomic and ecological impacts.

1. Unstructured releases - poorly controlled releases 
2. Regulated releases with diversified economy - coordinated releases of water for both agricultural development and ecosystem services
3. Regulated releases with single sector (agriculture) - full releases to support chosen agricultural development

Impacts to ES from Scenario (2)

Modelled findings indicate that scenario 1 would favour elites/powerful who are most likely to dictate flow releases, leading to decline in all identified ecosystem services. Scenario 2 contributes to poverty alleviation with minimal impacts to ecosystem services while encouraging diversification and sustainability. Scenario 3 contributes in the short term significantly to poverty alleviation and economic growth but causes decline in ecosystem services comparable to scenario 1 which may have substantial impacts in the long run (As seen in Lake Victoria). 

Hydrological modelling, although inevitably carrying a degree of uncertainty, allows for informed decisions regarding future management and justification for an alteration to current management strategies. Simulating hydrological processes under climate change or development scenarios, models are useful in assessing future changes to hydrological and ecosystem functioning which will have knock-on impacts to the provision of ecosystem services.

Wetlands and Lakes III - GaMampa Wetlands

In this post, I will address the economic valuation of freshwater ecosystem services in terms of policy and decision making with a specific example at the GaMampa wetland in South Africa.

GaMampa Wetlands

20% of the South African landscape is covered by inland wetlands. The GaMampa wetland is an example of such small inland wetlands. Located within the Mohlapetsi river catchment, the GaMampa wetland covers an area of >120 ha and is crucial to the livelihoods of surrounding local communities. 

Ecosystem Services provision:

Although the wetlands merely covers around 1% of the entire catchment of the Mohlapetsi River basin, it contributes significantly to dry season flows through a natural springs, comprising >15% of the dry season flow of the Olifants River (Mohlapetsi trib.).

Source

Provisioning services include the provision of natural resources (grass for grazing, reed for handicrafts), water supply provision, fuel wood and fisheries. Regulatory services include carbon storage and cultural/recreational services include the ever-expanding eco-tourism. 5 villages are located within the vicinity of the wetlands and almost all households were found to be actively engaging with at least one or more of the wetland services (Adekola 2007). However, while there is no doubt of the wide range of ecosystem services the wetlands provides, it does not imply equal access. ES usage across households often reveals underlying social conditions (class, wealth, power relations). Poorer households were found to be less frequently engaged with ecosystem services than medium to high wealth groups which tends to actively exploit wetlands services, most notably through high soil fertility and wetland conversions (McCartney et.al. 2011). This also reveals the inherent traits of trade-offs within the usage of ecosystem services where agricultural productivity and food provision may be prioritised at the expense of hidden services, eventually and ironically leading to the collapse/decline of the initially prioritised services.

Economic valuation:

McCartney et.al. 2011 concluded that the net value of $USD 80,000 significantly exceeds the annual cash income of households within the area, suggesting a major contribution of ES delivery/provision to local livelihoods. Total wetland benefits if shared among households of surrounding villages was found to be able to contribute >$400 per household (Adekola 2007).

However, while these economic values may look encouraging for poverty alleviation, it masks the fact that wetland conversions has been dramatic in recent years with the wetlands halving in size between 1996 and 2002, illustrating the reality of trade-offs within different ecosystem services. 

Management and decision-making:

There is no doubt the GaMampa wetlands plays an important role in sustaining local livelihoods, survival and water/food security through both direct benefits (cropping, fuel wood, water) and indirect benefits (streamflow generation, water quality regulation, eco-tourism). Economic valuation, although may risk neglecting hidden services, is ultimately useful tool for decision-making and future management of wetlands if used with the wide appreciation of the ES concept. Within the Gamampa wetlands, the economic valuation of the wetlands and the increased scientific research within the area did increase local environmental awareness and agricultural land conversion has been markedly reduced since 2004. Combing biophysical (wetland hydrology) research with economic valuation can help reach agreement and decisions over future governance of the area and may stimulate government/NGO involvement to optimize benefits and limit degradation. Ultimately, I do think that the economic valuation of ecosystem services, if  used among an entire suite of other ways of valuation, is a powerful tool in stimulating action and sustainable management. This was shown through Sylvie et.al. 2010, where a modelling study using STELLA modelling language was used to assess trade-offs within the GaMampa wetlands, including not only the value of natural services, but also the hydrology, community well-being, population dynamics, future environmental change and future management scenarios. Descending into a theoretical/ethical debate over valuing/commodifying nature may therefore not be helpful.

In the next post, we will look at environmental change on future provision of ecosystem services.

Payments for Ecosystem Services II - WfW Programme, South Africa

In this post, I will blog in detail about the largest payment for ecosystem service scheme in the African continent.

Working for Water Programme

The WfW programme in South Africa launched in 1995 aims to address the spread of invasive species and the safeguard of freshwater resources and at the same time alleviate poverty through financial incentives. The programme identifies invasive species as a major threat to freshwater resources with the colonization of riparian zones by invasive trees, resulting in a loss of usable water comparable to >4% of total water use in South Africa (Cullis et.al. 2007). Anoxic conditions are also induced by invasions, leading to reduction in fish yields and reduced delivery of cultural and regulating services. It is the largest single natural resource based poverty alleviation scheme in the country and the largest PES scheme in the African continent. Among representative catchments investigated in SA by Mairtre et.al. 2012, it was identified that invasive species reduced natural river flows by 6-22%. Strategically managed to bring together hydrologists, ecologists, engineers and rural populations, the WfW scheme offers the following with an annual budget of USD $50 million (Van Wilgen and Maitre 2008):

1. Employment and training for previously unemployed South Africans to eliminate spread of high water consuming invasive alien plants

2. Sustainable funding and investment in research on invasive species and its impacts 

3. Improvement in international cooperation and reorganization of water management personnel

Benefits

Water is a clear constraint to economic growth, particularly in a chronically water stressed country. There are thus understandably increasing pressure for more efficient and sustainable delivery and use of freshwater. PES schemes should inherently be socially progressive as the sustainable delivery of ecosystem services are societally beneficial and that financial incentives attached to ES delivery are capable of empowerment (Suich et.al. 2015). The WfW scheme aims to simultaneously tackle the spread of invasive plants, the efficient delivery of water resources and the empowerment of marginalized communities (Gorgens and van Wilgen 2004). It is the only widespread PES scheme in the continent and is widely regarded as one of the most successful natural resources investment plan in the African continent. Some of the major benefits are listed below:

Benefits of the WfW Scheme
Red boxes indicate potential benefits 
(Underlying graphic indicates general ecosystem services benefits from
water resource management taken from Suich et.al. 2015)

Environmental

- Encourages biodiversity conservation

- Limit spread of invasive alien plants detrimental to ecosystem and water supply

- >1 million ha of invasive plants cleared - release of >40 million ha cubic meters of water per annum

Social

- Provision of >30,000 temporary jobs over 300 projects across all provinces of S.Africa

- Promote gender quality and empowerment - 52% of those employed were women

- Encourages small business entrepreneurs to bid and compete in WfW contracts in locations where invasive plants are significantly detrimental ecologically and hydrologically 

Economic

- Revenue from poverty relief funding 

- Creation of secondary industries in communities (eg. furniture making)

- Restoration of agriculturally productive land

Trade-offs

No scheme of this size can be carried out without criticism. There has been some major criticisms to its legislation, management and potential trade-offs. These criticisms also reveal some general pitfalls and concerns of PES schemes.

There are pretty obvious conflicts of interests which the scheme does not address sufficiently. Invasive alien plants, although detrimental to the environment and water provision, are provisioning ecosystem services themselves. Local rural communities often use them as fuel wood, fencing materials and participate in agro-forestry industries. Furthermore, the agro-forestry plantation industry employs over 100,000 people and covers 1.4 million ha.  This complicates the successful implementation of the scheme as plantations occupy 10% of land which yields 60% of  surface water (Hope 2006). 

Socially, as the scheme is dependent on poverty relief funding and is targeted mainly as a poverty alleviation scheme,  the scheme risks over reliance on relief funding and may find itself unable to compete with alternative poverty relief programmes in the future (Turpie et.al. 2008).  There were also criticisms due to the top-down approach of implementation. Poor communication channels, insufficient information and lack of local community participation led to assertion by some that the government led scheme fails to understand the true nature of work and reality of local life (Buch and Dixon 2008). The scheme merely provides a temporary solution to chronic problems in which participation of laborers are limited to only 2 years after which citizens are required to secure alternative permanent employment. However, the scheme failed to properly address the fact that comparable employment may not be available. Even if they are available, some may not be qualified as the scheme merely trains them in specialist subjects (invasive plant removal) rather than general training (Hope 2006). Income constraints dictated by the climate and erratic working patterns exacerbates the problem. This has led to the WfW scheme being the only secure employer, creating a situation where long-lasting poverty alleviation may be at odds with the top down management of the scheme.

Concluding Thoughts

There is no doubt that this is the largest natural resources based poverty relief scheme in the country and the continent. The practical application of economically valuing ecosystem services (water supply) and impacts (invasive plants) has also proven to be largely successful. There are obvious drawbacks and major trade-offs, particularly problems associated with a managerial, top down approach is applicable across many PES and water supply schemes. More local participation would certainty improve the scheme as success rates of a conservation or development scheme is highest when local people are involved in the decision making process. Nonetheless, the implementation of this scheme in a country where conservation are largely reserved for the rich does effectively integrates sustainability with equity and economic growth and have had significant success.  

Payments for Ecosystem Services I

In this short post, I will introduce the concept of payments for ecosystem services. 

Payments for Ecosystem Services (PES)

PES is a market-based mechanism to translate external values of ecosystem functioning by financial incentives to the provision of ES by local actors. The basis of PES lies within the economic theory of market failure when public goods and services are not delivered or provided in sufficient quantity/quality/efficiency (Derissen and Lohmann 2013). PES schemes are often voluntary with financial transactions for the services provided by a well-defined, often singular ecosystem function. The central economic theory behind PES schemes are one of non-rivalry, that the benefit and consumption by one user does not affect benefts and consumption by another (Engel et.al. 2008). This, obviously, is not true in reality and may often lead to complex power dynamics as seen from the commodification of water in the last post and will be discussed further in the WfW programme in South Africa.  

Characteristics of PES:

1. Presence of buyers - users of ES or governments/NGOs, either user-financed or government-financed through central organizations
2. Sellers - stakeholders in position to protect, maintain and assist ES delivery, often land owners or government
3. Payments offered to sellers (ecosystem managers) must exceed benefits they would otherwise receive from land conversion or alternative use 

Disadvantages:

1. Inefficient if ES are spatially dispersed and distributed with widespread impact areas
2. Non-rivalry often not realistic - eg. Commodification of water (see previous post) - water rights holder hold power to prioritize beneficiaries 
3. Payments may be insufficient to cover costs and leads to continued undesirable land uses
4. Inefficient if payments are made to convert land use but land conversion would have been adopted without payments anyways

In the next post, I will discuss in detail the WfW programme.

Valuing Ecosystem Services II - Commodifying water

The idea that paying for water is not new and whether or not water should be treated as commodities are widely debated. 

Valuing Water

The valuation of water resources is often driven primarily by capitalistic production and accumulation dynamics. This often goes against the initial aim of the ecosystem services framework and risks leaving out alternative values of the system. This includes not only monetary values of water supply provision, but biophysical and ecological values provided by regulating and cultural services (Castro 2013). Short-term market considerations for water supply often overshadows multi-dimensional functions and services of the hydrological cycle as a whole.

Commodifying Water 

While water should be a public good, there has been immense pressure to market and commodify water through water trading and privatisation as demand outstrips supply. This raises ethical questions on power relations and ultimately result in differential access to the provisioning service of water supply which were often a public good and available free of charge before water commodification (Walsh 2011). The commodification of water thus alters the supply of water and the availability of water to maintain other ecosystem services and environmental flows. An interesting example of this is wetland mitigation banking where ES produced by wetlands are sold as wetland credits by restoring pre-settlement wetland conditions. This marketization of previously public goods often bend to the will of capitalism in a bid to sell nature (Robertson 2003) without understanding integratively the underlying relationships between ecosystem functions and ecosystem service delivery.

In a Friends of the Earth investigative report on 'selling water and biodiversity', it was highlighted that bribes, underinvestment in infrastructure, unaffordable increase in water prices and poor water quality has been characteristics of water supply after privatization and commodification. In 1970s Nigeria, the water market was privatized after inadequate maintanence from the government and transformed water into a tradable commodity. General water supply provision declined as people were priced out of the water market with supply favouring rich communities,   streams/rivers were continually polluted due to industrial development and private companies often fails to manage water sustainably and depletes aquifer and springs.

I believe that using an ecosystem services framework to look at water supply would be beneficial only if attention is not paid predominantly on the economic and monetary valuation of services but instead to the fundamental biophysical and ecological concept of ecosystem functioning and services delivery (Schroter et.al. 2014). The inter-linked relationships within multiple elements of the hydrological cycle should be fully recognized for sustainable management to take place.

Valuing Ecosystem Services

Welcome back! In this post, I will address the economic valuation of ES.

ES Valuation

Viewing ecosystems in monetary terms is an integral part of the ES approach in an attempt to explicitly articulate economic values of certain services as natural capital or goods and services. It aims to a directly encourage the conservation of ecosystems and promote political action from otherwise often sceptical policy makers (Redford and Adams 2009). Valuation of ES can occur in both use and nonuse elements. Use elements are directly beneficial and used by humans, such as fisheries while nonuse elements are indirect impacts such as water quality regulation and carbon sequestration. Valuation of ecosystem services can be conducted via the following four pathways (Brauman et.al 2007):

1) Valuing total ES flow
2) Value of alterations to ES
3) Valuing the distribution of costs and benefits from ES production and delivery

The economic valuation of ES represents natural capital, one of four kinds of capital in 21st century economic theory grounded in the economic concept of substitutability and market environmentalism (Chee 2004).

Source

The mainstreaming of the ES concept since the publication of the Millennium Ecosystem Assessment in scientific literature had led to intense, seemingly obsessive tendency to assign monetary values to ecosystem services using market-based instruments. Gomez-Baggathun et.al. (2010) identified three stages in the historical development in valuing ES in economic terms (Table 1). Conceptualised initially to raising awareness and allow ethical justification for environmental conservation, the ES concept gradually shifted to an emphasis on different ways to cash in ES as commodities on potential markets. What is also interesting is a shift in the concept nature and human-nature relationships, from valuing the physical usage of land and labor to the monetary analysis and exchange values available for monetization. 

Two practical approaches to addressing ES delivery through market-based instruments are markets for ecosystem services schemes and payments for ecosystem services schemes (Simpson 2011).

• Markets for Ecosystem Services - polluter pays principle 
• Payments for Ecosystem Services - compensation from beneficiaries for the maintenance and protection of ecosystem services 

Criticisms of economic valuation of ES

Redford and Adams (2009) identified 7 major problems with the ES concept:

1. Obsession with economic logic - monetary valuation and its implications often outweighs scientific justification for environmental conservation
2. Not all ES sustains human life - raises question of interlinked ecosystem functions
• Promotes an anthropocentric view of ES rather than bio-centric views/intrinsic values of nature (Schroter et.al. 2014)
• Not all ES have desirable outcomes to humans (McCauley 2006); presence of disservices such as diseases and pathogen diffusion
3. Some ES may be provided by unnatural systems as well as natural systems - defeats primary aim of conservation, values provided such as monocultural agriculture are often from unnatural systems (Simpson 2011)
4. Increasing justified to maximize single services at the expense of others - novel ecosystems: anthropogenic construct which effectively delivers ES but lack biodiversity of natural systems
5. Markets may not exist for some ES which does not lend themselves to pricing
6. Power relations neglected in ES concept - rights to ES complicates the design of market-based schemes with problems of power, access and maximization of revenue/profit
• ES often used May not safeguard biodiversity and instead divert attention to economics
7. Unknown impacts of climate change on ES delivery

Commodification

Apart from the concerns outlined above, many have criticised the ES concept in bringing conservation too close to economic logic and risks 'selling out to nature' (McCauley 2006). I do agree with this to some degree as ES does not exist solely for human exploitation and nature conservation should occur solely to protect the intrinsic natural functioning instead of turning a profit. This leads to widespread debate on whether the ES concept encourages the treatment of natural systems as purely tradable commodities available for human exploitation. Discrete quantification of monetary values of a single service also risks neglecting the complex linkages between ecosystem functions (Gomez-Baggethun and Ruiz-Perez 2011).

I do take a more practical view in that while the ES concept has its pitfalls and may rely too much on economic logic, it does encourage interdisciplinary research on ecosystem science and ecosystem functioning. As we shall discuss, there are successful examples which utilizes the ES concept to reach conservation aims.

Wetlands and Lakes II - Lake Victoria

In this post, I will be discussing ecosystem services delivery at a specific African location. I have chosen to focus on the lake-wetland system at Lake Victoria basin, East Africa. 

Location

Lake Victoria is located in East Africa and its catchment area spans across 6 countries. It is the largest lake in Africa and the second largest freshwater body in the world. Lake Victoria covers an area of 69,000 km2 with its total catchment area spanning over 180,000 km2. Located in the upper reaches of the Nile River, the only outflow of Lake Victoria is the Victoria Nile river within the complex White Nile river basin. Formed 400,000 years ago, the lake is formed by structural uplift around the basin and is one of the Great Lakes of Africa. 

Source

Ecosystem services

The Lake Victoria basin is characterized by a complex array of rivers, wetlands and satellite lakes which supports the livelihoods of over 25 million people and maintains hydrological balance of the Nile River system downstream. This interdependent relationship is a prime example of the balance between the different types of ecosystem services.

Population within the basin depends on rain-fed and flood recession agriculture from riparian wetlands and satellite lakes as well as hydroelectric power and commercial industry in and around the lake (Balirwa et.al 2003). Products and provisioning services of wetlands are largely understood and extensively exploited by local communities. These services include flood recession cultivation, wetland fisheries, grazing land and potable water resources. This results in Lake Victoria being Africa's largest and most important inland fishery source. However, the regulating services within the basin are often poorly understood/managed and taken for granted (Kansiime et.al 2007). A prime example of this is the water quality and buffer services provided by wetlands and satellite lakes. The presence of riparian wetlands around the lake determines transport characteristics of nutrients and sediments into the lake. Highly productive macrophytic vegetation in wetlands direct absorbs nutrients and filtrates any undesired releases into the lake. Wetlands also serves as a buffer for external impacts, increasing the ecological and hydrological resilience of the lake (Kassenga 1997). 

Threats

Despite the high reliance on provisioning services and importance of regulatory services, management in the Lake Victoria basin can be characterized as being highly extractive for the past 50 years. Overfishing, demographic change, expansion of urban settlements and expansion of intensive agriculture since the 1970s are the major threats to the capabilities of freshwater ecosystems to deliver ecosystem services (Odada et.al. 2009). The fisheries industry at Lake Victoria had been subjected to the introduction of more productive fish species in the early 20th century. Overfishing, increased nutrient runoff and a 'fishing down' process driven by population growth and food demands led to the depletion of native cichlid populations and the domination of the introduced Nile perch in the 1980s (Bilirwa et.al. 2003). The introduced Nile perch dominated over the previously cichlid-dominated ecosystem, leading to the deterioration in services provided by cichlid-phytoplankton feedback loops which previously regulated oxygen depletion. This had led to both a collapse in the fishery industry and a reduction in regulatory services when deep changes in food web structures were revealed and no more economically viable fish stocks were available.

The high variety of ecosystem services delivered by the lake-wetland system also caused dramatic demographic change with population growth within the basin being significantly higher than the rest of Africa (Fig.1). This has led to increased conversion of riparian wetlands into urban settlements and agricultural land, resulting in the loss of wetland vegetation and functioning. Loss of regulatory services from wetlands led to the deterioration of water quality and increased eutrophic status of the main lake due to industrial nutrient runoff and urban discharge (Odada et.al. 2009). Knock-on impacts to human well-being were experienced due to to fact that water abstracted from the lake for direct consumption and industrial use often undergo little to no additional treatment. 

Fig 1 Changes in population density between 1970 and 1990
- large scale conversion of riparian wetlands to urban settlements

Trade-offs

The economic valuation of ecosystem services are integral to the ecosystem services concept which also reveals the nature and inevitability of trade-offs. Trade-offs occur when management choices changes the relative magnitude and type of ecosystem services provided. Ecosystem services delivery are often in conflict with the need to meet increasing demands and the need to maintain ecosystem biodiversity and functioning. Large loss of forests and gains in agricultural land in upland regions and the increase in vegetation production and loss of intact wetlands in the lowlands led to increased food production and food provisioning services but was succeeded by a simultaneous decline in other provisioning services and the majority of regulating services (Swallow et.al. 2009). Furthermore, the introduction of invasive Nile perch dramatically boosted economic activity of the area initially but led to the overfishing and the eventual demise of native biodiversity and the fishery industry (McCauley 2006). 

Using a bio-economic model of the fishery industry including wetland-water quality interactions, Simonit and Perrings (2011) concluded that if wetlands in sub-basins were reduced by 60%, nutrient enrichment will lead to an expected loss of $1.98 mil USD/year and $216 USD per ha per year in fishery production. This reflects the inevitability of management decisions resulting in trade-offs among ES which may have varying economic implications. There should therefore be better monitored agricultural development along with informed and integrated water and land management practices in order to resolve conflict between development and ecosystem integrity.

Before I begin...

Before I begin, I found this short video produced by Wetlands International illustrating how wetlands can support livelihoods of farmers and people in Malawi and Zambia. Although filmed in Central Africa, the dependency of livelihoods on wetland/lake resources and the inadequate management of trade-offs are evident across the continent. Enjoy the video! I hope it is a good introduction to some specific threats wetlands and its valuable ecosystem services are facing. 

In the next post, I will introduce a case study of ecosystem services delivery at Lake Victoria. 

Wetlands and Lakes I

After looking at the general principles of ecosystem services and the distribution of water resources in Africa, I aim to explore in detail hydrologic services with particular attention paid to lakes and floodplain wetlands.

Wetlands

Characterized as 'natural assets' (Barbier 2012), wetlands are some of the most hydro-ecological productive and diverse ecosystem. Wetlands can be characterized by unique characteristics (Maltby and Acreman 2011):

1. Presence of surface water or within root zone
2. Unique soil/sediment characteristics compared with adjacent non-wetlands
3. Presence of adaptive vegetation to varying degree of wetness

Source

Wetlands are widely distributed across the floodplains of Sub-saharan Africa within all major river basins (Rebelo 2010). Hydrological processes initiates ecosystem functions which drives biogeochemical interactions and subsequently modulates the performance of ecosystem services beneficial to human well-being. Due to high connectivity in the hydrological cycle, ecosystem system delivery and beneficiaries extend well beyond the boundaries of wetlands/lakes, supporting the livelihoods of rural and urban citizens alike and ensuring food and water security while having substantial impacts on poverty alleviation and international development. Irrespective of size/catchment area, wetlands of all sizes are capable of delivering pivotal ecosystem services (from water quality regulation to recreation) along hydrological pathways and trade-offs can only be fully understood if all scales are consulted (Blackwell and Pilgrim 2011). 

Schuyt (2005) identifies 4 categories of ecosystem functions:

1. Regulating functions - climate regulation, water regulation, nutrient regulations
2. Carrier functions - space for human settlement, energy production, agricultural production
3. Production functions - food production, water supply, support for raw materials (eg. timber)
4. Informal functions - recreation, tourism, spiritual health, scientific studies

Interdisciplinary involvement in research between
wetland and ecosystem services delivery (Source)

Lakes

Closed water bodies of fresh/brackish water also provides an entire suite of ecosystem services  beneficial to human well-being (Schallenberg et.al. 2013). Wetlands, lakes and rivers are integral and interrelated parts of the hydrologic cycle. Ecosystem delivery or dis-service in a lake/river will no doubt influence the ecosystem services delivery in wetlands. Similarly,  reduced services by wetlands will have knock-on impacts to services in lakes. 

Threats

Threats to ecosystem services often arises from the inherent trade-offs after alteration of the natural environmental conditions. Trade-offs arise from distributional effects after the wetland/lake ecosystem is altered and the natural hydrological state changed.  Freshwater ecosystem services are determined by geographic location, timing of flow, quantity of flow and water quality. Modulated by regional climate, any changes to the hydrological conditions, whether anthropogenic or not, will risk compromising the integrity of the wetland/lake. Although wetlands only cover less than 3% of global land mass, they deliver over 40% of renewable ecosystem services each year (Zedler and Kercher 2005). Despite the variety of ecosystem services provided, wetlands has been subjected to increasing anthropogenic development with little consideration of service trade-offs. Hard engineering approaches for irrigation/agricultural expansion is the main threat to wetlands ecosystem services in Africa. Decision-makers often favour short term economic gains rather than long term benefits of human well-being from ecosystem services (Shuyt 2005). 

Reinventing Freshwater Metrics

I came across a recently published article outlining frameworks for a new water availability metric. Unlike most popular water scarcity indexes and metrics, this metric embraces the ecosystem services (ES) approach in recognizing human-environment relationships and the impacts of downstream ecosystem functions degradation. Particularly in line with the module syllabus, I feel like it is appropriate to comment on its findings before continuing the original aims of this blog. 

The paper titled 'Freshwater ecosystem services supporting humans: Pivoting from water crisis to water solutions' was published in Global Environmental Change by Green et.al. and introduces a new metric that incorporates both impacts at point of service and impacts downstream. Recognizing the importance of provisioning ES provided by freshwater ecosystems, the freshwater provisioning index quantifies the provision of freshwater ecosystem services. 

Summary

Freshwater Provisioning Index:

• Traces freshwater sources to point of service and delineates spatial extent of upstream provision areas and downstream beneficiaries
• Calculated by taking into account population density and infrastructure support
• Threat/vulnerability-based - 2 levels of threat identified
• Incident Threat - threat to ES prior to mitigation
• Residual Threat - reduction of incident threat by engineering/management intervention aimed at rehabilitation of ecosystem 

Main Findings:

• Strong positive correlation between level of economic/human development (HDI), downstream population density and incident threat to freshwater ecosystems
• Effective and efficient investments in water delivery infrastructure globally reduced incident threat to freshwater ecosystems with lower overall residual threat
• Countries with low HDI and highly dependent on freshwater resources often lack investments in infrastructure development and thus benefit little from threat reduction (ie. remaining red/yellow in residual threat in map below)
• Near entirety of the world benefits from freshwater sources which are comprised to some extent by anthropogenic activities

Regional Findings (Africa):

• Lack of development and low efficiency in infrastructure results in high residual threat on freshwater ES
• Freshwater ecosystems located upstream of large industrial/population hubs in Africa are among most threatened (indicated by red in map shown below)
• Land use/habitat change is the single most important threat to freshwater provision areas in Africa
• Management should embrace 'service area conservation' - protection of upstream freshwater provision sources (eg. Wetlands in Congo River Basin/Niger River Delta)
• Diseconomies of scale persist in water provision due to lack of appropriate delivery infrastructure and often high water tariffs

Source

Concluding Thoughts:

This index introduced by Green et.al. 2015 effectively addresses the importance and widespread spatial influence of ES. The positive correlation revealed between HDI and freshwater ecosystem threat also sheds light on a crucial point that the problem of water scarcity in Africa is one of distribution and not quantity. This was echoed in ethnographic studies indicating an overall decline in reliability of water delivery infrastructure over a period of 30 years (Thomson et.al. 2000), leading to high residual threat to freshwater ecosystems.

However, there were some major omissions. Firstly, the index fails to include the relationships between groundwater and the ES it provides despite clear importance of such sources in some SSA nations with little surface water. Secondly, the focus on threats only to provisioning services (ie.water supply) by downstream populations detracts attention to other forms of ES. This may lead to underestimation of threats faced by freshwater ecosystems which may not provide water to a large number of downstream users. Examples of this may include the Amazon Basin in South America, which as seen from the map above, were considered low threat under this metric despite widespread scientific concern of an Amazonian dieback. The same could be said for the Congo River Basin in Africa. Thirdly, population density was included as the major threat to freshwater provision zones, risks neglecting other stressors which may have a large impact to freshwater ecosystems. As the author identified as well, the index could be improved through including downstream volume demand and freshwater sources in storage (GW).

All these potential pitfalls of the metric highlights the challenge of quantifying ES and the difficulty in incorporating all relevant ES. Vollmer et.al. (2016) found substantial variation in the services selected/measured among different ES based freshwater indexes. Apart from water provisioning, other kinds of services provided by freshwater ecosystems have yet to be universally included in water assessments. Lastly, this also raises the question of how best to assess freshwater resources through an ES approach. There are considerable debate surrounding the reduction of services to monetary value and the economic valuation of ES which will be addressed in later posts.

The Physical Distribution of Water Across Africa

In this post, we will discuss the physical distribution of water resources across the continent.

Source

Global Climate Dynamics

It is far too often when one picture the African continent to immediately reduce it to an extensive piece of land that is eternally dry and water-scarce. In reality, high variability in precipitation and hydrology results in a myriad of different landscapes and ecosystems at different times of the year.

Source

Precipitation across Africa is controlled by global patterns of atmospheric circulation and the Intercontinental Convergence Zone (ITCZ). The ITCZ is formed at the equatorial trough where deflected moisture-rich northeastern and southeastern trade winds converges after the completion of the Hadley circulation cell. The ITCZ migrates both north and south according to the axial tilt of Earth's orbit as shown in the figure below. This migration controls both intra-annual variability (seasonality) and spatial variability of rainfall across Africa (Taylor, 2004)

Geology and Elevation

Water is distributed across Africa as lakes, wetlands, rivers, swamped forests or reservoirs (Rebelo et.al. 2010). While the regulation of global atmospheric circulation determines precipitation and runoff patterns, the spatial distribution of water resources as lakes or wetlands is primarily determined by local geology and elevation. On the one hand, areas with a rise in elevation would induce orographic rainfall effects with increased precipitation in mountainous regions relative to low-lying adjacent regions. On the other hand, extensive low-lying, low relief surfaces favours ponding and the formation of lakes (eg. Lake Victoria) or widespread floodplains and the formation of wetlands.

Importance

In one of the most recent comprehensive study on the distribution of wetlands and rivers across sub-Saharan Africa, Rebelo et.al. (2010) concluded that lakes, wetlands, rivers and reservoirs is the dominant source of freshwater with a cumulative area of 1,448,771 km2, covering 6% of the African continent. 143 sites in sub-Saharan Africa are designated as Wetlands of International Importance at the RAMSAR Convention. One of the most alarming statistics taken from this publication is that >90% of the listed RAMSAR sites in the region are used for agricultural or fisheries purposes but >70% of which are threatened because of supporting agricultural or fisheries uses. This fully highlights the importance of an ecosystem services approach in which the quantification of monetary value of wetland systems and economic costs of wetland degradation is urgently needed.  

(Source)

Owing to global atmospheric circulation, surface geology and elevation, water resources across Africa is highly diverse and plentiful. However, due to seasonal and spatial variability, the distribution of water resources and thus the ecosystem services they provide are not evenly distributed across the continent. This means that different types and levels of access to ecosystems services exists across local regions. Power relations and problems of access will no doubt influence the valuation and economic incentive of ecosystem services which may lead to trade-offs which are detrimental to complex ecosystem functions or other ecosystem resources (Ryan et.al. 2016). 

The following questions will be addressed in the upcoming series of blogs:

1) What are the current status of provision of and access to freshwater ecosystem services in sub-Saharan Africa?

2) How will the provision of ecosystem services change according to changes to people's access of    ecosystems?

3) How does poverty alleviation, agricultural expansion and global environmental change impact the provision of and access to ecosystem services?

4) Is payment for ecosystem services and the economic valuation of ecosystem services the future for sub-Saharan Africa? 

Introduction - An Ecosystem Services Approach

Welcome to my blog! Over the course of my university module on 'Water and Development in Africa', I will be exploring and blogging about the relationships between water resources and various ecosystem services it provides. A wide range of topics and examples will be investigated, ranging from the physical processes generating ecosystem services to possible changes in the provision of, access to and types of ecosystem services provided by water resources in the future depending on environmental change, and socio-economic trends.

Ecosystem Services?

Popularized by the Millennium Ecosystems Assessment 2005, Ecosystem services is defined as:

  

'The benefits people obtain from ecosystems. These include provisioning services such as food and water; regulating services such as regulation of floods, drought, land degradation, and disease; supporting services such as soil formation and nutrient cycling; and cultural services such as recreational, spiritual, religious and other nonmaterial benefits.'

Source

The ecosystem services approach implies that any changes to the services provided will affect human well-being in some ways, linking the physical distribution of water to socio-economic impacts. Growing demand for ecosystem services may lead to either 1) development at the expense of another resource which may be of equal or even greater importance or 2) simultaneous growth in demand and degradation in resource itself. Despite relying on the provision of ecosystem services, management interventions rarely consider environmental impacts and often undervalues or completely disregard ecosystem services.

Freshwater as an 'umbrella service'

Water is essential to the healthy functioning of the hydrologic cycle and sustains a wide range of freshwater-dependent ecosystems. Water can be viewed as being the 'umbrella service', being the basis to services within both consumptive and non-consumptive uses. The following table taken from IIED, 2007 summarises some of the provisioning, regulating, supporting and cultural services provided by freshwater ecosystems.

Table 1 Source

The ecosystem services approach views ecosystems as provider of marketable goods and services. The concept of valuing nature in monetary terms is highly controversial and while it indeed provides economic incentives to preserve and protect certain ecosystems/resources, critics argue that a neo-liberal approach in commodifying nature may lead to unequal access or even irreversible damage to other natural resources (Gomez-Baggethunand Ruiz-Perez, 2011).


Although an ecosystem services approach is more integrative than approaches dominated by environmental determinism, it should be noted that issues of access and power relations between stakeholders are not directly implied and are often excluded in studies advocating for an ecosystem services approach. Critical issues of this approach will be investigated in later posts.