Ecosystem Services: Why and What

Hello all!

Having enrolled in the ‘Water and Development in Africa’ module, I have chosen to examine the relationship between water resources and the provision of ecosystem services. My choice stemmed from my module preferences in the previous academic year: a) Ecological Patterns and Processes, b) Surface and Groundwater Hydrology, and c) Development Geography. The premise of water being considered an ecosystem service therefore stood out to me as an effective way to consolidate my knowledge from these three different subject areas of Geography. In this post, I will briefly talk about  the role of water within ecosystem functions, and provide a framework which may help for future posts.

Water: The Heart of Life

Figure 1. Basic ecosystem services/functions arising from water (Van Leeuwen et al. 2012).

Ecosystem services can briefly be defined as “the benefits human populations derive, directly or indirectly, from ecosystem functions" (Costanza et al. 1997). Water lies at the heart of many of these ecosystem functions, evident from Figure 1 - water is a necessity to the survival needs of human population, to the maintenance of biodiversity (eg. habitat for fish, for human consumption and livelihoods), and to the maintenance of forests for timbre and wood. Water has therefore also been cited as an "umbrella service" within the field of ecosystem functions, and that efforts to better manage and conserve water in watersheds indirectly help to preserve other ecosystem functions as explained earlier (Turpie et al. 2008: 789) .

The Common International Classification of Ecosystem Services has emerged as a framework to represent ecosystem services in the form of a hierarchy, classifying ecosystems services at the most general level in the familiar categories used in the Millenium Ecosystem Assesment (2005): provisioning, regulating, and cultural services. I have chosen the CICES as a framework in preference to the MEA due to the explicit quantification of benefits to human populations within the sub-categories; the CICES is also broader in its functions, including abiotic energy sources such as tidal energy (Turpie et al. 2017). I have extracted examples from the CICES Version 4.3 in relation to water resources in Table 1 as shown below (BISE, 2017)

Table 1. Selected sections of the Version 4.3 Common International Classification of Ecosystem Services (BISE, 2017).

Section	Division	Group	Class	Class Type
Provisioning	Nutrition	Water	Surface water for drinking	Eg. 100mm of surface water from rivers for drinking
			Groundwater for drinking	Eg. 240mm of freshwater from groundwater for drinking
	Materials	Water	Surface water for non-drinking purposes	Eg. 100mm of abstracted surface water from rivers for washing and cleaning.
			Groundwater for non-drinking purposes	Eg. 240mm of freshwater from groundwater for irrigation and livestock consumption.
Regulation and Maintenance	Mediation of waste, toxics and other nuisances	Mediation by ecosystems	Dilution by atmosphere, freshwater and marine ecosystems	Eg. Dilution of fluids and solid waste in lakes.
	Mediation of flows	Liquid flows	Hydrological cycle and water flow maintenance	Eg. Rainfall recharge into a 200m^3 river.
	Maintenance of physical, chemical and biological conditions	Water conditions	Chemical composition of freshwaters	Eg. Buffering of chemical composition of freshwater column by re-mineralisation of phosphorus.
			Chemical composition of salt waters	Eg. Buffering of chemical composition of seawater column and sediment for favourable living conditions (eg. denitrification).
Cultural	Physical and intellectual interactions with biota, ecosystems and landscapes.	Physical and experiential interactions	Experiential use of plants, animals and landscapes in different environments.	Eg. Snorkelling, diving.

In my next post, I will elaborate more on the academic motivations for studying the relationship between water and ecosystem functions, and hopefully contextualise within my regional area of interest: Sub-Saharan Africa.

See you next week!