|
|
| Line 1: |
Line 1: |
| | | | |
| − | An ecosystem is a [http://en.wikipedia.org/wiki/Community_(ecology) Community (ecology)] of living organisms (plants, animals and microbes) in conjunction with the abiotic components [http://en.wikipedia.org/wiki/Abiotic_component Abiotic component] of their environment (air, water, soil), interacting as a system. These components are linked together through nutrient cycles and energy flows.<ref name="Tansley">Tansley, AG (1935): The use and abuse of vegetation terms and concepts; Ecology 16 (3): 284–307.</ref><ref name="Smith">Smith, T.- M.; R.-L. Smith (2012). Elements of Ecology. Boston, Benjamin Cum-mings, ISBN 978-0-321-73607-9.</ref><ref name="Odum">Odum, EP (1971): Fundamentals of ecology, third edition, Saunders New York</ref> | + | An ecosystem is a [http://en.wikipedia.org/wiki/Community_(ecology) Community (ecology)] of living organisms (plants, animals and microbes) in conjunction with the abiotic components [http://en.wikipedia.org/wiki/Abiotic_component Abiotic component] of their environment (air, water, soil), interacting as a system. These components are linked together through nutrient cycles and energy flows 8Tansley, 1934; Smith & SMith 2012, p.G-5, Odum, 1971).<ref name="Tansley">Tansley, AG (1935): The use and abuse of vegetation terms and concepts; Ecology 16 (3): 284–307.</ref><ref name="Smith">Smith, T.- M.; R.-L. Smith (2012). Elements of Ecology. Boston, Benjamin Cum-mings, ISBN 978-0-321-73607-9.</ref><ref name="Odum">Odum, EP (1971): Fundamentals of ecology, third edition, Saunders New York</ref> |
| | | | |
| | Water and its qualities are main components of almost all ecosystems. Differentiation is made between aquatic and terrestrial ecosystems; the existence of terrestrial ecosystems is indirectly or directly often dependent on the state of neighboring aquatic ecosystems. For instance, many terrestrial bird species have their breeding areas at lake shores. Wetlands, mangrove forests, coastal zones, and river ecosystems, as well as deserts, forests and plains, are just a selection of the existing types of ecosystems. Natural ecosystems are being threatened by human activities such as agriculture and fisheries, and increasingly disturbed and influenced by climate change. Hence, a bundle of measures are necessary to work effectively against their continuous and rapid degradation. | | Water and its qualities are main components of almost all ecosystems. Differentiation is made between aquatic and terrestrial ecosystems; the existence of terrestrial ecosystems is indirectly or directly often dependent on the state of neighboring aquatic ecosystems. For instance, many terrestrial bird species have their breeding areas at lake shores. Wetlands, mangrove forests, coastal zones, and river ecosystems, as well as deserts, forests and plains, are just a selection of the existing types of ecosystems. Natural ecosystems are being threatened by human activities such as agriculture and fisheries, and increasingly disturbed and influenced by climate change. Hence, a bundle of measures are necessary to work effectively against their continuous and rapid degradation. |
| Line 42: |
Line 42: |
| | [3] Safe Yield: The annual amount of [http://en.mimi.hu/environment/water.html water] that can be taken from a source of supply over a period of years without depleting that source beyond its ability to be replenished naturally in "wet years." [http://www.polytechnic.edu.na/academics/schools/engine infotech/civil/libraries/glossarywaterenvironment/GlossaryWaterEnvironment-26.htm http://www.polytechnic.edu.na/academics/schools/engine infotech/civil/libraries/.] | | [3] Safe Yield: The annual amount of [http://en.mimi.hu/environment/water.html water] that can be taken from a source of supply over a period of years without depleting that source beyond its ability to be replenished naturally in "wet years." [http://www.polytechnic.edu.na/academics/schools/engine infotech/civil/libraries/glossarywaterenvironment/GlossaryWaterEnvironment-26.htm http://www.polytechnic.edu.na/academics/schools/engine infotech/civil/libraries/.] |
| | </div></div> | | </div></div> |
| − | <br/>
| |
| − |
| |
| | == Impacts of climate change on ecosystems and food security == | | == Impacts of climate change on ecosystems and food security == |
| | | | |
Revision as of 07:59, 8 February 2013
An ecosystem is a Community (ecology) of living organisms (plants, animals and microbes) in conjunction with the abiotic components Abiotic component of their environment (air, water, soil), interacting as a system. These components are linked together through nutrient cycles and energy flows 8Tansley, 1934; Smith & SMith 2012, p.G-5, Odum, 1971).[1][2][3]
Water and its qualities are main components of almost all ecosystems. Differentiation is made between aquatic and terrestrial ecosystems; the existence of terrestrial ecosystems is indirectly or directly often dependent on the state of neighboring aquatic ecosystems. For instance, many terrestrial bird species have their breeding areas at lake shores. Wetlands, mangrove forests, coastal zones, and river ecosystems, as well as deserts, forests and plains, are just a selection of the existing types of ecosystems. Natural ecosystems are being threatened by human activities such as agriculture and fisheries, and increasingly disturbed and influenced by climate change. Hence, a bundle of measures are necessary to work effectively against their continuous and rapid degradation.
Background
The nature and value of ecosystems
The components of an ecosystem are connected through interrelations and have their own regulatory capacity. An example is the assimilative capacity of aquatic ecosystems, through which lakes or rivers are able to return to their original state, such as after a poisonous incident. According to the type, strength and duration of the external interference, the ecosystem can change completely; sometimes new ecosystems develop, harboring a specific but different living organism community. This is seen in particular in agro-ecosystems, which can develop from natural bush or grasslands through constant grazing or regular swath. Although these agro-ecosystems can be highly bio diverse and unique in its character, the natural ecosystem has disappeared.
Similar types of habitats are not simply interchangeable, since individual ecosystems are existing which are extremely rich in species and can accommodate hundreds of endemic species, such as Lake Tanganyika in central Africa. Since the decline of such ecosystems can be associated with the extinction of hundreds of life forms, their protection is extremely important. Such highly diverse ecosystems still exist, especially in developing countries. While these systems often are locally of low benefit, globally they are of great significance due to their high biodiversity. The maintenance of the ecosystem by the developing country should be compensated by the industrialized countries.
While ecological science evaluates the value of an ecosystem mainly according to its biodiversity, singularity, and the degree of human intervention, economic science focusses on the benefits or ecological services people obtain from it. These benefits 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 (Millennium Ecosystem Assessment, 2005: 39).[4]
The degradation of ecosystems
Today, ecosystems are degrading more rapidly than at any time recorded in human history. According to the Millennium Ecosystem Assessment/ MEA (2005) the most significant change has been the transformation of approximately one-quarter (24%) of Earth’s terrestrial surface to cultivated systems (see Figure 1[4]). Although the most rapid changes in ecosystems are now taking place in developing countries, industrial countries have historically also experienced comparable rates of change. Figure 2 summarizes important trends in different ecosystems according to MEA.
Figure 1: Conversion of Terrestrial Biomes, MEA 2005
The most important reasons for the degradation of terrestrial ecosystems are physical changes and land-use change to agriculture. According to MEA (2005)
[4] [1], the rate of conversion of ecosystems has recently begun to slow down. This is largely due to the fact that in temperate zones the major potential of land is already used and hence further conversions cannot take place at the same rates as before.
The ecosystems and biomes that have been most significantly altered globally by human activity include marine and freshwater ecosystems, temperate broadleaf forests, temperate grasslands, Mediterranean forests, and tropical dry forests. Freshwater ecosystems have been diminished most radically through the withdrawal of water for irrigation and other uses. The construction of dams and other structures along rivers affect flows in 60% of the large river systems in the world. Water removal for human uses has reduced the flow of many rivers to the extent that they dry up before reaching the sea. As water flows have declined, so have sediment flows which are the source of nutrients important for the maintenance of estuaries. Worldwide, although human activities have increased sediment flows in rivers by about 20%, reservoirs and water diversions prevent about 30% of sediments from reaching the oceans, resulting in a net reduction of roughly 10% of sediment delivery to estuaries. Marine systems are also highly affected by overuse: the world’s demand for food and animal feed over the last 50 years has resulted in fishing pressure so strong that the biomass of both targeted species and those caught as “by catch” has been reduced in much of the world to one-tenth of the levels prior to the onset of industrial fishing (MEA, 2005).[4]
Figure 2: Living Planet Index for tropical and temperate zones, WWF 2012
The
Living Planet Index (LPI) [2] summarizes the state and trends in biodiversity. In total, the LPI declined by almost 30% between 1970 and 2008, with large differences between tropical and temperate zones. Whereas for tropical zones the index declined by 60%, for temperate zones it increased by 31% during the same period. However, these figures must be interpreted against the extensive historical losses prior to 1970 in temperate zones (see Figure 2). Globally, the terrestrial, freshwater and marine indices all declined, with the freshwater index declining globally at 37%, whereas the tropical freshwater index declined even more precipitously, by 70%. Marine ecosystems exhibit the largest discrepancy between tropical and temperate species: the tropical marine index shows a decline of around 60% between 1970 and 2008, while the temperate marine index increased by around 50%. There is evidence that temperate marine and coastal species experienced massive long-term declines over the past few centuries; therefore the temperate marine index started from a much lower baseline in 1970 than the tropical index. The relative increase in temperate marine populations since then is likely a reflection of a slight recovery from historic lows.
Figure 3a: Freshwater LPI, WWF 2012
Figure 3b: Marine LPI, WWF 2012
One major reason for the decline of the freshwater living index (see Figure 3) is the increasing scarcity of freshwater, which is mainly due to its overuse in agriculture, i.e. for irrigation. This overuse is fostered by population growth, inefficient irrigation techniques, and water intensive life styles and diets. The so-called ‘safe yield’ [3] for rivers and groundwater aquifers is often crossed by either the sum of individual water users or by large operators of commercial irrigation schemes. Since until today, water is free of charge for agricultural uses in most countries, there are not enough incentives to save water. Other reasons for the decline of freshwater ecosystems are the fragmentation of rivers, i.e. habitats by the construction of dams; extraction of fish; water pollution through households, agriculture and industries; and the introduction of exotic species which may displace native breeds. It is usually a combination of factors and a complex interaction of influences which cause the change to the living community and all parameters in a habitat.
[1] Major dominant (terrestrial) ecosystems with the same kind of biotic and abiotic factors spread over a large area are termed as biomes. An ecosystem has many biotopes and a biome is a major habitat type. Some examples of habitats are ponds, trees, streams, creeks, and burrows in the sand or soil (see Wikipedia: Die freie Enzyklopädie 29.12.2012).
[2] The Living Planet Index (LPI) was developed by the WWF in collaboration with UNEP-WCMC and reflects the state of ecosystems by tracking trends in over 9,000 populations of vertebrate species (WWF, 2012: 149).[5]
Impacts of climate change on ecosystems and food security
Climate change is accelerating the degradation of ecosystems significantly and thus threating the services ecosystems offer for the inhabitants, the capacity of natural regulation decreases. Furthermore the recreational, cultural, and aesthetic value of the ecosystem is at risk. Overall, the impacts of climate change are projected to result in a net loss of global biodiversity and in major shifts in the provision of ecosystem services. The UN’s Global Biodiversity Outlook summarized some concerns that climate change will have on ecosystems:
“Climate change is already having an impact on biodiversity, and is projected to become a progressively more significant threat in the coming decades. Loss of Arctic sea ice threatens biodiversity across an entire biome and beyond. The related pressure of ocean acidification, resulting from higher concentrations of carbon dioxide in the atmosphere, is also already being observed. Ecosystems are already showing negative impacts under current levels of climate change - which is modest compared to future projected changes. In addition to warming temperatures, more frequent extreme weather events and changing patterns of rainfall and drought can be expected to have significant impacts on biodiversity.”
Source: Secretariat of the CBD; Global Biodiversity Outlook 3 (2010: 56)
In more concrete terms, climate change is causing many terrestrial and aquatic species to shift their geographical ranges and distributions: species and populations that are unable to shift or have narrow environmental tolerances are at risk of extinction. It is projected that every 1°C rise in temperature will put an additional 10% of species at increased risk of extinction (Webbe, 2011: 26). The range and abundance of economically important marine fish is already changing due to climate change and is projected to continue changing to the extent that some local fisheries are very likely to cease to be viable. It is obvious that these developments will have immense impacts on food security and nutrition worldwide, especially for the local communities depending on income from fisheries.
As well as gradual changes, extreme weather events cause ecosystem transitions, increase transport of nutrients and pollutants to downstream ecosystems, and overwhelm the ability of natural systems to mitigate harm to people from these events. More intense storms and increased drought coupled with warming can shift grasslands into shrub lands, or facilitate domination by other grass types. A rise in heavy rainfall also increases movement of nutrients and pollutants to downstream ecosystems, thus restructuring processes, biota, and habitats. As a consequence, regulation of drinking water quality is very likely to be strained as high rainfall and river discharge lead to higher levels of nitrogen in rivers and greater risk of waterborne disease outbreaks. Also, these changes will have direct impacts on the food security of local communities (see Staudinger et al. 2012). The ecosystem services provided by coastal habitats are especially vulnerable to sea-level rise and more severe storms. Coastal protection services provided by wetlands and coral reefs will be lost. Along the coasts, erosion of dunes due to increasing wave heights is projected to be an increasing problem for coastal communities. Climate change responses employed by other sectors (e.g. energy, agriculture, transportation) are creating new ecosystem stresses, but also can incorporate ecosystem-based approaches to improve their efficacy (Staudinger et al. 2012).
Why preserve ecosystems and how?
While scientists and environmentalists have discussed the value of ecosystems and ecosystem services for decades, these services were formalized by the United Nations 2005 Millennium Ecosystem Assessment/ MEA, which is a four-year study involving more than 1300 scientists worldwide. The authors grouped ecosystem services into four broad categories:
- provisioning, such as the production of food and water;
- regulating, such as the control of climate and disease;
- supporting, such as nutrient cycles and crop pollination;
- cultural, such as spiritual and recreational benefits
Figure 4 shows the ecosystem services with their constituents of well-being for human kind.
Figure 4: Linkages between Ecosystem Services and Human Well-being, MEA 2005
Targets and Approaches
In order to slow down ecosystem degradation, it is necessary to act in a multidimensional and multisectoral manner on the global, national, sub-national and local level, using complementary strategies and measures.
On the global level: To date, several international agreements for the conservation of ecosystems and on the maintenance of biodiversity have been adopted. The currently most discussed international treaty focusing on ecosystems is the Convention on Biological Diversity (CBD), known informally as the Biodiversity Convention. The Convention has three main goals:
- conservation of ecosystems, species and genetic diversity within species
- sustainable use of its components
- fair and equitable sharing of benefits arising from genetic resources
The CBD is one of the key documents regarding Sustainable development, with the objective to develop national strategies for the conservation and sustainable use of biological diversity. The Convention was opened for signature at the United Nations Conference on Environment and Development (UNCED) in Rio 1992, and became effective in 1993. Every two years the contractual partners hold meetings (COP 1-10) in order to negotiate sub-topics to the treaty. The CBD is regarded as successful with 191 contracting parties, but its weakness lies in the non-binding formulations. This has resulted in many states failing, until today, to establish national biodiversity strategies. Exceptions are the so-called 2010 Objectives and the 16 Targets of the Global Strategy for Plant Conservation (see http://www.cbd.int/gspc/). By ratifying the CBD, industrialized nations committed themselves to support developing countries in their efforts to implement the Convention, with the Global Environment Facility (GEF) created as the funding mechanism.
On the national and sub-national level: In order to reduce the tension between environmental and agricultural objectives, not only strategies within the environmental sector, but also in the agricultural and other related sectors (industry, energy, drinking water), are necessary. Agriculture must seek to be more productive in order to avoid — as far as possible — additional land being converted. On the other hand, agricultural management must be sustained in such a way that the depletion of the ‘water and soil’ resources and the disturbance of the micro-organisms living in these habitats are as minimal as possible.
Since the existing incentives for farmers (or other potential ecosystem service providers) to manage their natural resources in a way that maintains biodiversity are not strong enough, the concept of Payments for Ecosystem Services (PES) was developed. In this system, incentives are offered to farmers or landowners (or other ecosystem service providers) in exchange for their providing some sort of ecological service in the management of their land. In the FAO context, PES refers to voluntary transactions where a service provider is paid by or on behalf of service beneficiaries, for agricultural land, forestry, coastal or marine management practices, that are expected to result in continued or improved service provision beyond what would have been provided without the payment (see FAO, 2007).[6]
Best Practices
German government promotes projects aimed at the maintenance of ecosystems at all levels. On the global level, the implementation of the Rio Conventions is supported. Concurrently, the German Development Cooperation is also engaged in the agricultural sector to promote sustainable management methods on the sub-national and local level, as shown by the following examples.
Project example on the global level
Implementing the Biodiversity Convention (BIODIV)
On behalf of the Ministry of Economic Cooperation and Development (BMZ), GIZ is executing a variety of bilateral projects for the conservation of biodiversity. In 1994, a special nationwide project "Implementing the Biodiversity Convention" (BIODIV) was established. This is an integrated approach to support the accelerated implementation of the Convention. Concepts of sustainable use of biological resources are to be developed and designed, and a favorable political environment shall be encouraged. BIODIV is based on two pillars:
1) More than 20 pilot projects of governmental and non-governmental agencies are supported in order to implement specific measures for biodiversity conservation. The experience gained from these projects shall improve the general conditions.
2) BIODIV also contributes to the development of the Convention and its instruments and entities. This includes the support at the international negotiation and consultation process, participation in national and international biodiversity relevant committees and panels, as well as the realization of events and workshops and the preparation of conceptual contributions to the design of the convention.
Source: BMZ / GTZ brochure 2004: Biodiversity in German Development Cooperation
Project example on national levels
Protection of Agrobiodiversity in Rural Area (AGROBIODIV)
This GIZ project develops policies and strategies to reduce the loss of genetic resources for food and agriculture in the long term. In parallel, the project seeks to enhance the awareness of the importance of biodiversity in plant varieties, as well as in animal species, for achieving food security and poverty reduction. Decision-makers in developing countries and in German international cooperation are supplied with the necessary information for policy debates and decision taking. Project partners are counseled regarding the implementation of international agreements and action plans at local, regional and national levels for the benefit of the affected population.
Source: GIZ /AGROBIODIV
Project example on the sub-national and local level
Adaptation to Climate Change and Conservation of Biodiversity in the Philippines (ACCBio)
This project is being implemented on behalf of Germany’s Federal Environmental Ministry (BMU) and aims to support the development and implementation of adaptation strategies that compensate for the effects of climate change and the loss of biodiversity in selected areas of the Philippines. The project provides an approach for ecosystem-based adaptation through the following components:
- Institutional support: GIZ is supporting the IACCC in technical and administrative matters, especially upgrading its Secretariat into a Climate Change Office
- Policies and Strategies: The project has helped to formulate the Philippine Strategy on Climate Change Adaptation by fostering a multi-stakeholder and participatory collabo-ration process amongst key government agencies, academia and civil society.
- Awareness-raising: The project is supporting relevant Philippine stakeholders in raising awareness of climate change and environmental issues
Source: Climate@giz.de Innovative Approaches - Broad Experience - Clear Impacts
References and further reading
- ↑ Tansley, AG (1935): The use and abuse of vegetation terms and concepts; Ecology 16 (3): 284–307.
- ↑ Smith, T.- M.; R.-L. Smith (2012). Elements of Ecology. Boston, Benjamin Cum-mings, ISBN 978-0-321-73607-9.
- ↑ Odum, EP (1971): Fundamentals of ecology, third edition, Saunders New York
- ↑ 4.0 4.1 4.2 4.3 Millennium Ecosystem Assessment/ MEA (2005): Ecosystems and Human Well-being: Synthesis. Island Press, Washington, DC. World Resources Institute
- ↑ WWF/ World Wide Fund for Nature (2012): Living Planet Report 2012
- ↑ FAO (2007): The State of Food and Agriculture – Paying Farmers for Environmental Services. FAO Agriculture Series No. 38, ISSN 0081-4539
Amend T., Brown J., Kothari A., Phillips A. and Stolton S.(eds.) (2008): Protected Landscapes and Agrobiodiversity Values. Volume 1, Protected Landscapes and Seascapes, IUCN & GTZ. Kasparek Verlag, Heidelberg.
Falkenmark, Malin/ V. Galaz (2007): Agriculture, Water and Ecosystems. Swedish Water House Policy Brief
Nr. 6. SIWI, 2007.
FAO/ Food and Agricultural Organization (2012): The State of Food and Agriculture. Payment for Ecosystem Services. FAO Agriculture Series No. 38 http://ftp.fao.org/docrep/fao/010/a1200e/a1200e00.pdf
FAO (2007): The State of Food and Agriculture – Paying Farmers for Environmental Services. FAO Agriculture Series No. 38, ISSN 0081-4539.
FAO (2010): Global Forest Resources Assessment.
FAO (2010): The State of World Fisheries and Aquaculture.
FAO (2011): The State of the World’s Land and Water Resources for Food and Agriculture: http://www.fao.org/AG/agp/agps/Pgrfa/pdf/overvi_e.pdf
GCP/ Global Canopy Programme: The Little Biodiversity Finance Book.
GIZ/ Gesellschaft für Internationale Zusammenarbeit, Petermann, T. (1993): Irrigation and the Environment. A review of environmental issues.
GIZ (2008) Themenblätter: People, Food and Biodiversity. Der Erhalt landwirtschaftlicher Vielfalt und seine Finanzierung.
GIZ (2010): Biodiversity in German Development Cooperation.
GIZ (o.A.): Implementing the Biodiversity Conventions. Environment and Climate Change Program, Factsheets.
Millennium Ecosystem Assessment/ MEA (2005): Ecosystems and Human Well-being: Synthesis. Island Press, Washington, DC. World Resources Institute.
Molden, David (International Water Management Institute/ IWMI) (2007): Water for Food, Water for Life: A Comprehensive Assessment of Water Management in Agriculture.
Odum, EP (1971): Fundamentals of ecology, third edition, Saunders New York.
Schulze, E.-D.; Erwin Beck; Klaus Müller-Hohenstein (2005): Plant Ecology. Berlin: Springer. International Standard Book Number Special:BookSources/3-540-20833-X.
SIWI/ Stockholm International Water Institute (2009): Securing Water for Ecosystems and Human Well-being: The Importance of Environmental Flows. http://www.siwi.org/documents/Resources/Reports/Report24_E-Flows-low-res.pdf
Smith, T.- M.; R.-L. Smith (2012). Elements of Ecology. Boston, Benjamin Cummings, International Standard Book Number Special:BookSources/978-0-321-73607-9.
Staudinger, Michelle D.; Nancy B. Grimm; Amanda Staudt, et al. (2012): Impacts of Climate Change on Biodiversity, Ecosystems, and Ecosystem Services: Technical Input to the 2013 National Climate Assessment. Cooperative Report to the 2013 National Climate Assessment, 296 p.
Stuart, Chapin, F.; Pamela A. Matson; Harold A. Mooney (2002): Principles of Terrestrial Ecosystem Ecology. New York: Springer. International Standard Book Number Special:BookSources/0-387-95443-0.
Tansley, AG (1935): The use and abuse of vegetation terms and concepts; Ecology 16 (3): 284–307
UNEP/ IWMI (2011): Ecosystems for Water and Food security. http://www.unep.org/pdf/depi-ecosystems-food-secur.pdf
Webbe, Jame (2011): Secretariat of the United Nations Convention on Biological Diversity. In: GIZ: Adaptation to Climate Change. New findings, methods, and solutions.
WWF/ World Wide Fund for Nature: Living Planet Report 2012: http://wwf.panda.org/about_our_earth/all_publications/living_planet_report/
Websites
http://www.biodiv.org
http://www.cbd.int
http://ccafs.cgiar.org/
http://www.conservationfinance.org
http://www.ecoagriculture.org
http://www.epa.gov/ada/
http://www.globalissues.org
http://www.grain.org
http://www.ipcc.ch
http://www.iwmi.cgiar.org/
http://www.sei-international.org
http://www.siwi.org/publications
