Work package 2F: Ecosystems and Forests Review of literature
REVIEW OF LITERATURE:Ecosystems and Forests
Authors Britta Tietjen, Wolfgang Cramer
Potsdam Institute for Climate Impact Research (PIK)
Hannes Böttcher, Michael Obersteiner
International Institute for Applied Systems Analysis (IIASA)
Alistair Hunt
Metroeconomica (Metro)
Paul Watkiss
Paul Watkiss Associates (PWA)
Grant Agreement:
Project acronym:
Project title:
Research area: / 212774
ClimateCost
Full Costs of Climate Change
ENV.2007.1.1.6.1.
Deliverable Number: 2F1
Actual submission date: 1.7.2009
Title: / REVIEW OF LITERATURE: Ecosystems and Forests
Purpose: / Assessment of the economic damages, with and without adaptation, from climate change on ecosystems in physical impacts and monetary values, for the scenarios from WP1 for Europe, China, India and the USA
Filename: / Deliverable 2_1F vs 1.doc
Date: / July 2009
Authors: / Britta Tietjen, Wolfgang Cramer
Hannes Böttcher, Michael Obersteiner
Alistair Hunt
Paul Watkiss
Document history:
Status:
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Stockholm Environment Institute, Oxford
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Work package 2F: Ecosystems and Forests Review of literature
Table of Contents
Review of literature 1
Role of ecosystems for the human welfare 1
Provision and stability of ecosystem services 2
Effects of climate change on ecosystems 4
Effects of climate change on biodiversity 8
Effects of climate change on ecosystem services 8
Monetary valuation of Biodiversity and Ecosystems 9
Impacts of climate change on forests and forestry 10
Possible research strategy for ClimateCost 12
Input data from other work packages 14
Potential input to the IAM and CGM tasks 14
References 16
Work package 2F: Ecosystems and Forests Review of literature
Review of literature
The aim of this task is to assess the impacts of climate change on ecosystems, biodiversity, and forestry in Europe, China, India, and the USA. Ecosystems are a dynamic complex of plant, animal, and microorganism community (biotic factors) and the nonliving environment (abiotic factors) interacting as a functional unit (Millenium Ecosystem Assessment, 2005a). Assessing their changes under climate change therefore requires taking these complex interactions into account. For example, changes in abiotic components such as water availability impact the biotic factors of a system, which in turn feedbacks on the water cycle. To assess the impacts of climate change on ecosystems, physical impacts can be measured (e.g. primary production, carbon storage, ecosystem composition, runoff), and the resulting monetary values can be determined. Often, monetary values of ecosystems are not evaluated directly, but indirectly via the services that ecosystems provide to humans. This report first gives an introduction into ecosystem services, analyses how these services are provided, and names afterwards potential impacts of climate change on ecosystems and ecosystem services. The most recent knowledge of climate change impacts on forest ecosystems is reviewed and the current situation that can affect the forestry sector in the proposed region is addressed. Here, a special focus is put on the impacts of climate change on forestry.
Role of ecosystems for the human welfare
Ecosystems directly and indirectly provide various goods and services to humans; these range from regulating services such as climate regulation to food and fresh water provision and recreative values. Measuring these services in economic values is a challenge, since ecosystem services are not fully covered in economic markets (Balmford et al. 2002). Therefore, concepts have been developed to assess the willingness of a society to pay for a service or to accept to forego a service (Farber et al. 2002).
A first thorough attempt to assess the value of the world’s ecosystem services and natural capital was performed by Costanza et al. (1997). Based on more than 100 attempts of previous studies on single ecosystems or services, they estimated a minimum value of renewable ecosystem services for global biomes. Their estimation includes 17 broad goods and services, covering regulating services, supporting services, provisioning services and cultural services (Table 1). Summarising the contribution of each biome to these services leads to a total value of US$ 33 trillion per year (accounting for uncertainties leads to a range of US$ 16-54 trillion per year).
A follow up study by Balmford et al. (2002) assessed the marginal value of goods and services delivered by a biome when relatively intact and when converted to typical forms of human use. Their clear message is the high net present value of intact ecosystems, and they conclude that the overall benefit:cost ratio of an effective global program for the conservation of remaining wild nature is at least 100:1.
Table 1: Ecosystem good and services and their values included in the economic assessment of Costanza et al. (1997). Goods and services are classified according to the Millenium Ecosystem Assessment (MA 2005c).
and Services / Example / Global Value
(109 $ yr-1)
Regulating Services
1 / Gas regulation / CO2/O2 balance / 1,341
2 / Climate regulation / Greenhouse gas regulation, / 684
3 / Disturbance regulation / Storm protection, flood control / 1,779
4 / Water regulation / Water for agriculture / 1,115
5 / Erosion control / Prevention of soil losses by wind or water / 576
6 / Pollination / Pollinators for the reproduction of plant populations / 117
7 / Biological control / Reduction of herbivory / 417
Supporting Services
8 / Soil formation / Accumulation of organic material / 53
9 / Nutrient cycling / Nitrogen fixation / 17,075
10 / Waste treatment / Detoxification / 2,277
11 / Refugia / Habitat for migratory species / 124
Provisioning Services
12 / Water supply / Provision of water / 1,692
13 / Food production / Production of fish, game, crops / 1,386
14 / Raw materials / Production of lumber and fuel / 721
15 / Genetic resources / Medicinal plants, genes for resistance to plant pathogens / 79
Cultural Services
16 / Recreation / Outdoor recreational activities / 815
17 / Other cultural services / Aesthetic or spiritual values / 3,015
Certainly, these values have to be treated with care, since numerous sources of errors can arise as a result of the great uncertainties in the detection of services, and their valuation methodology. Also, the study of Costanza et al. (1997) neglected the evaluation of services with uncertain value, and therefore provides only a minimal assessment. Additionally, services undergo tremendous changes in time and space and can feedback on each other. Nevertheless, these highly cited studies show that ecosystem services provide an important total contribution to human welfare, and that it is of utter importance to understand the future development of ecosystems.
Provision and stability of ecosystem services
Having in mind the great value of ecosystem services, the question arises how these services are provided and how stable they are. Naturally, various factors influence the provision of services, for example the area of ecosystems, their species composition, and external factors such as climate and other abiotic conditions. However, a general theory on the linkage of these factors to ecosystem services is still missing. In the following, we will briefly describe the role of some key factors for ecosystem services.
Spatial structure of ecosystems
The spatial structure of ecosystems can strongly determine, whether and in which quantity ecosystem services are provided, and how stable they are. For example, a minimal spatial extent of a watershed must be maintained as forests to provide clear water (Kremen and Ostfeld 2005). Also, the spatial distribution of fragmented ecosystems is important for services such as pollination or pest control (Kremen et al. 2004). Altering adjacent ecosystems to agricultural land can for example strongly impact pollination services, as a study on coffee yields dependent on the surrounding forest structure showed (Ricketts et al. 2004). Here, surrounding native tropical forests lead to a more abundant pollinator community, increasing the quantity and quality of the harvested coffee.
In Europe, especially field margins and hedges are discussed as landscape elements that interact with agriculture. Hedgerows and field margins provide the fundamental habitat to various crop pollinators, pest predators, and bird species (Hinsley and Bellamy 2000, Marshall and Moonen 2002). Additionally, species richness of farmlands is greatly enhanced by small sown margin stripes (Marshall et al. 2006).
Biodiversity
Biodiversity is defined as the diversity among living organisms in terrestrial, marine, and other aquatic ecosystems and the ecological complexes of which they are part (MA 2005b). It includes diversity at different levels, ranging from genes and populations over species to communities and ecosystems. Although it is clear that biodiversity is linked to ecosystem stability and ecosystem services, generalising these linkages and quantifying them is not a trivial mission. For example, it has been found that species composition is often more important for ecosystem processes than the number of species (Díaz and Cabido 2001). Also, artificially increasing the species richness in naturally species-poor areas does not necessarily result into an improvement of ecosystem services (MA 2005b). In general, biodiversity seems to enhance the resistance and resilience of desirable ecosystem states (Elmqvist et al. 2003), i.e. the capacity of an ecosystem to remain in the same state, and the recovery rate of ecosystems after perturbations. Here, one important factor can be whether keystone process species can be substituted by others, in case of their local extinction (Folke et al. 1996).
A comprehensive summary on which of the above given components of biodiversity relates to which ecosystem goods and services provided in Table 1 can be found in the Millenium Ecosystem Assessment (MA 2005c).
Climatic Conditions/Biome
Different climate conditions on earth have led to various biomes. A biome consists of ecologically similar climatic conditions, and represents broad habitat and vegetation types (MA 2005a). Naturally, these biomes not only differ in their primary production (e.g. low productivity in tundras vs. high productivity in tropical rainforests), but also provide different ecosystem services. For example, water regulation functions of forests differ greatly from those of grasslands, and grasslands provide other sources of food than forests. Following the assessment of Costanza et al. (1997), Table 2 provides an overview on the so far known contribution of different biomes to the four classes of services discussed above. It especially shows that little is known about various biomes, such as deserts or the tundra.
Effects of climate change on ecosystems
Value per ha in 1994 ($ ha-1 yr-1)Biome / Area
(106 ha) / Regulating Services / Supporting Services / Provisioning Services / Cultural Services
Marine / Open ocean / 33200 / 43 / 118 / 15 / 76
Costal
Estuaries / 180 / 645 / 21231 / 546 / 410
Seagrass/ algae beds / 200 / 0 / 19002 / 2 / 0
Coral reefs / 62 / 2755 / 65 / 247 / 3009
Shelf / 2660 / 39 / 1431 / 70 / 70
Terrestrial / Forest
Tropical / 1900 / 479 / 1019 / 396 / 114
Temperate/ boreal / 2955 / 92 / 97 / 75 / 38
Grass/ rangelands / 3898 / 87 / 88 / 67 / 2
Wetlands
Tidal marsh/ mangroves / 165 / 1839 / 6865 / 628 / 658
Swamps/ floodplains / 165 / 7535 / 2098 / 7696 / 2252
Lakes/ rivers / 200 / 5445 / 655 / 2158 / 230
Deserts / 1925
Tundra / 743
Ice/ rock / 1640
Cropland / 1400 / 38 / 54
Urban / 332
The projected climate change will act as an important driving force on natural ecosystems (Parmesan and Yohe 2003), and will therefore also alter their services. Various studies show a change in the phenology of species, i.e. the timing of seasonal activities of animals and plants, as a result of changing climate conditions (see reviews in Walther et al. 2002, and Parmesan 2006). For example, some bird species have been found to breed earlier due to recent climate change (Crick and Sparks 1999, Both et al. 2004) and plants shoot and flower earlier in spring (Fitter and Fitter 2002). These changes can be problematic, since changes are not synchronised among species. For example, the arrival of some long-distance migrant birds is determined by endogenous factors and therefore independent on climate conditions on their breeding grounds. If due to climate change spring activities occur earlier at these breeding grounds, this leads de facto to a delayed arrival of the migrant birds (Both and Visser 2001), and therefore to altered food availability and other conditions. Also, interacting predator-prey species can respond asynchronously to changes in the climatic conditions, leading to disturbances of natural cycles (Visser and Both 2005).
Table 2: Known values of ecosystem goods and services according to Costanza et al. (1997). Goods and services are classified according to the Millenium Ecosystem Assessment (MA 2005c). Blank spaces indicate that the value is unknown. The given values provide only a minimal assessment, since not all services are fully captured in the study.
In addition to the phenomenological response of various species, a shift in the range and distribution of species has been observed during recent climate change. This is caused by species-specific physiological thresholds leading to specific “climate envelopes” in which a species can occur. The general warming trend leads to a shift of species towards the poles (Bradshaw and Holzapfel 2006). Migratory species can respond relatively quickly, e.g. by altering the destination of migration. However, resident populations respond much slower. Here, a shift does not occur by the movement of individuals, but by changing extinction and colonisation rates at the northern and southern boundaries of the range: the extinction at unsuitable habitats increases, while new suitable habitats at the poleward end of the range can be colonised (Parmesan et al. 1999).
Various evidences across ecosystems have been found for this poleward shift caused by recent climate change. This includes plant species (e.g. replacement of cold-temperate ecosystems by Mediterranean ecosystems: Peñuelas and Boada 2003; northward shift of a species with a northern margin related to the 0 °C-isocline: Walther et al. 2005) as well as animal species (e.g. intertidal community shift in the range category of species – decline of northern and increase in southern species: Barry et al. 1995; northward shift in the range of birds: Thomas and Lennon 1999; poleward shifts in butterfly species: Parmesan et al. 1999; northward range shift of British dragonflies and damselflies: Hickling et al. 2005). Shifts in species’ ranges have also been observed towards higher altitudes with lower temperatures (e.g. mountain plants in the Alps: Grabherr et al. 1994; upward shift of tree limits: Kullman 2001). But also changes in the water availability can lead to rapid shifts in ecosystems (e.g. drought-induced shift from forests to woodlands: Allen and Breshears 1998).