studies Flashcards
Slivertown 2015
The paper explores whether the concept of ecosystem services (ES) has been “oversold,” particularly focusing on the monetization of nature. Silvertown argues that while the ES paradigm has brought attention to the essential benefits nature provides to humans, it has also aligned too closely with neoliberal economic ideologies, leading to a problematic trend of commodifying and monetizing nature.
Key Points:
1.Anthropocentrism and Monetization: The ES concept often reduces the intrinsic value of nature to its usefulness to humans, leading to its commodification. This is rooted in anthropocentric views, which prioritize human needs and economic value over the broader ecological importance of biodiversity.
2.Historical Development: The idea of ecosystem services evolved from the abstract notion of ecosystems in the 1930s, which later became commodified and monetized in the 1980s and 1990s. This shift in perspective has led to the financialization of nature, where services like carbon trading or biodiversity offsets are used in markets.
3.Problems with Monetization: The paper critiques the monetization of ecosystem services, arguing that it can devalue nature and lead to flawed market-based conservation strategies. Silvertown points out that markets often fail to protect biodiversity and may exacerbate inequality by favouring the wealthy who can afford to “buy” nature.
4.Alternatives to ES Monetization: The paper suggests alternatives to the monetization of nature, such as public investment in conservation and a broader recognition of nature’s non-monetary values. Silvertown calls for a more nuanced approach, where ecosystem services are valued without necessarily attaching a price to them.
5.Questioning Effectiveness: There is limited evidence that monetizing ES leads to actual conservation benefits. Many programs, such as Payments for Ecosystem Services (PES), have mixed outcomes and often fail to protect biodiversity as intended.
Conclusion:
Silvertown concludes that the ecosystem services paradigm, particularly its focus on monetization, may have oversold the idea that markets can effectively protect biodiversity. He advocates for more diverse approaches to valuing nature, emphasizing that monetization is not the only way to achieve conservation goals. Instead, a combination of public investment, democratic control, and moral consideration for nature’s intrinsic value should guide conservation efforts.
Atwood and Hammell 2018
The paper explores the critical role that marine predators play in the maintenance of ecosystem services provided by coastal plant communities, such as kelp forests, seagrass beds, mangroves, and salt marshes. It investigates how changes in predator populations influence the ecosystem services that these plant communities provide, including coastal protection, carbon sequestration, and ecosystem stability. The study also conducts a meta-analysis to assess the strength and direction of trophic cascades in these ecosystems, examining how predators affect herbivores and, subsequently, plant communities.
Key Points:
1.Marine Predators and Ecosystem Services: The study highlights the importance of marine predators in coastal ecosystems. The loss of these predators, largely due to overharvesting, can lead to trophic cascades that affect plant community structure, reducing the ability of these ecosystems to provide services like coastal protection and carbon sequestration.
2.Coastal Protection: Coastal plant communities protect shorelines from erosion and storm surges. The decline in predator populations can lead to increased herbivory, which weakens plant communities and diminishes their capacity to protect coasts. Restoring predator populations could mitigate these impacts.
3.Carbon Sequestration: Coastal plants such as mangroves, salt marshes, and seagrasses are significant carbon sinks. Marine predators regulate herbivore populations, helping to maintain plant biomass, which in turn enhances carbon storage. Without predators, overgrazing can lead to reduced carbon sequestration.
4.Ecosystem Stability and Resilience: Predators contribute to the resilience of coastal plant communities by controlling herbivore populations and promoting biodiversity. In the absence of predators, ecosystems may become less stable and more vulnerable to disturbances.
5.Trophic Cascade Variability: The meta-analysis shows variability in the strength of trophic cascades across different ecosystems. Predators have a strong positive effect on plants in salt marshes, a moderate positive effect in mangroves and kelp forests, and no significant effect in seagrass beds. This variability indicates that different ecosystems respond differently to predator declines.
6.Gaps in Research: The paper identifies a lack of studies on trophic cascades in mangroves and seagrasses, particularly in regions like Africa and South America, where marine ecosystems are heavily exploited. There is also limited research on large-bodied predators and herbivores.
Conclusion: Atwood and Hammill emphasize the crucial role of marine predators in sustaining coastal ecosystem services. However, they also caution that the current body of research is insufficient to make broad generalizations about predator effects, particularly in under-researched ecosystems like mangroves and seagrass beds. The paper calls for more studies to better understand these dynamics and to inform conservation strategies. The authors suggest that while scientific evidence continues to accumulate, conservation decisions regarding predator protection must be made urgently to prevent further degradation of coastal ecosystems.
Economic: damage control, building the sea wall.
The Millennium Ecosystem Assessment (MEA)
Diaz et al. 2018
The paper introduces the concept of Nature’s Contributions to People (NCP) as an evolution of the widely known ecosystem services framework. NCP aims to integrate broader perspectives, emphasizing the importance of culture and indigenous knowledge in the relationship between humans and nature. This approach is developed under the guidance of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) to more inclusively assess biodiversity and ecosystems.
Key Points:
1.NCP vs. Ecosystem Services: While similar to the ecosystem services concept popularized by the Millennium Ecosystem Assessment (MA), NCP broadens the framework by explicitly recognizing cultural and indigenous perspectives. It aims to move beyond the stock-and-flow model of ecosystem services, which was dominated by ecological and economic perspectives.
2.Inclusivity and Cultural Emphasis: NCP emphasizes that nature’s contributions are not universally experienced. Instead, they are understood through different cultural, social, and local lenses, acknowledging that benefits or detriments from nature are context-dependent. This shift incorporates indigenous and local knowledge, which had been marginalized in previous ecosystem service models.
3.Generalizing vs. Context-Specific Perspectives: The paper outlines two main perspectives:
*The generalizing perspective, which is more aligned with natural sciences and aims to create universal categories of nature’s contributions.
*The context-specific perspective, more typical of local and indigenous knowledge systems, which resist universal categories and focus on culturally specific relationships with nature.
4.Categories of NCP: NCP is divided into three broad categories:
*Material contributions: Direct physical benefits like food, energy, and raw materials.
*Nonmaterial contributions: Contributions to psychological well-being, cultural identity, and inspiration.
*Regulating contributions: Ecosystem processes that indirectly benefit people, like water purification or climate regulation.
5.Paradigm Shift in Environmental Assessments: The NCP approach marks a shift in environmental assessments by integrating social and cultural aspects alongside ecological and economic ones. This broader perspective enhances the legitimacy of assessments and improves their relevance to policy and practice.
6.Impact on Policy and Governance: NCP facilitates a more inclusive dialogue in environmental governance, enabling policies that better reflect diverse values and perspectives. This is crucial for initiatives like the Convention on Biological Diversity’s strategic objectives, where inclusivity enhances political legitimacy.
Conclusion:
The NCP framework represents a significant shift in how human-nature relationships are understood and assessed. By incorporating diverse knowledge systems and recognizing the central role of culture, NCP offers a more inclusive and nuanced way of evaluating nature’s contributions. This approach is more likely to inform effective policy and governance by aligning with rights-based approaches and supporting equitable and culturally relevant conservation strategies.
Groot et al. 2012
How can the economic value of ecosystem services across different biomes be quantified and standardized in monetary terms to inform better decision-making and policy development for biodiversity conservation and sustainable ecosystem management?
The paper provides a comprehensive overview of the monetary valuation of ecosystem services across different biomes, using data from over 320 publications and 665 value estimates. It builds on the Ecosystem Service Value Database (ESVD), which was developed as part of the global effort to quantify the economic importance of ecosystems and biodiversity. The goal is to provide better insights into the economic value of ecosystem services for more informed decision-making and policy development regarding conservation and sustainable management.
Key Points:
1.Ecosystem Service Value Database (ESVD): The ESVD contains more than 1,350 data points from case studies across 10 major biomes, including open oceans, coral reefs, wetlands, forests, and grasslands. The data are standardized into a common metric of International Dollars per hectare per year (Int$/ha/year), enabling value comparison across ecosystems.
2.Valuation Methodology: The study uses various valuation methods, including direct market pricing, contingent valuation, avoided cost, and replacement cost. The choice of valuation method can significantly affect the outcome, and the paper emphasizes the need to consider socio-economic contexts when transferring values between regions.
3.Value Ranges: Ecosystem service values vary greatly by biome and type of service. Coral reefs, for instance, show a particularly high economic value due to services like tourism and coastal protection, with an average potential value of around 352,000 Int$/ha/year. In contrast, open oceans, while covering a vast area, have lower service values (491 Int$/ha/year).
4.Non-Market Values: The majority of ecosystem services are public goods and do not have a direct market value. Their true economic worth lies in their non-market benefits, such as climate regulation, waste treatment, and cultural services, which are often undervalued or ignored in decision-making processes.
5.Policy Implications: The results underscore the importance of incorporating ecosystem service values into national accounting systems and policies, as highlighted by international frameworks like the Convention on Biological Diversity (CBD). Proper valuation can help guide conservation efforts, identify critical areas for protection, and enhance the well-being of communities dependent on ecosystem services.
Conclusion:
The study demonstrates the vast economic significance of ecosystem services across different biomes. While challenges remain in terms of data availability, valuation methods, and socio-economic factors, the ESVD provides a valuable tool for informing policy and improving conservation strategies. The authors advocate for the integration of these monetary valuations into policy frameworks to ensure the sustainable management of ecosystems, emphasising that failure to account for the true value of ecosystem services could lead to significant losses for future generations.
Heilmayr et al. 2020
The paper evaluates the environmental impacts of Chile’s long-standing afforestation subsidies under Decree Law 701 (DL 701) on forest cover, carbon storage, and biodiversity. The study uses an econometric land use change model to simulate the impacts of these subsidies from 1986 to 2011, comparing scenarios with and without subsidies to assess their influence on plantation expansion, native forest loss, carbon sequestration, and biodiversity.
Key Points:
1.Afforestation Subsidies: DL 701 was designed to incentivize the expansion of forest plantations in Chile, initially as a means to address soil erosion and later to foster economic growth. However, the subsidies mostly promoted the planting of non-native, commercial species (e.g., pine and eucalyptus) rather than the regeneration of native forests.
2.Impact on Forest Cover: The subsidies did lead to increased plantation area, but this expansion often replaced native forests, shrublands, and marginal agricultural lands. The study estimates that only 3.28% of the plantation expansion was attributable to the subsidies, as much of the expansion would have occurred due to other economic drivers.
3.Carbon Sequestration: Although afforestation increased forest cover, the replacement of native forests with plantations reduced overall carbon storage. Native forests store more carbon than plantations, so the net effect of the subsidies was a small decrease in carbon storage (-46 ktC). However, if the subsidies had been restricted to non-forested lands, carbon storage could have increased by 573 ktC.
4.Biodiversity Loss: Native forests in Chile are more biodiverse than plantations. The subsidies resulted in a net decline in species richness, contributing to a 0.0016 s.d. reduction in the area’s biodiversity. Stronger protections against the conversion of native forests could have mitigated 78% of these biodiversity losses.
5.Policy Lessons: The study highlights the importance of designing afforestation policies that avoid replacing carbon-rich and biodiverse native ecosystems with plantations. Enforcing restrictions on subsidies for plantations on native forest lands would improve both carbon sequestration and biodiversity outcomes.
Conclusion:
The study concludes that while afforestation subsidies under DL 701 succeeded in expanding forest cover, they failed to increase carbon storage and had negative impacts on biodiversity due to the conversion of native forests to plantations. The results emphasize the need for stronger safeguards to prevent the loss of native ecosystems in future afforestation initiatives, especially in light of global reforestation goals like the Bonn Challenge. Policy design must carefully balance the economic benefits of plantation forestry with the ecological importance of preserving native forests.
Barbier (2015)
The paper focuses on the economic valuation of the storm protection services provided by estuarine and coastal ecosystems (ECEs) such as marshes and mangroves. These ecosystems play a critical role in reducing the impact of storm surges and coastal flooding, protecting coastal communities from property damage and loss of life. The study highlights the importance of improving valuation methods to more accurately capture the protective value of these ecosystems and introduces the Expected Damage Function (EDF) approach as an alternative to the traditional Replacement Cost method for valuing storm protection services.
Key Points:
1.Estuarine and Coastal Ecosystems (ECEs): ECEs such as marshes, mangroves, coral reefs, and sand dunes provide natural barriers against storms by attenuating waves and reducing storm surge impacts. These ecosystems offer a significant economic benefit by protecting property and lives in coastal areas.
2.Valuation Methods: Traditionally, the replacement cost method has been used to estimate the value of ECEs by calculating the cost of constructing artificial barriers like sea walls to replace the services provided by ecosystems. However, this method often overestimates the value because it does not account for the natural variation and interconnectedness of ecosystems.
3.Expected Damage Function (EDF) Approach: The paper introduces the EDF approach, which models the protective service of ECEs by estimating the expected reduction in storm damages (in terms of property loss and other economic damages) due to the presence of ecosystems. This method provides a more accurate measure of the value of storm protection by incorporating factors like storm characteristics, coastal topography, and ecosystem health.
4.Case Studies: The paper uses examples from Thailand (mangroves) and the U.S. Gulf Coast (marshes) to compare the EDF and replacement cost methods. The EDF approach generally produces more reliable and conservative estimates of the protective value of ecosystems than the replacement cost method.
5.Challenges and Future Directions: Barbier emphasizes the need to improve hydrodynamic modelling and incorporate factors like vegetation density, storm severity, and coastal landscape into the valuation process. Additionally, understanding the connectivity between different ecosystems (e.g., mangroves and coral reefs) can enhance the accuracy of storm protection value estimates.
Conclusion:
Barbier concludes that valuing the storm protection services of ECEs is crucial for guiding policy and management decisions, especially in light of ongoing habitat loss and the increasing frequency of severe storms. The Expected Damage Function approach provides a promising alternative to traditional valuation methods by offering a more accurate and context-sensitive assessment of the protective value of ecosystems. Policymakers should incorporate these valuation methods into coastal management and restoration projects to ensure the protection of valuable ecosystems and the communities they safeguard.
McArthur & Wilson’s (1967) Equilibrium theory of island biogeography.
-Species richness in an island community is a dynamic balance between immigration and extinction.
-Over time immigration rate declines and extinction rates increase, this leads to a dynamic balance which determines the number of species on an island.
-The first immigrants to reach the island are good dispersers, so once they have all passed through, things slow down and extinction then increases.
-When the equilibrium is reached, it doesn’t stop, it just means the balance remains constant (dynamic).
-Other factors can also be involved, more species are likely to reach a larger island compared to a small one.
-More likely to survive on a larger island compared to a small one as well.
McArthur and Wilson explain one reason that might give this pattern (large islands have more species than small ones). This is only one model that can predict it. They came up with an equation.
They also predicted that the species no. declines with remoteness, but the no. of species is roughly constant throughout time. No. of species is a result of turnover of species through immigration and extinction-dynamic equilibrium.
Species-area relationship: S = cAZ. .Then if you log both sides you get Y = C + mX which is very similar to the equation for a straight line.
Simberloff & Wilson
Defaunation experiments in mangrove islands near Florida Keys, they used knock-down insecticide to remove arboreal invertebrates.
-They reassembled very quickly but found that the islands that were previously species rich, were again species rich. And the areas that were species poor remained that way as well.
-They also found that competition began after 100 days. There were differenced in species composition however, because it basically first comes, first serve.
Taylor & Gotelli (1994)
Focus: Analyses the patterns and processes influencing the distribution and species richness of European freshwater fish, emphasizing the roles of habitat preference, migratory behaviour, and body size in relation to glaciation and geographic barriers.
Species Richness Patterns: Species richness declines with distance from the Ponto-Caspian region, with non-endemic species richness decreasing to the north and west. Endemic species richness primarily declines with latitude.
Habitat and Migratory Patterns: Generalist species are more successful in colonizing glaciated regions compared to riverine specialists. Diadromous species (those migrating between sea and freshwater) show no geographic variation in richness, while potamodromous and resident species are limited by glaciation and geographic barriers. Body Size Trends: The mean body size of fish species in regions increases with latitude, as larger species are more prevalent in northern, glaciated areas. Range Sizes and Endemism: Roughly half of all European freshwater fish are endemic to one region, particularly in Mediterranean climate zones. Range size correlates with habitat preference and migration type rather than body size.
Conclusion: The study finds that freshwater fish distributions in Europe are shaped by a complex interplay of historical glaciation, habitat variability, and migratory capacity. Generalist and migratory species are better adapted to colonize diverse habitats, including glaciated areas, while riverine specialists remain concentrated in southern, unglaciated regions with stable freshwater habitats. The findings highlight that adaptability in migration and habitat use is crucial for survival and dispersion, particularly in response to historical climatic shifts.
Calosi et al. (2010)
Focus: Explores how temperature and nutrient levels influence the abundance and community structure of colonizing aquatic insects in experimental freshwater habitats.
Methodology: A controlled mesocosm experiment with temperature manipulation (0, 1, or 2 heaters per tank) and nutrient addition was conducted to examine habitat selection and community assembly among colonizing insects.
Results on Temperature Effects: Higher temperatures (heated mesocosms) resulted in lower overall insect abundance. Heat influenced insect community composition, with significant differences in diversity (alpha and beta diversity) and species composition across temperature treatments.
Results on Nutrient Effects: Nutrient addition had minimal effects on insect colonization, likely due to the rapid assimilation of nutrients, suggesting that colonization was more sensitive to temperature than nutrient enrichment. Species-Specific Responses: Certain taxa (e.g., Copelatus glyphicus) showed strong temperature-based habitat preferences, while others did not respond significantly to either temperature or nutrients.
Conclusion: The study demonstrates that temperature is a critical determinant of habitat selection and species composition for colonizing aquatic insects, overshadowing the effects of nutrient addition. In a warming climate, these findings suggest that habitat selection for cooler microenvironments could help insects mitigate thermal stress, although limited availability of suitable habitats may constrain this adaptive strategy. The work underscores the complexity of temperature impacts on freshwater communities, suggesting cascading effects on biodiversity as global temperatures rise.
Verberk et al. (2010)
Focus: Investigates thermal adaptation and evolutionary changes in life history and heat tolerance in the damselfly Ischnura elegans during its range expansion to warmer (southeast Spain) and cooler (northwest Spain) regions.
Methodology: The researchers conducted controlled “common-garden” experiments, rearing first-generation larvae across temperatures (16°–28°C) to analyze traits like growth rate, development, and heat tolerance (CTmax).
Results for Warmer Region:
Increased heat tolerance (CTmax) and higher developmental rates at 28°C.Likely adaptation to increased “voltinism” (more generations per year) in warmer environments. Evolutionary increase in thermal plasticity, aiding adaptation to extreme temperatures.
Results for Cooler Region:
Faster growth rates associated with countergradient variation, helping buffer against cooler temperatures. No significant evolution in heat tolerance, likely due to lower thermal extremes in this region.
Similarities: Both expansions showed evolutionary increases in growth rates, but only the warmer region showed increased heat tolerance.
Conclusion: The study highlights that range expansions toward warmer and cooler regions can drive distinct but sometimes parallel evolutionary adaptations in life history and thermal tolerance. Adaptations in heat tolerance appear crucial for survival in warmer regions, while faster growth compensates for shorter growing seasons in cooler regions. These findings emphasize the complex role of evolutionary plasticity in responding to varied climate pressures and support the necessity of evolutionary traits alongside plasticity for coping with changing thermal regimes.
