Biodiversity and Ecosystem function lec 5 BioCon
UNDERSTANDING ECOSYSTEM FUNCTION
Definition of Ecosystem
Arthur Tansley (1935): Integration of biotic community and physical environment as a fundamental ecological unit
Contemporary Definition: An ecosystem includes all living beings (plants, animals, and other organisms) in an area, interacting with their non-living environments (weather, earth, sun, soil, climate, atmosphere).
ECOSYSTEM FUNCTION
Definition: Biological, ecological, geochemical, and physical processes occurring within an ecosystem.
Categories of Ecosystem Functions (de Groot et al. 2002):
Regulation Functions: Involvement in maintaining homeostasis, such as climate regulation.
Habitat Functions: Provision of shelter and environments for various species.
Production Functions: Biomass generation and energy flow within ecosystems.
Information Functions: Storing genetic information and ecological knowledge.
Example: Soil formation through weathering and accumulation of organic matter.
LINKING BIODIVERSITY TO ECOSYSTEM FUNCTION
Importance of Biodiversity-Ecosystem Function (BEF) Relationships:
High biodiversity levels support healthy ecosystem functions.
Essential for providing ecosystem services (clean water, pollination, etc.).
Arguments for Conservation: Clear positive relationships between biodiversity and both ecosystem function and services are essential.
DEVELOPMENT OF BEF RESEARCH
Theoretical BEF Relationships:
Linear: Loss of species leads to consistent decline in ecosystem function (EF).
Redundancy: Losses beyond saturation have minimal impact on EF as other species compensate. If loss occurs below saturation, EF declines rapidly.
Keystone Species: Loss leads to significant decline in EF.
Rivet Model: Driver species loss results in greater EF decline compared to passenger species loss.
MECHANISTIC EXPLANATIONS FOR BEF RELATIONSHIPS
Niche Complementarity: More species occupy different niches, enhancing resource use efficiency.
Functional Facilitation: Beneficial interactions among species lead to improved EF.
Sampling Effect: Increased species richness raises the likelihood of presence of functionally important species.
Dilution Effect: Higher species richness may lead to lower pathogen transmission, increasing EF.
SYNTHESIS OF BEF STUDIES
Review of studies supports BEF relationships, with 71% noting positive effects of biodiversity on EF.
Variation observed in ecosystem types and functions.
51% in grassland communities demonstrated positive relationships.
Only 44% of studies related to decomposition showed positive BEF relationships.
BIODIVERSITY AND ECOSYSTEM SERVICES
Definition of Ecosystem Services: Direct and indirect contributions of ecosystems to human well-being.
Example of services includes carbon storage, regulating pests, and beauty through aesthetic enjoyment.
Goal of conservation: Ensuring multifunctionality of ecosystems through biodiversity management.
FUNCTIONAL TRAITS AS MEASURE OF BIODIVERSITY
Definition: Species traits that influence biotic and abiotic interactions in ecosystems, measurable at individual levels.
Importance: Leads to better understanding of species roles within ecosystems and their contributions to ecosystem functioning.
Inclusion of specific properties like leaf size, shape, dispersal mode, and size classifications.
VALUATION OF BIODIVERSITY
Intrinsic Value: The worth of species independent of their direct human benefits.
Moral obligation to protect biodiversity.
Economic Valuation: Essential for framing conservation in terms of financial implications due to economic causes of environmental damage.
Types:
Direct Values: Consumptive (local resources) and Productive (commercial products).
Indirect Values: Include social and cultural, aesthetic value, and ecosystem service value.
Economic estimates of ecosystem services can reach trillions annually.
COMMUNITY VALUES AND ENGAGEMENT
Understanding diverse community perspectives on biodiversity helps tailor conservation efforts and tree planting strategies, ensuring they reflect local values and experiences.
UNDERSTANDING ECOSYSTEM FUNCTION
Definition of Ecosystem - Arthur Tansley (1935): Integration of biotic community and physical environment as a fundamental ecological unit.
Contemporary Definition: An ecosystem is a dynamic complex of plant, animal, fungal, and microorganism communities and their non-living environment, interacting as a functional unit. It includes all living beings (plants, animals, and other organisms) in an area, interacting with their non-living environments (weather, earth, sun, soil, climate, atmosphere).
ECOSYSTEM FUNCTION
Definition: Biological, ecological, geochemical, and physical processes occurring within an ecosystem that contribute to its overall health and stability. Ecosystem functions can include energy transfer, nutrient cycling, and habitat provisioning.
Categories of Ecosystem Functions (de Groot et al. 2002):
Regulation Functions: Involvement in maintaining homeostasis, such as climate regulation, water purification, and disease regulation.
Habitat Functions: Provision of shelter and environments for various species, thus supporting biodiversity. This can include forest habitats, wetlands, and marine ecosystems.
Production Functions: Biomass generation (through photosynthesis, for example) and energy flow within ecosystems, which provides food and resources for different trophic levels.
Information Functions: Storing genetic information and ecological knowledge which can support evolutionary processes and adaptive responses.
Example: Soil formation through weathering of rocks and accumulation of organic matter, which is crucial for supporting plant life.
LINKING BIODIVERSITY TO ECOSYSTEM FUNCTION
Importance of Biodiversity-Ecosystem Function (BEF) Relationships:
High biodiversity levels support healthy ecosystem functions, making ecosystems more resilient to changes and disturbances.
Essential for providing vital ecosystem services such as clean water, pollination of crops, and climate regulation, which are critical for human survival and well-being.
Arguments for Conservation: Highlighting that clear positive relationships between biodiversity and both ecosystem function and services are essential; conservation efforts must prioritize biodiversity retention to ensure ecosystem health and service continuity.
DEVELOPMENT OF BEF RESEARCH
Theoretical BEF Relationships:
Linear Model: Suggests that the loss of species leads to a consistent decline in ecosystem function (EF), illustrating a direct relationship.
Redundancy Model: Indicates that losses beyond a saturation point have minimal impact on EF as other species can compensate for the loss. However, if loss occurs below saturation, EF declines rapidly.
Keystone Species: Certain species play a crucial role in maintaining the structure of an ecosystem; their loss can lead to significant declines in EF. Examples include top predators or important pollinators.
Rivet Model: Proposes that the loss of driver species leads to greater declines in EF compared to the loss of passenger species, highlighting the importance of specific species to ecosystem integrity.
MECHANISTIC EXPLANATIONS FOR BEF RELATIONSHIPS
Niche Complementarity: More species occupy different niches, enhancing resource use efficiency and productivity, leading to better overall ecosystem performance.
Functional Facilitation: Interactions among species, such as mutualism and commensalism, can enhance ecosystem functioning by promoting growth and survival.
Sampling Effect: Increased species richness raises the likelihood of the presence of functionally important species, thereby enhancing ecosystem function.
Dilution Effect: Greater species richness may reduce pathogen transmission rates and increase EF by creating a more complex ecosystem structure.
SYNTHESIS OF BEF STUDIES
Review of studies supports BEF relationships, with approximately 71% noting positive effects of biodiversity on EF.
Variation observed in ecosystem types and functions
51% of studies conducted in grassland communities demonstrated positive relationships.
Only 44% of studies related to decomposition processes showed positive BEF relationships, indicating that certain functions may be more sensitive to biodiversity loss.
BIODIVERSITY AND ECOSYSTEM SERVICES
Definition of Ecosystem Services: Direct and indirect contributions of ecosystems to human well-being, encompassing both ecological and socio-economic aspects.
Examples of services include carbon storage, pest regulation, pollination, flood control, and aesthetic enjoyment of nature.
Goal of conservation: Ensuring multifunctionality of ecosystems through biodiversity management to secure ecosystem services for future generations.
FUNCTIONAL TRAITS AS MEASURE OF BIODIVERSITY
Definition: Species traits that influence biotic and abiotic interactions in ecosystems, measurable at individual levels. Traits might include size, shape, and behavior that determine an organism's role within an ecosystem.
Importance: Leads to better understanding of species roles within ecosystems and their contributions to ecosystem functioning, enabling targeted conservation efforts.
Inclusion of specific properties like leaf size, leaf shape, dispersal mode, and size classifications associated with functional roles in ecosystems.
VALUATION OF BIODIVERSITY
Intrinsic Value: The worth of species independent of their direct human benefits, emphasizing a moral obligation to protect biodiversity for its own sake.
Economic Valuation: Essential for framing conservation in terms of financial implications, recognizing the integration of economic and environmental issues. Economic causes of environmental damage necessitate a valuation framework.
Types:
Direct Values: Consumptive (harvesting local resources) and Productive (commercial products derived from ecosystems).
Indirect Values: Include social and cultural perspectives, aesthetic value, and the inherent value of ecosystem service contributions.
Economic estimates of ecosystem services can reach several trillions of dollars annually, highlighting their importance in global economies.
COMMUNITY VALUES AND ENGAGEMENT
Understanding diverse community perspectives on biodiversity is critical for promoting sustainable conservation efforts. Engaging with local communities helps to tailor conservation initiatives and tree planting strategies to ensure they reflect local values, needs, and experiences, thus enhancing the success and sustainability of such programs.