Earth as a Living System FOCUS ON ECOSYSTEM FUNCTIONS AND ECOSYSTEM SERVICES THROSTURTH@HI.IS
Earth as a Living System Earth itself is a system of biological communities Biota: All the organisms of all species living in an area or region up to and including the biosphere Biosphere: 1. That part of a planet where life exists 2. The planetary system that includes and sustains life
Structure Ecosystems A set of interacting species that occur in the same place and functioning together Food chains, food webs, trophic levels (autotrophs, heterotrophs) From a small pond to Biomes Biomes: Areas with similar climate and plant life A heterotroph is an organism that cannot fix carbon and uses organic carbon for growth. An autotroph is an organism that produces complex organic compounds from simple substances present in its surroundings, generally using energy from light or inorganic chemical reactions.
Ecosystem A community of organisms and its local nonliving environment in which matter (chemical elements) cycles and energy flows. Life sustained by interactions of many different organisms, functioning together, and interacting through their physical and chemical environment Inherently complex
Basic Characteristics of Ecosystems Structure Living (Ecological Communities) Hierarchical interactions Non-living (physical/chemical environment) Processes and organization Growth (already covered) Cycling of chemical elements important and complex Inflows, recycling, no waste in nature, interactions Food webs Flow of energy Between trophic levels Change Evolution Succession TROPHIC LEVELS: 1: Plants and algae make their own food and are called primary producers. 2: Herbivores eat plants and are called primary consumers. 3: Carnivores which eat herbivores are called secondary consumers. 4: Carnivores which eat other carnivores are called tertiary consumers. 5: Apex predators which have no predators are at the top of the food chain
The Community Effect Population: group of individuals belonging to the same species living in the same area Species interact directly and indirectly Symbiosis Competition Predator - prey Examples?
Community level interactions Community-level interactions Generalists vs. specialists Niches Keystone species Have large effects on it s community or ecosystem It s removal changes the basic nature of the community Example: Sea otter Holistic View Needed
Indirect effects Sea otters, urchins and kelp Sea otters promote recovery of seagrass beds http://phys.org/news/2013-08-seaotters-recovery-seagrass-beds.html In the news Sep 2012: http://www.sciencedaily.com/relea ses/2012/09/120907161437.htm
Other species Types Classification depends on: Intrinsic growth rate, r Carrying capacity, K Specialization r selected K - selected
Change Evolution change in genetic material Succession The sequential change in the relative abundances of the dominant species in a biological community converging to a climax state Primary succession: beginning from an abiotic environment following a catastrophic disturbance. Secondary succession: beginning from a major disturbance, but all forms of life are not destroyed
Change Stages of Succession Early: plants typically small with short lifecycles (annuals ), rapid seed dispersal, environmental stabilizers. r selected, generalists Middle: plants typically longer lived, slower seed dispersal, and in woodland systems: larger. Late: plants and animal species are those associated with older, more mature ecosystem. K-selected species, niches Climax? - followed by a disturbance
Forest succession
Resiliency An ecosystem is resilient if it can maintain its functional integrity when subjected to some disturbance Property of the system How to maintain? Threshold Keystone species Diversity
Evolution The process of change over time Biological evolution Change in the genetic material via Mutations Genetic drift Natural selection Genotypes (the genetic makeup of a cell, organism, or individual) Phenotypes (observable characteristics) Survival of the fittest fittest? http://www.cdhgenetics.c om/genetic-overview.cfm
Co-evolution One species is affected by the evolution of another species A species is affected by change in the environment Co-evolution between environment and the economy Institutions e.g. Can you think of any examples of co-evolution?
Different productivity of Biomes
Processes and Organization Cycling of chemical elements No waste - Closed loops Food webs Food chains Trophic levels Autotrophs Heterotrophs Herbivores Carnivores Omnivores
A food-web for a woodland ecosystem
The trophic pyramid Trophic level
Food Chains and Food Webs A Terrestrial Food Chain Many trophic levels: Autotrophs Herbivores Carnivores Decomposers People are omnivores (omnivores = animal that eats either other animals or plants) The Food Web of the Harp Seal
Energy Flows in Ecosystems 10% efficiency between levels Decomposers Fungi, Bacteria Animals Resease nutrients
Energy flow
Ecosystem services (MEA) Supporting services Nutrient recycling, primary production, soil formation. Provisioning services Food, raw materials, Regulating services Waste decomposition, purification of water & air, Cultural services Recreational, spiritual, cultural, education
Examples In New York City, where the quality of drinking water had fallen below standards required by the U.S. Environmental Protection Agency (EPA), authorities opted to restore the polluted Catskill Watershed. The cost of this investment in natural capital was estimated between $1 1.5 billion, which contrasted dramatically with the estimated $6 8 billion cost of constructing a water filtration plant plus the $300 million annual running costs. [21] Pollination of crops by bees https://en.wikipedia.org/wiki/ecosystem_services
Examples In the 1980s, mineral water company Vittel (now a brand of Nestlé Waters) faced a critical problem. Nitrates and pesticides were entering the company s springs in northeastern France. Local farmers had intensified agricultural practices and cleared native vegetation that previously had filtered water before it seeped into the aquifer used by Vittel. In response Vittel developed an incentive package for farmers to improve their agricultural practices and consequently reduce water pollution that had affected Vittel's product. This is an example of a Payment for ecosystem services program. [25] It was counted that to plant 15 000 ha new woodland in UK, if we consider only the value of timber, it would cost 79 000 000 which is more than the benefit of 65 000 000. If, however, we include all other benefits the trees in lowland could provide (like soil stabilization, wind deflection, recreation wind defense, food production, air purification, carbon storage, wildlife habitat, fuel production, cooling, flood prevention), the costs will increase due to displacing the profitable farmland (would be around 231 000 000) but will be overweight by benefits of 546 000 000. [26] https://en.wikipedia.org/wiki/ecosystem_services