FBS 36 Chapter 2 - Ecosystem Concept (PDF)

FBS 36. Fundamentals of Forest Ecology Ecosystem Concept Chapter 2 OUTLINE Definition of an Ecosystem Components of an Ecosystem Properties and Functions of an Ecosystem Schools of thought in studying ecosystem Natural Terrestrial and Agroecosys...

FBS 36. Fundamentals of Forest Ecology Ecosystem Concept Chapter 2 OUTLINE Definition of an Ecosystem Components of an Ecosystem Properties and Functions of an Ecosystem Schools of thought in studying ecosystem Natural Terrestrial and Agroecosystem 2  A series of ecosystem that has relatively the same biotic and abiotic factors spread all over the area. Ecological organization Member of Individuals of the an area occupied an organism same species living by 2 or more in 1 geographical species and may area and interbreed interact but not interbreed Reference: https://ecologyproject10.weebly.com/uploads/2/8/7/9/28792783/6506305_orig.jpg?455 3  Ecosystem Concept a bounded ecological system consisting of all the organisms in an area and the physical environment with which they interact (Chapin et al. 2002) a region with a specific and recognizable landscape form based on geographical features such as hills, mountains, plains, rivers, lakes, Photo by: MEGDC coastal areas or island 4 Ecosystem Concept The sum of all of the biological and non-biological parts of an area that interact to cause plants to grow and decay, soil or sediments to form, and the chemistry of water to change community sustainably interacting with the environment 5 Ecosystem Concept Definition: An ecosystem is a dynamic system where the biotic and abiotic components constantly act and react upon each other, bringing forth structural and functional changes in a community. ‘Ecosystem’ was coined first by British Ecologist A.G. Tansely (1935). “An ecosystem is a complex interacting system of a community and its abiotic environment.” 6  2 Major Ecosystem types Aquatic ecosystem Terrestrial ecosystem found in water bodies, including freshwater and characterized by their soil composition, marine environments. topography, climate, and vegetation types i.e., lakes, rivers, wetlands, ponds, estuaries, and i.e., forests, grasslands, and deserts to tundra and oceans wetlands are influenced by factors such as water depth, temperature, salinity, and nutrient availability. 7 Photo credit : MEGDC More about ecosystem Some ecosystems are fairly robust while others are highly vulnerable to disturbance The interaction among the components makes each ecosystem distinct Borders are not rigid and ecosystems may blend 8 Abiotic: water, light, Biotic: producers, temperature, Rh, wind consumers, decomposers Photo credit : MEGDC Components of an ecosystem 9 Biotic Components of an Ecosystem Producers Consumers Decomposers "Monkey in Jozani Forest" by Transformers Travel Aficionado is licensed under CC BY-SA 2.0. 10  Mode of nourishment Biotic/ Producers Green plants, photosynthetic bacteria, chemosynthetic bacteria Living Macro-consumers Herbivores, carnivores, omnivores, parasitic animals Micro-consumers Fungi, bacteria, and actinomycetes Odum, E.P. 1971. Fundamentals of Ecology. New York:John Wiley and Sons, Inc. 11  Photosynthetic organisms – green plants (unicellular or multicellular) makes organic compounds by converting light energy to Autotrophs Producers/ chemical energy (e.g. glucose) or in layman’s terms food (light + nourishment) Chemosynthetic organisms – unicellular organisms (cousins of the bacteria) capable of breaking salts and capture heat into food. These are referred to as chemoautotrophs (chemical + nourishment) 12 13  Consumers (phagotrophs) heterotrophs which usually pass food through a mouth, pass intestines, and undigested material is expelled through an anal opening as fecal material Omnivores- eat Herbivores – eat Carnivores- eat both plants and plants only meat only animals 14  Decomposers (saprotrophs) heterotrophs that team together in effecting biodegradation of dead animal, plant and microbe bodies which are divided into two groups Macrodecomposer/ Faunal Microdecomposer/ Flora decomposers – Decomposer – break detritus or litter by means of enzymes to animals that eat detritus or litter, like reduce them into small organic substances that could pass through cell wall (Osmotroph=to pass earthworms and termites through); (Saprotrophs=dead remains) 15  Transformers Refers to certain types of bacteria that attack on materials excreted by other living organisms (even dead plants and animals ). They transform the above into either organic or inorganic substances. These substances are suitable for the nutrition of green plants. https://www.gardenmyths.com/soil-microbes-need-to-add-them-garden/ help in recycling the nutrients which came as waste already 16 Biotic Components based on Mode of Nutrition Retrieve from: https://ib.bioninja.com.au/ 17 Abiotic Components of an Ecosystem Climatic and physical factors Inorganic substances Organic substances 18 Climatic and physical factors air, water, soil and sunlight; rainfall, temperature, humidity, soil texture and geomorphic conditions Photo credits: MEGDC 19  Inorganic Compounds these consist of simple chemical substances like water (H2O), carbon dioxide (CO2), table salt (NaCl), nitrate (NO3), phosphate (PO4), sulphate (SO4), methane (CH4) involve in the cycling of materials in the ecosystems 20  Organic Compounds proteins, carbohydrates, lipids, humic substances that are largely formed the living body and link the abiotic compounds with the biotic factor All of these decompose or burn giving off heat and the by- products CO2 and H2O "Cassava plant" by IITA Image Library is licensed under. To view a copy of this license, visit undefined?ref=openverse&atype=rich 21 Parameter Organic Compounds Inorganic Compounds Contain carbon-hydrogen (C-H) bonds and other Do not contain carbon-hydrogen (C-H) bonds elements like oxygen, nitrogen, sulfur, Composition Consist of metals, nonmetals, or metalloids phosphorus, halogens Complexity More complex and diverse molecular structures Generally simpler structures Bonding Type Predominantly covalent bonding May exhibit ionic, metallic, or covalent bonding Found in living organisms or synthesized Source Found in living and non-living systems artificially Higher melting and boiling points, greater Physical Lower melting and boiling points, often softer hardness Properties due to weaker intermolecular forces and lower volatility Generally soluble in organic solvents (alcohol, Variable solubility characteristics, some soluble in Solubility ether, acetone) water, others insoluble Serve diverse functions including structural support, electrolyte balance, and catalysis of Serve as building blocks for cells, enzymes, Role in Nature chemical; & involve in the cycling of materials hormones and other biomolecules in the ecosystems 22 23 To be continued on September 18, 2024 Definition of an Ecosystem Components of an Ecosystem Properties and Functions of an Ecosystem Schools of thought in studying ecosystem Natural Terrestrial and Agroecosystem 24 Properties of an Ecosystem Energy flow Nutrient cycling Pattern of diversity Homeostasis Stability Productivity Sustainability 25 Energy flow No energy is retained to an individual—it must be passed on! Detritus food chain start once the organism die Based on the source of their nutrition or food, organisms occupy a specific place in the food chain that is known as their trophic level 26 only 10 % of the energy is transferred to each trophic level from the lower trophic level https://ncert.nic.in/textbook/pdf/lebo114.pdf 27 Nutrient cycling also known as biogeochemical cycle refers to the movement of nutrient elements through the various components of an ecosystem nutrients are never lost from the ecosystem and recycled time and again indefinitely 28 Nutrient cycling Nutrients refer to the material required by an organism, and include elements such as carbon, nitrogen and phosphorus The supply of inorganic nutrients on Earth is finite – new elements cannot simply be created and so are in limited supply 29  Hence chemical elements are constantly recycled after they are used: Autotrophs obtain inorganic nutrients from the air, water and soil and convert them into organic compounds Heterotrophs ingest these organic compounds and use them for growth and respiration, releasing inorganic byproducts When organisms die, saprotrophs decompose the remains and free inorganic materials into the soil The return of inorganic nutrients to the soil ensures the continual supply of raw materials for the autotrophs 30 Pattern of biodiversity the attribute of the ecosystem in terms of its variety of gene pools, populations and habitats. This can be partly be due to evolution and ecological succession 31 Diversity-Stability Theory Theoretical models suggest that there could be multiple relationships between diversity and stability (reviewed by Ives & Carpenter 2007). Figure 1 shows how having multiple species present in a plant community can stabilize ecosystem processes if species vary in their responses to environmental fluctuations such that an increased abundance of one species can compensate for the decreased Figure 1: Conceptual diagram showing how increasing diversity can stabilize ecosystem functioning abundance of another. Reference: https://www.nature.com/scitable/knowledge/library/biodiversity- and-ecosystem-stability-17059965/ 32 Stability overall ability of the ecosystem to resist and recover from changes or disturbances (like natural disasters or human activities). ⮚elastic (quickness of recovery; how fast it can bounce back to normal state) ⮚constant (resisting swings; resistance of ecosystem to swing back and forth away from normal set-point) 33 Stability ⮚elastic (quickness of recovery; how fast it can bounce back to normal state) ⮚constant (resisting swings; resistance of ecosystem to swing back and forth away from normal set-point) ⮚amplifying (the allowed deviation from normal set- point); there’s some room for things to move a bit away from normal, but only within the limits ⮚efficient (energy use; the ability to convert energy into biomass and useful outcomes with little waste) 34 Stability ability of the system to resist external stress ⮚a stable ecosystem can bounce back quickly, avoid wild changes, handle small deviations, and use its energy efficiently to sustain life. 35 Resilience An ecosystem is resilient if it can maintain its functional integrity when subjected to some disturbance How to maintain? Threshold Keystone species diversity Top 5 benefits of Resilient Ecosystem Reference: Forest Fire Management Victoria 36 Factors affecting Ecosystem Resilience 1. The more diverse/complex an ecosystem, the more resilient it tends to be (more interactions between species). 2. The greater the species biodiversity, the greater the likelihood there is a species that can replace another if it dies (to maintain equilibrium) 3. The greater the genetic diversity within a species, the greater resilience (monoculture can be wiped by disease if none of the plants have genetic resistance) 37 Factors affecting Ecosystem Resilience 4. Species that can shift geographic ranges are more resilient. 5. The climate affects resilience. In the arctic regeneration of plants is slow (low temps slow down Ps/cell Rs). But in TRF, growth rates are fast. 6. The faster the rate at which species can reproduce means recovery is faster. r-strategist (fast reproductive rate) can recolonize the system better than K-strategists (slow producers). 7. Humans can remove or mitigate threats to the system (pollution, invasive species)-resulting in faster recovery. 38 r-strategist versus K strategist 39 Homeostasis the tendency of ecosystems to bounce back to normal stable set-point after stress is withdrawn (capability to self-regulation in attaining system equilibrium) the ability of an ecosystem to maintain internal balance despite external changes. It involves self-regulation mechanisms that keep the ecosystem within a certain range of conditions, like temperature, moisture, or population levels. 40 Homeostasis is like balancing a tightrope: You constantly make small adjustments to keep from falling off. If you lean a little to one side, you adjust your body to stay balanced. Similarly, an ecosystem is constantly making adjustments (e.g., predator- prey relationships, nutrient cycling) to keep everything in balance. 41 Sustainability reliability of self-regulating ecosystem to sustain life in spite of stress from the environment Involves conserving the productivity of water sources, soils and the ecosystem as a whole and minimizing human impact on the balance of natural environment (Univ. of Gavle) 42 Sustainability There are three main components required for sustainability in an ecosystem: Energy availability – light from the sun provides the initial energy source for almost all communities Nutrient availability – saprotrophic decomposers ensure the constant recycling of inorganic nutrients within an environment Recycling of wastes – certain bacteria can detoxify harmful waste byproducts (e.g. denitrifying bacteria such as Nitrosomonas) 43  Functions of an Ecosystem relates to the capacity of natural and semi-natural ecosystems to regulate essential ecological processes and life support systems through BGC and other Regulatory function biospheric processres Ex: clean air, water and soil, and biological control service 44 Functions of an Ecosystem natural ecosystems provide refuge and a reproduction habitat to wild plants and animals Habitat function contribute to the (in situ) conservation of biological and genetic diversity and the evolutionary process 45 Illustration of the seven TreM forms defined by Larrieu et al. (2018b), and link between TreM forms and taxa in European temperate and Mediterranean forests. 46 Functions of an Ecosystem Photosynthesis and nutrient uptake by autotrophs converts energy, carbon dioxide, water and nutrients into a wide variety of carbohydrates– source of energy Production function provides many ecosystem food for consumption and raw materials to energy resources and genetic material 47  Functions of an Ecosystem natural ecosystems contribute to the maintenance of human mental health “Shinrin-yoku”- mindfully connecting with nature Information function ecosystem provide opportunities for reflection, spiritual enrichment, cognitive development, recreation and aesthetic experience 48 Distinguish: Ecosystem services & functions The term “functions” and “services” can be confusing Functions are considered as the biological processes underpinning and maintaining the ecosystems Ecosystem services are defined as direct an indirect contributions of an ecosystem to human well-being Step 1. Classification of services Step 2. Identification Step 3. Valuation 49  Step 1. Classification of Services Different approaches Approach 1 Approach 2 Approach 3 Supporting Regulation functions Provision of production inputs (nutrient cycling, soil formation, (Maintenance of essential (inputs from environment) primary production) ecological processes and life support systems) Provisioning Habitat functions Sustaining plant and animal life (food, wood, fresh water, fuel) (Refugium function, nursery (life support services) function) Regulating Production functions Provision of existence value (climate regulation, flood (food, raw materials, genetic (amenity services) prevention, disease prevention, resources, medical resources, water purification) ornamental resources) Cultural Information functions Provision of option value (aesthetic, spiritual, recreational, (aesthetic value, recreation, (future services) educational) cultural and artistic information, spiritual and historic information, science and education) 50 Step 2: Identification Identify what species and processes are required to perform each service Depends on the ecosystem Scale issues Separability Step 3: Valuation Value the importance of those services using economic evaluation E.g., the value of carbon sequestration Different methods for different services 51  Troubleshooting ecosystems concept: Philosophical perspectives Holistic School of ecology Ecosystem is a big organismic unit with distinct boundaries Individualistic An accidental rendezvous of individual organisms with no distinct boundaries 52 Holistic School of Ecology (Clements et al., 1916, 1928) Ecosystem is superorganism 1 Ecological succession: born, grow, 2 mature, & die Entitation process precedes field 3 sampling (deductive approach) 53 Ecotone transition area between two biological communities ecology plus -tone, from “tonos” or tension – a place where ecologies are in tension discrete boundaries between 2 ecosystem Englund Ecotone SNA" by minnesota_snas is licensed with CC BY-NC-ND 2.0. 54 Ecotone- where two community types come together, such as a forest and field. Species at the transition do not exist in either of the ecosystem 55 What is Ecotone? Species in Zone A Species in Zone B Species in transition zone only Zone A Zone B Number of species 56 Individualistic School of Ecology (Gleason et al., 1926) Ecosystem are only meeting places of FIT 1 individuals in multidimensional gradient of factors Field sampling observation precedes vegetation 2 classification (inductive approach) No ecotone exists and only the most fitted 3 individuals spread 57 Individualistic School of Ecology (Gleason et al., 1926) Only individual organisms: real biophysical entity 4 Biotic community is a function of: - available set of organisms that supply new offsprings (seeds or juveniles) - presence of dispersal agents/media 5 - genotypic and phenotypic compatibility of individuals with prevailing environmental factors 58 Ecosystem – an Accidental Meeting Place of Individual Organism meeting of different individuals representing different species Biotic community is a function of : (1) available set of organisms that supply new offsprings (2) the presence of dispersal agents (3)the genotypic and phenotypic compatibility of individuals with prevailing environmental factors. 59 Approach in Vegetation analysis Ordination (a statistical technique in which Individualistic data from a large number of sites or populations are represented as points in a two- or three-dimensional coordinate frame) observations from field samples precede classification of vegetation for that particular area Entitation (process of Holistic identifying and describing discrete vegetation units (entities) precedes field sampling 60 Synthesis of the Holistic and Individualistic School Works Inductively Individualistic Holistic Approach Approach Works Deductively Reconcile for better understanding of natural ecosystems 61 Natural Terrestrial Ecosystem versus Agroecosystem 62 Geographical distribution of forest in the world governed by a combination of historical factors, ecophysiology and biotic interaction plant biogeographers mapped natural vegetation types in biosphere locally- present species possess the physiological adaptations needed to survive the environmental conditions therein l 63 Aspects considered for geographical distribution ✔Physiognomy (appearance: height, stratification, 1 taxonomic composition, structural complexity) ✔Climatic (pertains to pattern of wet and dry 2 season) ✔Physiographic (pertains to elevation) 3 ✔Edaphic (pertains to the dominant type of soil) 4 64  Formation: Biome: Vegetation type is determined by climate, Dominant formation elevation, & soil + fauna Temperature and precipitation largely determine the types of plants that grow in a given area 65 Plant communities are broadly distributed into biomes based on the form of the dominant plant species 66 Source:http://bouchillonlifescience2.wikispaces.com/Coniferous+ Forest+Key+Facts  Tropical Rain BIOMES Forest (TRF) perhumid tropics Semi-arid rainy temperate Temperate Deciduous areas Forest (TdF) Savannah and outside the BIOMES Grasslands periphery of Temperate semi-arid tropics and Coniferous Forest tundras subtropics Tropical Deciduous Tundra humid tropics Forest (TDF) close to permafrost around the arctic very arid areas Desert 67  Philippine Formations Alpine formation Semi- Dipterocarp Evergreen Forest Dipterocarp Deciduous Forest Molave Beach Forest Forest Imperata & Mangrove runo Forest Miscanthus grassland Ultramafic Bamboo Pine Forest Forest Forest 68 Disturbance Due to repeated farming and subsequent soil erosion, cogon Imperata grassland and the runo Miscanthus grassland take over in low-medium to high elevation areas "Top of Mt Tapyas with Gazebo" by brownpau is licensed with CC BY 2.0 69 Broad categories of ecosystems Natural ecosystem those that are existing in nature which can either be terrestrial and Ecosystem aquatic (formations) Artificial ecosystem human-made, unstable and subjected to human intervention and manipulation 70 Agroecosystem Narrow sense: Land set aside to grow crops of agriculturists and silviculturists Broad sense: All lands alienated to serve human’s whims (cropland, agricultural fields The different land uses prevent natural forest ecosystem reclaim its lost grounds Rapidly expanded at the expense of N.T. E. 71 Reality bites…. Philippines natural forest cover in 1900 is now only 20%, of which only 4M hectares remain old growth natural terrestrial ecosystems in the country will be gone in less than 25 years (projected) Only coupling agroecosystems and natural forest ecosystems at farmers' level will culturally and spatially tie the farmer again with nature 72  CHARACTERISTICS NATURAL ECOSYSTEMS AGRO-ECOSYSTEMS Human control Low High Net productivity Medium High Soil formation Erosion Succession Land preparation, weeding Species & genetic diversity High Low Biodiverse Extirpation Indigenous Exotic Natural selection Breeding Trophic interactions Complex Simple, linear Natural checks & balances Pesticides, manual removal Habitat heterogeneity Complex Simple Nutrient cycles Closed Open Water recharge Wasteful Carbon storage Emitter Nutrient accumulator Loss Stability (resilience) High Low 73  Mutual exclusivity of NTE and AE "Mt. Makiling Traverse Day Hike v11.03" by incrediblethots is licensed with CC BY-NC-ND 2.0. "testing3" by IRRI Images is licensed with CC BY 2.0. cannot occupy the same place although it is possible that there may be some species shared by both 74 Factors to Consider Exclusivity of Ecosystems 1.Succession versus land preparation and weeding 2.Natural selection versus artificial breeding 3.Natural checks and balances versus crop protection 4.Soil formation versus soil erosion 5.Indigenous versus exotic species 6.Biodiversity versus erosion of genepool, habitats, and species diversity 7.Water recharge versus wasteful water use 8.Energy and carbon saver versus energy and carbon dissipater 9.Nutrient accumulator versus nutrient loser 75 Something to read Reading Assignment (Files are available in Google Classroom) Factors to Consider Exclusivity of Ecosystem Review Article on Moving Toward a New Era of Ecosystem Science 76  FBS 36 LECTURE SCHEDULE (FS 2024-2025) Date Topics Aug 28/30 Course Orientation Sep 4/6 Chapter 1. Introduction to Forest Ecology Sep 11/13/18 Chapter 2. The Ecosystem Concept CFNR OCREL Seminar Series from 9:00 to 10:00 AM in Lansigan Sep 20 Auditorium Sep 25 First Long Quiz Sep 27 Chapter 3. Ecosystem Productivity (Online Asynchronous) Oct 2 Chapter 3. Ecosystem Productivity (F2F) Oct 4/9/11 Chapter 4. Material Flow and Cycling: Nitrogen, Phosphorus, Sulfur Oct 14-18 READING AND WELLNESS BREAK Oct 23 FIRST LECTURE EXAMINATION 7 7 Thank you for your attention! 79