Ecology cheat sheet PDF

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Lecture 1 Ecological niches of species are linked to environmental conditions and resources, underpinning patterns in species distribution and abundance Ecology’s scientific mission Identify and understand relationships between living organisms, including humans and their physical environment Understand connections and dependencies between plants and animals and the world around them Determine how we can use earth’s resources in ways that leave the environment healthy for future generations Real world applications Pollution – flood plumes Introduced species – crown of thorns starfish Agriculture Threatened species Aims of ecology Ecology is science, Explain ecological systems, Proximate and ultimate explanations Understand their mechanics Observation, experimentation, mathematical models Predict what they will do Control utilize conserve Some Ecological Maxims You can never do just one thing –interaction and connectiveness of nature and the environment. Everything goes somewhere – no ultimate waste No population can increase forever – limits in resources and growth There is no free lunch – energy and resources are finite; and there are trade-offs Evolution matters – trust in evolution and change over time; mistakes are made by treating things as static. Time matters – Ecosystems change, and past can help predict future Space matters – conditions can change across space; but variation is important. Life would be impossible without species interactions – all species are dependent on one-another for energy, nutrients, and habitat. Understanding mechanics Aims of ecology Observation Observe changes in the abundance and distribution of species in time across space to establish ecological patterns The effects of introduced species on the behaviour of other species and how it influences observations of abundance Experimentation – manipulative experiments to determine causes of patterns, laboratory or field Mechanics Exploration, prediction, approximation, caution, real data Models Predict Scale and hierarchy in ecology 1. Properties observed at a particular level arise out of the functioning of parts at the level below 2. To understand the mechanics of a property at a particular level one need to look at the next level down 3. But properties observed at a given level can be predicted without the functioning at lower levels Nested Hierarchy in ecology Biosphere – places on earth supporting life Biome - A major category of the world’s distinctive plant assemblages Ecosystem – the plants, animals, physical, chemical components community , species, population, individual Importance of ecology Biodiversity – total of all the organisms that make up life on earth from genes to ecosystems The result of millions of years of evolution o Why conserve? – under threat, value, conservation – the science of increasing the probability that the earth’s biodiversity will persist into the future

Value of biodiversity Consumptive use value, Products of a nature that do not pass through a market, Food, medicine, fuel, building materials, Ecosystem service value, Natural ecosystems sustain human life Fuel, food water and air purification

Lecture 2 Ecology and Evolution Adaptative traits Processes – selective pressures, ancestors and specialized evolution traits reflect successes, continuing selection, genetic change Links ecology and evolution Evidence for adaptation – is it heritable, is it functionable, does it increase fitness, how did it first evolve Requirements for natural selection – excess production + different individuals(not identical) + inheritance (genetic basis, traits passed down, heritability, genotype and phenotype) + unequal contribution Genotype – an organisms full hereditary information; the set of genes that it carries Phenotype – an organisms observed characteristics, influenced both by its genotype and by the environment Geographic variation Environments experienced by a species in different parts of its range are different to some extent Natural selection may favour different variants within species  Variation among populations within the same species  Precursor to understanding the origin of new species Explanation for variation in traits among population 1. Local adaptation (within species evolution) 2. Phenotypic plasticity (ability to vary response) – individuals in different populations in contrasting environments display different phenotypes but have the same genetic makeup Under contrasting conditions High plasticity (the adaptability of an organism to changes in its environment or differences between its various habitats) in individuals o Environmental factors have a strong influence on the particular phenotype that develops from the genotype Low plasticity in individuals o Phenotype from the genotype fairly consistent irrespective of environmental variation Speciation Splitting of populations into evolutionarily independent units Speciation is a product of evolution within species Allopatric Speciation Allopatric speciation as a result of isolation of population 2 main models – dispersal – Darwin’s finches Morphological/dietary divergences Molecular analysis reveals evolutionary relationships Monophyletic radiation Warbler finch first to split from founding group Can lead to the evolution of endemic species Vicariance Different populations of a species become isolated in space Driver of vicariance – continental drift, tectonic plates carries migrating continents, land areas moving through climate zones Sexual selection Advantageous traits over others in terms of mating Do not help an organism adapt to its environment Choice by members of one sex for certain members of other sex Competition among members of one sex for access to members of other sex Combat, Sperm competition, Display

Lecture 3 Conditions and resources Conditions Properties of the environment determine where organisms can live Physiochemical features of the environment Conditions are not consumed or used up by activities of organisms Consumed items are no longer available to another consumer The presence of an organism alters environmental conditions Effects of conditions Induce physiological responses in organisms Temperature Conditions act as stimuli for growth and development Conditions and Biomes Terrestrial biomes Climactic conditions define the major categories of the worlds distinctive plant assemblages Use a cross classification of temperature and rainfall Aquatic biome on the continent Stream, river, lake, pond and wetland, Cover nutrient eutrophication of lakes and streams

Lecture 4 Ecological communities Ecological communities: community – an assemblage of species populations that occur together in space and time Properties of individual organisms (behaviour) -> properties of populations(density, ratio) -> properties of communities(richness, diversity) Species richness – the number of species in an area Taxonomic issue for estimates of species richness in a region - Misidentification of species When only done with richness , abundance is ignored

Simpsons diversity index Richness, rarity and commonness S = total number of species in the community Pi = the proportional abundance of species i Rank abundance Curve Broken stick, log-normal, log series, geometrical series

Species composition – the actual species comprising the community Food webs Summary of the feeding relationships within a community Community succession Succession- a process of replacement over time of one community by another Primary succession – a temporal succession of species on an exposed landform that has not previously been influenced by a community – lava flows, craters from meteors, substrate after glacial retreat Secondary succession –succession in an area where vestiges of a previous community are still present Vegetation partially removed by fire, storm, humans, abandonment Degradative succession – a temporal succession of species that occurs on a degradable resource Short time periods (months or years) Degradation uses up some resources making others available Environmental conditions shift over time Ends when the resource is completely metabolized and mineralized Decomposition Arrivals - Calliphoridae (blow flies) - Sarcophagidae (flesh flies) - Muscidae (house flies) - Formicidae (ants) - Piphilidae (true flies) - Fannidae (true flies) - Coleoptera o Staphylinidae (rove beetles) o Silphidae (carrion beetles) o Cleridae (checkered beetles) o Histeridae (clown beetles) - Sepsidae (ensign flies)

Lecture 5 species interactions 1 Direct vs indirect Direct – the direct impact of one individual on another when not mediated or transmitted through a third individual ( A->B) Indirect – another species is involved (A->B when there is a not intentional A->C) Why do we care – global declines in biodiversity = loss for ecosystems and the goods and services they provide Intraspecific (within species) interspecific (between or among species) Types of direct interaction 1. Mutualism – both species derive benefit (+,+), ecosystem engineering can be viewed as mutualistic Obligate Mutualism: interaction is required to persist Facultative Mutualism: interaction is not required to persist 2. Commensalism – when one organisms is positively affected other is not affected ( +,0) 3. Contramensalism – (+,-) predation, herbivory, parasitism(consumes part of host organism not always lethal) Lotka- Volterra predator prey model – predicts species abundance over time Co evolution -Two species  consistent interactions  gene

pool changes Protozoan parasite Toxoplamsa gondii, condition known as toxoplasmosis Types of parasites

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Obligate Parasite: restricted to one host species; dependent for fitness. Host = environment. Facultative Parasite: Does not entirely rely on host for fitness.

Edemic parasites -> adapted to each other Enzooic disease -> chronic Epizootic disease Epidemic disease- short term impact (host), major and fatal diseases 4. Amensalism (-,0) 5. Competition – occurs when two organisms compete for the same resource (-,-) Measured in field experiments 6. Neutralism (0,0) Lactobacillius and streptoccus Rare in nature Gause’s law no two species can occupy the exact same niche - Competition would be too intense - Humans outcompete other species

Maladaptation -failure to adjust adequately or appropriately to the environment or situation.

Exaptation - the process by which features acquire functions for which they were not originally adapted or selected. 

Lecture 6 coral reef ecosystems What is a coral reef Increased Carbon dioxide = increase pH Gradual decline in coral cover since 1980s, big loss 2016-17 bleach Stress types Press (constant), pulse Strategies for survival - Adapt, migrate, refuge, preconditioned, human intervention – mitigation of climate change, repair, facilitation of adaptation, biocontrol

Opal reef Stakeholder driven solution at high value sites Future: enhanced tolerance, scalability, restoration activity

coral reef restoration considerations legislative  is it in a marine park  what’s the current management  future changes in legislation planned? social  traditional owners  what is the history of the site  who are the stakeholders  what do they want scientific  what tools do we currently have  what new tools do we need  what would success look like  how can we track success  associated risks of restoration ecological  type of stress  has the stress been removed  reef type  species composition change  why did some species survive  histortical change  associated stressors  significant value of reef e.g. source of reef

Lecture 7 species interactions 2 Indirect species interaction One species indirectly alters the abundance of another by changing the abundance of an intermediary species that interacts iwht them both Indirect species interaction can have global effects, potential to change climate, nutrient cycling and effect wider ecosystems Keystone species – species more tightly woven into foodweb, removal = significant effect Top-Down Vs Bottom up control What is the dominant control? Bottom up- soil nutrients controls the foodweb Top down- population size controlled by top trophic levels Apparent competition Negative indirect interactions between victim species beacuase of natural enemy Two types: shared predator, single trophic level Indirect commensalism Indirect positive effect of one species on another Competition between resource species leads indirectly to positive interactions Indirect Amensalism Abundance of one species is reduced while the abundance of another species is not influenced Interaction modifications Behaviour – one species indifrectly affects the abundance of another by modifying the behaviour of an intermediary species that interacts with both Complex interactions Assumption – interactions don’t change in strength or direction Main factors influence complex interactions 1. Behaviour – interactions between species can change depending on solitary or group living 2. Density – strength of interactions vary with densities of the species involved 3. Time – interactions vary in type/intensity at different times

Lecture 8 restoration ecology Ecological restoration: assisting the recovery of an ecosystem that has been degraded, damaged or destroyed Restoration ecology: the scientific process of developing theory to guid restoration and using restoration to advance ecology Been practiced since 198-s Conservation role Complements conservation biology – speaks to protect existing habitat species and biodiversity Restoration seeks to reverse environmental degradation and habitat loss They can work together, create corridors to connect reserves, create buffer zones to reduce edge effects and enlarge reserves Why study restoration ecology? Measure effectiveness, assign priorities – funding, resources, refine techniques, avoid unintended consequences Landscape ecology Patches and patterns, connectivity and corridors to link patches, spatial scale – restoration can be large or small scale Small scale – one or a few cleared patches to impove connectivity Large scale – revegetate entire ridge Fragmentation Loss of continuity/connection between patches Creates isolated islands Probability of extinction increases with decreasing patch size Regeneration of degraded areas reduce the risk and rate of species loss Disturbance Change in conditions that interferes with normal functioning of a biological system Clearing contamination weed invasion stream alteration Succession Restoration often makes use of succession processes e.g. revegetation – start with grasses to stabilise soil and create favourable conditions for more complex vegetation Ecosystem function Water, energy and nutrient transfers Important in maintain ecosystem services: clean air, water, carbon sequestration, recreation Genetics Maintaining integrity of local gene pools can be important Restoration may include restoring genetic integrity and preventing hybridisation Goals Return to natural conditions Create an alternative new ecosystem or simple restore some functions Targets Species - Keystone species, endangered species, assemblages Ecosystem function – material and energy flows, biotic/abiotic components, ecosystem services Approaches Passive restoration – eliminate source of disturbance and allow the environment to restore itself Active restoration – intervene to speed up natural processes, replanting native species or reintroducing animals Examples Weed removal, revegtation/bush regeneratio, removal of non native animals/re-introduction of native animals, stream restoration, contaminated site remediation Reserva ecologica de Beunos Aries 1978-1984 abandoned - passive Plants and animals self established, ecological reserve 1986 by council Sydney Olympic park - active Restoration of degraded contaminated industrial site for Olympics Coastal salt marsh for migratory birds – alteration of banks and riparian areas Cooks river – flow reduced to 1% below Jindabyne 1974 active Fairfield city council 5 creeks project Restoring degraded creeks and streams to improve water quality Converted concrete channels to more natural conditions

Lecture 9 population ecology Population dynamics Study changes in size of populations Population boundaries vary among species and from studyto study Generalised dispersion patterns Population distribution 1. Clumping -> resources available 2. Uniform dispersion -> resources limited 3. Random dispersion -> resources abundant Clumps 1. Species tend to cluster where resources are available 2. Groups have a better chance of finding clumped resources 3. Protects some animals from predators 4. Packs allow some to get prey How do we assess a pop and what do we need to consider 1. Age structure – pre/post/reproductive age 2. Conditions and resources – availability, limit which can reproduce Populations are dynamic Modelling can – describe pop growth/decline, examining the influence of abiotic and biotic conditions Population growth size of population controlled by limiting factors light, water, space, nutrients, exposure to competition/disease Carrying capacity (K) – maximum population a given habitat can sustain (that does not impact on the surrounding ecosystem/s) How do we establish population growth Pop size = N, pop change through time = t the number of N in a pop at a time is Nt Population growth processes that change the size of populations Birth, death, movement – immigration, emigration

Assumptions – closed population, pop growth is continuous Over short time interval Instantaneous birth rate (b) B=bN Rearange Over short time interval instantaneous death rate (d) D=dN Let b-d = r = intrinsic rate of increase (r measures the per capita rate of increase over time) To predict population size Nt=N0ert N0= initial pop size Nt= population at size t, e= e on calculator Resource limitation When resources are unlimited (b) and (d) remain constant This is Density dependence calls upon intraspecific competition Formula for decreasing birth rate = b’ = b- aN b = birth rate a = strength of density dependence on the birth rate higher a leads to sharper drops in birth rate with each individual added to the population same for death ^ larger N higher death rate dN/dt = rN(1-N/K)

Lecture 10 from micro to macro Life cycles and reproduction Can have implications on resourcing Implications on wider population Cicada periodical cicadas (Magicicada) Life cycle 13 or 17 years Invasive, introduced or native Native – native species have evolved and adapted to their normal habitats and neighbours over many thousands of years Introduced – a species that is introduced to a region of the world where it has not historically existed Invasive – an introduced species that spreads rapidly and has negative effects on other species or ecosystem services Why do we care? – biological invasions Multiple pervasive effects on ecosystems, potentially disrupting species interactions and global ecological processes Affect the distribution, abundance and reproduction of many native species Assessing impact Introduced species -> influence evolution of natives Evolutionary changes can result in: - Altered anti predator defences - Changes in resources and habitats used What can natives do? Respond evolutionaryily Depends on: - Demographic impact of the invader - Genetic architecture and genetic variability of the native population - History of past invasions A return to genetics Individuals not identical Variation among individuals in apopulation and among populations in many traits Key innovations arise through mutation. An adaptive radiation in one lineage often leads to radiations in other taxa that interact with them Implications of introduction Dispersal -> individals can bring new genetic material to a genetically distinct population, only require a low establishment rate to be biologically and genetically significant The movement of individuals between locations can facilitate enhanced genetic diversity -> pending successful reproduction If they carry novel alleles, they will contribute new gene variants to the population -> increased genetic and genotypic diversity. Pioneer species –...