Ecology PDF

Mangroves - Abiotic Factor - - changing levels salt water Environmental factors Biotic Factor-crabs heron fish manatees Environmental factors: , , , features that affect...

Mangroves - Abiotic Factor - - changing levels salt water Environmental factors Biotic Factor-crabs heron fish manatees Environmental factors: , , , features that affect individual organisms, populations, communities, landscapes, etc. May be biotic or abiotic, natural or anthropogenic Affect functions such as: Acadian hairstreak productivity, butterfly is influenced by biotic and abiotic decomposition, nutrient environmental factors cycling 18  Abiotic environmental factors How Mangroves Temperature grab energ a Sun Moisture Radiation Wind currents Water currents Nutrients Toxic substances Etc. Cranberry in wet, nutrient-poor habitats 19  Biotic environmental factors Other organisms another species same mangrove - tree Conspecific or competition ① next to you interspecific organisms - & different species Direct effects such as predation Indirect effects such as competition for resources Etc. Ferns in limited light of the forest understory 20  Limiting factors abiotic Mineral nutrients are - often a limiting factor for ecosystem productivity can be biotic or abiotic Limiting factor: factor with lowest availability relative to need Phosphorus often limits lake productivity… Additional Phosphorus Phosphorus is often may lead to limiting factor for lake productivity euotrophication ↳ becomes enriched with nutrients water body overly life 21 of leading to the plentiful growth simple plant  Principle of limiting factors lowest limit factor Growth is controlled not ↑ by the total amount of resources available, but by the resource that is in - shortest supply - (e.g. growth > limit phosphorus in lakes) - - Developed by Justus von Liebig, the father of Organic Chemistry 22 We Dump lot of phosphorus into 1 the. environment Fertilizer Lake eutrophication. 2 Factor Washing Machine - Laundry Detergent & Limiting No longerO2 available - fish can't breath BOX 2.1 - algaeofbloom the consume O2 al 25  Niche ↳ LIMITING In most ecosystems, unfavourable conditions limit growth Niche: all environmental factors that limit distribution, growth, and reproduction of a species Geraniums have low Niche: the physical frost tolerance; grow in space occupied by an Ontario when sheltered from cold organism or species 33  Niche Fundamental niche: The complete range of conditions under which a species can establish, grow, and reproduce when it is free from interference Mangrove in tree middle of growing by itself Geraniums have low beach its fundamental niche occupying frost tolerance; grow in - free to grow no other Ontario when fighting mangroves all for soil sheltered from cold space got resources & Fundamental Niche : no extreme first frost 34  niche competition resists the realized by limiting the resources and oppurtunities available by Niche of conditions used set actually organism to the animal after interactions given with , other species (predation and into competition) - has been taken account Realized niche: the observed resource used by a species in nature, where distribution is restricted by environmental factors Narrower than fundamental niche Oriental lilies tolerate Ontario climate, but do Fundamental Niche of Mangrove -. not survive in face of weeds and herbivory soil Anywhere w and tropical sunlight Realized of G Outcompeted by other organisms Where ocean Niche meets Mangrove fresh water - In Ontario realized niche does not exist -> COMPETITION 35  Adaptation, fitness Organisms can be adapted to stress The degree of adaptation influences the organism’s performance and fitness Dandelion is adapted to drought moreso than lawn grass 36  no moisture Genotype, phenotype offspring launch out into would > - lots of moisture & Genotype: genetic information that is encoded within DNA Phenotype: actual expression of genetic potential (depends on environment) Phenotypic plasticity allows acclimatization of a genotype to stress Shaded dandelions invest in leaves; exposed ones in seeds 37  Phenotypic plasticity Phenotypic plasticity: ability of an organism to change its phenotype in response to changes in the environment There are limits to how far a phenotype can “stretch” Genotype is your Fundamental Niche Phenotype is your Realized Niche 38  Environmental stressors Stressor: Environmental factor that limits performance of organisms, populations, communities and landscapes Performance: Productivity and reproductive fitness, relative to genetic potential Quantify stressors in terms of impact on productivity, decomposition, nutrient cycling 40  Environmental stressors Exposure to stressors can: be instantaneous and intense (e.g. wildfire, hurricane) accumulate over long periods (e.g. toxicity, dessication) 41  Environmental stressors Tolerance (resistance): organisms, populations, communities, etc. have the capacity to function in a “healthy” manner within a range of environmental stressors Tolerance of an increasing intensity of environmental stress can take many forms 42  Environmental stressors Resilience: speed and degree to which an organism, population, community, etc. can recover to its original state following an event of disturbance Jack Pine: high resilience to Atlantic cod: low resilience forest fire to over-harvesting don't to let open pine seeds burned 45 - out unless trees die but comes - forest open - new  Categories of stressors Chronic stressor: long term influence (e.g. nutrients in water and primary productivity) Disturbance stressor: powerful but short-lived event (e.g. severe windstorm, fire, etc.) Natural stressors: present for very long time periods (eons) Anthropogenic stressors: stressors associated with human development 46  Types of stress Climatic stress: temperature, solar radiation, wind, moisture, combinations thereof Chemical stress: high concentrations that cause toxicity (e.g. lead, mercury) Wildfire: combustion of biomass Physical stress: e.g. volcanic eruption Biological stress: interaction among organisms 47  Anthropogenic stressors Many stressors are caused by or modified by human activity: – Increased levels of toxic substances – Changed climate or hydrology – Diminishing of wild populations Pollutants along the Detroit river stress our local ecosystems 51  Pollution Human activity can locally increase the concentrations of natural substances such as metals The concentrations and ecological effects often decrease with increasing distance from the source Past emissions gave toxic concentrations of copper, nickel in Sudbury 52 Outcome of environmental stressors Decrease of productivity, increases in mortality, and reproductive failure – E.g. endocrine disruptors (see section 2.3 p.38) Sensitive species are replaced with tolerant species Top predators and large- bodied species are lost Male fathead minnows Species richness and feminized by exposure diversity decrease to birth conrol pills 53