stability and change

• Stability is the ability to maintain or support systems and processes continuously over time
• Stability for ecosystems can mean consistent supply of sunlight or energy, deprivation of disturbances that can affect the ecosystem negatively, climates within tolerance limits, high genetic diversity creating increased changes to survive selection, and consistent nutrient cycling without leakages
• Many ecosystems keep this stability without human disturbance/management ex. The Bödmerenwald in Kanton Schwyz in Switzerland arising 7000 years ago
• Erosion is a disturbance that can lead to a loss of nutrients during nutrient cycling, threatening stability
• Harvesting and removal of materials disrupts nutrient cycles and food webs
• Eutrophication is the over nutrientification of water which causes population imbalances
• Poaching and selective removal disrupts ecosystems structures and food webs, especially in the case of a targeted keystone species
• The tipping point for ecosystem stability signifies the point at which its reversal might be difficult or impossible
• Positive feedback loops drive ecosystems to achieving new forms of stability and equilibrium by amplifying effects
• Amazon rainforest experiences increased droughts due to burning and deforestation for space to grazing and housing and for timber and mining. Disturbances to positive feedback loops like the water cycle further the impacts and might lead to a tipping point
• The water cycle dictates the amount of water transpired and returned to the air as moisture. Less trees make less moist wind which means the deforestation of the Amazon has caused an increase in river discharge by 20%. This creates dry air that is more concentrated with carbon and leaves trees dry and easy to spark fire.
• Primary forests are the densest forest and the most ecologically diverse
• Tropical tree covers maps the trees inside and outside of dense forests across tropics
• Peatland is the wet-land of decaying plants and incompletely decomposed organic materials
• Tree cover is where tree patches cover more than 1 hectare and provide shade
• Land cover is the observed physical cover of vegetation, etc.
• Mesocosms are small experimental areas to model ecosystems that are completely sealed up and closed with only light entering as energy
• A keystone species is one that is critical to the survival of other species in a system
• American Beavers are a keystone species as they hold water in natural valleys to prevent downstream flow in the case of excessive rain, lend their burrows as shelters for animals like martins, makes filler pools that provide space for fish, amphibians, water birds, dragon flies and marsh plants to thrive, and, when leaving, leaves twigs from felted trees for large grazers to feed on and prompts stump and meadow regrowth.
• Sustainability is the responsible maintenance of ecological systems so that there is no reduction of conditions for future generations, ensuring long-term viability of a system.
• Finnish forests have provided food, shelter, employment, and income for native persons and its Forest Act provides a framework for forest management with the leading principle of obligation to regenerate after logging
• Fishes like the Cod are on the verge of extinction in the North Atlantic mostly due to overfishing, making the problems with international conservation programs and sustainability goals more important to solve than ever.
• Healthy fisheries are dependent on long-term strategies like identifying the age, type and composition of the fishies and their ecosystems from which they are being harvested (encourage seasonal and targeted fishing, utilizing indigenous and traditional methods)
• Soil erosion is caused by the tillage and plowing and harrowing of land which decreases soil quality and affects agricultural yields
• Fertilizers increase crop yields but decrease natural nutrients in the soil and can sink into the soil and leach into water systems, bringing it excess nitrogen and phosphates, prompting eutrophication
• Leaching allows for soil exposure during rain to wash away nutrients and makes plant unable to access them, impacting agricultural yields
• Carbon footprints are created by agricultural machines and glasshouses creating power in the form of CO2 and leaving footprints
• Monoculture agriculture is practicing the growth of only one type of plant which prompt the same pests and creates pollution with prompted use of pesticides
• Eutrophication is the excessive nutrient enrichment of water which favors algae growth causing algae blooms. These blooms block light for the plants below them which die off and prevents oxygen dissolvation in the water. Then, they die and saprotrophic bacteria uses oxygen to decompose them, taking oxygen from the stream and leaving too little for the fishes
• Natural eutrophication occurs through gradual drying up pools of water which disproportionally increases the amount of nutrient rich sediments.
• In artificial eutrophication, it is caused by the leakage of excess chemicals used in the agriculture which is digested by marine organisms in the water bodies and broken down into nitrogen and phosphates that autotrophs use to boost their growth
• Biological oxygen demand (BOD) indirectly denotes the amount of pollution in aquatic system because more will need more oxygen to be broken down by organisms to absorb their nutrients
• BOD is measured by taking a measured volume of water from a source and measuring the dissolved oxygen content on day 1 in ml/L using an oxygen probe and then placing it in the dark at 20 celsius for 5 days to prevent photosynthesis and measuring it again. The difference between the two measurements is the BOD.
• As eutrophication increases, more algae blooms, increasing oxygen demand
• Less oxygen being available for marine species means the environment changes and becomes more competitive, leading to the depletion of certain species and hence changes the food chain
• Bioaccumulation is the increase in the concentrations of a toxin in body tissues during an animal's lifetime happening with fat soluable chemicals which cannot be excreted
• Biomagnification is the increase in the concentration of a chemical at each successive trophic level in a food chain- used by predators to accumulate higher chemicals of a toxin than their prey.
• Top predators like shark, swordfish, mackerel, cod, and bluefin tuna consume many prey like shellfish containing traces of mercury in droplets of fat in adipose tissue. With every added trophic level, more prey is consumed than before, causing increasing accumulation of mercury through biomagnification meaning top predators have a lot
• Dichlorodiphenyltrichloroethane (DDT) is an agricultural insecticide that is banned due to its tendency to accumulate in the fat tissues of animals feeding on insects.
• Macroplastics are large, visible, and larger than 5mm in size